DISEASES OF THE FEET Canker.Looking upon the integument of the foot as a modified portion of the skin, can ker may be defined as a chronic hypertrophic moist eczematous dermatitis, a definition which answers the description of the disease in its most typical form. The condition is not so common now as formerly, owing apparently to the advance of hygiene in connection with the care of horses, for it is generally admitted that the affection is greatly favoured by dirty sur roundings, keeping horses in dirty, ill-drained stables, with the feet constantly in contact with litter soiled with faeces and saturated with urine, which macerates the horn and exposes the sensitive tissues to injury and infection which may be a predisposing if it is not an exciting cause of the lesions. This theory is also borne out by the fact that it is the hind feet which are most commonly affected. Marshy localities seem to have a determining influence on the malady, as it is certainly more common in them than in upland districts. It is more common in the East Midlands of England than in other parts of the country. Lymphatic temperament is a predisposing cause of canker, as it occurs most frequently in coarse - bred, phlegmatic subjects. It is commonly believed that there is a hereditary tendency to the disease, and it is looked upon by many as a local manifestation of a constitutional affection like other skin eruptions. The disease presents features which are suggestive of its being of an infectious nature, but so far no specific organism has been found in connection with it. Spirochmtes and various forms of bacteria have been found in the lesions, but the disease could never be set up experi mentally by any of them.
Canker may remain localized in one foot for a long time and then attack successively the other feet, and after being apparently cured it may suddenly break out again. It begins either as a sort of grease or moist eczema in the skin of the back of the pastern or beneath the horn.
In the former case the affection gradually encroaches on the sub-corneal tissue, whilst in the latter case it commences insidiously and may remain unsuspected for a long time until the separated horn is removed with the farrier's knife or is worn by use. It is the middle lacuna or cleft of the frog which first shows symptoms of the disease as a rule, the affection spreading from there with more or less rapidity beneath the branches of the frog to the lateral 'mum and thence to the sole, from which it may extend under the wall to the coronet.
Symptoms. When a considerable area of the foot is involved and the disease is well estab lished the symptoms are very characteristic. The horn overlying the affected part is separated (underrun), more or less ragged, and sodden with moisture, having the appearance in the case of white horn of having been soaked in oil. In an advanced case the horn is absent, and the lesion of the sensitive tissues is exposed. They appear to be affected with chronic inflammation, being covered with a whitish caseous exudation having a very foetid odour, and showing in places vegetations or hypertrophied papillEe or finger like processes, which in old-standing lesions may be capped with horn constituting what are known as ergots, and which have been likened to the pads of a toad, this accounting for the French name for the disease, viz. crapaud. The foul-smelling caseous material also forms between the ergots and vegetations. There is evidently no acute inflammation as a rule, because lameness is frequently absent even in a well-marked form of the affection, and when it is present it may be the result of a contusion of the exposed sensitive structures. In bad cases where the os pedis is exposed, either as a result of the disease or injudicious treatment of it, the lame ness is very pronounced, and when the laminae are involved it may be well marked.
Diagnosis is generally easy. The appearance of the lesion is diagnostic, viz.: the underrun and sodden horn, the discharge, the vegetations, the ergots, and the very penetrating, offensive odour. Wherever the horn is adherent the disease is absent.
Prognosis depends on the extent of the disease and the number of feet affected. It has no tendency to undergo spontaneous cure; on the contrary it is progressive in its course. Except treatment is carried out with great pains and very thorough measures are adopted, it will fail to have the desired effect. Sometimes when it is almost cured discontinuing the treatment causes it to break out afresh. When all the feet are badly affected it is hardly worth treating.
Nevertheless, when the malady is not too extensive or far gone, does not extend beneath the wall, and the os pedis is not exposed, proper treatment generally effects a cure within an average period of six weeks, and during two or more weeks of this time the horse may be working.
Treatment.The exact cause not being known, the surgeon is at the disadvantage of not being able to remove it, but he can avail himself of his knowledge of the admitted predisposing causes to avoid them as far as possible in combating the affection. Experience has shown that the principles of treatment which have given the best results are as follows: (a) After removing the loose horn, thoroughly cleansing and disinfecting the affected foot by enveloping it in antiseptic compresses for twenty-four hours, excise the ergots and vegeta tions when present.
(b) Apply to the affected part, a caustic, an astringent, or merely an antiseptic according to the nature of the lesion.
(c) Exert great pressure on the affected region by means of twisted pledgets of tow firmly com pressed by the aid of a metal sole fixed to the shoe, or by strips of hoop-iron inserted between the shoe and the hoof.
(d) Attend to the general health of the patient, and prescribe arsenic or one of its preparations to be administered daily for a while at intervals until the disease is cured.
(1) Removal of the vegetations and ergots is necessary to bring the affected part on a level with the normal tissues. Care must be taken in so doing not to expose the pedal bone, and in operating on the frog to follow its configura tion and not mutilate it unnecessarily.
It is also advisable to thin the normal horn for a short distance beyond the periphery of the affected region to facilitate equalizing the distri bution of the pressure, and to prevent irritation of the sensitive tissues by the edges of the horn.
(2) Nearly all the common caustic and astrin gent drugs in the pharmacopoeia have been recommended by different authorities for applica tion to the diseased surface. Probably any one of these is as efficacious as another, success depending rather upon the method of applica tion than upon the agent employed. The following applications have been lauded by different practitioners: Nitric acid, sulphuric acid, pure or mixed with alum (Plassis paste); hydrochloric acid, butyr of antimony, carbolic acid, acetate of copper, sulphate of copper, creosote, salicylic acid, formalin, Czerny's solution (arsenic 1, methylated spirit 40, water 40), nitrate of lead, a mixture of carbide of calcium, iodoform, acetate of copper and starch, a mixture of the three sulphates of copper, zinc, and iron, and powdered chinosol, etc.
With each one of the foregoing topics success has been obtained, while failure has also been recorded, and one can hardly be said to possess more virtues than another.
The hot iron is also strongly recommended by many veterinary surgeons as having an excellent effect when its edge is passed lightly over the affected region before applying an astringent dressing, such as the three sulphates, as advised by Malcolm and others. After first applying a caustic to slough away the diseased surface, apply an antiseptic powder before putting on the tow, such as iodoform or a mixture of it with starch and oxide of zinc or powdered chinosol. As the case progresses favourably, avoid the frequent use of caustics and depend chiefly on antiseptic powder associated with pressure.
(3) In arranging for pressure take precautions to have it firm and equally distributed.
The pledgets of tow should be in the form of hard cords of assorted sizes for adaptation to the different parts of the foot, care being taken that the immix of the frog are well packed with rolls of corresponding shape and size. Apply a series of large thick pledgets on the outside. Bring pressure on the tow either by means of pieces of hoop-iron bent in the form of a bow to permit of their ends being introduced beneath the foot-surface of the shoe, where they are driven in by striking the convexity with a hammer, or by a metal sole driven in from behind between the shoe and the hoof, or screwed on to the sole of the shoe. The strips of iron are more satisfactory than a metal sole.
In order to carry out these measures thor oughly it is generally necessary to have the horse fixed in stocks or cast, and when vegeta tions have to be removed, chloroform anaes thesia is advisable. The case should be dressed daily for a while until considerable improvement occurs, when the intervals between dressings are gradually extended until once per week proves sufficient, the surgeon being guided by the state of the lesion. If lameness be absent it is an advantage to keep the horse working. During the early stages of the treatment the severity of the dressings, and the great pressure exerted on the exposed sensitive tissues, may cause some lameness and necessitate keeping the horse idle for a while.
Working on dry clay favours recovery, and may be sufficient of itself to effect it should it be possible to continue it for a long period.
(4) The administration of arsenic has long been known as beneficial in the treatment of the affection, and comparatively recently the late Major Holmes, A.V.C., found, when treating surra, in India with a course of arsenic, that those animals which happened to be affected with canker at the same time became cured of the latter disease as a result of the treatment. In the United Kingdom, however, it has not proved a specific.
Quittor. Quittor is a sinus or suppurating passage opening on the coronet at the level of the lateral cartilage, and due to necrosis of this structure.
Etiology. The cause of the condition may be: (1) Injury and infection of the cartilage such as may result from a tread on the coronet causing a contused or punctured open wound, which is more likely to occur when the shoes have calkins, and especially when the latter are sharpened for frost.
(2) Necrosis of the skin in the affected region resulting from the effects of cold associated with dust and bacterial infection spreading subse quently to the cartilage.
(3) A suppurating corn or sand-crack or lesion resulting from a punctured foot or a picked-up nail from which infection extends to the car tilage.
The cartilage may be involved in an open wound without undergoing necrosis, but the latter is very likely to ensue owing to the feeble vascularity of the part, making it an easy prey to the organisms invading the wound. Once necrosis begins in the cartilage it has a great tendency gradually to affect the whole structure on account of its poor blood supply, and the close continuity of the dead and healthy parts. Spontaneous separation of the necrotic piece of cartilage may, however, take place, and should it escape with the discharge natural cure will result. This is much more likely to occur posteriorly than anteriorly, because in the former situation the cartilage is more interspersed with fibrous tissue, separating it into islets which are comparatively easily detached.
Symptoms. The symptoms are those of a sinus with a combination of more or less acute and chronic inflammation in its vicinity.
The inflammatory swelling varies in size according to the extent of the disease. It may correspond only to a part or to the whole of the cartilage. It projects beyond the level of the wall of the hoof, and bulges it outwards at the coronet. It generally begins at the heel and spreads thence forwards. It is more or less painful on manipulation, the pain being usually most marked when the antero-inferior extremity of the cartilage is affected, and being always very acute when an abscess is being formed.
When the skin is unpigmented the redness due to the inflammation is noticeable, and varies in intensity according to the acuteness of the condition. The sinus usually has only one orifice on the coronet, but in rare cases it has two or three openings here. When there are more than one opening they all communicate with the necrotic centre. The entrance to the sinus may be only large enough to admit a probe, and is often obscured by a mass of granulations or proud flesh.
It may be infundibuliform in shape, and is constantly weeping or discharging a greyish purulent fluid which may be streaked with blood due to rupture of some of the capillaries in the granulation tissue of the part. The calibre of the sinus varies in different cases. It may be branched. Its course is usually oblique, a common direction being downwards and forwards, terminating on the wing of the os pedis in well-established cases.
When the condition is a complication of a corn or sand-crack there may be a plantar or parietal sinus respectively in addition to that on the coronet, or rarely the latter may be absent until the disease has been in existence for a con siderable time. There may be one or more cicatrices on the skin over the swelling represent ing orifices that have healed after the pus had gained exit in a new situation through the medium of a secondary abscess. Afterwards some horizontal rings or rugm form on the wall beneath the affected part, due to the latter interfering with the secretory function of the coronary band in this region. By noticing the depth to which these extend, and remembering that the horn grows at the rate of inch to inch per month, one can estimate approxi mately the duration of the affection. The degree of lameness varies according to the nature of the lesion. When the superior or posterior part of the cartilage only is affected it is slight or absent, but when the disease is in the vicinity of the antero - lateral ligament, or when the latter is involved, it is very marked. If arthritis supervene its symptoms will be manifested.
Complications. The complications which may arise are: 1. Necrosis of the antero-lateral ligament, which may in consequence become ulcerated through exposing the joint to infection.
2. Septic arthritis resulting from No. 1, or from perforation of the cul-de-sac of the synovial membrane of the articulation where it comes in contact with the antero-internal aspect of the cartilage, allowing infection of the joint.
3. Necrosis of the Os Pedis. Infection may spread from the cartilage to the os pedis, causing necrosis thereof. If this occur near the articular surface septic arthritis may supervene.
4. Necrosis of the Sensitive Lamince or Plantar Cushion or Plantar Aponeurosis, the latter being rare. The plantar aponeurosis is more likely to be affected when the quittor results from a suppurating corn than when it arises in some other way.
5. An abscess which may form at the inner side of the cartilage and burst on the skin.
6. Gangrene of the skin over the affected region.
Diagnosis is generally easy on account of the circumscribed swelling at the level of the cartilage and the presence of the sinus. Wounds of the coronet and abscesses not involving the cartilage heal easily.
Prognosis. Quittor is an obstinate affection, having practically no tendency to spontaneous cure, and often resisting ordinary therapeutic measures for months. The condition is not so serious when confined to the superior or posterior part of the cartilage as already explained. Operative treatment is nearly always suc cessful, but it may be followed by some deformity of the hoof, or by hyperxsthesia of the cicatrix.
Great depth of the sinus and a copious dis charge of pus are unfavourable signs.
The presence of complications makes the affection more serious. The lesion is more easily dealt with in the hind limb, because the cartilage there is less dense and more vascular than in the fore limb.
Treatment. The principles of treatment are those of a sinus, and comprise measures for the removal of the necrotic tissue, the provision of drainage for the pus, and the destruction of bacteria, with the object of causing a healthy granulating wound which will undergo eicatriza tion and bring about recovery.
The method of procedure may be: 1. The injection of an antiseptic liquid by means of a syringe with a long narrow nozzle into the depth of the sinus two or three times daily in order to pluck out loose necrotic tissue, arrest the development of bacteria, render the lesion sterile, and thus allow healing to take place. This may succeed in a recent case where the sinus is not deep and the necrotic cartilage is near the surface, that is, affecting its upper or posterior border. Otherwise it is generally a failure, the affected part being too deep-seated to be effectively acted upon by the injection, or to permit of the escape of necrotic material. To obtain the best results from it, it is necessary to enlarge the entrance to the sinus in order to facilitate reaching the affected area with the germicidal agent. The patient resents this treatment, and it is generally disappointing in its results.
2. The Injection of a Caustic Liquid. This is more effective than No. 1, the agent being a more powerful germicide and having an eschar otic effect which brings about separation of necrotic tissue and removal of the lining of the sinus, thereby opening it up and facilitating the escape of necrotic debris and purulent matter. It is carried out in the same way as No. 1, and when thoroughly done it often effects a cure within two or three weeks, the discharge becom ing gradually less and the inflammation and lameness disappearing by degrees. It is, how ever, by no means infallible, and is contra indicated when the sinus is deep and anteriorly situated on account of the risk of sloughing of the thin layer of tissue protecting the joint in this region and causing arthritis. Various pre parations have been used with more or less success, including the following: (1) Corrosive sublimate 1, alcohol 10; (2) corrosive sublimate 17, methylated spirit 140, hydrochloric acid 2-4, acetate of lead 34; (3) sulphate of zinc 5-10 per cent solution; (4) chloride of zinc 5 -10 per cent. The result depends not so much on the agent used as the manner in which it is applied to ensure its reaching the affected part.
3. The use of solid caustics, that is, the intro duction into the bottom of the sinus of a caustic in the form of a powder or pencil or plug, the one most commonly and successfully employed being corrosive sublimate. To allow of its deep insertion it is necessary to open up the sinus with a knife. The powder may be en veloped in blotting-paper to enable it to be passed into the sinus. It has the effect of causing an eschar or slough, which comes away in the course of ten or fifteen days, carrying with it the diseased cartilage, in favourable cases, and leaving a gaping, granulating wound which rapidly cicatrizes. A second application of the caustic may be necessary in some cases where a portion of the necrotic cartilage remains inside after the separation of the eschar.
This procedure is spoken of as the"coring out"treatment on account of the formation of the eschar or"core."It often fails owing to the agent employed not"touching the spot."Used in the vicinity of the joint it may lead to opening of the latter with fatal consequences.
4. The Use of the Thermo-cautery. A red-hot iron rapidly plunged into the lowest part of the sinus and rapidly withdrawn has often proved effective in sloughing out its lining, including the necrotic cartilage, while at the same time it acts as a powerful bactericide, destroying all the microbes with which it comes in contact. Its use is dangerous in the vicinity of the joint on account of the risk of penetrating it with the instrument, which must be inserted blindly, without any reliable guide as to the exact course which it takes or the depth to which it reaches. If not inserted deeply it will not have the desired effect.
5. A combination of Nos, 3 and 4 is often employed, and proves more successful than either alone. All these caustic applications cause severe inflammation, rendering interference with the part very painful and provocative of resent ment by the horse, which may become very restive and difficult to control.
B. The use of a seton or piece of tape passed into the sinus above and brought out through the wall of the hoof at the level of the bottom of the passage to ensure drainage through the counter opening, and to enable a caustic applied on the seton to be brought into contact with all parts of the lesion, a method of treatment which is often efficacious.
7. Extirpation of the Cartilage. The steps of the extirpation are as follows : (1) Preparation of the Foot. The day before operation remove the shoe, thoroughly clean and scrape the entire hoof, clip the hair up to II the fetlock, wash the digit with soap and water, bathe it with an antiseptic lotion, and envelop the foot in a moist antiseptic compress covered with a boot.
(2) Thinning or Removal of the Horn of the Wall in the Affected Region. Thin the wall beneath the lesion until the sensitive laminae are reached, from the anterior to the posterior extremity of the cartilage above, and over a smaller area below, so that the thinned surface is considerably greater in its upper than in its lower part. Instead of thinning the horn it may be stripped off as follows : make a groove through the wall obliquely downwards and back wards from the anterior extremity of the car tilage to the plantar aspect of the hoof ; make another groove parallel to this at the heel ; join the two grooves by a third one at the white line. Seize the lower end of the isolated piece of horn with a pincers, and, pulling forcibly upwards, strip it from the sensitive tissues.
(3) Ire,ci8ion of the Seratogenous Membrane.— Apply a tourniquet round the pastern to prevent haemorrhage during the operation. Make a linear incision between the coronary band and the laminae, extending from the anterior to the posterior extremity of the cartilage going through the keratogenous membrane.
(4) Separation of the Coronary Band and the Skin from the Outer Surface of the Cartilage. Inserting a knife through the incision just described, separate the coronary band from the underlying tissue throughout the entire length of the wound. Insert a retractor' beneath the separated band and have it held up by an assistant. By means of a double-edged sage knife separate the skin from the whole of the outer surface of the cartilage. Having thor oughly exposed the latter, introduce the blade of one of the sage knives (right or left) to the inner aspect of the cartilage behind, and, cutting vigorously from within outwards, remove the posterior part of the structure. Excise the anterior portion by successive slices so as to avoid opening the joint by cutting into the process of synovial membrane which is in contact with the inner face of the cartilage in front. Further to guard against this accident, have the foot held in extension when operating in this region in order to stretch the membrane and keep it out of the way of the knife.
To remove the extreme anterior part of the cartilage in contact with the bone, or to scrape the latter when diseased, use the curette or sharp spoon, scraping from within outwards to avoid entering the joint. Irrigate the wound with an antiseptic solution. If the antero lateral ligament is altered on its surface from superficial necrosis swab it with tincture of iodine. Take off the tourniquet, and if bleeding vessels can be recognized secure them by torsion or ligation. Apply an antiseptic powder to the wound, cover the seat of operation with a large antiseptic pad of gauze, cotton-wool, or tow, kept in position by a bandage. Put on a leather boot enclosing the whole foot, or use an impro vized boot of plaited straw, formed by uniting two large plaits of straw at their centres at right angles to each other, the foot being placed at their centre and the ends applied longitudinally on the limb, and fixed there by a soft rope or a bandage. The boot may be dispensed with, and the ordinary shoe and a leather or metal sole applied.
Renew the dressing on the following day and do so daily for a while, after which an occasional renewal of the dressing will be sufficient. If the bleeding is practically nil the original dress ing may be left on for two or three weeks, when the wound may be almost healed. As new horn forms on the coronary band keep it pared until the wound is healed; otherwise it may inter fere with the drainage from the wound, or encroach on the latter, wounding the delicate granulations and perhaps giving rise to an abscess beneath the flap of skin.
Results of Operation. —If thoroughly per formed, and the wound is protected from infection, cure will be effected within five weeks, when the horse is usually sound and fit to do light work if carefully shod so as to have no bearing on the hoof in the vicinity of the affected region, which should be covered with a dressing of tar, tow, and a short bandage, the latter also being smeared with tar on the out side. A leather sole is advisable as a protection against dirt, and a three-quarter bar shoe is generally suitable. As a rule, once the horn has grown down to the ground no sign of the lesion or operation is visible, but occasionally a space persists between the laminal and coronary horn in which foreign matter may accumulate and cause lameness from pressure on the sensitive tissues.
The remedy for this condition is to thin or pare away the outer layer of horn and remove any dirt or foreign material that has accumu lated beneath it, and then apply a dressing of tar and tow to prevent its recurrence.
Rarely lameness persists from hyperaesthesia in the cicatrix, for which needle-point firing of the coronet in the affected region may be successful. If not, neurectomy will be necessary.
Modifications of Operation. 1. Bayer's Opera tion. Make a semicircular groove in the wall extending from the anterior to the posterior extremity of the cartilage, with its convexity downwards and the summit of the latter about 12 inch above the plantar border of the hoof. Strip off the isolated piece of horn. About inch inside the periphery of the exposed sur face make a semicircular incision going through the skin, for a short distance above the coronet, the coronary cushion, and the podophyllous membrane.
Reflect the semicircular flap thus marked out, thereby thoroughly exposing the cartilage. Remove the latter as described, replace the flap in position, and suture the cut edges of skin and laminal membrane and dress as before. The advantage of this method is that it greatly facilitates the excision of the cartilage, white its objectionable feature is that it involves cut ting the coronary band in two places, causing two false quarters or defects in the wall, which, however, are very slight and of no great conse quence.
2. Divide the Flap by a Mesial Incision. Proceed as in the original operation until the cartilage is laid bare. Then divide the flap by a menial incision into an anterior and a posterior half and reflect them to expedite the removal of the cartilages. Unite the two parts of the flap by sutures, pins being the most suitable for the purpose. The sutures do not always succeed in keeping the cut edges in apposition, and they may then overlap, causing deformity. A false quarter is formed opposite the point of section of the coronary band.
3. Operate from above the Coronary Band. Remove an elliptical or circular piece of skin surrounding the orifice of the sinus, and dissect the skin from the cartilage for some distance beyond this point. Following the sinus to its depth, ascertained by the use of the probe, remove all the necrotic cartilage by means of the curette and fill up the cavity with a reliable antiseptic powder, such as a mixture of boric acid and iodoform, or potass. permang. 1 and boric acid 1 0, or biniodide of mercury.
Acute Laminitis.Acute inflammation of the sensitive laminae may occur in all the feet, or in both fore or both hind feet, or in one foot, but never in two diagonal or two lateral feet.
Etiology. This comprises: 1. Predisposing causes; 2. Exciting causes.
1. Predisposing Causes. These include: (a) Heavy body weight, big heavy horses or those whose bodies seem too heavy for their limbs, like fat ponies and idle stallions, being likely subjects.
(b) Unfit Condition. Horses being left in the stable for days without or with insufficient exercise, and then made to go a long journey, often become affected at the end of the latter. Young horses put to work for the first time are apt to suffer from the disease if made to do more work than their immature condition is fitted to bear.
(c) Plethora. Plethoric subjects are more sus ceptible than those in moderate hard condition.
(d) Hot weather favours the onset of the malady.
(e) Abnormal Conformation of the Feet. Flat spreading feet and narrow contracted feet are more often attacked than normal feet.
2. Exciting Causes. — The exciting causes may be: (a) Errors in diet, such as overfeeding, especi ally on nitrogenous food — for example, oats, rye, barley, wheat, peas, and beans; or taking a big feed of any stuff to which the animal is not accustomed. Green cereals partaken of in undue quantity may give rise to it, viz. lucerne, sainfoin, and vetches, particularly when recently gathered. Horses eating too much of the gleanings in the harvest-time sometimes become affected.
(b) Overwork. Horses doing long fatiguing journeys by road frequently become affected in consequence of the prolonged concussion on the feet. When (a) and (b) are associated the condition is still more likely to supervene.
(c) Exposure to cold and damp has been blamed as a cause on the Continent, but in this country it does not seem to have a predisposing or determining effect on the disease. When it does appear under these circumstances it seems to be of a rheumatoid nature.
(d) Excessive weight on one foot, owing to the presence of a painful lesion in the other limb, may cause laminitis in the former.
(e) Toxcemia, resulting from an infectious disease such as purpura, pneumonia, or metritis, or from the absorption of toxins from the ali mentary tract following an attack of colic. It is a very common complication of simple metritis in the mare.
Symptoms. The symptoms vary according as the disease affects one, two, or four feet and according to the acuteness of the attack. They are general and local.
General Symptoms. The general symptoms are those of pain and fever.
Pain is evinced by the attitude and expression of the patient.
When the two fore feet or all the feet are affected the horse stands with the fore limbs in front of the body and the hind limbs well under it, his object being to let most of the weight fall on the heels. If the hind limbs only are affected he keeps all the feet under the body to make the fore feet bear most of the weight and to make the heels of the hind feet bear most of the pressure. The animal stands persistently and is very unwilling to move, and when forced to do so groans. When the patient is recum bent he lies stretched out and is very reluctant to rise, being afraid of the pain caused by putting weight on the feet.
During progression the gait is of a peculiar crouching character, the heels being put to the ground first and the feet lifted quickly as if they were burnt by contact with the earth. The subject trembles with pain. When only one foot is affected weight is alternately placed on it and the other foot which is always suffering from some other painful lesion. The expression is anxious and indicative of suffering.
Fever is manifested by the usual symptoms of febrile disturbance.
The temperature is 103° to 106° F., the pulse is frequent and strong in the early stages of the affection before exhaustion supervenes, when it becomes weak. It may be 70 to 120 per minute. The respirations are accelerated, due chiefly to the pain.
The conjunctiva is injected.
The local symptoms are those of more or less acute inflammation. Abnormal heat is readily detected by placing the hand on the hoof, and throbbing can be felt in the digital arteries. Pain is evinced on the slightest percussion of the foot by the animal snatching it smartly from the ground.
In the course of four to twelve days these symptoms usually subside and resolution sets in, the horse gradually regaining his normal condition. Sometimes, however, they become intensified due to haemorrhage or exudation taking place beneath the horn. Haemorrhage is due to rupture of the sensitive laminae as the result of severe congestion and the drag caused upon them by the downward pressure of the os pedis under the body weight. The blood accumulates between the wall and the os pedis, and its pressure on the sensitive structure causes excruciating agony, the patient lying prostrate, bathed in sweat, and groaning with pain. Occa sionally some of the blood escapes at the coronet through a separation between the horn and the coronary band.
Death soon follows in a bad case of this kind.
The collection of inflammatory exudate in the same situation causes similar symptoms, and some of it may ooze out between hair and hoof. Gangrene may supervene on one of the latter conditions, due to infection gaining entrance to the inflamed region. Its onset is characterized by suppression of the intense symptoms of pain and inflammation, giving the impression that the patient is better, but the cold sweat which, bedews the body, the feeble, frequent, or im perceptible pulse, and the cold extremities indicate that death is nigh.
Diagnosis. Diagnosis is generally easy after careful examination of the case, which prevents the condition being confounded with tetanus, coronitis, sprained back, or rheumatism.
Prognosis. The prognosis varies according to the nature of the attack. It is more serious when all the feet are affected than when two or only one foot is involved. The condition is generally more grave in horses that have been doing fast work than in those that have been engaged in slow work, in highly-strung nervous animals than in lymphatic subjects, and in big than in small horses.
If a cure is not obtained within fourteen days the affection is apt to become chronic, or still more acute and to terminate in death. When the symptoms are alarming in the beginning the prognosis is generally gloomy.
Prevention consists in avoiding the .causes mentioned and in keeping animals under good hygienic conditions.
Treatment should be prompt and energetic. Its general principles are those recommended for fever and acute local inflammation.
Constitutional Treatment. This comprises: 1. Jugular Phlebotomy. Removing one to two gallons of blood in a sthenic subject. This has undoubtedly a good effect when promptly performed, soon after the commencement of the attack. The objection to it is the risk of phlebitis.
2. Purgation. Prompt purgation is decidedly beneficial. Consequently the administration of eserine or arecoline hypodermically is indicated on account of its rapid effect. Pilocarpine may be combined with the former. Arecoline is par ticularly efficacious and is looked upon by some authorities as a specific, its action being so frequently followed by immediate amelioration of the disease. It is not, however, invariably successful.
3. The administration of febrifuges, such as tincture of aconite, salicylate of soda, quinine sulphate, spts. ether nit., liq. ammon. acet., or sodium hyposulphite.
Tincture of aconite is probably the most effective febrifuge in the early stages of an acute attack, but neither it nor any of the others has a very striking influence on the course of the disease.
4. Counter-irritation. On the Continent coun ter - irritation of the upper part of the limbs, the chest, and abdominal walls by rubbing in a rubefacient application is done with the object of causing a deviation of blood thereto from the feet so as to relieve the congestion of the laminae.
Local Treatment. Local treatment comprises: 1. Cold applications in the form of a foot-bath, moist compresses, or constant irrigation.
The foot-bath may be provided by a stream or pool or by digging a hollow in a clay floor in the stable or in the open, or by a thick bed of sawdust or sand saturated with cold water, the patient being allowed to stand in the bath for the greater part of the day or constantly. Cold swabs applied round the pasterns and over hanging the hoofs may be used in the intervals between the baths, or instead of them, especi ally when the patient is recumbent. They should be kept cool by frequent application of cold water. Constant irrigation through a perforated rubber bracelet round the limb above the fetlock communicating with a rubber tube from a tank of water above the level of the horse is a very effective means of carrying out this method of treatment. In the winter snow or ice may be procurable for the application of cold and prove more beneficial than water.
2. Astringent applications to be used alter nately with the cold applications, and including the usual refrigerant lotions such as liquor plumbi subacetatis, white lotion, etc.
3. Bleeding from the Toe. Paring the horn of the sole at the toe and drawing blood from the sensitive tissues in this region has had con siderable vogue and is certainly a good method of relieving congestion in the inflamed part, but it has the serious objection that it favours infection therein with its dangerous sequel, suppuration and gangrene. If it is done anti septic precautions are necessary.
4. Hot Applications. Hot poultices or hot moist compresses are favoured by some prac titioners, but they are probably not so useful as the cold treatment.
5. Hypodermic Injection of Adrenalin. The hypodermic injection of adrenalin in a dose of twenty to thirty minims diluted with an equal quantity of normal saline solution over each digital artery usually has a marked beneficial effect, causing a rapid fall in the temperature and a decided and prompt improvement in the animal's gait. Nevertheless, it is not an in fallible agent for bringing about a cure, and sometimes it is followed by sloughing at the seat of injection.
6. Hypodermic injection of cocaine over the plantar nerves, removing sensation for a while from the feet, gives the patient some intervals of relief from pain, allowing him to rest and recover to some extent from the exhaustion caused by suffering, and permits of his being exercised freely with good effect in dispelling the congestion by stimulating the activity of the circulation in the foot.
7. Bier's Treatment. Applying a rubber band over a thin layer of cotton-wool covered with a bandage round the upper part of each affected limb, sufficiently tightly to arrest the venous circulation without stopping the flow of arterial blood, has been done with good effect, the ex planation being that the venous congestion causes increased phagocytosis and an out pouring of serum containing anti-bodies which act beneficially in counteracting the effects of bacteria and their toxins which may be present at the seat of the lesion.
The band is left in position for two to four hours daily until improvement occurs.
8. Grooving the hoof at the junction of the wall and the sole at the toe to permit o1 the escape of inflammatory exudate.
This has the same objection as bleeding from the toe, viz. opening an avenue for infection of the inflamed part; otherwise it has the good effect of relieving pain.
9. Ligation of the Digital Artery. - - When the condition is not responding to ordinary measures or persists in a subacute form, ligation of one of the digital arteries is indicated to relieve the congestion in the sensitive laminae. The artery is easily isolated on the outer aspect of the fetlock, ligatured in two places, and cut between the ligatures. It generally has good results, improvement following immediately after the operation, the inflammation subsiding and the freedom of gait being restored.
Exercise is an important indication recog nized by most practitioners as having a marked effect in favouring resolution. It should be continued for twenty minutes to half an hour twice daily on soft ground. If the hoofs are strong the horse may go barefooted or wear ordinary shoes, but if they are affected with dropped soles rocking shoes should be applied, that is, shoes thin at the heels and toe and thick at the quarters with a wide web and well seated on the foot surface.
Diet. Soft, laxative diet is indicated, as bran and linseed mashes and grass if in season. A little magnesium sulphate and potass nitrate in the drinking water has a febrifuge effect and keeps the excretory organs active.
When pain is very severe a hypodermic or intravenous injection of morphia may be given.
Chronic Laminitis. Chronic laminitis is a sequel to the acute form, or occurs spon taneously.
Its local characteristics are changes in the form of the foot.
It becomes elongated antero - posteriorly, narrow transversely, and somewhat flattened in front. The heels are higher than normal, and the wall approaches the horizontal direction in the region of the lower part of the toe, whilst in its upper part it is inclined to the vertical direction, so that its central portion appears depressed or constricted. Rings or rugs form on the wall parallel to the coronet, compara tively widely' spaced behind and almost con fluent in front. The sole is convex or flat anteriorly, the lateral lacuna are abnormally deep, more so than in an ordinary flat - foot. The sole may be perforated in front of the frog, exposing the sensitive tissues, which become inflamed, emitting a serous, sanguinolent, or greyish purulent discharge, and may also undergo necrosis. The wall becomes separated from the laminae in front, receding from the sole at the white line, the inter-space being empty or filled with abnormal horn secreted by the laminae. The space is widest at the centre of the toe, where it may measure 2-3 inches. When the condition follows the acute form the symp toms of the latter have disappeared, but a certain amount of hyper-sensitiveness persists in the affected feet. The degree of lameness varies. It may be absent, but the gait is always abnormal, being characterized by the horse going decidedly on the heels.
If an antero-posterior section of a chronic laminitic foot be made, the alterations in its conformation will be very apparent.
The wall is thicker than normal, projected forwards at the toe and not parallel to the anterior surface of the os pedis, which is more vertical than usual.
Between the wall and the sensitive laminae in front the space already alluded to is evident, filled with homogeneous laminal horn or practi cally vacant, except for a small deposit of horn covering the laminae. In a recent case there may be osteophytes on the bone, but in an old case it may show some atrophy. The mechan ism by which these changes occur is probably as follows: The sensitive lamina in front rupture, whilst those at the heels, being much less involved in the inflammatory process, remain intact, and in consequence the os pedis tends to descend in front, under the body weight, and the perforans muscle asserting its superiority over its anta gonist, the extensor pedis, causes the bone to swing backwards on the horizontal axis formed by the intact lamina at the sides, thus bringing the anterior plantar border of the bone to press on the sole, causing it to bulge downwards and become flat or convex. In consequence of this pressure the sensitive sole undergoes atrophy and ceases to secrete horn. When the existing horn becomes worn away perforation takes place. The descent of the os pedis causes stretching and bending of the papillae on the coronary band, so that the horn formed by them is more vertical than usual, and thicker than normal, on account of their secretory activity being stimulated by this interference.
This accounts for the prominence and upright direction of the horn near the coronet. During progression the horse puts most weight on the heels, thus pushing the separated wall at the toe forwards and making it approach the hori zontal direction.
Diagnosis is usually easy, even when the toe is shortened and the rings removed by the rasp, the convexity of the sole, the deep lacunae, and the space between the wall and sole being characteristic.
Prognosis. The prognosis is unfavourable, the deformity and abnormal gait persisting. Recurrent attacks of subacute inflammation may supervene, especially after a long journey by road. For a long time the horse affected can only be used at slow work on soft ground.
Treatment. Treatment comprises dressing of the foot and the application of appropriate shoes. Remove the excess of horn at the toe but spare the horn on the sole, quarters, and heels. Apply a wide-webbed shoe well seated on the foot surface, so as to afford protection to the dropped sole without bearing on it. In order to avoid making the shoe very heavy, to enable it to be well seated a strip of leather may be interposed between the bearing surface of the shoe and the wall, so as to keep the former away from the sole. A leather plate is desirable as a protection to the sole. The horse gener ally goes best in a long-heeled shoe, that is, one whose heels project well behind those of the hoof, ensuring the posterior part of the foot striking the ground first, thus saving jar to the hypersensitive anterior laminal region. As time goes on the shape of the foot may improve. When the sole is perforated, immerse the foot in an antiseptic bath if inflammation is present, and after it has subsided dress the part with tar and tow cover the sole with a metal plate fixed between the hoof and the shoe.
Navicular Disease. — Navicular arthritis, or groggy lameness, is a disease due to chronic ostitis of the navicular bone, associated usually with more or less chronic synovitis of the navi cular bursa and inflammation of the plantar aponeurosis.
The condition is practically confined to the fore feet, affecting both as a rule. The hind feet are rarely affected. The most notable change in the navicular bone is the presence of ulcers on its tendinous aspect, appearing as outcuts in the cartilage thereon. Osteophytes may also form on this surface, especially near its extremities. The articular aspect remains intact. Owing to the rarefaction of the bone due to the ostitis it becomes weak and brittle, and may fracture under the body weight, espe cially if the foot is brought forcibly to the ground in an unexpected manner. Adhesion may occur between the bone and the tendon as the result of fibrinous synovitis. The tendon sometimes becomes fibrillated from friction against the roughened posterior surface of the bone.
Etiology.The real exciting cause of the disease is obscure, but the circumstances under which it most commonly occurs are well known. It is most common in light horses, especially those doing fast work on hard roads, parti cularly when they are not getting regular exercise but are subjected to work at a rapid pace occasionally, after more or less prolonged rest in the stable. Cart horses are rarely affected. Heredity is believed to be a cause, an hereditary tendency to the malady being believed to exist in certain breeds of horses of the roadster type. The conformation of the foot is looked upon as a factor in the produc tion of the disease, which most commonly occurs in narrow, upright, or contracted feet. The cause in this case may, however, be confounded with the effect, for when the disease has been in existence for some time it tends to produce this conformation.
Navicular disease is usually gradual in its onset and insidious in its appearance, being generally well established before the symptoms are sufficiently well developed to attract the serious attention of the owner. Rarely it appears suddenly as the result of shock on the foot, as may occur during jumping or prancing in a fresh horse, or from making a false step. The cause might be of a toxic nature, resulting from rheumatism or some infectious disease like strangles or influenza.
The absence of frog pressure preventing the action of the anti-concussion mechanism of the foot is undoubtedly a contributing cause of the affection.
Hence a defective system of shoeing, such as the application of thick-heeled shoes or those furnished with calkins, on horses engaged in fast work on hard ground favours the onset of the condition, as do also a long toe and a sloping pastern by throwing excessive weight on the posterior region of the foot.
Symptoms. The first symptom as a rule to attract attention is the horse pointing his foot when at rest, and as both feet are usually involved he points them alternately. Afterward the animal is observed to go tender occasionally, but when given a rest for a few days he goes sound again. As time passes the lameness becomes decided and is characterized by the subject taking a short stride, going on the toe, with a tendency to stumble when the toe strikes the ground.
The gait is pottering or groggy, and the seat of lameness appears to be the shoulders, on account of the shortened stride. The lameness is most marked on starting after resting for a while, and diminishes with exercise. It is more pronounced on hard than on soft ground, and is intensified by frog pressure and by the use of thin shoes, which have not the same effect in breaking the shock on the feet as thick shoes. When the disease is well established the lame ness is continuous. When the horse is turning he screws round on his fore feet instead of lifting them.
The local symptoms comprise the alterations in the form of the foot, which becomes"boxy,"that is, contracted and high at the heels, with a very concave sole, deep lateral lacunae, and an atrophied frog, some swelling in the hollow of the heel due to distension of the navicular bursa, not a constant symptom, some pain on per cussion of the frog, not always manifested, and abnormal heat on palpation, only noticeable as a rule after a long journey.
In the rare cases in which the affection is sudden in its appearance the lameness is severe from the beginning.
When the hind foot is affected the horse rests it more than usual, and during progression goes on the toe. If both hind feet are attacked, the lameness is characterized by stiffness of the posterior limbs.
When the condition has been in existence for some time the muscles of the shoulder undergo atrophy and the foot becomes more contracted, both changes being due to the prolonged restricted use of the limb on account of the constant lameness. The disease usually affects horses in their prime, when about seven years old.
Diagnosis. The diagnosis is made out from the history of the case, the changes in the foot, and the nature of the lameness. When in doubt, the injection of cocaine over the digital or plantar nerves will decide whether the seat of lameness is in the foot or higher up.
Prognosis. The prognosis is bad, because once the disease is established it is incurable, and the best that can be hoped for is that the horse will prove useful for a reasonable time after the performance of neurectomy. A comparatively favourable but rare termination of the malady is adhesion between the navicular bone and the perforans tendon as the result of plastic syno vitis, as it arrests the friction between the two structures and thereby prevents the pain and laceration of the tendon caused in this way, and enables the horse to go sound if the inflammation is not too severe in the bone. In bad cases rupture of the tendon may supervene after repeated laceration by friction against the rough bone.
Treatment. - On account of the incurable nature of the disease treatment is unsatis factory. Veterinary surgeons of the old school claimed to have treated it successfully by bleeding from the jugular, by purgation, by applying poultices to the feet, and by giving prolonged rest or by turning the horse out on marshy pasture; also by the insertion of a frog seton passing through the plantar cushion from the hollow of the heel to the point of the frog just behind the plantar aponeurosis and left in position for about three weeks, and cleaned daily, its object being to favour union between the navicular bone and the perforans tendon.
Grooving the contracted hoofs and applying light shoes are other procedures said to have good effect. The former usually has a palli ative result by relieving the pressure on the inflamed region, but the light shoes can only be beneficial in favouring frog pressure and acting as a preventive rather than as a curative agent. Many of the so-called cures were cases of tem porary improvement or mistaken diagnosis, for it is now universally admitted that in a true case of the disease cure is out of the question. In order to render the animal workable, it is necessary to remove or diminish sensation in the foot by performing neurectomy on the digital or plantar nerves or on the median nerve. Digital neurectomy is usually sufficient, but sometimes, at a variable period' afterwards, lameness recurs, due to the inflammation spread ing above the seat of the operation, when it is necessary to do either double plantar or median neurectomy. The latter frequently has the desired effect and is then preferable to the former, inasmuch as it does not entirely deprive the foot of its innervation, some being still supplied by the ulnar nerve through the external plantar, which is formed by the union of the ulnar with' a branch from the median, the internal plantar being formed entirely by the latter. The objection to completely unnerving the foot is that it may in consequence undergo degeneration and lose its vitality, with the result that the hoof is shed or that the perforans tendon ruptures, necessitating the destruction of the horse. Fracture of the navicular bone is a fairly common sequel to the operation, being favoured by the brittleness caused by rarefying ostitis, and actually produced by the foot being brought more forcibly to the ground on account of the absence of sensation therein. An open wound of the tissues below the seat of opera tion greatly favours their degeneration by allowing the entrance of infection. A wound may be inflicted in the foot, and escape notice owing to the patient not feeling any pain for want of nerve supply.
(For"Neurectomy,"see pp. 999-1003.) Sand-crack. Sand-crack is a fissure in the wall of the hoof, extending from the coronet downwards to the horn fibres, involving only a part or the whole of the height of the wall. It may appear at any part of the hoof, but is most commonly situated at the toe of the hind foot and at the quarter of the fore foot. The crack may be complete or incomplete, superficial or deep, recent or old, and simple or complicated.
Predisposing causes are alternate moisture and dryness of the horn, rendering it brittle; any thing which weakens the horn, such as excessive rasping of the wall, or injury to the coronary band causing it to secrete inferior horn; and heredity.
Symptoms. The chief local symptom is the presence of the crack, which varies in character. It may be a simple fissure, or complicated with injury and inflammation of the sensitive laminae, causing a discharge from the crack of blood or serum or pus, when infection has gained entrance. Injury to the sensitive tissues is caused by tearing of the laminae or by their getting pinched between the lips of the crack. In cases of decided inflammation there is a painful swelling on the coronet in the vicinity of the split in the wall.
If there be necrosis of the exposed tissues, or caries of the pedal bone, a large inflammatory swelling forms, extending over the digital region. Lameness only occurs when there is inflamma tion of the sub-corneal tissues, or when they are pinched in the crack during progression.
When lameness accompanies a sand-crack at the toe, the horse lifts the leg, usually a hind one, spasmodically, as in stringhalt, holds it suspended for a while, and then carries it well forward and puts it cautiously on the ground, heel first. This peculiarity of gait is more noticeable in the hind than in the fore limb.
Prognosis of a simple crack is good, as it usually responds readily to treatment. Com plicated cases vary in gravity according to the nature of the complication. Non-purulent or slightly purulent inflammation is comparatively easily dealt with, but complications such as extensive suppuration beneath the horn, gan grene of the soft tissues, necrosis of the extensor pedis tendon or of the lateral cartilage, and purulent ostitis are troublesome lesions, while septic arthritis when it supervenes is an incur able condition.
Diagnosis is usually easy when the foot is carefully examined. If the hoof is covered with mud the sand-crack may be hidden, or it may be skilfully concealed by filling it with wax or gutta-percha. In a doubtful case, scraping the suspected region with a hoof knife will decide the matter. A crack beginning at the plantar aspect of the wall and only ex tending through a part of its height is not a true sand-crack, being simply due to the lower border of the wall being split as the result of becoming overgrown or not being protected by a shoe.
Sand-crack at the Toe. Sand-crack at the toe of the foot is most common in the hind limb of the cart horse, and is apparently due to the pressure caused on the coronary border of the hoof by the os corona when the horse is bearing on the toe during heavy draught. It may be due to slipping from one pavement block on to another when pulling a heavy load on a paved street. It is certainly most frequently met with in heavy horses working in cities.
Treatment. — I. Simple Sand-crack without Lameness. The treatment comprises: 1. Im mobilization of the lips of the crack. 2. Stimu lation of the coronary band to secrete new horn to fill up the crack.
1. Immobilization of the lips of the crack may be effected by (a) a special shoe; (b) a bandage; (c) the use of sutures made by horseshoe nails or clasps; (d) plugging the fissure with a piece of wood or gutta-percha; (e) by making grooves across the fissure; (f) by thinning the borders of the crack.
(a) Special Shoe. A special shoe, divided in the inner half of its width at the toe, and pro vided with clips at the inner aspect of the heels, which fit into the lateral has been em ployed. After the shoe has been nailed on, an instrument is applied between the branches of the shoe at the heels by means of which the latter are dilated, with the result that the hoof is also expanded posteriorly and the edges of the crack are brought into and kept in closer apposition. This method of procedure has often given good results.
(b) A Bandage. This is usually in the form of a tar rope coiled round the hoof. It can have little effect in preventing movement of the edges of the crack, and probably its chief use is in keeping dirt out of the fissure and diminishing the risk of infection and inflammation. A strong rubber band round the hoof has been used effectively by Mr. Charles Allen, F.R.C.V.S., of Dublin.
(c) Sutures. Driving a horseshoe nail across the crack, cutting off its ends and clenching it towards the fissure, is very effective. It requires considerable skill to insert the nail sufficiently deeply to get a good grip without injuring the sensitive tissues. A little transverse groove is first made on either side of the slit to receive the nail, which is then driven through with a hammer. To facilitate its introduction, a hole may be made with a drill to accommodate the nail. The hot iron used in connection with the clasps may be employed here to make the groove for the nail. One nail may be sufficient, but it is usual to insert two, the upper one being about half an inch below the coronary band and the other about the centre of the wall. Wire clasps, inserted by a special forceps in much the same manner as a pig ring is introduced, are not so serviceable as the nails, not having so deep a hold, and sometimes becoming loose and falling out. A depression is first made with a special hot iron to receive the clasp, which is easily and rapidly introduced by means of the forceps, into whose jaws it fits exactly.
(d) Inserting a Piece of Wood into the Crack. A piece of wood driven into the fissure from its plantar aspect prevents pinching of the sensitive laminae and excludes dirt therefrom. The horn on either side of the crack must be pared to make room for the piece of board, which should be made to fit into a slot on either side like the lid of a crayon box.
(e) Making a groove across the crack in its upper third intercepting the transmission of pressure along its borders towards the coronet diminishes their pinching effects superiorly. Two or three such grooves are more effective, having the desired result lower as well as above.
This procedure, however, cannot be very effectual in preventing movement of the borders of the fissure.
(f) Thinning of the Lips of the Crack. Paring the borders of the slit to relieve the pressure of the horn on the sensitive tissucs may be done. Making a groove on either side of the crack at about half an inch from it on its upper part converging to meet it at its lower end, thus mapping out a V-shaped area, and thinning the horn within it, is another way of producing the same effect.
In all cases it is advisable to relieve the bearing on the shoe in the vicinity of the affected part by lowering the wall here or by truncating the shoe on its corresponding foot surface.
2. Stimulation of the Coronary Band. This is effected by blistering or firing the coronet. When the hot iron is used three transverse lines may be made, viz. one across the crack at its lower third, one at its upper third, and one on the coronet, or one may be made about half an inch below the coronary band, one on it, and one about half an inch above it. Those on the wall go almost right through the horn, and simply have the effect of preventing the transmission of pressure along the edges of the crack.
II. When Lameness is Present.In this case measures are taken to allay the inflammation in the sensitive tissues by removing the shoe and treating the foot with warm antiseptic baths, as the result of which the lameness may disappear when the case is treated as already described. If the lameness persist after this procedure has had a fair trial it will be necessary to relieve the pressure on the inflamed part by thinning the borders of the fissure, or better, by thinning a V-shaped area as explained above. If this be insufficient and a purulent discharge continue to ooze from the cleft, there is evidence of the presence of infected tissue in the inflamed region, and it must be removed by an operation, which consists either in thinning the horn at its level, or stripping it off here by making a groove right through the wall on either side of the fissure and another at the white line, and tearing off the isolated piece of horn by means of a pincers, and then excising the necrotic lamina' tissue with a knife and scraping the os pedis with a curette if it be affected with superficial necrosis.
The wound is dressed with an antiseptic pad and bandage covered by a strong leather boot, or by an improvised boot made from plaited straw. The dressing is removed after two or three days and then reapplied. The horn growing from the coronary band must be re dressed occasionally until the wound is com pletely healed. When the breach in the wall is covered by provisional horn formed by the laminee, it should be covered with tar and tow kept in position with a strap buckled round the hoof, or it may be filled with gutta-percha.
at the Quarter. at the quarter is most common on 'the inner aspect of the fore foot and in horses doing fast work. Contracted feet are most likely to be affected. Feet with low heels are also subject to it. When there is deformity of the feet, such as turned-in or turned-out toes, it is the surcharged quarter which is likely to become fissured.
Treatment. The treatment is on the same general principles as that of sand-crack at the toe, but nails or clasps driven across the crack are not suitable, as the horn is hardly thick enough to bear them as a rule. The most common procedure here is the formation of a groove crossing the crack at its upper part intercepting the transmission of pressure from the ground towards the coronet. If lameness supervene the foot should be treated for in flammation as before.
in one of the Bars.Treatment here is to thin the horn in its vicinity and protect the part with a wide-webbed shoe and a leather o r metal sole, keeping a dressing of tow and tar in contact with the part.
Seedy-Toe. "Seedy-toe"is an affection of the foot characterized by separation of the wall from the sub-corneal horn and the formation m the interspace of crumbly pumice-stone-like horn secreted by the sensitive laminae. This abnormal horn does not completely fill the space beneath the wall, which is consequently more or less hollow.
Etiology. The cause is generally obscure, but the condition would appear to be the result of a local chronic laminitis following traumatic injury such as might be caused by a too closely driven nail, or by the compression of a large clip. Wide spreading feet are most subject to it.
Symptoms. The lesion may be present for a good while before being detected, and is usually first recognized by the farrier when preparing the hoof for shoeing. The foot appears quite normal when resting on the ground, but if the wall be struck on its outer aspect with a hammer a hollow sound will be emitted opposite the affected part. The extent of the affection varies in depth and peripheral area. It may occupy any region of the circumference of the wall, and may affect only the lower portion of the latter, or extend even as far as the coronet. Lameness is absent when the area affected is small, but when there is considerable separation of the horn the sensitive laminae are insufficiently protected from concussion, and foreign matter accumulates in the space, causing pressure on the laminal surface, the result being more or less well-marked lameness. The abnormal horn is easily broken down with the knife.
Prognosis depends on the depth and area of the lesion. When circumscribed it is not of much consequence, not causing lameness and allowing the horse to work during treatment.. When a large part of the foot is involved to a great depth beneath the wall, causing lameness, months may elapse before the horse is fit to work.
Treatment. Pare away the new formation of horn to diminish the pressure on the sensitive structures, pack the cavity with tar and tow, and apply a shoe, having no bearing on the affected region, and a leather sole to keep the dressing in position.
If the disease extend far up beneath the wall it will be necessary to remove a portion of the latter at the level of the lesion in order to expose it and enable the abnormal horn to be pared away.
A bar shoe with a breach in the iron opposite the affected part is suitable. Apply a blister to the coronet to promote the growth of normal horn.
Etiology. The condition is due to hyper activity of the laminae or coronary band, caused by some injury or irritant, whereby an abnormal quantity of horn is secreted. In this way it may result from mechanical injury of the wall or coronet, or from a closely driven nail com pressing or penetrating the laminae, or from dirt gaining entrance through a sand-crack or a separation between the wall and the sole. There is another and comparatively rare form of keratoma which appears independently of inflammation or irritation of the horn-secreting structures. It may be adherent or free, and of similar dimensions to the one just described.
Symptoms. The tumour may develop in sidiously, and be present for a considerable time before being detected. Its presence is recognized on examination of the plantar aspect of the foot by the abnormal appearance of the horn at the place corresponding to the lower end of the growth, between the wall and the sole, the white line being deviated inwards here. If fistulous, a probe can be passed into it, and the fistula may be discharging pus. The pressure of the tumour on the laminae and the os pedis may cause inflammation and lameness.
The former is indicated locally by pain on percussion at the level of the lesion, and by abnormal heat on palpation.
The latter varies in degree. The abnormality in gait may be of the nature of stringhalt. The wall may bulge over the tumour. When the sensitive tissues become infected through the fistula the affected laminae may undergo necrosis and the os pedis may become affected with caries. The pressure of the new horn causes atrophy of the laminae, which eventually dis appear, preventing further increase in size of the tumour. The pedal bone may also undergo atrophy and become weakened in consequence, so that it may fracture under the body weight.
Diagnosis of the condition is easy, owing to the characteristic appearance of the horn at the lower end of the tumour or to the presence of the fistulous orifice, into which a probe can be passed to abut on the tumour or pass through it as mentioned.
Prognosis. The prognosis, generally speaking, is unfavourable, there being no tendency to spontaneous cure, and no means of effecting the latter except by operation, after which the tumour may recur.
Treatment. If there be neither pain nor lameness it is sufficient to regulate the shoeing so as to have a minimum amount of bearing on the affected region.
When lameness supervenes palliative or cura tive measures may be adopted.
Palliative treatment comprises rest and anti phlogistic applications, which may cause tem porary improvement, and, if these fail, paring out the tumour from below with a searcher, or boring it with a drill to allow it to collapse on itself and thus diminish the pressure on and consequent pain in the sensitive tissues until the tumour increases in size, when this procedure will require repetition.
Curative treatment consists in extirpating the portion of the wall on which the tumour is growing as follows: Make a groove right through the wall from the coronet to the plantar aspect on either side of the affected part, and another groove joining these at the white line. Seize the isolated portion of wall at its lower extremity with a pincers and forcibly strip it off. Protect the breach in the wall with an antiseptic dressing until it becomes covered with new horn. Then apply a dressing of tar and tow, kept in position by a bandage or a leather and strap round the hoof, the horse, if sound, being allowed to go to work wearing a shoe with the pressure relieved in the vicinity of the affected region.
Should the sensitive laminae in the affected part be found necrotic or much altered by pressure or suppuration, they should be excised, and if the terminal phalanx is affected with caries the diseased surface should be curetted.
Separation of the wall from the sub-corneal tissue may occur apart from a horn tumour; for example, in wide - spreading feet of horses working on streets without lameness, or follow ing the operation for quittor, or after contusion of the wall. When contusion affects the sub coronary region only, the separation is confined to this situation, and the condition is only suspected by the hollow sound emitted when the wall here is struck by a hammer. The treatment is to clean out any foreign matter that has accumulated in the space, and then fill the latter with pitch or tar and tow. If this proves insufficient in a case of lameness, it will be necessary to thin the separated horn to relieve pressure on the underlying parts, and if the laminae are exposed and inflamed the use of a disinfectant is indicated.
A horn tumour sometimes forms on the deep face of the sole in flat or convex feet, in which it may arise from circumscribed chronic inflam mation resulting from contusion. It is hemi spherical in shape, its base being flush with the sole. The velvety tissue becomes atrophied through its pressure, and the os pedis may become excavated from the same cause. It is diagnosed by pain confined to the region affected, and elicited by percussion with a hammer, and by the dry, hard consistence of the horn of the tumour, which retains these characters after considerable paring, whilst that of its periphery, when cut to the same extent, causes bleeding by wounding the sensitive part. Infection of the lesion is rare.
Treatment. Thin or hollow out the tumour to diminish its compressive effects, or remove it radically and excise necrotic tissue if present. Cover the wound until healed with an antiseptic dressing and a metal or leather sole fixed under the shoe.
Gathered Nail.Punctured wound of the plantar aspect of the foot.
Etiology. Punctured wound of the plantar aspect of the foot is caused by the horse treading on a sharp-pointed, hard resisting body, which penetrates the horn and enters the sensitive tissues to a varying depth. The wounding body may be a nail, a sharp piece of iron, the clip of a shoe, a stub of wood, a ladies' hat pin, a piece of shrapnel or portion of a shell.
The point of entrance may be in the sole or frog. When the sole is hard, concave, and free from cracks the offending object may glide from it into the lateral lacuna and enter the foot there. In the frog the commonest seat of puncture is near its point. The bar is seldom penetrated, owing to its obliquity and hardness.
The thinner and softer the horn the greater the risk of sharp bodies passing through it into the sensitive tissues.
The direction of the wound depends on the angle at which the foot meets the projecting point, and on the deviation which the latter may undergo by the weight exerted upon it. The lesion is one of the commonest affections of the foot, and is particularly frequent in horses working in places where objects of the nature mentioned are strewn. In military horses on active service it is the chief source of foot trouble.
Symptoms. When the foreign body enters the horn it may not at once penetrate the sensitive tissues. This may occur from repeated force applied to it by the foot striking the ground during progression. Attention is generally first attracted by lameness, and when the foot is examined the cause of the trouble is usually discovered at once by finding the foreign body more or less firmly embedded in its plantar region. It may require a pincers to remove it from the foot. The object may, however, be broken on a level with the horn, when its situa tion may be recognized by a dark or abnormal spot corresponding to its distal extremity, or it may have become divided at some distance in from the surface of the horn and require to be searched for with the hoof knife before being discovered. When it is removed the lameness may disappear, and the resulting perforation in the horn may be so small that it is hardly visible. There may be some blood on the object when withdrawn, or a little haemorrhage may appear at the orifice after its removal. When the wound is slight it may heal at once without further symptoms. If not, and the condition has existed for some days, infection will have supervened, and there will be a purulent dis charge from the wound, blackish or whitish in colour or mixed with blood. The deep layers of the horn in the affected part will be infiltrated with moisture, yellowish, separated from the sensitive tissues. There is severe local inflamma tion, causing great pain and lameness. At a later stage the tissues will be more altered, owing to the prolonged action of the organisms causing more or less necrosis of the velvety sole or plantar cushion, and the purulent discharge will be more copious, a sinus being present. When important deep-seated structures are involved in the necrotic or septic lesion special symptoms are manifested according to the nature of the complication. If the os pedis undergo necrosis there will be a profuse escape of bloody pus, and a probe passed into the sinus will come in contact with the bone. The plantar aponeurosis may become necrotic, causing a constant purulent discharge until the affected portion is removed. Should the synovial sheath be opened there will be a purulent synovial discharge, and an in flammatory swelling will form in the hollow of the heel at the level of the sheath. The navi cular bone may be ulcerated on its tendinous aspect or completely fractured. The inter osseous ligament may be destroyed, allowing infection into the joint, setting up arthritis, which becomes manifested by a prominent coronary swelling with perhaps abscesses, which on bursting discharge offensive purulent synovia, and persist as fistulae until the horse dies from septicaemia or toxaemia, or is destroyed, the case being hopeless.
Lameness is always well marked in connection with these deep-seated complications, which may prevent any weight being borne by the affected limb.
Diagnosis is easy after removing the shoe and paring the foot.
Prognosis. The prognosis depends on the part affected and on the nature of the injury inflicted. Taking the plantar region of the foot as being composed of an anterior, middle, and posterior region, the most serious part to be perforated in a more or less upright manner is the middle region, because most of the important structures of the foot are situated directly above it. After it comes the anterior regions, in which the os pedis may be injured. The posterior region is made up practically entirely of the plantar cushion, lesions of which are compara tively benign, being always followed by recovery when rationally treated. When the case is seen early, before complications have arisen, the latter may be prevented by careful treat ment. All the septic lesions of the foot arising in the manner described respond to treatment except arthritis, extensive disease of the os pedis, and fracture of the navicular bone.
The degree of lameness present and the horse's temperature serve as guides as to the gravity of the condition. The lameness, however, may be extremely severe, no weight being borne by the affected limb, and yet the case may be amenable to treatment; for example, septic synovitis of the small sesamodean sheath causes alarming symptoms, but when it is properly treated recovery ensues. When arthritis supervenes, or when the navicular bone is fractured, the case is hopeless, but ulceration of the cartilaginous surface of the tendinous aspect of the bone may be successfully treated by curetting the affected spots and using antiseptic applications.
Treatment. An injection of anti-tetanic serum is indicated to prevent tetanus. The treatment in a recent case before suppuration has had time to ensue is that of an ordinary open wound. It consists in removing the offending body and any other foreign matter that may have gained entrance, providing drainage, and applying anti septic solutions to prevent the development of micro-organisms and the complications to which they give rise. These indications are carried out as follows: Having extracted the wounding body, thin the horn round the orifice of the wound over an area of the diameter of a half to a crown piece, to facilitate the escape of discharge should it form, to relieve pressure on the injured region, and to allow the antiseptic lotion to come into contact with the wound.
It is a good and common practice to pour into the wound immediately a little pure carbolic acid or pure creolin, which ensures the destruc tion of any bacteria that are present, and causes no ill effects from the superficial destruction of sensitive tissue to which it gives rise. After wards protect the wound with an antiseptic dressing of iodoform and cotton-wool or a moist antiseptic compress, kept in position by a bandage and boot, or by strips of hoop-iron or a metal plate inserted between the shoe and the hoof. An excellent treatment is to immerse the foot, after thoroughly cleaning it, in a warm antiseptic bath made with any reliable antiseptic agent for at least half an hour two or three times daily, there being perhaps nothing better than perchloride of mercury (1-1000), the wound in the intervals being dressed as described. When inflammatory symptoms fail to appear and the horse goes sound it is evident that the treatment has had the desired effect in preventing septic infection, and the animal may be allowed to work with the protective dressing applied. Should the wound be fairly large and the sensi tive tissues exposed, excessive granulations are likely to form from the irritation caused by the edge of the surrounding horn, and it will be necessary to remove them with the knife if large, or, if smaller, by the application of a caustic, such as powdered sulphate of zinc or perchloride of mercury or sulphate of copper. When the
exposed wound is cicatrized and covered by horn, put on a dressing of tar and tow covered with a metal or leather sole.
In slight cases where the wound is superficial one or two applications of an antiseptic dressing are generally sufficient.
When the lesion is of some standing and dis charging pus, it must be treated as a sinus by adopting measures to provide for the drainage of the purulent material, to remove necrotic tissue, and destroy the organisms which have invaded the affected part. Paring the horn round the seat of injury, and removing it entirely where it is under-run, followed by the use of the antiseptic foot bath once or twice daily and an antiseptic dressing in the meantime, often proves effective in the course of a few days. Should this procedure fail it may be concluded that there is necrotic tissue in the wound requiring removal. This may be effected by the use of a caustic, or the hot iron, or by surgical inter ference. The operation consists in opening the sinus to its depth and curetting its interior, so as to remove all unhealthy tissue and leave a clean open wound which will granulate and heal in the ordinary way, when carefully protected from infection, until it is uniformly covered by granulations. It may involve incision of the plantar aponeurosis where it is inserted into the plantar aspect of the os pedis, scraping of the latter when affected with necrosis, or curetting the ulcerated surface of the navicular bone. It is necessary to remove the greater part of the plantar cushion to enable these deep-seated parts to be operated upon.
To resect the plantar aponeurosis, first expose it by excising the greater portion of the plantar cushion, excavating a cone-shaped wound whose depth represents the apex of the cone, and then cut it transversely at the level of the navicular bone and remove its distal portion from its insertion into the third phalanx. Irrigate the cavity with an antiseptic solution, paint it with tincture of iodine, powder it with iodoform, pack it with sterilized gauze, and cover it with a pad of sterilized cotton-wool and tow.
Envelop the foot in canvas and enclose it in a boot, or keep the dressing in position by strips of iron or a sole, as mentioned before. It is advisable to put the horse in slings, as he is unable to stand on the affected limb for some time. To ensure keeping the wound sterile im merse the foot daily for a while in an antiseptic bath and renew the dressing. When granu lating throughout, occasionally dressing the wound without using a lotion will be sufficient. The result of the operation when carefully per formed and followed by strict attention to the wound is usually successful, the latter gradually granulating and closing in to become completely healed in about six weeks. After about a fort night the patient commences to put weight on the limb, and thence onwards improves by degrees until he goes almost, if not completely, sound in the course of six or eight weeks. Sometimes an abscess forms in the hollow of the heel, but is not of serious consequence, healing as a rule on bursting or being opened and drained. A seton passed vertically through the cavity acts as a drainage-tube. Rarely the proximal end of the perforans tendon undergoes necrosis, requiring renewed intervention to remove the affected part and protracting the duration of recovery. In exceptional cases, lameness persists after healing of the sinus, due sometimes to hypernsthesia in the cicatrix and at other times to contraction of the hoof follow ing the prolonged inactivity of the foot and the removal of the frog and greater part of the plantar cushion.
To avoid removal of the frog and consequent contraction of the heels after the operation, it has been suggested to incise the plantar cushion antero-posteriorly, reflect each half laterally to enable the aponeurosis to be reached, and after wards unite the two parts of the cushion by wire sutures. It does not seem to be a very practicable procedure.
Corns. A corn is a contusion of the sensitive tissues at the heel in the angle between the wall and the bar, the structure affected being the sensitive tissue of the sole, wall, or bar. The condition is most common in horses working in cities.
In an ordinary recent or dry corn there is merely an escape of blood from the injured vessels, causing more or less staining or ecchy mosis of the overlying horn in a punctiform, linear, or diffuse manner. If the cause be re peated, the condition becomes aggravated and the inflammation becomes more severe, but re mains aseptic so long as there is no breach in the horn to allow the entrance of infection. When the contusion is severe the horn in the affected part becomes infiltrated with serum, or the latter may accumulate beneath the horn, giving rise in either case to a moist corn. When infec tion ensues through an accidental fissure in the horn, or as the result of excessive paring of it, the lesion suppurates and a suppurating or festered corn is produced.
The corn is said to be complicated when it is accompanied by necrosis of any of the tissues in its vicinity, such as the laminae, the plantar aponeurosis, the lateral cartilage, or the plantar cushion.
Etiology. Corns are very rare in unshod feet. Consequently shoeing is blamed as the primary cause of the affection.
Any defect in shoeing which results in ex cessive pressure or weight being brought to bear on the seat of corn favours the condition. Fitting the shoe very close on the inside to avoid the risk of brushing may have this effect, and the frequency with which this is done probably accounts for corns being more common in the inner heel. Faulty conformation of the limbs causing unequal distribution of weight on the foot is a predisposing cause, and it is for this reason that corn more often affects the outer heel when the toe is turned in.
Interference with the anti-concussion mechan ism such as is caused by atrophy of the frog, high-heeled shoes preventing the frog reaching the ground, high contracted heels preventing expansion of the posterior region of the foot, upright pasterns causing increased concussion on the bony column of the limb, favours the production of the lesion. Fast work on hard roads, especially in the case of heavy horses, is a fruitful source of contusion of the heels if the shoeing is not carefully attended to. That concussion is a prime factor in producing corns is proved by the fact that they are very rare in the hind feet while they are very common in the fore feet, where concussion is greater.
Wide spreading feet with low weak heels are likely to become affected owing to the horn affording insufficient protection to the sensitive tissues of the region where the greatest shock is received by the foot. Leaving the shoes on too long causes them to be drawn forwards by the growing wall, and may thus result in their heels being brought to bear on the seat of corn and to give rise to the affection.
A stone accidentally fixed between the heel of the shoe and the frog may cause a bruise in this situation.
Symptoms. A corn during the acute stage is characterized by local symptoms of a contusion with more or less acute inflammation and by a varying degree of lameness. The local ena are in accordance with the nature of the lesion. Pain is evinced on percussion and com pression of the affected heel. Abnormal heat is revealed on palpation. In the case of a dry corn, paring the horn in the affected region dis closes the staining of its deeper layers varying from a glossy yellowish appearance to a deep red tinge, occupying an area of varying dimen sions in different cases.
In a moist corn the overlying horn is infil trated with serum, which makes it moist in its deeper parts, or the liquid may accumulate beneath it and escape when an exit is made with the knife. When suppuration supervenes the inflammatory symptoms are very intense, and, if the pus is not allowed to escape by removing the horn which confines it, it will extend up wards to the coronet and become discharged there through the medium of an abscess.
The pain is very acute until the pus gets an outlet, when it is greatly relieved.
When a sinus persists it is due to necrosis of some of the tissues in the region caused by septic organisms, and a probe passed into it will give an idea of the depth of the lesion and the part affected.
Quittor is a common sequel to suppurating corn and is very likely to ensue after the pus has reached the coronet, and when it does supervene in this case the orifice of the first abscess between hair and hoof does not consti tute the opening of the quittor, which forms at a higher level by the bursting of a secondary abscess after the primary one has healed. The sinus may also appear on the plantar aponeur osis or the os pedis. The lameness varies in its degree according to the nature of the local lesion. In a well-marked case the horse goes on his toe with the heels clear of the ground and, when standing,"points"the affected foot, that is, holds it in front of the other one, resting only on the toe. When both feet are involved the animal has a short pottering gait and at rest points the two feet alternately. In"suppurating corn"the lameness is extreme until vent is given to the pus.
In an old-standing case of corn in which the pain and lameness have disappeared, the only indication of the lesion will be the discoloration revealed on paring the corn.
Diagnosis. The diagnosis is easy and is made out from the symptoms. The changes in the horn are characteristic.
Prognosis. The prognosis depends on the character of the lesion. If it be simple con tusion it is of little or no consequence, lameness being slight or perhaps absent; when more marked it is more serious, causing greater lame ness, which may persist for a considerable time. Purulent corn is serious on account of the trouble some complications to which it may give rise.
' Treatment. Treatment consists in removing the cause and adopting the usual methods for dealing with inflammation or an abscess or a sinus, as the case may be.
Removal of an offending shoe may be all that is necessary. Paring the horn over the corn has a decidedly good effect in relieving tension on the affected part, but care must be exercised not to overdo it by wounding the sensitive tissues and causing a risk of infection.
When suppuration supervenes a free exit must be made for the pus by removing the underrun horn, and the foot should be immersed in an antiseptic bath for a half-hour to one hour morning and evening until the discharge ceases, the lesion being protected in the mean time by an antiseptic compress or a dry dressing. The wound in the sensitive tissues usually granu lates excessively owing to the irritation caused by the edges of the cut horn. The exuberant granulations must be removed with a knife or caustic, the wound being afterwards treated with an astringent or slight caustic to prevent recurrence. When suppuration has extended upwards beneath the wall it is advisable to remove a A-portion of the latter to ensure the escape of the pus. Complications must be treated according to their nature, the prin ciples of treatment being those of a sinus.
When the wound following a suppurating corn is healed and covered with horn, and in all cases where the horse is going sound, a shoe having no bearing on the affected region, and a leather sole with a dressing of tar and tow, should be applied. An ordinary shoe, with the wall shortened so as not to bear on it at the affected heel, or a shoe truncated or excavated on its foot surface, or a bar shoe with the bar resting on the frog or a three-quarter bar shoe, the iron being omitted opposite the seat of corn, may be used.
Pricks in Shoeing.A prick or wound, caused by driving a nail into the sensitive tissues in the act of nailing on a shoe, is of two kinds, viz. (1) where the offending nail is withdrawn im mediately after being driven, and (2) where it is not withdrawn. Another variety of the lesion similar to the second is one caused by an old stump, remaining in the wall since the previous shoeing, being driven into the sub - corneal tissues by the force of the newly-driven nail which comes in contact with it.
Etiology. The accident is favoured by several circumstances such as: 1. Contraction of the hoof, rendering the wall less oblique and thereby making the nail more likely to take an inward course. 2. Thinness of the horn, which accounts for pricking being more common in the inner than in the outer quarter of the foot. 3. Want of skill on the part of the doorman in failing to drive the nail properly. 4. Faulty workman ship in making the shoe, stamping the holes too coarse or too oblique, causing the nails when driven to be diverted towards the sensitive laminae. 6. Badly - shaped nails, the malfor mation making the nails take a wrong direction. 7. of the horse, resulting in the animal violently snatching his foot from the shoer when a nail is only partly driven and stamping the foot with great force on the ground and forcing the nail into the flesh.
The lesion is more common in hind than in fore feet, due probably to the fact that the horn is more upright behind than in front and that the hind foot is often more difficult to control than the fore foot.
During the busy time when horses are being roughed for frost, the hurried way in which shoes are put on after being removed may lead to pricking.
The amount of damage done by the nail will, of course, vary according to the depth of the injury and the part affected. The nail may merely touch the sensitive laminw, or it may wound or even fracture the pedal bone.
Symptoms. During the process of shoeing it may be recognized that the nail is being wrongly driven by (a) the sound of the hammering which, instead of becoming clearer, becomes duller, due to the nail entering the soft tissues; (b) the nail meeting with less resistance as it pene trates deeply, showing it is not taking an outward course towards the hard surface of the wall; (c) resentment of the horse, which snatches away the limb suddenly; (d) blood appearing on the nail when it is withdrawn or oozing from the orifice in the horn.
The blood, however, may be wiped off the nail in its passage through the horn and the hole in the latter may close by its walls falling into contact, thus preventing the escape of blood. The flinching of the horse may be pre vented by the use of a twitch, or ascribed to temperament when the animal is of a fidgety disposition, or it may not be noticed.
A simple prick where the nail is immediately withdrawn and the nail - hole left vacant is usually of no consequence, but when the nail is left more or less embedded in the soft tissues lameness supervenes immediately or may be delayed for a day or perhaps for several days.
The diagnosis of the cause of the lameness is easy. The horse having been recently shod, irregularity of the clenches, one or more being unusually high, perhaps the absence of a nail, arouse suspicion, which is confirmed by examina tion of the foot revealing symptoms of inflam mation at the seat of injury. Pain is evinced on percussion, and abnormal heat is felt on palpation here. Cutting the clench of the offending nail and traction on the corresponding branch of the shoe in removing it are resented by the patient. When the nail which caused the injury is withdrawn it is seen to be black, from the action of the sulphur of the horn on the nail. A greyish, whitish, or blackish discharge escapes from the hole in the horn, When the nail-bed is pared out it is found to be surrounded by soft blackish horn infiltrated with the puru lent discharge and more or less separated from the sub-corneal tissue.
Prognosis. A simple slight prick of the sensi tive tissues, in which the nail is at once extracted and omitted, is usually of no consequence, neither pain nor lameness supervening. The other form of prick caused by the nail being left inserted in the sensitive laminae may have serious consequences, such as diffuse inflamma tion of the foot, or necrosis of the horn-secreting structures, the os pedis, or the lateral cartilage.
Treatment. - When the prick has been dis covered during the shoeing, it is usually suffi cient to leave the corresponding nail - hole vacant, but to prevent the possibility of infec tion a little antiseptic solution may be poured into the orifice, or the latter may be closed by collodion, or a red-hot nail may be passed rapidly into the hole in the horn and quickly withdrawn, to act as a germicide. This is a common prac tice with farriers.
Should a severe wound be inflicted, the horn all round the track of the nail should be thinned to favour the exit of discharge in case any may form as the result of infection of the wound, which should be prevented as far as possible by antiseptic applications such as a little pure or strong solution of carbolic acid or creolin poured into the orifice, or the use of a foot-bath. No lameness may ensue; if it does, the treatment –should be continued and the horse kept at rest until it disappears. In the case where inflam mation and suppuration have taken place before the condition is detected, or as a sequel to infection in the first case, the shoe must be removed, the horn thinned in the vicinity of the affected region, and the foot immersed in an antiseptic bath for half an hour to an hour morning and evening until the discharge ceases and the lameness disappears, the part being protected in the intervals between the im mersions by a moist or dry antiseptic pad kept in position by a boot or poultice-bag. When suppuration is extensive beneath the wall it is advisable to remove a portion of the latter to provide free drainage and relieve pressure on the inflamed area.
There is usually no difficulty with the case when treated on these lines provided that some of the complications mentioned have not arisen, when special measures may be required accord ing to the nature of the case as described else where.
When the horse is sound a dressing of tar and tow should be applied over the seat of the lesion and kept in place by a leather sole. The animal is then fit to go to work.
Contracted Hoof.A contracted hoof is one whose wall has become contracted or shrunken in one or more situations, usually in the regions of the quarter and heels on one or both sides of the foot.
The condition is more common in the fore than in the hind feet.
Etiology. — Anything causing dryness or brittleness of the horn, or which prevents ex pansion of the hoof, favours its contraction, for example: 1. Injudicious use of the rasp, filing the outer surface of the wall and thereby removing the periople or varnish, which prevents evaporation, and consequent dryness and shrinking of the horn, and also removing some of the superficial fibres of the horn, thus exposing the deeper ones to the action of the air and allowing them to become dry and contracted.
2. Chronic lameness, diminishing the activity of the foot and consequently its expansion.
3. Excessive paring of the frog, causing it to become dry and contracted, and preventing its coming in contact with the ground to promote dilatation of the heel region of the foot.
4. Mutilating the bars, and in this way re moving or weakening the buttresses or stays of the wall and permitting it to fall inwards at the heels.
5. Shoeing with calkins or thick-heeled shoes, absolutely preventing the frog bearing on the ground and acting as an expansile apparatus.
Want of frog pressure is probably the chief cause of the abnormality.
Navicular disease affords a good illustration of the symptomatic form of contraction, as it is a symptom of this malady and due apparently to the horse going on the toes and easing the heels.
Symptoms. When the foot is on the ground and viewed from in front, the deformity is noticed, and when unilateral, the contrast be tween the two sides of the hoof is very striking. When looked at from the plantar aspect, the marked difference in length of the antero posterior and transverse diameters of the hoof is observed, the former being decidedly in excess of the latter, whereas a normal fore foot is about as broad ruesial1y as it is long. The narrowness is most noticeable in the posterior part of the quarter and at the heels. The normal length of the hoof is not altered. The bars are less divergent posteriorly than usual, having a ten dency to approach each other behind. The frog is always more or less atrophied and the lateral lacunT are abnormally deep.
Frequently the horn is dry and brittle.
Lameness may be present as the result of the contraction alone or of the disease which gave rise to it.
Prevention of the deformity consists in avoid ing the causes mentioned, and, above all, in maintaining frog pressure as far as possible by shoeing with tips or thin-heeled shoes or by the Charlier system, by leaving the frog intact when preparing the hoof, and by the use of rubber pads bearing on the frog when the latter is not sufficiently developed to reach the ground with an ordinary shoe applied.
Treatment comprises: (1) Improvement of the method of shoeing; (2) the use of dilating or expanding shoes; (3) grooving the wall to permit of its expansion.
(1) Improvement in the method of shoeing may be sufficient in slight cases, such as substi tuting flat shoes for those with calkins, or adopting some of the measures mentioned under the heading of prevention.
(2) The use of mechanical means to cause expansion of a contracted hoof is not much in vogue, although several special shoes have been invented for this purpose, especially on the Continent. None of them is of sufficiently proved merit to deserve description.
A shoe whose bearing surface, instead of being horizontal, is made to slope downwards and outwards, is believed to have some effect in expanding the hoof.
(3) When the hoof is decidedly contracted, and especially if lameness is present, the best treatment is to groove the horn in the affected region as follows: At the anterior part of the contracted region make a vertical groove in the wall about iw of an inch wide, by means of a firing-iron and a searcher, going right through the horn without injuring the sensitive tissues. At the heel make a similar groove almost parallel to the horn fibres, downwards and forwards.
Between these grooves make two others parallel to the posterior one. Join all these grooves by one made through the white line, that is, the commissure between the sole and the wall. Remove the lower ends of the isolated portion of horn with the rasp and knife to prevent their coming in contact with the shoe afterwards. Operate on one or both sides according as the condition is uni- or bilateral. Fill the grooves with tar. Put on a bar-shoe with a leather sole, the bar resting on the frog and the shoe having no bearing on the grooved portion of the wall.
If the frog be too atrophied to reach the bar of the shoe interpose a rubber pad between them to bring pressure on the former. Have the horse exercised daily to promote frog pressure and expansion. If the hoof is very hard the foot may be poulticed for a few days to soften the horn and make it more elastic and dilatable. In the course of about three weeks the good effect of the operation will be noticed, the hoof being decidedly wider in the region where it was contracted and the horse going much better, if not quite sound. Even if the condition is the result of navicular disease temporary improve ment may ensue. If the patient does not eventually become completely sound, it may generally be concluded that the case is one of navicular disease, and must be treated accord ingly.
Nail Binding. The condition known as"nail binding"is that caused by driving a nail or nails too close to the sensitive lamina; without wounding them, but causing more or less pain or discomfort by pressure thereon.
It most commonly occurs in feet with a thin crust.
Symptoms. The affection is manifested by cramped action or lameness, which is usually slight, and by symptoms of mild local inflam mation, viz. pain on percussion or compression, and some abnormal heat on palpation of the affected part.
Treatment. Removal of the shoe and the application of cold or hot compresses or swabs for two or three days have the desired effect. A prick is generally suspected, and, if care is not exercised in searching for it, the sensitive tissue may be wounded and infected, compli cating the condition.
Bruised Sole. Contusion of the sole may be caused by the foot treading heavily on a pro jecting or loose stone or by a badly-fitting shoe. The bearing surface of the hoof on the shoe should be confined to the wall, the white line, and that portion of the sole in contact with the wall.
Chronic Coronitis or Villitis. Chronic derma titis of the perioplic band and coronary cushion.
Etiology. The etiology is often obscure. A form of the affection accompanies skin diseases in some cases or follows a febrile condition.
The typical form of it often occurs without any apparent cause, or results from repeated irritation or injury of the coronet. But in all cases there may be an hereditary predisposition to the malady, associated perhaps with rheum atism.
It most commonly affects light horses, those engaged in fast work. It is particularly common in the ass and mule.
The chief site of the disease is the toe and quarters.
The perioplic band appears to become more active, secreting a horny material disposed in irregular masses separated by narrow fissures resembling somewhat the bark of an old tree.
The coronary cushion in the affected part produces thickened abnormal horn of the same appearance as that formed by the perioplic ring. The skin in the vicinity may also be covered with a horny formation fissured in every direction and sometimes discharging from the cracks a purulent fluid. In old-standing cases there may be separation of the horn at the coronet.
The subcutaneous tissue becomes thickened at the level of the lesion in typical old cases, causing a swelling which projects over the hoof. Sometimes an ulcer forms between the swelling and the horn. In the subacute form accom panying a febrile disease or a skin affection the whole of the coronet is involved and reveals slight symptoms of inflammation, chiefly abnor mal heat. In this case there is more or less marked lameness, characterized by a shuffling gait something like that of subacute laminitis.
In the ordinary chronic form of the disease, with local changes as described, lameness may or may not be present. When the new forma tion of horn on the coronet is thick, or when the wall is separated from the coronary band, lame ness supervenes.
Treatment. —When apparently of constitu tional origin one should treat the general affection from which the animal is suffering. If it seem to be associated with rheumatism, sodium salicylate should be prescribed. When local inflammation is present it is to be treated as such. Cold-water swabs applied to the coronets are generally useful. Afterwards the application of a hoof ointment on the coronet to promote the growth of good horn and render it supple or elastic is beneficial, such as equal parts of Stockholm tar and mutton suet boiled together, or one part of coal-tar mixed with six parts of fish-oil. Blistering the coronet may have a good effect in a case of long standing.
When the new growth of horn is thick it should be thinned to a pellicle and the weeping cracks therein should be treated with an anti septic lotion. Ulceration should be combated by the use of a wound stimulant or caustic to excite a healthy reaction and bring about granu lation and cicatrization. In all cases the horn beneath the affected part of the coronet should be made as thin as possible with the rasp to diminish the pressure and pain in the inflamed part.
Delperier, a well-known French authority on the horse's foot, recommends washing and drying the affected part every five days, and then applying rapidly over its surface the flat portion of a red-hot firing-iron and passing its edges into the fissures. Slight repeated appli cations of nitric acid, more or less dilute, or of chloride of zinc (5 to 10 per cent), or of pyro gallic acid or picric acid, in saturated aqueous solution or as an ointment (1 to 10 of vaseline), has often had good results.
Necrosis of the coronet or sloughing of a portion of the coronet or subcorneal tissues may result from an open wound and infection by the necrosis bacillus.
The condition is fairly common in horses constantly standing in mud, especially in very cold, frosty weather, the severe cold diminishing the vitality or resistance of the tissues.
The lesion has been very prevalent in Army horses during the winter months as the result of the causes mentioned.
Symptoms. — The symptoms are those of intensely acute inflammation in the region of the coronet and severe lameness. An extremely painful swelling, more or less diffuse, forms here, the skin, if not pigmented, becomes dark red, and serum oozes from the surface, which becomes clammy owing to desquamation of the epithe lium, which can be scraped off like a scum. The affected part then becomes insensitive, and a line of demarcation is observed between the dead and healthy tissues.
If infection does not extend beneath the horn the lameness attenuates when the scar is formed. When the subcorneal tissue is involved, the pain is more excruciating owing to com pression of the inflamed part by the resistant horn, and it does not subside with the formation of the slough, which cannot be cast off on account of being confined by the horn, the result being that the organisms continue to exercise their pathogenic effects, causing further necrosis of the sensitive parts, including the laminae or extensor pedis tendon, the lateral cartilage, or the pedal bone.
Treatment. The treatment is that for necrosis and inflammation. The extremity of the limb should be thoroughly cleaned, the hair on the affected part clipped or shaved, the horn at the level of the lesion should be thinned to a pellicle to relieve compression, and the foot should be immersed in a warm antiseptic bath at frequent intervals to destroy the organisms and limit infection. The hot bath may be objected to on the ground that the heat favours the develop ment of microbes, but its germicidal effect and the hyperaemia and increased phagocytosis which it produces probably discount this objection. Moreover, the moist heat softens the slough and hastens its separation when the latter does not involve important structures.
Contusion, Crushing, and Open Wounds of the Foot.Contusion or crushing of the foot is generally caused by direct violence inflicted from above downwards on the upper part of the foot in the region of the toe, quarters, or heels, the offending agent being usually the wheel of a heavy vehicle passing over the coronet. The foot may also be crushed between the curbstone of a footpath and a heavy wheel.
Symptoms. A slight contusion is of little consequence, causing more or less lameness, which disappears in the course of a few days. The changes in the affected part are the usual ones for a contusion, there being slight hsamo rrhage or ecchymoses in the bruised tissues.
When the contusion is caused by severe violence, or when the foot is actually crushed, the animal becomes extremely lame, and if there be no breach in the horn there may be no local symptoms present, but in many instances some trace of the accident is left on the horn, or the coronet reveals symptoms of a contusion at its level, viz. heat, pain, or swelling. Pain is evinced when the injured part is pressed with the fingers.
The damage done to the foot may vary in degree from slight bruising of the superficial sensitive tissues to extensive deep injury of them, with extravasation of much blood, which may collect beneath the hoof, or in the small sesamoidean sheath or even in the joint, and perhaps fracture of the pedal bone.
Although infection may be excluded, the disorganization of the tissues may be so great that return to the normal condition is impossible.
Exostoses frequently form, giving rise . to prominent low ring-bone causing permanent lameness. Occasionally in these accidents the hoof is completely torn off, with comparatively little injury to the deep structures of the foot.
Should the lesion in the foot become septic more or less serious complications may ensue, due to necrosis of the parts affected.
Diagnosis. If there be no history to the case and no mark of injury on the hoof diagnosis may be difficult. But, as a rule, there is some trace of the accident on the foot. When the horn of the plantar region is pared ecchymosis may be detected at the white line. These symptoms, associated with severe lameness and the acute pain evinced on percussion or compression, generally lead to a correct conclusion. It is not always easy, however, to state exactly the nature of the lesion or the extent of the injury inflicted.
When there is an open wound the structures affected may be evident and the seat of the trauma will be a guide to the parts likely to be involved. The tendons, lateral cartilages, or bones may be more or less seriously altered.
Crepitation on manipulation of the foot will reveal fracture, and a synovial discharge from a wound in the coronet will be proof of an open corono-pedal joint.
Prognosis. The prognosis depends on the gravity of the lesion. In cases of moderate contusion cure is effected after some days.
When the tissues are severely damaged there is always the danger of secondary changes occurring, such as the formation of exostoses or anchylosis of the pedal joint, causing incurable lameness. This must be kept in mind when giving an opinion as to the possible ultimate result of a severe traumatic lesion of the foot even without breach of surface.
These changes may not supervene until months have elapsed since the accident. Injury of the anterior or middle regions of the foot is more likely to have serious consequences than that confined to the region of the heel.
Deep - seated septic conditions are always serious and may defy treatment.
Infected open joint is of course hopeless, as is also compound fracture of the os pedis or navicular bone.
Treatment.This comprises removal of the shoe, the use of antiphlogistic or antiseptic applications, and, when the lameness is very severe, placing the patient in slings.
At first immersing the foot in a cold bath or irrigating it with a constant stream of cold water, and afterwards using hot fomentations and compresses, are indicated in cases where there is no open wound. When the latter is present rigorous cleanliness and antisepsis are essential to prevent septic complications. All foreign matter and destroyed tissue must be removed, the skin of the coronet and pastern in the vicinity should be shaved, the whole hoof should be thoroughly washed and disinfected, and the foot should then be kept in a warm antiseptic bath for half an hour or an hour two or three times daily, the wound in the meantime being dressed with iodoform or some reliable application, and the hoof kept clean by being enclosed in a boot. When the wound is cicatriz ing, that is, covered uniformly with granulations, dry dressing only should be used.
Separation or Avulsion of the Hoof. Separa tion of the hoof may be caused by degeneration of its attachments through the agency of infec tion, or their rupture by mechanical violence.
Degeneration may ensue from extensive sup puration beneath the horn, and it is favoured by the use of poultices which have no antiseptic effect on bacteria. It most frequently occurs, however, as a sequel to neurectomy, especially double plantar or posterior tibial neurectomy, which entirely removes sensation from the foot. It more rarely follows median or even single plantar neurectomy.
Mechanical violence acts as a cause, when all the muscles of the limb are violently contracted in an effort to extricate the foot which has become fixed between two resistant objects, or when the foot is crushed from above downwards by a heavy weight such as a waggon-wheel passing over it and the pain thus caused makes the animal endeavour to snatch it away suddenly.
Symptoms.The local symptoms are obvious, the sensitive tissues being all exposed and more or less injured when the result of violence. Evidence of pain is not always marked. It is surprising how slight it is in some cases. In stances are recorded where the horse continued to trot fairly well after losing one or two hoofs.
Prognosis.When the condition is the result of degeneration or sloughing after neurectomy it is hopeless. But if the case be noticed when separation is commencing at the coronet it may be possible to arrest the process of separation by rest and antiseptic foot-baths. When the loss of the hoof is due to mechanical violence the chances of recovery depend on the amount of injury inflicted on the tissues.
In every case it will take from six to nine months for a new hoof to form. Sometimes the newly-formed horn is deformed, and occasion ally, although the regenerated hoof is fairly normal in shape, lameness persists from morbid sensitiveness in the subcorneal structures. The hoof, however, may be perfectly reproduced, and even in cases where a piece of bone has been torn away with a portion of the horn - secreting membrane, recovery may occur to an extent sufficient to enable the animal to go to work.
Treatment.Treatment comprises the removal of shreds of necrotic tissue, thoroughly cleaning and disinfecting the foot after clipping or shav ing the pastern, and applying a dressing of iodoform covered with gauze and several layers of cotton-wool kept in position by a bandage, and protected from the dirt of the stable floor by a boot. The frequency of renewal of the dressing will depend on the progress of the case. When ever it becomes moist from discharge it should be removed and replaced by a fresh application. When the tissues become covered with horn it will be sufficient to keep the foot covered with tar until the new wall is formed.
If the hemorrhage after the accident be rather profuse it is advisable to apply a tourni quet above the fetlock to arrest it until the foot is enveloped in the compressive dressing.
Sidebones. A sidebone is an ossified lateral cartilage of the foot.
Etiology.The actual exciting cause of side bones is not always clear.
The ossification of the cartilage may be due to: (1) Heredity, as apparently obtains in draught horses in which sidebones are very common, without any visible external cause to account for them.
(2) A natural tendency for cartilage continu ous with bone to become ossified, as occurs in the development of bone.
(3) Concussion causing shock or inflammation of the bone at the base of the cartilage, stimulat ing proliferation of the osteoblasts, which then invade the cartilage and produce ossification therein.
The prevalence of sidebones in heavy horses, their comparative rarity in light horses, and the fact that they are seldom associated with inflammation, do not support this theory as a common cause of their occurrence. Anything which favours concussion would act as a cause under this heading; e.g. interference with the anti-concussion mechanism of the foot, such as contracted heels and absence of frog pressure.
Sidebones being practically confined to the fore feet is evidence in favour of the concussion theory, as is also the fact that cart horses are usually shod with calkins in front, which increase the shock on the region of the heels.
(4) Direct violence, such as a blow, a tread, or a weight falling on the region of the cartilage. Sidcbone has often occurred in this way on the outer side of the inner limb of horses working in pairs.
Symptoms. When the lateral cartilage becomes ossified it also increases in size, and in some instances assumes enormous dimensions. The presence of ossification is revealed by the absence of flexibility in the structure, recognized by grasping it between the finger and thumb when the foot is on and off the ground and trying to bend it. The entire cartilage is usually involved. In the early stages of the process its upper portion may not be affected. The condition is non-inflammatory, there being no evidence of pain, heat, or exudation. Side bones per se are therefore not likely to be a cause of lameness, although indirectly they may act as such, especially in horses doing fast road work and in those with contracted feet, owing to their favouring concussion by pre venting expansion of the posterior part of the foot and leading to corns or compression and pain of the sensitive tissue beneath the hoof. A sidebone may be present on the inside or outside of the foot or in both situations, and on one or both fore limbs. It is rare in a hind foot.
Diagnosis is easy when the whole cartilage is transformed into bone, but there is some times difference of opinion as to whether it is partially ossified or normal, or in the former event whether it should be classed as a side bone or not. When there is a doubt one is justified in giving the horse the benefit of it.
Prognosis. Sidebones in horses with good open feet and doing slow work are of no con sequence. They are present in a large pro portion of cart horses without doing any harm.
In animals intended for fast work on the road, and in those with contracted feet, they are more serious for the reasons stated.
Treatment. If sidebones are not associated with pain or lameness no treatment is indicated. Nothing can be done to get rid of the sidebone except operation, which is_ seldom desirable and can have little or no beneficial effect except the removal of an unsightly enlargement when the structure is very prominent. Counter irritation by blistering or firing or both is some times done, on the assumption that lameness when present is due to chronic inflammation in the new bone.
When the hoof is contracted, grooving it is indicated, to permit of its expansion and relieve pressure on the subcorneal tissues. It can be done in two ways as follows: First Method. Make a vertical groove, by means of a firing iron and a searcher or a special saw, right through the wall from its coronary to its plantar aspect at the level of the anterior extremity of the sidebone. Make a similar groove at its posterior extremity directed down wards and forwards. Between these grooves make two others parallel to the posterior one.
Complete the operation by making a groove through the horn at the white line joining those in the wall. Remove the lower ends of the isolated portions of horn, so that when the shoe is in position they will not bear upon it. Fill the grooves with tar and put on a bar shoe with the bar resting on the frog and having no bearing on the parts operated upon. A leather sole is advisable but is not essential, unless the sensitive tissues have been wounded, when tar and tow should be applied beneath it to protect against infection.
Second Method. Make a horizontal groove through the wall about half an inch below the coronet, extending from the anterior to the posterior extremity of the sidebone. From the ends of this groove make two others, converging slightly downward to the inferior aspect of the wall. Fill the grooves with tar and apply a shoe as in the first method. The horse should be exercised daily. In the course of about three weeks obvious expansion will have taken place, and in many cases the lameness will have disappeared.
There are two ways of operating for the removal of a sidebone, viz.: 1. Partial Operation. Cast the horse on the opposite side after injecting a solution of cocaine over the corresponding plantar nerves. Fix the two fore limbs together above the knees by a soft rope or web in a figure-of-eight fashion. Release the affected limb from the hobble and have it held taut by means of a rope round the hoof below the coronary band. Or the limb may be secured as for the operation for quittor. Shave and disinfect the skin over the affected region. Make a horizontal cutane ous incision at the level of the coronet, extending from the posterior to the anterior extremity of the sidebone. Bisect this by an incision extend ing from the upper border of the bone. Reflect the two flaps of „skin thus marked out, com pletely exposing the outer aspect of the ossified cartilage. Saw through the latter at the level of the first incision and remove the isolated portion. Replace the flaps in position and unite them by sutures. Cover the wound with a dry antiseptic pad and bandage. The wound heals without complication by first or second intention.
2. Radical Operation. Proceed as in the operation for quittor due to a diseased carti lage 670). A drastic operation of this kind is hardly justifiable for a mere sidebone.
Diseases of the Feet in the Ox Affections of the feet are not so common in the ox as in the horse. Even the working ox is less subject to inflammatory affections of the foot than the horse, due probably to the fact that the bovine works at a slower pace, and that its digits are more mobile and elastic than those of the equine, the result being that the shock or concussion on the foot is less. Nevertheless nearly all the diseases of the feet encountered in the horse are met with in the ox.
The definition and etiology of sand-crack are practically the same as in the horse. It is more common in the fore feet and in the outer aspect of the claw. The chief exciting cause is the force applied to the horn when weight is put on the foot, especially during the pulling of a load.
Treatment. Treatment is on the same prin ciples as in the horse, but clasps or horse-shoe nails for immobilizing the lips of the crack cannot be employed, the horn being too thin to bear them.
Transverse cracks parallel to the coronet are fairly common in the fore feet. They may be due to separation of the horn at the coronary band, the separation appearing afterwards as a crack when the new horn has grown down, otherwise the cause is not very evident. If the condition causes trouble its lips should be thinned as in the case of an ordinary crack.
Contusion of the Sole.Contusion is caused by the animal treading on a hard resistant body, such as a stone projecting in its path. A long journey by road in unshod oxen or those wearing very thin shoes is a common cause of the condi tion, or it may be due to the shoe being convex on its upper surface and causing too much pressure on the sole. Fat cattle driven a long distance to shows or fairs are frequent sufferers, their heavy weight being a contributing cause. It is more common in the hind feet owing to the horn being thinner there.
Symptoms. The symptoms are those of lame ness and local inflammation. When the animal is left at rest he lies down almost constantly, and when standing holds the affected limb in front of the other one. On examination of the foot the seat of the lesion is detected by the usual means for ascertaining the presence of inflamma tion therein, viz. palpation, percussion, and paring.
When the horn is pared in a decided case of bruise it is found to be ecchymosed, and may be softened and moist from infiltration with serum, and more or less separated from the underlying tissues. If the case has been neglected the separation may be extensive, involving the greater part of the sole and perhaps part of the wall on account of the inflammation spreading and the serum or inflammatory exudate gradu ally insinuating itself between the horn and sensitive tissues, whose union is less intimate than in the horse. Should infection gain entrance, suppuration will supervene, and the inflammatory symptoms will be intensified, and separation of the horn will more readily occur, leading in some cases of long standing to shed ding of the hoof.
Treatment. In slight cases, where the beasts are merely foot-sore, or tender on their feet after walking a long distance by road, rest in the field or on soft litter is sufficient to bring about resolution. Otherwise the treatment is that recommended for the same lesion in the horse.
Should necrosis supervene a sinus will develop, and must be treated accordingly by removing the dead tissue, providing drainage, and dressing antiseptically.
Pricks in Shoeing.Pricks in shoeing are more common in the ox than in the horse owing to the horn of the hoof being thinner in the former. The lesion in no practical way differs from that in the horse.
Nail or Open Wound of the Foot. The horn of the hoof being thinner than in the horse it is more easily penetrated by sharp bodies such as broken glass, but the commonest seat of injury in the ox is the interdigital space, where a foreign body frequently becomes lodged, such as a stone, a piece of wood, a nail, etc.
Symptoms. The symptoms are those of a punctured wound, inflammation, and lameness.
Prognosis depends on the seat and depth of the injury. Complications which may arise are necrosis of the interdigital ligament, the tendon or bone, and septic arthritis.
Treatment is the same as that described for the horse. If arthritis supervene, or necrosis of the bone prove difficult to cure, the best treat ment is to amputate the affected phalanx or phalanges, after which healing occurs without interruption. A foreign body often becomes fixed between the claws, causing pain and lame ness without wounding the tissues. Its removal gives immediate relief.
Separation of the Hoof.The hoof may be torn away from the the same circum stances as in the horse. It will take three or four months for the new hoof to grow. The treatment is the same as in the horse.
Acute Laminitis. This condition is usually the result of walking a long distance by road. It may also be caused by conveying animals long journeys by rail, the enforced standing and the shaking of the wagons accounting for the inflammation in the feet. Fat beasts like those prepared for show are predisposed to the affec tion owing to their great weight.
One foot or two fore or two hind feet or all the feet may be affected. The inflammation may be more marked in the internal digit.
The symptoms are similar to those in the horse, the same attitude being assumed when standing, but the attack is generally less severe in the bovine.
Febrile disturbance is present, with loss of appetite, and the animal rapidly falls away in condition.
Prognosis. Resolution is the rule, but in severe cases more or less separation of the horn may occur. Its outset is indicated by diffuse swelling of the digital region, by prominence of the coronet, which becomes dark red, and by increased symptoms of pain. About a week after the commencement of the disease a blood stained serum escapes between the hoof and the coronet. The separation is generally confined to the posterior region of the foot, but it may extend further and bring about shedding of the hoof. The disease seldom becomes chronic, although lameness sometimes persists from the flexor tendons becoming contracted, the abnor mality being usually confined to the inner claw, with the result that excessive weight is then thrown on the other one, causing perhaps sprain of the ligaments of the fetlock and the inter phalangeal articulations, which may lead to periostitis and the formation of exostoses, and giving rise to the condition sometimes spoken of as"big foot." Treatment. The treatment is on the same lines as in the horse. It comprises bleeding from the jugular vein, purgation by sulphate of magnesia or by the injection of arecoline and local antiphlogistic applications. One should hesitate about bleeding, owing to the risk of phlebitis. The animal should be kept on a thick bed of short litter, peat moss, or sawdust or damped chaff.
When separation of the horn occurs, anti sepsis is necessary to prevent septic complica tions. When the sensitive tissues are covered with new horn, tar and tow covered by a piece of leather buckled round the pastern should be applied until the new wall is formed. After about a couple of months the animal may be fit to work on soft ground.
Simple dermatitis of the interdigital region, or scald, is common in the ox. It is due to the action of an irritant on the skin, such as dirty wet bedding, or mud.
Symptoms. The symptoms are those of more or less inflammation in the interdigital region, where the skin becomes red and swollen, and lameness.
Treatment. Remove the cause by cleaning the foot and keeping the animal in a clean place, and apply some astringent, such as a 5 per cent solution of sulphate or chloride of zinc, or sulphate of copper, or an ointment made with the latter, which soon brings about a cure.
Toxic Dermatitis.Toxic dermatitis, which occasionally results from eating brewers' or distillers' grains, may affect the digits. It is characterized by intense inflammation of the skin, and in some cases by necrosis occurring in patches, which may extend to the deeper tissues and even involve a joint, causing septic arthritis. Constitutional symptoms of toxemia may also be present.
Treatment. The first indication is to remove the cause by ceasing to feed the cattle on grains. The local treatment is that for inflammation or necrosis, antiseptic applications being always necessary to counteract the effects of micro organisms.
Chronic Vegetative or Verrucose Dermatitis. Chronic dermatitis of the interdigital space is a chronic inflammation of the skin, which becomes thickened, red, and slightly painful. The thickening is noticed as a ridge or prominence appearing in front of the space between the claws. Later, owing to the persistence of the inflammation, granulations or vegetations, wart like growths swollen at their summits and arranged in tufts, due to hypertrophy of the papilla of the skin, are formed. The condition is more common in the hind than in the fore feet. It may affect one or both feet. Occasion ally both fore and hind feet are affected.
Etiology. The lesion is apparently due to the constant action of an irritant on the skin of this region, as may result from an animal always standing on dirty wet bedding, or in a muddy place, especially in cold weather. Frosty dew on the grass is sometimes blamed for caus ing the affection in animals on pasture. There is believed to be a predisposition to the malady. Symptoms. In the early stages of the in flammation there is slight lameness, but this disappears after a while, when the condition becomes chronic, to reappear later when acutc inflammation is produced by the vegetations becoming pinched and injured between the claws during progression, causing them to ulcerate and suppurate. The digits are pushed apart by the presence of the vegetations.
Treatment. Treatment comprises excision of the vegetations with the knife or scissors and cauterization of their bases with a mild caustic such as silver nitrate or powdered sulphate of zinc or sulphate of copper. The hot iron lightly applied may also be used; it is caustic and haemostatic.
It is necessary to have the animal well secured or fixed in the cast position to perform the operation, which must be done with the usual antiseptic precautions. The patient must be kept in a perfectly dry clean place until the wounds are healed. Astringent lotions such as sulphate of zinc and acetate of lead, one ounce of each to a pint of water, will be necessary during the healing process to prevent the granulations becoming exuberant, which they have a tendency to do owing to the irritation caused by the movement of the claws. When they become excessive the caustic must be applied to destroy them and make the wound level. A dry dressing of equal parts of oxide of zinc and boric acid is indicated when the wound is uniformly granulating. It is astrin gent and absorbent, and tends to keep the granulations firm and healthy. It is kept in contact with the wound by means of a pledget of cotton-wool or tow, maintained in position by a bandage. Copper sulphate ointment is also a very useful application when a powerful astringent is required.
Foul in the foot in its widest sense means a suppurating lesion in the interdigital region of the foot of the ox, but according to some authori ties it is confined to a necrotic lesion in this situation. In either case the condition is due to injury causing a breach of surface and con sequent infection of the part. It is often of the nature of carbuncle or boil, with a necrotic centre or"core." Symptoms. The symptoms are those of severe inflammation in the digital region and of a suppurating wound, or an abscess, or a sinus, or fistula in the interdigital space, with pronounced lameness and marked loss of condi tion. The sinus is due to the presence of necrotic tissue. The depth of the necrosis varies in different cases; it may be confined to the skin or affect the interdigital ligament or the tendons, or extend into the joint, causing septic arthritis, which is characterized by extreme lameness and by a foetid, purulent synovial discharge. The necrotic centre is recognized by its yellowish greyish colour and by being surrounded by an inflammatory sup purating zone causing a line of demarcation or separation, at the level of which the dead part may be eventually cast off. The death of the tissue is due to the presence of the bacillus of necrosis.
Prognosis. The prognosis depends on the nature of the lesion. When superficial, affect ing only the skin and subcutaneous tissues, it responds promptly to simple treatment, but when the ligament or tendon undergoes necrosis resolution is very tedious, the dead tissue being slow to separate, owing to the feeble vascularity of the part; and if the joint be infected recovery is impossible without amputation of the diseased portion of the digit.
Treatment. The treatment is as usual for a septic wound or abscess or sinus, its principles being to overcome the action of the microbes by disinfection, by providing drainage for pus, and by the removal of necrotic tissue. When these indications are effectively carried out cure will follow. When the case is recent immerse the foot in a warm antiseptic bath and apply antiseptic compresses as advised for septic foot lesions in the horse. When an abscess is present, open it; and if necrosis super vene, await spontaneous separation of the dead part while using the antiseptic applica tions. If the separation is too slow, operate and excise the necrotic tissue; or, if the latter is very extensive or the joint is diseased, amputate the affected part of the digit.
Contagious Foul in the Foot.Sometimes the condition just described appears as an enzootic in a herd and is then believed to be due to contagion, and is consequently spoken of as"contagious foul."In this case the lesion is generally one of necrosis. Several animals in a field or shed become affected about the same time. No specific organism other than the bacillus of necrosis has been found in connec tion with the disease, and this is a common saprophytic microbe which may gain entrance to any wound or breach of surface convenient to its habitat.
The affection is dealt with in the same way as the ordinary foul, except that special pre ventive measures are necessary here to arrest the spread of the disease.
The affected subjects must be isolated and the in-contacts kept under careful supervision, so as to recognize a case in its early stages should one occur. If the animals have been in a confined place such as a shed or straw yard this must be thoroughly cleaned and dis infected so as to remove the source of infection.
Fresh cattle should not be mixed with the affected herd until all trace of the disease has disappeared.
Deformity of the claws is due to the hoof becoming overgrown as the result of prolonged housing preventing wear of the horn.
Symptoms. — The toes become excessively long and are turned inwards or outwards, often overlapping in the former case. The sole becomes convex. When the deformity is well marked and allowed to persist for some time it causes pain and lameness by preventing equal distribution of weight on the foot and thereby overstretching some of the ligaments of the interphalangeal joints. The animal lies more than usual, and when standing is fidgety on its feet.
Treatment. — The treatment consists in re moving the excessive growth of horn by means of a fine sharp saw and a rasp. The American toeing knife is also very suitable for this purpose. If the beast be troublesome it may be more convenient to cast him for the operation. If the sole be very prominent it is advisable to level it to a slight extent with the rasp. The edges of the horn should be rounded with the file to prevent splitting, and a dressing of tar should be applied to the hoof.
Deformity may also result from chronic laminitis, and is then characterized by rings in the wall and by convexity and thinness of the sole. It may improve with time. Little can be done to remedy it.
Amputation of the Digit. The indications for this operation are septic arthritis of one of the interphalangeal joints or necrosis of one of the bones of the digit, which cannot be readily cured by ordinary treatment.
Control. Cast the animal and fix the foot in a convenient position for the operation. Chloroform may be carefully administered, or cocaine may be injected over the plantar nerves. Prepare the site of operation as usual by shaving the pastern and washing and disinfecting the digit. Remove the horn by means of the rasp for a distance of about two inches below the coronet all round the affected hoof until it yields to the pressure of the finger and the level of the joint can be made out by moving the claw. Apply a tourniquet above the fetlock.
Procedure. To remove the terminal phalanx, disarticulate the corono-pedal joint by incising all the tissues at its level with the knife below the coronary band, leaving the navicular bone in situ if it is not diseased.
If the os corona be involved, as in the case of arthritis of the corono-pedal joint, make a vertical incision through the skin and coronary band on the middle line of the anterior aspect of the digit extending to a point just above the place where the amputation is to be performed.
Reflect the two lateral flaps of skin thus mapped out. Saw through the os corona above its articular surface. Even when this bone is not affected it is advisable to cut off its articular extremity so as to leave a larger flap to cover the stump and to make a raw surface on the end of the latter, which will granulate more easily than a smooth, serous surface. Excise any necrotic soft tissues that are present. Remove the tourniquet and arrest the haemo rrhage by securing the bleeding vessels by torsion or ligation. Fold the flap over the stump, dress it with iodoform and boric acid, and cover it with a large pad of cotton-wool enclosed in gauze and kept in position with a bandage. Renew the dressing after three or four days, and occasionally afterwards until the wound is healed, that is, about one month after the operation.
Keep the patient in a hygienic place. The stump becomes covered with horn formed by the coronary band which was left in situ, and the animal recovers its normal health and suffers little inconvenience from the loss of the terminal portion of the digit.
Affections of the Feet in Sheep Traumatic Affections. The sheep's foot may be wounded in the same way as in other animals. A common seat of injury is the interdigital space, where infection may give rise to sup puration or necrosis, producing in the latter case a lesion similar to foul in the foot of the ox. The symptoms will vary according to the nature of the condition, those of more or less acute inflammation being always present and causing a varying degree of lameness. When necrosis supervenes there is an intensely in flammatory swelling in the digital region and the animal is unable to put the foot on the ground. The redness of the skin is very notice able when it is not pigmented, and of course the pain on manipulation is very severe. The patient is feverish and remains lying almost constantly.
Treatment. The treatment is the same as that described for similar conditions elsewhere. Warm antiseptic applications are indicated to overcome the action of the infecting bacteria and to hasten the removal of the scar when present. In the case of complications, such as necrosis of the phalanges or arthritis, amputa tion of the affected part of the digit as described for the ox is indicated.
Inflammation of the Biflex Canal. The bifiex canal is a blind passage which opens on either side of the middle line of the digit about a quarter of an inch above the entrance to the interdigital space in front, its orifice being marked by a tuft of hair.
Etiology. - Inflammation of the canal is due to irritation caused by foreign matter gaining entrance to it, such as mud and dust, etc., which may wound its lining and allow the infection which they carry with them to give rise to suppuration or necrosis.
Symptoms. The condition resembles the one just described, but is distinguished from it by the discharge which oozes from the canal when it is compressed by the fingers. The matter which escapes is of a fatty nature and exhales a fcetid odour. In the vicinity of the passage there is marked inflammation, and when gangrene occurs its symptoms become manifest. Lame ness is pronounced, the animal remains lying most of the time, and if both limbs are affected progresses on the knees. Complications may arise in neglected cases from infection extend ing to the deep-seated tissues.
Foot rot is a specific infectious and con tagious disease of the feet in sheep.
Etiology. The disease is due to a micro organism in the sole which gains entrance to the subcorneal tissue and there produces its pathogenic effects.
A favourite habitat of the organism is wet or marshy places, especially those soiled with an accumulation of excreta, such as dirty folds. When one case of the disease appears in such a place it rapidly spreads through the flock if preventive measures are not adopted.
The disease is rare in dry hilly districts. Allowing the hoofs to become overgrown, as often occurs in sheep on rich low-lying pastures owing to the horn not undergoing sufficient wear, favours the onset of the affection, as the superfluous horn becomes deformed, turned up at the toes, and splits, allowing dirt and infec tion to gain entrance to the sensitive tissues. The virulence of the causal organism becomes increased by its sojourn in the foot, thus account ing for the rapidity with which the malady spreads after a single case is established, and explaining the contagious nature of the affection. The bacillus of necrosis is usually found in the lesion, but its entrance is believed to be secondary.
Symptoms. Lameness first attracts attention, and it varies in degree according to the stage of the disease. It is always well marked, and in typical cases the affected foot is not allowed to touch the ground. The animal commonly rests on the knees when grazing, and always does so when both fore feet are attacked. If hind and fore feet are involved the animal is almost always lying, only changing its position when it has consumed all the grass within reach.
The disease may commence in any part of the foot, wherever the bacterium has gained entrance, but it usually begins towards its inner aspect near the heel, where the first in dication of it is separation of the horn exposing the sensitive tissue, which appears inflamed and covered with a whitish exudate. After a while it becomes ulcerated and angry, and excessive granulations or"proud flesh"form as the result of the irritation caused by the edges of the separated horn. The horn becomes overgrown and curved for want of wear.
If the infective process is not checked necrosis of the ligaments and tendons and arthritis may supervene.
Treatment. The first indication is to take measures to prevent further spread of the disease by isolating the affected animals and moving the in-contact subjects from the in fected area to a dry clean place after disinfecting their feet by making them walk through a bath containing a reliable disinfectant such as a 2 per cent solution of copper sulphate or Jeyes' Fluid. The sheep-fold must be thoroughly disinfected before it is used again. If the hoofs are overgrown they should be pared.
For the sheep slightly affected, walking through or standing for a while in this bath once or twice daily is sufficient to effect a cure. But those in which the disease is well established require individual treatment. The separated and overgrown horn must be removed and the inflamed tissue treated with an anti septic or slight caustic. If there be a pro truding mass of granulations it should be excised. Sulphate of copper ointment is an effective application.
In cases where cauterization is not necessary iodine ointment is preferable, made in the pro portion of about 1 to 20 of lard or vaseline, or tincture of iodine may be used. It is essential that the patients be kept in a dry place after being dressed. To maintain the dressing in contact with the lesion in severe cases it is advisable to put on a leather boot, which also protects the wound from being soiled from the ground.
Dermatitis of the Interdigital Region of the interdigital region, or"scald,"sometimes affects most of the sheep or lambs in a flock. Its cause is not always very clear. It may be due to the action of frosty dews when irritation from mud cannot be blamed. The inflammation is usually fairly acute, and makes the patients very lame. The pain which it causes prevents the animals thriving and makes them lose condition. This is particularly noticeable in young lambs.
Treatment. The condition readily responds to treatment with an astringent lotion, such as that made with sulphate of zinc and acetate of lead, one ounce of each to a quart of water. Boric acid powder has a soothing beneficial effect and may be sufficient to cure the affection. The cause, if evident, must be removed if possible.
Affections of the Feet in the Pig The pig may suffer from sore feet as the result of being driven some distance by road, especially when the animal is fat and heavy.
The degree of inflammation which super venes varies in different cases. It may be slight or fairly well marked, or very severe. It is manifested by the usual symptoms, which are more or less pronounced according to the nature of the case. The pig is always lame, and inclined to lie down on the road. In extreme cases suppuration may occur beneath the horn, which becomes separated, and the hoof may eventually be cast off. When the lesion is of this character there is intense inflammation of the digital region and constitutional dis turbance, characterized by a febrile reaction with diminished appetite and great thirst.
Treatment. —Keep the animals at rest on soft litter and apply cold applications and astringent lotions to the feet if the inflamma tion be fairly severe. If the horn be separated pare away the separated portion and apply an antiseptic dressing to the exposed tissues. Laxative medicine should be administered to counteract the febrile disturbance.
Affections of the Feet in the Dog and Cat Open Wounds of the Paws.The paw is frequently wounded by treading on a sharp body, such as a piece of broken glass, or a sharp stone or a tack or thorn, the commonest seat of injury being one of the pads, but the interdigital space may also be wounded. A foreign body may be lodged in the tissues.
The lesion will vary according to the depth and extent of the injury. It causes marked lameness.
Treatment is on the general principles of open wounds.
When the wound is punctured and small it may be necessary to examine each pad separately to find it. A foreign body should be searched for, and if found, removed. Anti septic lotions and powder are indicated, and a pad and bandage should be applied until the wound is healed. Occasionally the wound is callous and ulcerating when submitted for treatment, especially when affecting the pads. In the latter case excessive horn may develop on parts of the wound in the form of processes with intervening sore spaces. In this case the abnormal horn should be excised and the ulcerated part cauterized with silver nitrate, after which the foot should be protected with a dry antiseptic dressing.
A circular wound of the paw or metacarpal or metatarsal region is occasionally met with as the result of a rubber ring being placed on the limb and left in position, the ring by virtue of its elasticity becoming embedded and hidden in the tissues, where it causes a suppurating wound all round the limb. In a case of this kind the indication is to search for the ring and remove it if present, when the wound will heal easily.
It may have been on the limb for months before the case is brought for treatment.
The treatment here is to remove shreds of dead tissue and loose pieces of bone, clip the hair in the vicinity and immerse the foot in a warm antiseptic bath repeatedly until the wound granulates, when a dry dressing will be sufficient. A pad and bandage are necessary to protect the wound in the intervals of dressing, which should be renewed once daily. If a digit or digits are irreparably damaged, amputation must be performed.
A sinus may form between the digits, due to the presence of a foreign body or a piece of necrotic tendon or bone in its depth. The pro cedure in this case is to open up the sinus with the knife, explore it to its and remove the cause of the condition.
A separated sesamoid bone loose in the tissues has been found as the cause of the condition, and its removal brought about immediate recovery after the lesion had been in existence for twelve months, causing severe lameness.
The dog's or cat's paws may be burned or scalded at fireplaces, when an inflammatory lesion is produced as described under the head ing of"Burns and Scalds,"and must be treated accordingly.
Symptoms. While the dog is running the inflammation may not be very noticeable, but after he has rested for a while it becomes obvious, the animal being very tender on his feet, showing general lameness and evidently suffering pain.
He lies stretched out, and hesitates about putting weight on the feet. Examination of the pads reveals them hot, swollen, and painful, the patient resenting their manipulation by whining or attempting to bite.
Treatment consists in rest and the use of antijphlogistic applications, cold water and astringent topics being indicated when the case is recent. If the born be worn down to the flesh antiseptic solutions are advisable to prevent septic complications.
When the pain is severe anodyne preparations may be employed, such as a warm decoction of poppy-heads or a solution of green extract of belladonna or warm stupes, with or without the addition of a little tincture of opium.
Separation of the Nail.The nail may be torn off or partially separated by violence in an accident, causing intense pain and lameness. When the separation is slight the nail may become adherent again; if not, it should be removed.
If the phalanx be injured it must be dis articulated and the resulting wound protected with an antiseptic dressing until it is cicatrized.
Inflammation of the Nail - matrix may be acute or chronic. It is caused by injury, viz. a contusion or an open wound, or by eczema extending from the interdigital region.
Symptoms. A painful swelling is formed at the coronet, which may also become ulcerated or affected with little abscesses. There is marked lameness.
Treatment consists in applying warm anti septic lotions, such as a 2 per cent solution of Jeyes' Fluid, or cresyl, or 1 to 1000 potass. permanganate, and painting the ulcers with tincture of iodine and opening abscesses and disinfecting their cavities. When the condition is one of chronic eczema the internal administra tion of Fowler's solution of arsenic is indicated. In rebellious cases amputation of the terminal phalanx is the best course to adopt.
Ingrowing Nails.The nail of the dew claw, not being subjected to wear, often becomes curved and grows into the pad, causing acute pain and lameness by giving rise to a sup purating wound and by hurting the sensitive tissues. The treatment is to cut the offending nail and keep it shortened periodically, or amputate the dew claw to prevent recurrence of the condition. J. J. O'C.