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Surgical Affections of the Head

SURGICAL AFFECTIONS OF THE HEAD Contusions of the Cranium. Contusions of the cranium are not common in veterinary practice on account of the small area of the cranial surface exposed to injury and its being protected by the frontal sinus in the horse and still more so in the ox. In the dog the massive temporal muscles serve to guard the bones against traumatic lesions. A contusion or bruise is caused by violent contact with a blunt resistant object.

Symptoms. The symptoms are those common to a bruise in any part of the body, the lesion produced being an extravasation of blood or a Immatoma due to rupture of blood-vessels, and varying in dimensions in different cases. It may be subcutaneous, subaponeurotic, or sub periosteal. If the contusion be very severe the bone itself may be damaged, with ecchymosis into its substance, and even some of the mening eal vessels may be ruptured. Should infec tion gain entrance to the injured part an abscess may form in the integuments of the bone, and if sepsis extend deeply through the latter it may give rise to an abscess on the dura mater and cause meningo-encephalitis. The presence of infection is indicated by local symptoms of an abscess and by febrile disturbance, and lesions of the brain are revealed by cerebral excitement or stupor or vertigo.

Diagnosis. Diagnosis of the contusion is easy, but it may be difficult to ascertain the depth of the injury.

Prognosis. Prognosis should be guarded in the early stages of the affection, as it is impos sible then to say whether brain complications from compression of extravasated blood or infection may later supervene. Apart from injury to the brain or extensive necrosis of the bone, recovery is uneventful. When the bone is diseased a sinus persists until the sequestrum becomes separated and is removed. If the brain be involved the condition is serious, and should infection of it occur the case is hopeless. Symp toms due to compression may disappear owing to the effusion becoming absorbed when it is slight, but if it be copious fatal coma is apt to ensue.

Treatment. The treatment is that for con tusion in general (vide Contusions). It com prises the use of cold antiseptic applications to arrest extravasation and prevent infection through excoriation of the skin. If the hma toma persist beyond a reasonable time it should be opened, evacuated, and swabbed with tinc ture of iodine to bring about granulation and cicatrization of the cavity. If an abscess or sinus supervene treat accordingly, and if brain symptoms arise treat them according to their nature. Trephining May be done as a last resort to relieve compression by providing an exit for effusion or inflammatory exudate. It gener ally proves futile. Laxative and absorbent medicine is indicated internally.

Open Wounds. Open wounds of the cranium are only of special interest when complicated with fracture and injury to the brain or its meninges. They must be dealt with on general principles with the object of preventing sepsis and promoting rapid healing. Even very extensive wounds with considerable bruising or partial fracture of the bone heal quickly in this region when carefully dressed and sutured.

An antiseptic pad, kept in position by a wide bandage or a cap made to fit the head, is advis able to protect the wound, especially in the dog, which has a tendency to scratch it with its paw.

Symptoms of concussion of the brain may supervene when the violence causing the wound has been severe, although the brain may not be penetrated. If the brain be wounded the case is usually fatal, but in exceptional instances complete recovery follows when infection is excluded, or recovery may be incomplete, the patient remaining more or less paralysed or stupefied. Potassium iodide should be pre scribed in these cases with a view to causing absorption of effusion which may be pressing on the brain.

If a sinus result from the bone becoming affected with necrosis or caries deal with it as such, curetting the carious surface or removing the loose piece of bone and treating antiseptically.

Fractures. Fractures of the cranium are fairly common as the result of direct or indirect violence, more frequently the latter, which is usually due to the horse rearing and falling back on his poll, the fracture occurring in the basi-occipital or in the body of the sphenoid. This region of the cranium is easily fractured on account of its being weakened by the numerous foramina it contains.

Symptoms. The first symptoms to attract attention, as a rule, are those of concussion of the brain, the animal being in a state of collapse, which may terminate in death, or gradually disappear, the patient eventually recovering consciousness and rising in an almost normal condition, or in a state of vertigo or semi stupefaction.

When the lesion is on the anterior or lateral aspect of the cranium, the deformity caused by swelling or by depression of a fragment of bone, and the presence, perhaps, of an open wound, assist in diagnosis. The latter cannot be posi tive unless there is noticeable displacement of a portion of the bone or the fracture can be actually seen through the wound. The inner table of the bone may be fractured while the outer one remains intact, the explanation being that the former is the segment of a smaller arc than the latter and therefore cannot withstand the same amount of pressure without breaking.

Fracture of the base can only be inferred from the symptoms, bleeding from the nose and ears being practically diagnostic when it occurs after violence inflicted on the poll.

Prognosis. The prognosis of fractures of the cranium is always grave. In many cases the patient succumbs immediately from injury to the brain. Exceptionally, the animal gradually recovers from the concussion, but, as a rule, the recovery is imperfect, paralysis or loss of function in some part of the body persisting, or inflammation of the brain or meninges supervening in a few days.

Treatment. For fracture of the base of the cranium nothing can be done to prevent a fatal result.

In fracture of the vault the treatment is local and general.

Local treatment comprises: (1) The use of cold antiphlogistic applications to overcome local inflammation, arrest bleeding, and help to ward off meningitis and encephalitis.

(2) Trephining the cranium in the vicinity of the fracture to enable a lever to be inserted to raise a depressed fragment when symptoms of compression supervene.

When the fracture is compressed' the leverage may be done through the wound. In simple fracture operative interference should be avoided unless grave trouble is caused by the com pression of the bone. A certain amount of pressure can be tolerated by the brain. The operation of trephining the cranium is done in the same way as that for opening the facial sinuses, but care must be taken not to injure the dura mater or the brain with the trephine. To avoid this the point of the instrument should be withdrawn within the crown, when the groove in the bone is sufficiently deep to prevent the trephine slipping, and before the bone is per forated.

As the dura mater is being approached the in strument must be manipulated very cautiously to prevent injury to this structure. To raise the depressed fragments introduce a kind of spatula between the bone and the dura mater. Should the latter be distended with extra vasation, incise it to allow the liquid to escape; haemorrhage is usually slight. If the venous sinus be opened the bleeding can be arrested by the application of a pad and bandage. The operation wound should be sutured and sealed with collodion and iodoform, or a similar topic, and protected by a dressing of cotton - wool covered with a bandage.

Great care must be exercised to prevent infec tion and consequent septic and fatal meningo encephalitis .

Hernia of the brain-tissue may occur through the trephine opening. It cannot be reduced, and it is better to leave it alone, when it will slough away, than to remove it by the knife or ligature. it should be covered with moist antiseptic compresses until separation occurs. Recovery may supervene.

General treatment consists in: (1) Isolating the patient and keeping him in a quiet place.

(2) Bleeding from the jugular vein, when the patient is robust and the pulse is strong.

(3) The administration of a purgative to act as an eliminative and febrifuge and to diminish the risk of inflammation of the meninges and brain.

(4) Adopting appropriate measures for brain affections when they arise, cerebral excitement requiring the exhibition of nerve sedatives and coma indicating the application of the usual methods of resuscitation.

The most dangerous fractures of the vault are those of the parietal, temporal, and upper part of the frontal bones.

Fracture of the occipital crest is not serious, as it is rarely associated with cerebral disturb ance.

Tumours. The cranial region is not a common site of tumours, but some of the ordinary neo plasms may develop on the skin, or subcutaneous tissues at its level, such as papillomata, fibro mata, sarcomata, melanomata, or cysts.

Exostoses on the bones projecting into the cavity of the cranium rarely occur and are probably most frequently found in the ox. As a rule they cause no trouble and are only dis covered after death.

Treatment. The only treatment for tumours on the surface of the cranium is excision. Those involving the bones are inoperable, and malig nant tumours are generally incurable, as they usually recur after removal.

Cysts require to be extirpated by dissection from the surrounding tissues.

Tumours of the Brain.

Tumours of the brain are comparatively rare, and are most common in the horse, where they usually affect the choroid plexus. They may exist for a long time without betraying their presence, but usually when they attain considerable size they interfere with the function of the brain and give rise to symptoms which are evidently of cerebral origin, including those of nervous excitement, stupor, and paralysis of different parts of the body, depending upon the situation of the tumour. Inco-ordination of movement indi cates the cerebellum as the site of the new growth.

Treatment. Treatment is out of the question. Diagnosis from other brain affections not being easy, it is usual to adopt expectant treatment for a while in the hope that the disturbance may be temporary, and when improvement does not occur in a reasonable time to have the animal destroyed.

Dentigerous Cyst. A

dentigerous cyst is one containing a tooth growing from the bone where it is situated. It is a fairly common condition in the horse, and has been seen, though rarely, in the ox, sheep, and dog. It develops soon after birth, simultaneously with the eruption of the normal teeth. It is generally noticed within the first two years of age.

Symptoms. At first a soft, painless, more or less hemispherical swelling is detected in the temporal region, a little in front of the base of the ear, occupying a variable position between the middle line of the head and the zygomatic process of the squamous temporal bone. After a while the wall of the cyst ulcerates and it bursts, discharging a glairy fiqid, a fistula being then formed whose orifice varies in its situation. In exceptional cases it is not directly over the swelling, but is found in the face border of the concha of the ear near its base or, more rarely, on its inner aspect. A probe passed into the fistula comes in contact with the tooth. The latter is not very firmly fixed, as a rule, but occa sionally it is rigidly embedded in the bone, and more rarely causes a protrusion into the cranial cavity. Sometimes several teeth develop suc cessively, a new tooth replacing its predecessor repeatedly after removal of the latter. There may be more than one tooth in the cyst.

Treatment. Treatment consists in incising the cyst, exposing and removing the tooth, and dissecting out or destroying the lining of the cavity. Cast and anaesthetize the horse, pre pare the site of operation as usual, open up the fistula to its depth, arrest the bleeding, and, having thoroughly exposed the tooth, endeavour to seize and extract it with the forceps. If it be too small to be grasped by the forceps or too firmly fixed to be detached this way, loosen it by means of a chisel or punch and a mallet, using them cautiously for fear of fracturing the cranium, or a groove may be made round the base of the tooth by the aid of a sharp chisel handled with great care, to enable the tooth to be grasped with the forceps and to diminish its hold on the bone. The objection to wounding the bone is that infection may supervene and cause necrosis, and that the brain may become involved in the infective process. Moreover, there is a great risk of -injuring the brain by interfering with the bone in this way, as it is very likely to fracture, when splinters will probably penetrate the organ, with fatal con sequences. When the tooth is rigidly fixed and cannot be got away by using moderate force, it is better to abandon the case. The presence of the cyst will not interfere with the horse's usefulness.

After extracting the tooth, dissect out the lining of the cyst so as to leave a wounded surface, which will granulate and cause oblitera tion of the cavity by cicatrization. Swabbing with tincture of iodine may have the same effect.

In other animals the procedure is similar and the operation is usually successful. Occasion ally the tooth develops outside the cyst cavity.

Dermoid Cysts. A dermoid cyst may also be found in the temporal region of the horse and other animals, but is much less common in the horse than dentigerous cyst in this region.

The symptoms are similar to those of denti gerous cyst except that a tooth is not present. The treatment consists in dissecting out the lining of the cavity so as to leave an open wound, which will heal in the ordinary way.

Ccenurus Cerebralis (Sturdy, Gid). The Ccen urus cerebralis, the cystic or hydatid form of the Tcenia ccenurus of the dog, is frequently present on the brain of the sheep, less frequently on that of the ox and goat, and rarely on that of the horse.

This form of the parasite gains entrance to its host by the latter eating grass or food con taminated with the faces of the dog containing segments of the Tcenia ccenurus. The disease is perpetuated by dogs consuming the brains of sheep or cattle infested with the cystic form of the worm.

It is usually yearling or two-year-old sheep and young cattle that are affected.

Symptoms. The symptoms are local and general.

Local symptoms may be absent or quite distinct. In the latter case a swelling can be detected due to the cyst causing pressure, atrophy, and bulging of the bone at its level. The bony tissue may have disappeared when fluctuation can be felt.

General symptoms comprise those of dis turbance of the function of the brain, manifested by abnormal movements of the patient varying according to the situation of the cyst as follows: (1) When the crown of the head is held to one side with the corresponding ear at a lower level than the other one, and the animal keeps turning in a circle towards this side, it is a sign that the vesicle is situated on the surface of the cerebral hemisphere, which corresponds to the centre of the circle described. (2) When the sheep trots with the head high the cyst occupies the anterior part of the brain, the olfactory lobe, or the corpus striatum. (3) If localized in the cerebellum or posterior part of the cerebrum the animal has a staggering gait and frequently falls. (4) If developed on the pons Varolii the subject rolls round the long axis of its body. (5) If the eyes roll and lose the power of sight the optic tract is affected.

These movements, however, are not suffi ciently regular to be of much practical assistance in determining the exact site of the hydatid. Moreover, there may be more than one cyst on the brain affecting different parts of the organ.

Prevention. Prevention comprises measures having for their object the removal of the source of the trouble, by keeping sheep-dogs free from tapeworms by the administration of worm med icine, by not allowing, as far as possible, affected dogs on pastures, and by preventing dogs eating brains containing the cysts.

Treatment. Continuous cold irrigation of the cranium has had a good effect in some cases, causing great improvement in the condition or even complete cure in the course of twenty to thirty days. The surest treatment is the sur gical removal of the cyst, which is only possible when it is superficially situated. The operation may be done by means of the trephine or a special trocar and cannula.

(1) Trephine Method. Site. The site of operation is where the local symptoms are dis covered. In their absence operate about of an inch behind the inner border of the base of the horn or horn-core, keeping to one side of the middle line to avoid wounding the venous sinus.

Preparation. Prepare the site with the usual antiseptic precautions.

Procedure. Excise a circular - shaped piece of skin corresponding in diameter to that of the trephine. By means of the latter remove a disc of bone without injuring the dura mater. When the cyst comes into view remove it intact with forceps, or first puncture it and withdraw the fluid slowly in order to prevent the risk of apoplexy, which might result from the sudden removal of the pressure on the brain. Suture the wound, and seal it with collodion and iodoform, or leave it open and merely cover it with a dressing of tar which is antiseptic and protective from flies.

(2) Trocar and Cannula. A special instru ment, whose length does not much exceed the depth of the tissues to be penetrated and about of an inch in diameter, is used.

Having exposed the bone, place the trocar and cannula in position, directed slightly back wards, and drive it through the cranium by tapping it with a mallet. Draw out the trocar, and if the cyst has been penetrated its liquid will escape through the cannula. Empty it com pletely by means of a syringe or small pump. Tryalso to withdraw the cyst-wall after removing the cannula, and take it completely away with the forceps.

Some operators use a borer, with a trifacial point and a movable guard on the stem, to puncture the cranium, and then insert the tro car and cannula, leaving the cannula in position and applying the syringe or pump to remove the fluid from the cyst. After the cyst has been emptied the pump may be used to draw the cyst-wall into the cannula, when it is seized with forceps and removed along with the cannula.

Results. The results of the operation are very variable. When the cyst is superficially situated and removed with little or no inter ference with the brain, recovery is the rule; when it is deeply situated, searching for it usually causes death.

The complications to which the patient suc cumbs are haemorrhage and meningo-encephal itis.

In the ox and in rams, in which the frontal sinus is very extensive, it is necessary to go through it to reach the cranium. Sometimes the bulging caused by the cyst brings the two opposite walls of the sinus into contact so that its cavity at this point is obliterated.

Separation of the Horn. Etiology.The horn is sometimes torn away from the core as the result of direct violence, as often occurs when cattle are fighting in an enclosed place or pen, the beast striking its horn against that of its antagonist or against a wall or paling. It may also be caused in working oxen by the constant irritation of the yoke producing a chronic inflammation of the keratogenous membrane and consequent loosening of the horn, which eventually becomes detached by the animal knocking it against a fixed object. Striking the horns with a heavy stick may also cause luxa tion of the sheath.

Prognosis. Apart from the haemorrhage the accident is of no consequence except in working cattle, in which the yoke cannot be used until the new horn is formed.

Treatment. Clean and disinfect the exposed horn - core, and protect it with an antiseptic dressing consisting of tow or cotton - wool saturated with an antiseptic lotion (creolin 2 per cent or carbolic acid 2 per cent), kept in position by a bandage attached to the other horn.

Archangel tar smeared over the wounded surface and on the bandage after its application is a very suitable dressing, especially in the summer, when flies are troublesome. New horn is soon formed, but is never of as good quality or appearance as the original horn.

Fissures of the Horn.A fissure or crack of the horn is due to direct violence, such as a blow inflicted on the horn.

Symptoms. The fissure may be confined to the horn-core or to its covering, or affect both. In either of the latter cases the fissure is visible and blood is usually observed oozing from it. The bleeding, however, may be delayed for some hours after the accident. When the core only is fissured diagnosis of the condition is difficult, the only indication of the injury being some abnormal heat and hypersensitiveness of the horn in the region affected.

Prognosis. When the horny tissue only is fissured there is no fear of any complication, but when the core is involved bleeding may take place into the frontal sinus, where the blood will accumulate and lead to the formation of pus.

Treatment. Apply cold and astringent anti septic lotions to arrest the haemorrhage and prevent infection of the wound. A solution of tannic acid 2 to 5 per cent, or gelatine 5 per cent, or Goulard's extract diluted with 4 or 5 parts of water is suitable. The rich vascularity of the part promotes rapid healing of the lesion.

Fractures. Etiology. The cause of fracture of the horn is violent direct injury of the part, a blow or knock. The fracture may be incom plete, involving only part of the thickness of the horn, or complete, right through the struc ture. It may be situated near the point, or in the middle part, or in the base of the horn, or beneath the skin in the frontal hone. The direction of the fracture varies. The broken surface is always more or less irregular.

Symptoms. The fracture is easily recognized, whether it be complete or incomplete. In the latter case the mobility of the distal portion is apparent. When the fracture is in the frontal bone crepitation can be detected, and the whole horn is loose.

Treatment. The treatment varies somewhat according to the nature of the fracture, as follows: (1) Fracture of the Distal Third of the Horn. (a) Incomplete fracture, the horn and its core being partially severed. The usual procedure here is to amputate the horn with a fine sharp saw just below the seat of fracture and cover the stump with an antiseptic pad and bandage. Fix the free end of the bandage to the normal horn, and then wind it round the affected one over the pad from base to tip and back again, and fix it to the other horn after crossing the first part of the bandage in a figure of eight fashion. The wounded extremity of the stump may be further protected by a thick layer of cotton-wool placed on it and maintained in position by a cross-shaped bandage whose centre is placed on the pad with its four bands laid longitudinally on the horn and fixed by another circular bandage applied as described. Should it be necessary to conserve the horn entire, as in the case of a valuable show beast, an immobilizing dressing may be applied with a view to bringing about union of the fracture.

The best method of doing this is to apply a special wooden splint adapted exactly to the two horns and to the forehead between them, being slightly grooved to receive the horns on the posterior aspect of which it is placed, and notched transversely to accommodate the wire which is used to fix it to the horns, the fractured appendage being thus maintained in a rigid position until healing takes place. Coculit's apparatus answers this description and is the one usually employed.

(b) Complete Fracture. If the fractured sur face is irregular, amputate it and proceed as in (a).

(2) Fracture of the Middle Third. (a) In complete Fracture. Try and bring about union by the immobilizing apparatus, and if it fail perform amputation.

(b) Complete Fracture. Treat as for No. 1 (b).

(3) Fracture of the Base. (a) Incomplete Fracture. If the owner desires to save the horn try immobilization, which is difficult to realize on account of the length and weight of the horn above the seat of fracture, causing leverage and disturbance of the latter. If it fail amputate the horn.

(b) Complete Fracture. Treat as in other situations.

(4) Complete Subcutaneous Fracture. The frontal bone where the horn is attached is broken. Union may be attempted by the use of the special splint. It is difficult to attain, and if it fail to occur amputation must be resorted to. When compound, treat accordingly. In all cases the wound must be disinfected.

Complication. The complication of fractures of the horns that may arise is pus in the frontal sinus, which is dealt with under affections of the sinus.

Affections of the Nasal Cavities and Facial Sinuses. Exploration of the Nasal Cavities. The entrance to the nasal chambers can be readily examined without the aid of an instru ment, their middle portion can be fairly well illuminated and explored by reflecting natural or artificial light into it by means of a plane or concave mirror, but the depth of the cavities can only be viewed by means of a special, rather complicated, electrical apparatus known as a rhinolaryngoscope. Probably the best instru ment is Leiter's.

Affections of the Nostrils. Contusions.Con tusions of the nostrils are the result of direct violence caused by contact with blunt bodies, as may occur when the animal falls on this part of its head or receives a blow in this situation.

Symptoms. The symptoms are those asso ciated with contusions in general and usually epistaxis or bleeding from the nose. In severe cases there may be fracture of the nasal bones or of the septum nasi, and the formation of a submucous hmatonta or collection of blood.

Treatment. Apply cold and astringent anti septic lotions to check and limit extravasation and inflammatory exudate. Re covery is the rule in the course of a few days.

Open Wounds.The wings of the nostrils in the horse are often wounded by being torn with projecting nails or hooks against which the animal rubs its nose, and by bites from other horses when standing together in lines or in stables with low partitions, especially at feeding time. The wound may be superficial or deep, perforating the nostril. In the latter case, if the lesion is in the form of a cleft its edges will gape widely, and if not sutured will heal separ ately, leaving a permanent fissure in the nostril. If the cartilage be involved it may undergo necrosis.

Treatment. Clean and disinfect the wound and bring its edges into accurate contact with sutures, the pin suture being very useful as it keeps the lips of the wound immobile and in rigid. apposition. Interrupted stitches going right through the wings of the nostril are neces sary for perforating wounds.

If the edges of the wound are uneven as the result of laceration causing shreds of dead tissue, remove the latter with scissors, and if the lesion is not recent but granulating freshen it by snipping off the granulations before suturing. Primary union may occur in wounds that have been in existence for several days if they are freshened and sutured, the rich vascularity of the part being very favourable to cicatrization, which always takes place rapidly despite move ment and soiling of the part. Apply collodion and iodoform over the line of sutures.

Necrosis of the Cartilage of the Wing of the Nostril.Necrosis of the cartilage or of the septum nasi of the nostril is indicated by a hard swelling on the inner aspect of the orifice, uni- or bi-lateral according as one or both nostrils are involved, and containing a sinus discharging a greyish pus which may be streaked with blood. The submaxillary lymphatic glands of the affected side are swollen and more or less indurated. On casual examination the case is suggestive of glanders, but on close investigation diagnosis of the lesion is easy.

Prognosis. There is no tendency to spontane ous cure, and the condition may resist ordinary antiseptic treatment for months.

Treatment. Aim at removal of the cause by extirpating the necrotic portion of the cartilage by the use of caustics or by operation. Open up the sinus to its depth and swab it with tincture of iodine or a solution of chloride of zinc (1 in 10). This is generally sufficient in a recent case. The surest procedure is to curette or cut out the piece of necrotic cartilage. If the haemorrhage be pro fuse it may be arrested by plugging the nostril or by the hot iron. There may be more than one sinus requiring attention.

Oedema of the

Head. Oedema of the head chiefly affects the nasal region.

Etiology. It may be the result of a wound and infection giving rise to simple or malignant cedema or to erysipelas, or it may be a symptom of a specific disease such as purpura hxmo rrhagica in the horse or malignant catarrh in the ox. A dependent position of the head favours the condition.

Symptoms. The cedema is easily recognized by the great increase in size of the head. There is more or less dyspncea from encroachment of the swelling on the lumen of the nose, and even asphyxia may supervene.

Treatment. Treat the condition from which the symptoms arise. In simple cedema result ing from injury raising the head above the level of the body may be sufficient. This may be effected by putting a platform covered with a sack of hay in front of the horse and allowing him to rest his lower jaw on it. Pricking the swelling here and there, with antiseptic pre cautions, may have a good effect by allowing some of the serum to escape. If suffocation be threatening perform tracheotomy.

Fracture of the Nasal Bones and of the Septum Nash—Fractures of the nasal bones are fairly common in the horse and are always due to direct violence, such as falling on the face, colliding with a fixed object, or a kick from another horse.

Symptoms. The symptoms are those of local traumatic inflammation or contusion, with bleeding from the nose and perhaps deformity. When the lesion is subcutaneous and the swelling is not marked displacement of the fragments may be noticeable, but fractures may occur without displacement. When there is com minution of the bone crepitation can be detected. If the fracture be compound the broken bone is visible. The condition may be complicated with crushing of the turbinated bones, which may afterwards undergo necrosis as the result of infection of the seat of injury.

The septum nasi may be damaged and dis placed. In these bad cases there may be dyspncea from partial occlusion of the nasal chambers. Emphysema may ensue in the sur rounding tissues, but is never extensive. Necrosis of the nasal bone may be a sequel to infection in compound fracture.

Treatment. When there is no displacement treat as a contusion and give antiseptic inhala tions to allay inflammation of the nasal mucous membranes. Use cold douches on the face to combat epistaxis, which is usually easily arrested. To reduce a displaced fragment near the nasal orifice introduce a piece of wood guarded with a small pad on its end into the nostril and, using it as a lever of the first order, raise the depressed piece of bone. If it be higher up trephine the bone in its vicinitrand perform leverage through the opening thus made. Or the lever may be inserted through an incision at the level of the fracture.

An immobilizing dressing is not necessary. If the fracture be compound treat accordingly. Remove loose spicules of bone, replace attached portions that are displaced, and apply an anti septic lotion and powder. Treat complications according to their nature. Perform trache otomy if necessary.

Fracture of the Septum Nash—Fracture of the septum nasi occurs as a complication of that of the nasal bones. Its situation is usually in the upper and middle part of the cartilage (the head being horizontal). The structure is more or less crushed and deviated towards one of the nasal chambers. The mucous membrane covering it is lacerated and separated to a variable extent.

Symptoms. The symptoms are practically the same as those of fracture of the nasal bones. Blood accumulates beneath the mucous mem brane on either side of the septum, diminishing the lumen of the nasal passages and causing interference with respiration, which is mani fested by a snuffling or snoring noise.

Treatment. Take measures to arrest haemo rrhage, and reduce displaced fragments. If a heematoma persist beneath the mucous mem brane, puncture or incise it to allow the contents to escape. Necrosis of the cartilage may result from infection, and must be treated as described.

Tumours of the Nostrils.Papillomata or warts which are common on the skin of the muzzle in the horse are generally multiple and of small dimensions. They frequently disappear spontaneously when small. Large ones usually persist.

Treatment. The application of a solution of caustic potash or potassium chlorate causes small warts to wither and drop off. Larger ones may be snipped off with scissors. Those that are too big to be removed in this way can be dissected out with the knife, the operation being easily done in the standing position, under the influence of cocaine, the resulting wound being sutured. When very numerous and of consider able size treatment cannot be undertaken.

Other tumours are rare in the region of the nostrils, and when they are present must be extirpated. Malignant growths are usually incurable. The only chance of success with them is prompt and thorough eradication. Polypoid fibromata occasionally occur in the horse just inside the anterior nares. They may be multiple and then interfere with breathing, causing a respiratory noise when bilateral, and more or less dyspncea, depending upon the amount of obstruction of the air - passages caused by their presence. They may be removed by the ecraseur or a snare or by the knife. When in clusters they cannot be com pletely taken away, and the cicatricial contrac tion which follows their partial excision causes permanent stenosis of the nasal orifice, and if both sides are affected the dyspncea will be so marked that tracheotomy and the insertion of a tube will be necessary to enable the horse to work.

Cyst in the False Nostril. Atheroma.A sebaceous cyst may form in the false nostril in the horse, causing a local swelling and a respiratory nasal noise due to encroachment on the nasal passage.

Treatment. Puncturing the cyst to remove its contents and injecting pure or dilute tincture of iodine may effect a cure after repeated inter vention. Incision of the swelling, evacuating it, and swabbing its lining with tincture of iodine or any irritant or stimulating topic such as ammonia or turpentine liniment constitute a more effective method of treatment, care being taken that the irritant does not come in con tact with the mucous membrane of the nose. The surest procedure is dissecting out the cyst as if it were a new growth.

Paralysis of the False Nostril.Temporary paralysis of the false nostril due to loss of function in the dilator naris lateralis muscle is occasionally seen in the horse. When both sides are affected severe dyspnoea or threaten ing asphyxia may result, from the wing of the nostril falling in towards the lumen of the respiratory passage instead of being drawn out wards during inspiration. It is only during exercise that this distressed breathing is observed. The condition is probably due to injury of a branch of the facial nerve. The treatment is that for paralysis. When the nerve recovers from the injury its function returns.

Traumatic Lesions of Nasal Chamber. Traumatic lesions of the nasal cavities are associated as a rule with those described in connection with the nasal bones, but in rare instances they are due to the penetration of foreign bodies from the mouth through the floor of the nasal passage.

Injuries of the lower part of the chambers can be recognized through the nostrils, but those of their upper part are only revealed by epistaxis and a nasal respiratory noise. When the turbinated bones or septum nasi are in volved necrosis of these structures may super vene.

Treatment. Treat the lesion according to its nature. Wounds of the nasal cavities usually heal rapidly. Irrigate the passages with a gentle stream of a non-irritant antiseptic liquid like potassium permanganate (1 in 1000). Avoid the use of irritant solutions such as Jeyes' Fluid and take care not to use great force with the syringe for fear of causing the liquid to enter the larynx and bronchi and set up bronchopneumonia. Insuffiation of iodo form is indicated to assist in counteracting infection and preventing necrosis.

Epistaxis.Epistaxis (bleeding from the nose) may be (1) idiopathic or primary or essential, or (2) symptomatic or secondary. The haemo rrhage may be from one or both nostrils. The mucous membrane of the nasal chambers is very richly supplied with blood, being fenes trated with small vessels superficially situated and liable to be ruptured on comparatively slight provocation.

Etiology. (1) Idiopathic Haemorrhage. Occurs without any lesion of the nasal cavity, and the only apparent cause is congestion of the blood-vessels resulting from violent exertion, such as racing, especially when the weather is hot. Appearing under other circumstances it can only be ascribed to some affection of the blood or of the small blood-vessels (haemophilia, leummia).

(2) Secondary Haemorrhage. — Secondary haemorrhage is symptomatic of some lesion in the nose, usually of traumatic origin, or due to an ulcerating tumour or to glanders. It may also be caused by irritating dust getting into the nasal cavities, such as that from musty hay, and it has been seen in horses working in lime kilns, when it is due to finely-powdered lime suspended in the air having a corrosive effect on the blood-vessels of the Schneiderian membrane. Parasites or a foreign body in the nose may cause the condition.

If the haemorrhage be very profuse or pro longed, or repeated frequently at short intervals, it may prove fatal. Bleeding due to a morbid condition is frequently of a recurrent nature.

Diagnosis. Epistaxis is distinguished from Immoptysis or bleeding from the lungs by the blood in the latter case being foamy and always coming from both nostrils, and from the mouth as well in some cases. Moreover, the haemo rrhage in the lungs causes accelerated respira tion and dyspncea, and gives rise to hissing or mucous rales which can be heard on ausculta tion of the chest.

lamatemesis or bleeding from the stomach occurs through the mouth and nose, and the blood appears clotted and blackish like coffee grounds. When the seat of the haemorrhage is far up the nose it may be difficult to ascertain the cause of the condition. The rhino-laryngo scope would be useful for the purpose. Mallein can be employed when glanders is suspected.

Treatment. Apply cold douches to the face, inject hot water or a solution of vinegar or alum or tannin into the nasal cavity. Keep the patient quiet with the head raised, but not to a sufficient extent to enable the blood to flow into the larynx. If the bleeding be from one nostril only and be very profuse plug the cavity at the level of the bleeding part. Attach a piece of tape to a pledget of cotton-wool and push the latter up the chamber just beyond the affected region; then, holding the string with one hand, pack the cavity with more wool. The object of the tape is to prevent the plug going towards the posterior nares and perhaps into the pharynx, and to enable the whole of it to be removed the next day by traction on the string. The free end of the string may be fixed to the nose-band of the head-collar. Another method of inserting a tampon in the nose is to take a fairly large piece of gauze and spread it over the nostril and then push cotton-wool into its centre and up the nose to the required place, the edges of the gauze protruding through the nostril and being held by one hand while the other inserts the plug. If the hemorrhage be bilateral both nasal cavities of course cannot be plugged without first performing temporary tracheotomy and inserting an ordinary tube or a tampon cannula, the stem of the latter being enveloped in lint or gauze, which prevents the blood passing alongside it into the lungs. In ternal treatment is also indicated, giving cold or acidulated drinks, subcutaneous, intravenous, or rectal injections of normal saline or atropine, ergotine, or adrenalin hypodermically.

Necrosis of the Turbinated Bones.Necrosis of the turbinated bones occurs occasionally in the horse, but is rare in other animals.

Etiology. The lesion is generally due to strangles with an accumulation of pus in the folds of the bones, but it may also be the result of a wound inflicted directly through the nostril or through the nasal bones, followed by infection of the seat of injury, or it may be a complication of disease of the fang of a molar tooth in its vicinity.

Symptoms. The symptoms comprise a foetid, purulent nasal discharge, usually unilateral; interference with respiration, manifested by a snuffling or roaring noise; a swelling in the nasal chamber which may or may not be visible or palpable from the nostril; ulceration and discoloration of the bone, which may be felt rough by the finger if within reach; dulness on percussion of the affected region; and swelling of the submaxillary lymphatic glands.

Prognosis. When the necrotic portion can be entirely removed cure supervenes. Cast and anaesthetize the patient with the poll at a higher level than the nose.

Treatment. If the lower third is the portion of the bone involved, make an incision into the nasal chamber extending from the junction of the nasal and premaxillary bones to near the peak of the former, hugging the bone so as to avoid entering the false nostril. Sever the turbinated bone above and below the lesion by means of strong scissors or bone forceps. Seize the isolated portion with a sharp - pronged retractor and, cutting its remaining attachments with scissors, remove it. The hemorrhage is generally fairly profuse and should be arrested by plugging, as already described. Remove the plug the following day and irrigate the cavity with a mild antiseptic. If the disease is situated in the upper part of the bone, make trephine openings at the level of the affected part, and make them confluent by removing the interven ing portions of bone with the bone forceps, thus producing an orifice sufficiently large for the extraction of the necrotic tissue.

Continue the irrigation daily until the dis charge ceases and the fcetor disappears. It is also advisable to insuffiate iodoform into the nasal cavity. When cure occurs it is effected in about three weeks. Sometimes a recurrence of the condition takes place.

Abscess on the Septum Nasi.Occasionally an abscess forms on the septum nasi, especially in the horse, due to an open wound and infection, and causing a nasal respiratory noise. If it can be reached by the finger fluctuation can be detected in it, and it will be visible from the nostril. Otherwise diagnosis will be difficult.

The abscess may extend through the cartilage, forming a swelling in each nasal chamber. It may be acute or chronic.

Treatment. Open the abscess if possible; if not, prescribe inhalations of steam to hasten its maturation and wait until it bursts.

Cyst in the Nose.Sometimes in the colt or filly a cyst containing a syrupy liquid is found in one of the nasal cavities, It causes a noise during respiration, and may be felt and seen through the nostril. Its wall is thin and may rupture on pressure with the finger. It has been associated with a similar cystic condition in one of the maxillary sinuses. When largely opened by incision or by excision of a portion of its wall and its lining is swabbed with tincture of iodine it disappears permanently.

Foreign Bodies in the Nose.There are many cases on record of foreign bodies being found in the nasal chambers, gaining entrance through the anterior or posterior nares or through an abnormal communication between the mouth and nose.

Food material may be coughed into the nasal chambers from the pharynx or return this way in a case of dysphagia during an attack of pharyngitis, or in a case of paralysis of the pharynx. Alimentary matter may also reach the nose via the maxillary sinus in a case of dental fistula opening into the sinus after the affected tooth has been removed.

The author has reported a case in which the fifth molar tooth became displaced into the nasal fossa in an aged carriage-horse.

In the horse, various things have been found in the nasal chambers which were apparently introduced through the nostrils accidentally or intentionally, such as particles of hay or straw, a piece of sponge, a hit of wood, and strands of tow or wool. Pus may become inspissated in the turbinated bones after a case of strangles, and remain in situ indefinitely. A concretion may escape from the guttural pouch through the Eustachian tube and lodge in the nose.

Symptoms the foreign body be large there will be some symptoms of nasal obstruction, char acterized by a respiratory noise. The patient may reveal nasal irritation by snorting or rub bing the nose against objects, and when the body has been in position for some time it will give rise to a muco-purulent unilateral nasal dis charge. There may be epistaxis. Swelling of the sub-maxillary lymphatic glands is absent unless the case is of long standing. There is no deformity on the face. When the seat of lodge ment is near the nostril the object can be seen, but when in the upper part of the chamber it requires the use of the rhinoscope to recognize it.

Treatment. Remove the foreign body as soon as possible through the nostril, if it is within reach, by means of forceps. If this cannot be done, localize as far as possible the seat of the object, trephine the bone at its level, and extract it through the opening thus made, or insert a sound through the latter and, if practicable, push the foreign body towards the nasal orifice. Particles of hay, straw, wool, or tow must be picked out individually with forceps. A gentle stream of lukewarm boiled water directed up the nose or downwards through an artificial opening in the chamber may serve to dislodge material fixed therein. For this purpose Rey's nasal funnel is useful, as the water ascends one passage and descends through the other.

In the small animals, procedure is much more difficult on account of the small size of the anterior nares. It may be necessary to operate by trephining the nasal cavity.

Parasites in the Nasal Chambers.The only parasite with which the veterinarian is familiar in the nasal chambers is the Linguatula tcenioides, which is almost confined to the dog, being very rarely found in the horse, mule, sheep, and goat. It is very common in the dog in some places, whilst in others it is rarely met with. The parasite may take up its abode in any part of the cavity, but most commonly in the convolu tions of the ethmoid, and in the cul-de-sac of the middle meatus.

The dog becomes infested by eating the viscera of herbivora, usually the sheep and rabbit, containing the larvae of the parasite.

Symptoms. Frequently the number of para sites present does not exceed two, and then there may be no objective symptoms. When they are more numerous their presence may be revealed by agitation of the host, the dog scratching his nose with his paws, sneezing frequently, and sometimes showing aberrations simulating rabies.

Epileptiform fits may supervene. There may be a mucoid discharge from the nose which is occasionally streaked with blood.

The parasites remain for months in the nose, and eventually die or are expelled, when the symptoms to which they have given rise dis appear.

Diagnosis. Diagnosis is made out by finding the parasites or their eggs, the latter being dis covered on microscopic examination of the nasal discharge. The condition may be confounded with nasal catarrh, distemper, or rabies. On post-mortem examination exploration of the nasal chambers is indicated when a diagnosis of the cause of death is required under the circum stances mentioned.

Treatment. Treatment of the symptoms is of no avail while the Linguatula remains in situ. An errhine such as snuff may be used to make the dog sneeze, with a view to causing expulsion of the pest. It seldom has the desired effect. If the case is alarming, the only thing to do is to trephine the nose and remove the worms.

Slightly irritating injections have been used with some success, for example, dilute solutions of benzine or ammonia. These may be intro duced through the nostril or through an artificial opening, their object being to dislodge or destroy the cause of the trouble (see p. 399).

Tumours of the Nasal Chambers.Most of the common tumours of the body affect the nasal chambers in the domesticated animals, but probably the commonest neoplasms of this region are fibrous polypi. The principal sub jects are the horse, ox, and dog. The following new growths have also been found in the nose: papillomata, angiomata, lipomata, myxomata, sarcomata, carcinomata, and adenomata. Denti gerous cysts may be met with bulging into the nasal cavity from the bones of the jaws. Botryo mycotic tumours may develop in the nasal foswe of the horse, but they are very rare. Actinomycotic enlargements frequently encroach on the nasal passages in the ox.

Diagnosis. Diagnosis is easy when the tumour is well developed. The following symptoms are usually observed: a mucoid or muco-purulent discharge, epistaxis, not constantly present, more or less complete obstruction of the narial passage causing a respiratory bruit and deformity of the face due to bulging of the nasal bones. If the neoplasm be malignant it may be ulcer ating externally, and the submaxillary lymphatic glands may be enlarged by the formation of secondary growths when the primary one is a carcinoma.

Microscopic examination of a section of the tumour will reveal its nature, whether it is malignant or benign.

Treatment. Malignant tumours are incurable. It is useless to operate to remove them. Benign tumours, if fairly circumscribed, are amenable to treatment. They may be excised through the nostril, or through an opening to the inner side of the false nostril, or through a breach in the upper part of the nasal bones, depending upon the situation of the neoplasm. Peduncu lated tumours can be extirpated by means of the ecraseur or by ligation, the tumour being cut off on this side of the ligature, the stump afterwards sloughing away. The procedure for operation is similar to that described in connec tion with diseased turbinated bones. Cast the horse and, if respiration is not much interfered with, administer chloroform. Keep the poll raised so that blood will escape through the anterior nares instead of passing backwards into the larynx and causing, perhaps, suffocation.

If there is much obstruction of the nasal chambers perform tracheotomy, and insert a tube or tampon cannula before operating on the tumour.

Hmmorrhage near the nasal orifice may be arrested by the hot iron at a dull red heat. Further up the nose plugging will be necessary (epistaxis).

If benign tumours are multiple and their removal is impracticable, the usefulness of the horse may be prolonged by putting a tube in the trachea to facilitate breathing.

Affections of the Sinuses.Traumatic lesions, including contusions, often wounds and frac tures of the bones of the facial sinuses, are almost identical with those of the nasal bones and must be dealt with accordingly. Lesions of the sinuses and nasal cavities often coexist. Rarely the cranium and brain are involved in injuries of the frontal sinus. The prognosis of these affections, without complications, is usually good. The accumulation of blood in the sinus favours the proliferation of organisms therein, which may cause suppuration and a collection of pus in the cavity, necessitating further inter vention as described later.

Pus in the Sinuses. Sinusitis. Etiology. The causes of pus in the sinuses may be primary or secondary.

Primary Causes. The primary causes are injuries of the walls of the sinuses, viz. con tusions and open wounds, causing bleeding into the cavities, where pyogenic organisms may then multiply and cause suppuration, the pus accumulating owing to the want of a dependent orifice.

The prolonged sojourn of the pus in the sinus brings about chronic inflammation of its lining and may lead to necrosis of the turbinated bone, which then acts as a secondary cause.

A spicule of bone in a case of comminuted fracture may fall into the sinus and act as a foreign body, or the latter may gain entrance from the nasal cavity in the form of alimentary matter coughed up from the pharynx.

Secondary causes comprise dental affections associated with suppuration of the alveoli of the teeth with perforation of their walls into the sinus; malignant tumours involving the sinuses; CEstri ovis in the frontal sinus of the sheep; and injuries of the horns in cattle as described.

Symptoms. The first symptom to attract attention is nasal discharge, which at the com mencement of the affection is of a muco-purulent, non-offensive nature, but when it is well estab lished it is purely purulent and very fcetid. The pus is greyish, often contains yellowish white coagula, and may occasionally be streaked with blood, which may be an indication that the bone is ulcerated. The discharge is usually unilateral, one sinus only being affected as a rule, and it is constantly escaping. It is more copious during exercise, due to the movements of the head and the increased respiration caus ing rapid currents of air to pass through the sinus and force out more pus. Htlesubmaxillary lymphatic glands become swollen after some time but remain movable under the skin. If the sinus be distended with contents there will be a swelling at its level, and when the cavity is full of fluid there will be dulness on percus sion, which may also cause a little pain as shown by the resentment of the animal. There is seldom constitutional disturbance, but when the affection is of long standing the subject is generally somewhat unthrifty and more easily tired and sweated than usual. There may be some lachrymation of the eye of the affected side, and a clot of mucus may lodge in its inner canthus.

Diagnosis. The condition must be distin guished from affections of the nose, which are usually accompanied by a respiratory noise due to swelling therein and from glanders, which can be eliminated by the use of mallein. Posi tive diagnosis can be made by exploration of the sinus through an opening made by a gimlet or a trephine, preferably the latter, as it makes a larger aperture. When the gimlet is employed the pus may be seen hi the groove of the instru ment.

The characteristic features of pus in the guttural pouches and tumours of the nose, dealt with elsewhere, will serve to exclude them in considering the nature of the case.

Prognosis. The prognosis should generally be guarded, for, although the condition is not dangerous, it is often difficult to say whether it will recur or not after apparent cure. When the result of an injury which has not damaged the bones to an appreciable extent, rapid cure is the rule with simple treatment. When due to secondary causes, recovery depends on removal of these, and when this is not thoroughly carried out there is sure to be a recurrence of the malady.

Treatment consists in evacuating the sinuses of the pus, irrigating them with a mild anti septic solution, and removing the cause of the affection if possible.

To evacuate a sinus it is necessary to make an opening in its lower part by means of a trephine. It is also advisable to trephine its upper portion to enable the cavity to be flushed out from above.

Operation of Trephining. Horse.Control. The operation may be done standing, under the influence of cocaine or, if necessary, the animal may be cast on the opposite side and local or general anaesthesia employed. After the cutting of the skin the patient seems to suffer little pain when no anaesthetic is used.

Site of Operation. 1. Frontal Sinus. There are three sites, viz.: 1. To reach the upper part of the sinus take a line joining the middle points of the roots of the supra -orbital processes, bisect it by a vertical _line, and operate in the inferior angle of intersection of the lines.

2. To enter the middle part of the sinus operate midway between the inner canthus and the mesial suture.

3. To get into the lowest part of the sinus take a line joining the nasal canthus and the point of junction of the nasal and premaxillary bones, take 2i inches down on this line, and operate 1 inch in front of this point (Craig).

Superior Maxillary Sinus. Operate at a point 4 inch upwards from the lower end of the zygomatic ridge and 1 inch inwards towards the middle line. In young horses it is well to go a little further inwards to avoid the fangs of the molar teeth, which are longer in the young than in the old animal. The sinus is larger in the aged than in the youthful subject.

Inferior Maxillary Sinus. Take 1 inch in wards from the lower end of the zygomatic ridge and operate at that point.

Procedure. Having shaved and disinfected the skin, make a circular incision through it down to the bone, isolating a disc of skin and subcutaneous tissues having a diameter equal to that of the crown of the trephine.

Remove the tissues within the incision, com pletely exposing the bone. The periosteum may be scraped off the latter with a curette. Have the centre-pin of the trephine projecting beyond its cutting edge and insert it into the hole made with a gimlet in the centre of the exposed bone. Working the instrument with a to and fro circular movement, saw through the latter. The detached disc of bone usually comes away inside the crown of the trephine. Should it drop into the sinus remove it with a forceps at once or it may be lost.

Having made an opening at the upper part of the frontal and the lower part of the superior maxillary sinus, irrigate the cavities, which are in free communication, with a non-irritant anti septic solution not too forcibly injected for fear of its entering the lungs, via the nose, such as permanganate of potash (1 in 1000), hydrogen peroxide (1 in 10), or tinct. iodine 1, potass. iod. 5, water 100, etc. Later, an astringent lotion may be useful, viz. sulphate of zinc (1 or 2 in 100). Iodoform may also be insufflated. Keep the openings patent by plugging them with anti septic tow or cotton-wool or with pieces of cork perforated in the centre to allow escape of discharge. A piece of stout rubber-tubing may also be used for this purpose. Continue the dressing daily until the discharge ceases and the offensive smell disappears. Then omit the plugs from the openings and allow them to close. When this affection of the sinus is secondary to another condition, take measures to deal with the latter according to its nature.

The frontal and superior maxillary sinuses may be drained through the inferior maxillary sinus by breaking the thin bony septum between the maxillary sinuses by means of a chisel or punch. When the cause of the condition is obscure it is wise to open the inferior maxillary sinus, as it may be discovered there in the form of a diseased fang from which infection has spread through the bone into the upper sinus. When the cause is removed and free drainage is produced cure is generally effected within a month.

Those lesions from which empyema of the sinuses may arise will be treated in the sections to which they belong (Tumours, Affections of Teeth, etc.). A piece of bone around the open ing may undergo necrosis and be accompanied by inflammatory swelling of the overlying skin. After a while it exfoliates and causes no further trouble. Rarely, a portion of bone in the depth of the sinus becomes affected in this way and prevents healing until it is removed.

Operation in the Ox.Frontal Sinus. Control. —Standing or cast position.

Site. Operate in the superior angle formed by the lines mentioned in the case of the horse, taking care to avoid the supraorbital artery which occupies the supraorbital fissure. The opening in this situation is dependent. The upper part of the cavity can be entered through the base of the horn or by removing the latter, or at a point about one inch below the level of the horn. This sinus does not communicate with the maxillary sinus but has full communica tion with the nose by a number of openings.

The procedure and after-treatment are the same as in the horse.

Cold douches should be avoided as they seem to favour inflammation in the sinuses and may give rise to it in the normal cavity.

Maxillary Sinus. Operate immediately above the maxillary protuberance.

Operation in the Sheep.Frontal Sinus. Operate in the same position as in the horse.

Tumours.Tumours of the sinuses are fairly common in the horse and comparatively rare in other animals. They may be primary, taking origin in the sums, or secondary, extending thereto from neighbouring parts, viz. the nose, mouth, or pharynx. The new growth may be a cyst, a myxoma, an osteoma, a fibrous polypus, a sarcoma, or a carcinoma.

Symptoms and Diagnosis. Diagnosis of a tumour affecting the sinus is easy, but it may be difficult to say whether it is confined to it or involving neighbouring regions as well. It is recognized by deformity of the face, and by a muco-purulent or purulent discharge from the corresponding nostril. There may be epistaxis.

Examination of the mouth and nose may reveal whether these cavities are affected or not. Nodular enlargement of the submaxillary lymphatic glands indicates that the neoplasm is a carcinoma. When the tumour is malignant the bone over it is destroyed, ulceration may take place, and the centre of the neoplasm may become necrotic and putrefy, giving rise to a stinking, dark-red, semi-liquid discharge.

Prognosis. The prognosis is nearly always grave because, although the tumour may be benign, it is generally impossible to eradicate it thoroughly without encroaching on the important regions in the vicinity and causing perhaps irreparable damage. If, however, the tumour is decidedly circumscribed or polypoid it can be successfully removed. When the disease is malignant cure is out of the question.

Treatment. — Complete extirpation of the tumour is the only effective treatment. The procedure consists in thoroughly exposing the tumour by removing the bone which covers it and then eradicating it. Remove a piece of skin about the size and shape of a five-shilling piece at the seat of operation, and reflect the remaining skin over the sinus by dissection if a larger breach in the wall of the cavity is neces sary. Using a large trephine, make three trephine openings in the bone at a tangent to each other. Break down the intervening bridges of bone with bone forceps.

If the orifice thus made in the sinus is not sufficiently large to enable the tumour to be eradicated, enlarge it further by removing pieces of bone at its periphery with the forceps. Make the edges of the aperture smooth by the aid of a bone-scraper.

Dissect out the tumour or remove it piece meal. When it is an osteoma it may be neces sary to trephine it in sections, isolating cylinders of bone, which are detached separately by the use of a chisel and mallet.

If the tumour be pedunculated its excision is simple, but if it be wide-based it will be difficult to remove every trace of it. The curette may be required to scrape the interior of the sinus.

Hmmorrhage is usually more or less profuse, and measures may be necessary to arrest it before the operation is finished by plugging the cavity or applying the hot-iron. Two or more seances at an interval of one or two days may be necessary when the tumour is large and vascular. Ordinarily the operation wound heals completely in the course of four to six weeks, but occasionally, when the breach in the wall of the sinus is very large, it fails to close entirely, a permanent aperture remaining in the bone over which a piece of leather, suspended from the bridle, may be placed as a protection when the horse is at work.

Dentigerous cysts are sometimes found in the sinus of the young horse, and must be treated by extirpation of the cyst-wall and its contents. Evacuation of its contents and destruction of its lining by swabbing with pure tincture of iodine may have the desired effect.

After operating, the wound should be dressed daily with an antiseptic solution and antiseptic powder.

Foreign Bodies.Foreign bodies in the sinuses are not common. They may be inspissated pus, spicules of broken bone, alimentary matter gaining entrance through a breach in the floor of the sinus following the repulsion of a molar tooth or through a dental fistula communicating with the mouth, bits of wool or tow which had been used as plugs in trephine opening, and bits of shrapnel or shell - casing. Smooth, clean, foreign bodies that have entered the sinus without causing much damage to the tissues may remain in situ without causing much trouble beyond a little mucous discharge from the nose. Otherwise they set up the condition of"Pus in the Sinus,"when the treatment for the latter condition must be adopted and the foreign body removed. When the sinus becomes filled with alimentary material which has come from the mouth through the empty alveolus which is communicating with the air-cavity, it will be necessary to evacuate the sinus and plug the alveolus with gutta - percha to prevent recurrence of the condition. If the abnormal passage between the two cavities be recent it may be sufficient to plug its upper part with gauze until its oral portion becomes closed by granulations.

Parasites.The parasites found in the sinuses are the Linguatula in the frontal sinus of the dog, and the larvae of the Estrus ovis in that of the sheep.

The favourite habitat of the Linguatula is the nasal chambers of the dog, but occasionally it develops in the frontal sinus. The latter cavity is the predilection site of the Estrus ovis, but in rare instances it infests the maxillary sinus.

The number of larvae present in the sinus of the sheep is ordinarily two to six, but upwards of fifty have been found in it. Except a large number exists in the sinus there may be no symptoms betraying their presence. When they cause trouble there is a mucoid discharge from the nose, sneezing and snorting, and the animal rubs the nose with the claws or against a fixed object. Phenomena resembling those of sturdy may supervene.

Prevention. Preventive measures comprise the use of agents for keeping the flies at bay, such as tar smeared on the nostrils, and the destruction of the larvae.

Treatment. Treatment is not very satisfac tory. Drugs are of little use in destroying or dislodging the parasites except introduced directly into the sinus after trephining it. Benzene diluted with water and injected into the sinus is sometimes successful. Those that can be reached may be removed mechanically with forceps. The method of dealing with the Linguatula in the dog has been described in connection with affections of the nasal chambers.

Affections of the Jaws. Fracture of the Superior Maxilla. Fracture of the superior maxilla is caused by direct violence as may result from a fall or a collision, or the animal striking the head violently against a hard, fixed object. It may be accompanied by fracture of other bones of the skull. The seat of fracture may be the palatine plate or the alveolar border.

Symptoms. The following symptoms may be observed: deformity due to inflammation, and displacement of fragments; haemorrhage from the mouth and nose; crepitation; salivation; and interference with mastication.

Prognosis. — When the fracture is simple rapid cure usually takes place. When com pound it may also heal without complication, or infection of the wound may lead to pus in the maxillary sinus or necrosis of that bone, and if the alveolus of a tooth be involved dental fistula may supervene. General infection or may arise when the wound is contaminated by very virulent organisms.

Treatment. The treatment is that for con tusion or open wound and fractures in general. If there be neither a wound nor displacement no special intervention is required. Loose teeth may become fixed in a few days, and therefore should not be removed until suppuration occurs in their alveoli. Semi-liquid diet should be given which will not require mastication. If there be a wound in the mouth wash out the cavity after feeding to prevent food material lodging in the wound. Slight depression of fragments is of no consequence. In a bad case of compound comminuted fracture it may be necessary to cast the horse to remove loose spicules of bone, reduce displacements, and dress the wound. Trephining may be required to allow of leverage of a depressed fragment.

An immobilizing dressing is not essential, as a rule, but strips of adhesive plaster or bands of calico smeared with melted pitch may be applied across the face to maintain fragments in position. The head-collar should be left off, and to prevent the horse knocking the injured part against the manger he may be kept in a stall tied by the pillar-reins fixed to a strap round the neck, and fed from a trough or pail placed at a convenient level and removed after feeding, when a tight nose-band may be used to keep the jaws at rest. Complications are to be treated according to their nature.

Fracture of the Premaxilla. The premaxilla may be fractured by the horse falling forward on its nose or by receiving a kick from another horse in this region when the head is lowered. The fracture may be transverse or longitudinal or both, uni- or bilateral, and simple or com pound, usually the latter.

Treatment. Treatment is on general prin ciples for wounds and fractures. A stout piece of stick may be used to push the displaced frag ment into position, holding it by the two ends and pressing its middle part against the bone, the horse being in the cast position. When the displacement is inwards towards the mouth the stick may be used as a lever of the first order to raise the depressed bone.

Retention is best effected by means of silver wire wound round the teeth of the two pre maxilla), whether the fracture be transverse or longitudinal in direction. When there is dis placement upwards of both bones wire may be fixed to the incisors and to the first molar on either side, a hole being bored by means of a drill between the latter and the second molar to accommodate the wire. A niche should always be made with a file on the corner incisors to prevent the wire slipping. The canine teeth may also serve as points of support for the wire. If fixation of the teeth be not sufficient, the bones may be sutured with wire passed through holes made with the drill. The severed mucous membrane should also be united by sutures, and care should be taken that a portion of it does not become insinuated between the frag ments and prevent their union. Dress the ex ternal wound, when present, in the usual way. Remove loose spicules of bone. Some of the incisors may be broken. Projecting points should be removed with a file. Loose teeth should not be removed at once. They may become fixed again after a few days; if not, they should be then extracted. Wash out the mouth after meals with a mouth-wash. Give suitable diet requiring little mastication. The case usually makes a good recovery. Should necrosis of the bone supervene and union fail to occur, the loose fragment may be removed.

Fracture of the Inferior Maxilla. The inferior maxilla may be fractured by kicks, falls, or direct violence of any kind, and also, though rarely, by violent muscular effort, as has been known to occur from excessive contraction of the masseter muscles when a gag was placed in the mouth of the horse.

Repulsion of a tooth may cause the bone to fracture. In the dog it may be fractured by the vigorous movement of the hind limb of a beast or stag which it has seized in its jaws. Occasionally the lower jaw of the foetus is fractured as the result of severe traction on a hook fixed in it during delivery. The site of fracture may be the body, one or both rami, the condyle, or coronoid process of the bone.

The direction of the fracture in the body may be longitudinal, transverse, or oblique. The fracture may be simple or compound, usually the latter. In either case it may be com minuted.

Treatment. Treatment is carried out on

similar lines to those laid down for fractures of the premaxilla.

1. Fracture through the Symphysis.

Occurring in young animals. Replace the fragments in their normal position and maintain them there by joining the teeth on either side by wire. An alternative but less satisfactory procedure, in the dog, is to fix the two jaws together by means of a bandage and feed the animal artificially with liquid food introduced at the commissure of the lips or through an oesophageal tube.

2. Fracture through One Side of the Body.

After reduction wire the teeth as before, if those of the affected side are sufficiently intact for the purpose. Otherwise, the bones may be united by metallic sutures.

3. Transverse Fracture through the Body or through both Rami near the Symphysis. In this case the separated fragment is displaced down wards and it is difficult to keep it in place after reduction. Wiring the incisors to the first molars may be useful in conjunction with an apparatus in the form of a V fixed to the lower jaw, the apex of the V being spoon-shaped to support the chin, and its branches being grooved to adapt themselves to the horizontal rami. The parts in contact with the skin are padded and the apparatus is kept in position by padded straps over the face and poll. For small animals a device of this nature made in gutta-percha may prove satisfactory.

The objection to all these dressings is that they become displaced, cause excoriation of the skin, and interfere with mastication. A false joint may supervene owing to fibrous union taking place between the fragments.

Wire sutures through the bone are the best means of immobilizing the seat of fracture. Should every method fail to bring about union, or necrosis of the loose piece of bone supervene, the latter may be amputated. Bouley records successful amputation of the body of the bone in a horse (Recueil de Med. Vet., 1838).

4. Fracture of

one Ramus. This requires no treatment, there being practically no displace ment. Even when compound and comminuted recovery usually takes place. The vertical ramus may be fractured along with the hori zontal ramus, and healing take place in both lesions. When required, it is usual to apply a blister or a pitch-plaster on the skin at the level of the fracture. The blister causes swelling and inflammation which have an immobilizing effect, and brings about which hastens the healing process. The pitch-plaster also tends to immobilize the part. If the frac ture be compound or comminuted treat accord ingly. When there is a wound in the mouth it must be kept clean, especially after meals.

In all cases of fracture of the jaws, soft, easily masticated food is indicated.

Fracture of the coronoid process or condyle is rare. Fibrous union occurs in the former case and anchylosis of the joint is apt to super vene in the latter.

Contusion. Sinus. Fistuia.Contusions of the jaws are inflicted in the same way as fractures. They may give rise to osteo - periostitis. A common seat of injury is the inferior maxilla, where it is usually due to striking the jaw against the manger. The lesion in this case is not of an acute nature, as a rule, being gradually produced by repeated slight knocking of the posterior border of the bone against the edge of the manger, and assuming the form of an exostosis. The same condition may be caused by the constant use of a head-collar with a tight nose-band. Should infection gain entrance into the injured part necrosis of the bone may super vene and purulent osteomyelitis may extend to a variable depth. The sinus which results may abut on the fang of a tooth, constituting a form of dental fistula.

The base of the mouth may be injured by the bit, the bone becoming affected with acute osteo - periostitis, which frequently becomes septic from organisms penetrating through the abraded mucous membrane and causing necrosis of a shell of bone, which soon becomes loose and may fall out if it is not taken away. The disease may extend through the bone, causing a fistula opening on the posterior border of the jaw.

Symptoms. The symptoms are those of acute or chronic traumatic inflammation or of a sinus or fistula in the bone. When an exostosis is present on the posterior border of the lower jaw it is easily recognized. A sinus in the bone is characterized by a suppurating orifice sur rounded by a hard inflammatory enlargement. A probe passed into it comes in contact with the rough bone and may reveal a loose portion, or it may abut on the fang of a tooth, or it may be pushed into the mouth when there is another opening there. There may be a cavity in the bone filled with thick pus.

Treatment. Alter the manger or the method of feeding the horse. Discontinue the use of the bit until the mouth lesion heals and then use a rubber bit if the horse is a puller. Apply antiphlogistic measures for inflammation. Re move the sequestrum from the wound in the mouth when it is loose. When there is a sinus externally remove an elliptical piece of skin round its orifice. Enlarge the latter, remove loose pieces of bone, and curette the lining of the passage to its depth, paint it with tincture of iodine, dust it with iodoform, and plug the cavity with gauze. Remove the plug the following day and treat subsequently as an open wound, continuing the application of the iodine and iodoform until the cavity is found to be healing, when dry dressing will be sufficient. Although an offensive discharge persists for some days after the operation, cure is usually uninterrupted even in cases where the fang of the tooth is exposed.

If the exostosis is small and has a narrow base it can be easily removed by means of a chisel and mallet or fine saw. If it be large it is better to leave it alone. Open wounds of the jaws are only of special interest in that they may be accompanied by contusion and infection with the results just described, viz. suppuration and necrosis.

Tumours.What has been said about tumours of the sinuses applies in a general way to those of the upper jaw, which is more commonly affected than the lower jaw. Neoplasms of the jaws are fairly frequently met with in veter inary practice, especially in the horse and dog. In the ox actinomycotic tumours are very common. The following varieties may be found affecting the maxillary bones: 1. Dentigerous cysts, which are slow in develop ment and may persist for a long time without causing inconvenience; but occasionally they suppurate, causing necrosis of the bone and sinus formation.

2. Fibromata, most common in the dog, grow ing on the surface of the alveolar border. They may undergo calcification or ossification.

3. Chondromata, hard subperiosteal tumours, uniform or bosselated on their surface, slow in development, and having little tendency to spread to surrounding parts.

4. Sarcomata, developing in the substance of the bone or beneath the periosteum, growing and extending rapidly, accompanied by ulcera tion of the skin and mucous membrane, and interfering with respiration or mastication or both according to their situation. They often cause loosening or shedding of the teeth, haemo rrhage from the mouth or nose, and may become generalized, causing cachexia and death in a short time. The submaxillary lymphatic glands are seldom involved.

They affect animals of every age and are most common in the dog.

5. Carcinomata are almost confined to adult, and especially aged, subjects.

They are more common than sarcomata in the horse. They are characterized by the rapidity of their evolution, by a fcetid, purulent nasal discharge when the upper jaw is affected, by destruction of the bone, its place being taken by the tissue of the tumour, by ulceration of the skin in the later stages of the disease and a discharge of a very offensive liquid of a dark red colour mixed with pus from the centre of the growth, by loosening and eventual shedding of the teeth in the affected region, and ulti mately by enlargement of the submaxillary lymphatic glands due to invasion by the neo plasmic elements.

When some of the teeth are shed there is also a stinking discharge from the mouth. When the swelling has burst or is opened fun goid granulations form in the wound.

Treatment. If benign tumours are small and circumscribed extirpate them completely as described (Tumours of the Sinuses).

Actinomycotic tumours are dealt with in the article on"Actinomycosis." It is useless to intervene for malignant neo plasms.

Affections of the Articula tion.Contusions of this joint are the same as those of other articulations. They may cause synovitis, which interferes with mastication owing to the pain caused by movement of the joint. They respond to the ordinary methods of treatment. Rarely an osteo-periostitis super venes, causing the formation of an exostosis and anchylosis of the articulation.

Open

Wounds. Open wounds in the vicinity of and sometimes those penetrating the joint heal easily under antiseptic treatment. The prognosis, however, must be guarded when the joint is open, as there is always the risk of infection gaining entrance and causing septic arthritis and destruction of the articulation, with perhaps fatal consequences owing to the patient being unable to masticate.

The treatment of penetrating wounds of the joint, which are recognized by the escape of synovial fluid, is on the same lines as those re commended for synovial fistulae in general. In short, it comprises strict antisepsis and immo bilization of the joint as far as possible. When the case is chronic and the fistula shows no tendency to heal, the cauterization of the borders of its orifice or the application of a blister of biniodide of mercury (1 in 8) to the wound and its vicinity, or point-firing the latter generally, has the desired effect. A little powdered per chloride of mercury applied to the wound is often very effective, causing a scab under which healing takes place. Easily - masticated food should be given.

Arthritis.Dry arthritis of the joint has been seen in the horse and dog. Moller records a case in the dog in which both articulations were affected.

Symptoms. The affection is characterized by difficulty in mastication and, usually, by hard painful swelling at the level of the joint. Occa sionally there is little alteration externally. Crepitation may be detected, due to the friction of the ulcerated articular surfaces of the bones.

Treatment is useless when the joint is dis organized. Counter-irritation by blistering or needle point-firing may be tried in the hope that repair is possible, that the lesion has not gone beyond the stage of chronic synovitis.

Dislocations.Dislocation of the joint is not common even in carnivora. It would seem to be impossible in herbivore without fracture of the long coronoid process, yet cases of it in the horse and ass have been recorded by continental veterinarians. In this country we are only familiar with the condition in the dog. The displacement is almost always forwards. It occurs in the dog as the result of the animal seizing a large object with its jaws, in the stag hound from the stag violently snatching its hind limb from the grasp of the dog's mouth, and in the sheep-dog similarly from biting the hind limb of an ox.

Symptoms. The mouth remains wide open, the lower jaw being dropped and fixed rigidly in this position. Saliva trickles from the mouth, and the tongue is pendulous. Prehension is impossible. There may be exophthalmia owing to displacement of the coronoid process into the orbit. If the luxation is unilateral the jaw will be depressed and deviated from the affected side.

Diagnosis. It is distinguished from paralysis by the jaw, in the latter case, not being fixed but capable of being passively lifted.

If the paralysis be rabiform there will be other symptoms or a history to guide the clinician.

Treatment. Reduction of the dislocation is effected by two movements: (1) pushing the inferior maxilla downwards so as to bring the opposing articular surfaces on a level; and (2) pushing the bone backwards into its normal position.

It can be done by placing a stout piece of stick crosswise in the mouth as far back as possible between the molars and then forcibly bringing the jaws together.

In the dog it can be accomplished by the hands alone, by grasping the lower jaw with each hand with the thumb, protected by a glove finger or cloth, resting on the alveolar border and the fingers grasping the horizontal ramus and first depressing the jaw posteriorly and then pushing it backwards.

thesia, which is necessary in the large animals. To prevent recurrence give soft or liquid diet only for a few days.

Affections of the Mouth.Exploration of the illouth. In order to explore the horse's mouth proceed as follows: 1. Without the Aid of an instrument. Have the horse backed into a corner or a stall with plenty of light in front. Pass the left hand into the interdental space on the right side and, catching the tongue gently but firmly, draw it out at the side of the mouth. Pass the thumb of the right hand inside the cheek at the com missure of the lips and draw it outwards so as to expose the gums and teeth on this side. Re versing the hands, examine the other side of the mouth in the same way. To make the horse open the mouth wider for a general view of the cavity, press on the hard palate with the thumb of the right hand.

In the ox a similar procedure is adopted, the beast being well held by an assistant grasping a horn with one hand and having the fingers and thumb of the other hand in the nostrils.

In the dog, held by an assistant and pre vented from going backwards, pass the right hand under the throat with the latter be tween the fingers and thumb and grasp the lower jaw in order to steady the head. Pass the left hand gradually down the face and, pushing the upper lip inwards on either side beneath the upper jaw, grasp the latter with the fingers and thumb and, releasing the hold with the right hand, use it to depress the lower jaw by placing the thumb on the inner aspect of the incisor teeth.

In the cat the mouth is opened by separa ting the jaws by means of the two index fingers applied to the upper and lower incisors.

2. Using an Instrument. To keep the jaws separated in the horse use a speculum oris or mouth-gag, of which there are various patterns on the market. The simplest form consists of a vertical and two horizontal bars, the latter being introduced transversely into the mouth and affording sufficient room between them for the passage of the hand, the tongue being held out of the mouth by an assistant as described.

The improved varieties are capable of being adjusted by means of a screw regulating the distance between the horizontal bars. Most of them have the defect of hurting although not seriously injuring the roof and floor of the mouth, causing bleeding in some cases even when covered by india-rubber. Probably the best gag is the"Revelation Mouth Speculum,"in which the parts in the mouth are in the form of plates adapting themselves exactly to the upper and lower incisor teeth, on which all the pressure is borne without discomfort to the patient. A raised border in front prevents the plate slip ping. Each plate is jointed to a cheek-portion on each side. The upper and lower cheek-por tions are jointed posteriorly, moving on a hori zontal axis, and are capable of being fixed at any required distance from each other by means of a ratchet. The instrument is fixed in position by the aid of a strap over the poll and straps round the jaws. It is introduced with the upper and lower portions in contact, and after inser tion they are separated by pushing the jaws apart, the action of the ratchet preventing their closure; or they may be separated by a screw for the purpose. Special plates covered with leather to rest behind the incisors can be used when it is necessary to have the latter exposed or when the instrument is employed for the ox.

A useful gag for keeping the jaws apart for a cursory examination of the mouth and for simple dental operations is one in the form of two metal plates joined at one end in a V-shaped fashion, denticulated on their surfaces and provided with round raised borders to prevent displacement when inserted between the molars on one side with the apex of the V backwards. The open end is joined by a vertical bar, to which a ring is attached and bent so as to be parallel to the portion in the mouth and serving as a handle outside the cheek. A block of hard wood between the teeth with a metal clip attached, fitting close to the cheek on the out side, answers the same purpose and is more suitable for the young horse, as he offers less resistance to it than to the metal instrument.

Similar instruments can be used for the other animals. In small dogs and cats a piece of tape applied round each jaw behind the canine teeth and pulled in opposite directions answers the purpose admirably and is often preferable to the speculum. A piece of wood placed trans versely in the mouth between the molar teeth, pressing back the commissures of the lips, and fixed by a string from either end behind the ears, is useful for a refractory subject provided that it is not in 'the way of operative procedure.

The oral cavity can be illuminated by the aid of a mirror and artificial or natural light. An electric torch is very suitable for the purpose.

The molar teeth and alveolar borders of both jaws can be explored on their outer aspect by drawing the cheek outwards at the labial com missures by means of the finger or a smooth blunt instrument, even when the jaws are closed by a tape muzzle.

Affections of the Lips and Cheeks. Open wounds of the lips and cheek are common in the horse and are caused by bites, nails, or sharp hooks, against which the animal strikes the muzzle, by falls, and by kicks from other horses. The commissures of the lips may be excoriated by the pressure of the bit. Despite the mobility of the part, the soiling of the wounds by alimentary matter and their contamination by the organisms of the mouth, they cicatrize rapidly, on account of the great vascularity of the region. They are similar in most respects to those of the nostrils and are dealt with on the same plan.

Perforating wounds of the cheek require deep sutures right through its substance in addition to cutaneous sutures.

When the lesions have been in existence for some time they require to be freshened to permit of healing by first intention.

The most difficult cases to deal with success fully are those involving section of the com missures and those perforating the cheek, with loss of tissue, causing an oral fistula of consider able size. Mobility militates against healing in the former case and the discharge of alimentary matter and saliva associated with the gaping of the orifice are obstacles to it in the latter case. The indications are to overcome these difficulties by appropriate measures. After dressing, suturing, and sealing the wound give liquid diet only for a few days, fix the jaws with a nose-band when the animal is not feeding, and tie him on the pillar-reins as described in con nection with wounds of the nostrils. If the loss of tissue prevents intimate approximation of the lips of the fistulous wound an autoplastic operation may be performed as follows: Make a horizontal incision (head being hori zontal) at a tangent to the wound above and below extending a short distance to either side of it, mapping out rectangular flaps of skin, separated by the original wound. Mobilize each flap by dissecting it from the subcutaneous tissue, freshen the borders of the fistula, unite all the opposing edges with interrupted sutures, seal the wound with collodion and iodoform, and take the steps mentioned to favour the healing process. Loss of substance in the labial borders will prevent the horse drinking by suction in the ordinary way, and will necessitate his immersing his muzzle below the level of the commissures. If there be much loss of tissue their function as prehensible organs may be interfered with. Small loss of substance may be remedied by Syme's autoplastic operation for the same condition in man thus: Prolong the two borders of the wound upwards to form a V-shaped incision, d b e (Fig. 191, a). From the extremity of each branch of the V make another short incision to enable the skin to be drawn down afterwards to bring the edges db and eb into apposition. Mobilize the skin between the incisions and the borders of the wound by dissecting it, from the underlying tissue, and suture the edges db and b e. The two little triangular areas above the sutured wound will heal by granulations (Fig. 191, b). Freshen the border a b c, and bring the mucous membrane and skin together with sutures. In the case of the dog protect the wound by a muzzle until it heals, to prevent the animal rubbing or scratching it.

When Stenson's Duct is opened it is advisable, but not always essential, to perforate the cheek at the level of the wound before suturing the latter to allow the saliva to flow freely into the mouth instead of coming outwards and inter fering with the healing process.

Hare-lip (Congenital Fissure of the Upper Lip). —This may be uni- or bilateral and extend a variable distance into the lip. It may exist alone or be accompanied by cleft palate.

Treatment. Remove a thin slice of tissue from each border of the fissure and bring them into contact by deep sutures, not going through the mucous membrane. The pin suture is suitable. Apply collodion and orthoform to seal the wound.

The lower lip may be affected in a similar way, and the condition may be associated with a bifid inferior maxilla. If confined to the lip operation will prove successful.

Retraction of the Lip. Sometimes as the result of injury and the consequent development of much fibrous tissue between the lip and the gum, cicatricial contraction retracts the lip and prevents its meeting the other one. This may be remedied by making an incision between the gum and the lip so as to mobilize the latter and allow it to come down or up, as the case may be. Or some of the new tissue may be removed by making two parallel incisions transversely be tween the lip and jaw and excising the inter vening portion. The condition is apt to recur owing to the formation of more scar-tissue.

Dermatitis of the Lips in Lambs. A vegeta tive dermatitis has been seen affecting the borders of the lips in lambs, due, in the opinion of Megnin, to sarcosporidia. It is a contagious affection beginning in the form of excoriation on which granulations or vegetations afterwards develop. Excision of the vegetations and the application of a mild antiseptic (boracic acid, potass. permanganate) lotion effect a cure. It may be necessary to apply lunar caustic after the use of the knife or scissors when the wound granulates excessively. Take the usual precau tions to prevent the contagium spreading.

Ulceration of the Lip in the Cat. Occasionally in the cat one meets with a case of ulceration of the upper lip which gradually extends until a considerable portion of the organ is destroyed, exposing the teeth and gums. It commences at its free border either in the centre or to one side of the middle line. It may eventually become arrested and be followed by cure or it may remain progressive, causing pain and toxaemia followed by emaciation and death. The lesion may be tuberculous, and a microscopic examina tion for the tubercle bacillus should be made. If not due to this cause bathe it with antiseptic lotion two or three times daily and paint it with tincture of iodine or an aqueous solution of methylene blue. Isolate the patient and feed it generously, giving it a good allowance of meat.

Tumours. Papillomata

or warts are common on the lips of the horse and are less frequently seen on those of the ox. They have been dealt with in Tumours on the Nostrils.

Multiple papilloinata are often found on the buccal mucous membrane and gums in the dog, and appear to be of a contagious nature, as all the animals in a kennel may become affected one after another.

Symptoms. The tumours form in clusters and are of various dimensions. They cause salivation and usually an offensive smell from the mouth.

Prognosis. The warts may disappear spon taneously. They respond readily to treatment.

Treatment. Excise the large warts and apply an astringent mouth-wash to the remainder (solution of alum, potass. chlorate), or paint them with a slight irritant solution (dilute solution of acetic acid or ammonia). Administer saline laxative medicine internally such as mag nesia or soda bicarb.

Malignant tumours

are not common as primary growths on the lips of the large animals, but epithelioma frequently develops on the lips of the dog. It commences as a small, hard swelling which soon ulcerates and rapidly extends in area and depth, involving the bone. Its surface becomes red and angry and presents a mulberry - like appearance. The neighbouring lymphatic glands are easily affected. There is an offensive odour from the mouth, due to the decomposition of food which adheres to the diseased surface and to the discharge which comes from the latter.

Treatment. When the disease is well estab lished it is futile to interfere, as the tumour cannot then. be eradicated. When it is small and confined to the lip it may be excised by a V-shaped incision, the base of the V correspond ing to the free border of the lip, the resulting wound being deeply sutured, the stitches going right through the lip except the mucous mem brane. If necessary, Syme's autoplastic operation may be performed. (See"Wounds of Lips.") Cysts. A mucoid retention cyst, due appar ently to obstruction of the duct of a mucous gland, sometimes forms on the inner aspect of the lips. When opened a clear viscid fluid escapes. The treatment consists in removing a portion of its wall and destroying its lining by the application of an irritant such as tincture of iodine, or in complete extirpation of the cyst.

Paralysis of the Facial Nerve. Paralysis

of the facial nerve is not a rare condition in the horse. It may be uni- or bilateral, and its origin may be peripheral, intra-temporal, medullary, or cerebral.

Peripheral Paralysis. Etiology. The

cause maybe: (1) Traumatic, a contusion or wound involving the nerve where it turns round the inferior maxilla below the temporo-maxillary articula tion. (2) Toxic, occurring during the course of an infectious disease like influenza or strangles. (3) Physical, from exposure to severe cold, a rare occurrence. (4) A tumour in the parotid region pressing on the nerve. (5) Inflammation in the duct of Fallopius causing pressure on the nerve.

Symptoms. In unilateral paralysis the lips are drawn towards the sound side. When it is bilateral they are pendulous and incapable of prehension; the animal is unable to drink without immersing its muzzle above the level of the commissures; the nostrils are contracted; and the respiration, which is normal at rest, is noisy during movement. When the nerve is injured behind the origin of the anterior auri oular branch there is paralysis of the orbicular sphincter muscle and the patient is unable to close its eyelids. If the lesion be intratemporal there is paralysis of the ear of the affected side, the tongue may be involved, some deafness may be present, and there may be slight dysphagia. When the medulla is the seat of the cause the limbs of the opposite side of the body may also be paralysed. When the origin of the condition is in the cerebrum there is usually paralysis of the limbs of the same side of the body.

Treatment. The treatment is that for para lysis in general. The first indication is to ascertain the cause of the condition and remove it if possible. Peripheral paralysis is usually followed by recovery in the course of five or six weeks. Persistence of faradic irritability is a sign of early cure.

When the affection is the result of contusion treat the latter. If there be a tumour pressing on the nerve remove it if practicable. When the lesion appears to be in the brain prescribe potassium iodide. Electric therapy is also indi cated, using a continuous current of feeble power for five or ten minutes daily.

Care must be taken to supply food to the horse in such a way that he can grasp it with his teeth when both sides of the face are paralysed.

To relieve dyspncea during exercise the nos trils may be kept dilated by means of brass wire fixed to the brow-band of the bridle.

Traumatic Lesions. The mouth may be wounded from without inwards by the pene tration of sharp or pointed bodies entering through the cheek or jowl, by sharp molar or incisor teeth lacerating the cheeks and lips respectively, by fragments of bone in fracture of the jaw, by the bit affecting the bars, by foreign bodies taken in with the food such as nails, needles, pins, fish-hooks, etc., and by laymen lancing or burning the palate for lampas.

These wounds are only serious when import ant organs are involved or large vessels are ruptured Treatyient. Ordinary wounds of the mouth heal rapidly. It is only necessary to keep them clean by washing out the mouth with cold water after feeding. The cause should always be removed by extracting a foreign body if present, and by discontinuing the use of an offending bit. Soft or liquid diet should be given requiring little or no mastication. If necrosis of the inferior maxilla supervene from injury by the bit treat it as described in connection with affections of the jaws.

from the palato-labial artery is generally most conveniently arrested by the hot iron. The vessel is most commonly wounded at the level of the line joining the corner incisor teeth where it turns inwards on either side to meet its fellow. In this situation the bleeding can be stopped by tying a cord tightly round the upper jaw and beneath the upper lip, and leaving it in position for a few hours, or a pad soaked in tinct. Benz. co. may be applied over the wound and compressed by a cord as de scribed, or by a bandage over the face. A suture is often sufficient to arrest fairly profuse hemorrhage from a wound on the buccal aspect of the lips. Ligation may be performed on a bleeding vessel in the soft parts of the mouth if within reach.

Foreign Bodies in the Mouth.Foreign bodies lodged in the mouth are most common in the ox and dog, but are found in all our animals. They may be a needle embedded in the tongue or cheek, a piece of wood fixed across the palate or floor of the mouth or between the teeth and the cheek, a fish-hook embedded in the dog's or cat's cheek, and a piece of bone fixed on the molar teeth in carnivore.

Cattle are very prone to pick up foreign bodies, especially when pregnant.

Symptoms. The animal is unable to feed. Saliva trickles from the mouth, which may be half open; the patient appears more or less distressed; the dog rubs its paws against the jaws in an effort to dislodge the object, may hide in dark corners or beneath furniture and give the owner the impression that it is affected with rabies.

The cause of these symptoms is often over looked by the person in charge, with the result that he treats it for something else, and when the veterinarian sees the case the patient is weak and more or less emaciated for want of food.

On careful examination of the mouth the foreign body is discovered, and there is usually an offensive odour from the cavity when the object is of considerable size, due to food material adhering to it. It is most noticeable in the dog.

Treatment. Extract the foreign body with forceps or the hand. A needle generally has a piece of thread attached to it, and is usually inserted with the point forwards. Hence to remove it draw the thread backwards. Fish hooks in the cheeks are usually most readily taken out by pushing them outwards through the skin, the barbs preventing their being drawn towards the mouth.

Scalds.The mouth may be scalded by too hot drinks or mashes, or by caustic drugs or agents such as turpentine or ammonia in con centrated solution, or lime.

Symptoms. The symptoms are those of stomatitis, tenderness in the mouth, salivation, inability to eat coarse food, or difficulty in doing so.

Treatment. The case responds to expectant treatment, or to the use of astringent mouth washes, alkaline solutions such as those of soda bicarb. or lime or magnesia being indicated when the condition is due to an acid, and acidulated solutions of vinegar or tartaric acid being required when the lesion is caused by an alkali. Antiseptic lotion (cresyl 1 in 100 or thymol 1 in 1000 or potass. permanganate 1 in 1000) should be used afterwards to prevent the propagation of organisms.

Sloppy diet is indicated until recovery supervenes.

Affections of the Tongue. Wounds. The tongue is frequently wounded in various ways, for example, by needles, bits of glass or flint taken in with the food, by sharp teeth, by excessive traction on the organ when manipulat ing it in administering a bolus to a horse, by a cord tied round the lower jaw including the tongue, or by being bitten during anaesthesia.

The nature of the wound varies in different cases. It may be superficial or deep, affect the frtenum or the tongue proper, or involve section of more or less of the thickness of the organ or loss of a portion of it.

Hamorrhage is usually slight.

Although practically the whole of the free portion of the organ is lost by section or by gangrene, recovery usually takes place. If severed above the frEenum its function in assist ing in mastication by keeping the food between the teeth is destroyed and the herbivorous animal succumbs to inanition. Loss of the anterior part of the tongue prevents the dog lapping, but after a while it acquires the power of drinking by suction.

Treatment. In most cases simple washing out of the mouth with a suitable lotion, as men tioned before, is sufficient.

If the hyoglossal artery is cut it can be ligatured after casting the horse, if necessary. When the organ is partially severed it should be sutured by strong silk going right through its thickness.

Even if only held by a thin band of tissue the semi - detached and main portions may unite by first intention when they are kept in intimate contact by sutures.

Primary healing sometimes occurs after the wound has been in existence for some days, when its surfaces are freshened and sutured. A portion of one side of the organ may be destroyed and be followed by recovery without any loss of function. When the free portion of the tongue is lost in the horse or ox mastication is difficult for a while but eventually becomes normal except that the process is slower, the animal taking longer to finish its feed.

Cutting the fraanum renders the stump more mobile and thus more adaptable for performing the function required of it.

Strangulation of the free portion of the tongue has been caused in the horse by tying a string round it as a means of control when the animal is vicious or by including it in a cord fixed and left round the lower jaw. The organ becomes swollen and cyanotic from venous engorgement in front of the ligature and remains normal behind it. If relief is not forthcoming within about twenty-four hours the distal portion will undergo necrosis from arrest of the blood supply. The treatment is to remove the ligature and scarify the swelling on the dorsum of the organ to prevent pressure necrosis by the engorgement even after the ligature has been removed. There is no danger of wounding the artery as it is deeply situated.

Venous Immorrhage resulting from this pro cedure or other causes may be arrested by applying a thick layer of flour on the dorsum linguae as advised by Moller and keeping the jaws strapped together by a tight nose-baud.

Strangulation of the tongue in the dog may be caused by a rubber ring being slipped over it or by a section of a large blood-vessel, such as the aorta of the ox, becoming fixed round it, or it may be a portion of the trachea which causes this accident.

Tumours. Tumours of the tongue are exceed ingly rare in veterinary practice.

Mucoid, serous, dermoid, and glandular cysts have been found on the base of the organ, chiefly in the horse.

When of considerable size they interfere with mastication and deglutition and may cause dyspncea or even asphyxia.

The treatment is the usual one for a cyst, incision or partial excision and destruction of the lining of the cyst. Owing to difficulty in reaching it, complete removal is generally im possible. The hot-iron has been used success fully to cauterize the interior of the cyst after puncture and iodine injections had failed.

Neoplasms, including fibromata, lipomata, and angiomata, are recorded as affecting the tongue, in rare instances.

Carcinoma, confined to the tongue, is practi cally unknown in the domesticated animals. Epithelioma affecting the fauces usually in volves the tongue.

Symptoms. — Tumours cause difficulty in mastication characterized by the usual signs of trouble in the mouth, salivation, quidding, that is, partially chewing the food and allowing it to drop from the mouth soaked with saliva. Deglutition is also interfered with.

Treatment. Malignant tumours should not be interfered with except they are confined to the anterior portion of the organ, when prompt amputation of the whole of the free part of the tongue should be performed, using the knife for the purpose, arresting the hmmorrhage by ligation of the vessels, and treating the wound afterwards as already indicated.

Ranula. Ranula is a cystic swelling which sometimes forms at the side of the frrenum linguae, due apparently to obstruction of a mucous gland or one of the ducts of the sub lingual salivary gland. It has been seen in all veterinary patients, but is most frequently encountered in the dog. It interferes with mastication and swallowing, but is not inflam matory.

Its size seldom exceeds that of a hen's egg.

Treatment. Open it largely or remove a portion of it and paint its interior with tincture of iodine to cause inflammation, granulation, and cicatrization. Other agents which may be employed are chloride of zinc (10 in 100) or silver nitrate (10 to 20 per cent, or the pure stick). The caustic should not be allowed to touch the mucous membrane. Excess of the agent should be mopped up with a little cotton wool moistened with boiled water.

A cyst of a similar nature and origin but larger, as a rule, appears externally on the under aspect of the throat, in the dog causing a remarkably large, pendulous, painless swelling in this region.

Treat it in the same way as the cyst in the mouth.

Paralysis. Glossoplegia. — Paralysis of the tongue may be peripheral or central in origin, usually the latter when it is the result of menin gitis or hydrocephalus or some other lesion of the brain.

It is the first symptom of labio - glosso laryngeal paralysis. It may occur during the course of an infectious disease, such as influenza, distemper, contagious pleuro-pneumonia, and rabies. It may be of traumatic origin, resulting from a wound or excessive traction of the organ.

Symptoms. In a case of unilateral paralysis (monoplegia) the tongue is deviated towards the non-affected side.

When diplegia is present the organ hangs inert, protruding more or less from the mouth. When monoplegia has been in existence for some time the affected side of the tongue atrophies to such a degree that its dorsal and ventral mucous membranes come into contact.

Prognosis. Occurring during an infectious disease the condition is usually temporary, dis appearing in the course of seven to ten days. The same may be the case when it is due to traumatism provided that the nerve is not severed. In monoplegia the tongue is able to perform its functions, but in diplegia it is func tionless.

Treatment. Treat as for paralysis in general. Nux vomica and potassium iodide are always indicated internally. If improvement does not occur within a reasonable time in a case of diplegia there is no chance of recovery and the animal may be destroyed.

Affections of the Palate. Fissure.Congenital fissure of the soft palate has been seen in the foal, and the same condition of the hard palate has been recorded in the horse, ox, and dog, usually accompanied by other anomalies con stituting a monstrosity, but sometimes existing alone.

Fissures of the soft palate interfere with swallowing, and some of the milk or food material is returned by the nasal passages. The affected animal gradually wastes and, if not relieved, dies.

Treatment is not often undertaken in veterin ary practice, but it is possible to perform one of the following operations: 1. Staphylorrhaphy. — Suturing the edges of the fissure; very difficult to perform in the large animals owing to the depth of the mouth.

Anaesthetize the patient, fix him in the dorsal position with the head and neck extended. Have the mouth widely opened by a speculum. Freshen the edges of the fissure by means of long scissors or a bistoury, and unite them by interrupted silver wire sutures.

If it be impossible to keep the edges of the cleft in contact owing to their being far apart, make an incision on either side of and parallel to the fissure of sufficient extent to relieve the tension on the sutures.

2. Uranoplasty. Make a longitudinal incision on either side of the hard palate, hugging the bone to avoid the palatine artery. Separate the mucous membrane and its fibrous founda tion from the palatine bone between the fissure and the incision and then proceed as in the last case.

Affections of the Teeth.The affections of the teeth may be classified as follows: 1. Abnormalities of development.

2. Irregularities in the wear of the teeth.

3. Alterations in the substance of the teeth.

4. Affections of the alveolar periosteum. 1. Abnormalities of development comprise: (a) Abnormality in the number of the teeth.

(b) Irregularities in the shedding of the temporary teeth.

(c) Anomalies in the position and direction of the teeth.

(a) Abnormalities in the Number of the Teeth. Supplementary incisor, canine, and molar teeth are fairly often met with. A double row of incisor teeth in the horse is occasionally seen. The supernumerary incisors always belong to the permanent dentition. Additional canine teeth are rarely encountered, but increase in the number of molars is fairly common, the extra teeth being usually situated in the upper jaw in a line with the normal teeth or inside or out side the latter.

Diminution in the number of the teeth is less common but occasionally occurs.

(b) Irregularities in the Shedding of the Teeth.Sometimes the milk-teeth persist for an abnormal length of time, with the result that the permanent teeth take an abnormal course.

This most commonly occurs in connection with the incisors, the permanent appearing behind the temporary teeth.

(c) Abnormalities in the Position and Direc tion of the Teeth. Not infrequently the incisor teeth develop in abnormal positions, overlapping or assuming a transverse or an oblique direction, or being partially or completely rotated on their long axis.

Inequality in the length of the jaws prevents the upper and lower incisors coming into accurate contact.

The teeth consequently become excessively long for want of wear, and those of the shorter jaw may penetrate the soft tissues opposite. When the upper jaw is the longer the condition is called"parrot mouth,"and when the lower one is the longer it is called pig or"sow mouth." The teeth sometimes, instead of being arranged in close contact, have spaces between them in which food material lodges, causing inflammation of the gums and interfering with mastication. Some of the alimentary matter may become insinuated between the gum and the fang, leading to alveolar periostitis.

Symptoms. Many of the foregoing abnor malities may exist for a long time without causing any trouble or attracting attention, but there may be interference with mastication or prehension.

In the case of a pronounced"parrot"or sow mouth the horse has great difficulty in grazing, as the incisor teeth do not meet properly to cut the grass. A tooth abnormally situated and wounding the sensitive tissues such as the tongue, palate, jaws, cheeks, or lips causes pain, and consequently prevents normal mastication.

Spaces between the teeth have the effects mentioned. Just before separation of the temporary teeth, when they are in the form of shells, food material may penetrate beneath them, irritating the gums and causing symptoms of trouble in the mouth. The affected gum becomes inflamed and red, and there may be salivation and difficulty in feeding.

Treatment. The treatment consists in remov ing the cause of the trouble, shortening or extracting abnormally-situated teeth which have no opponents to keep them in wear and conse quently continue to increase in length and damage the soft tissues with which they come in contact. When the temporary teeth are a source of trouble just before eruption of the permanent successors, or persist along with the latter, causing an interspace for the accumula tion of alimentary matter, they should be removed.

2. Irregularities of Wear. Irregularities of the molar teeth, due to unequal wear of the different teeth, or of parts of individual teeth, are very common in the horse.

The various irregularities may be classified as follows: I. Sharp Teeth.The outer border of the upper molar and the inner border of the lower ones become sharp.

The factors which account for this condition are: (a) the upper jaw being wider than the lower one, and the movement of mastication being from side to side causing the inner aspect of the tables of the upper teeth and the outer aspect of those of the inferior teeth to undergo most wear. (b) Restricted lateral movement of the jaws from any cause, such as debility of the masseter muscles, inflammatory conditions of the cheeks, gums, or tongue, and giving food requiring little mastication, for example, bruised instead of whole corn. (c) The tables of the upper and lower molars being normally slightly inclined downwards and outwards (the head being horizontal).

When this irregularity is well marked it acts itself as a cause as well as an effect by causing overlapping of the upper and lower rows of teeth, and thus limiting lateral movement of the jaws.

Symptoms. The symptoms comprise: (1) Interference with mastication due to the sharp edges causing pain by lacerating the tongue and cheeks during movement of the jaws. It is manifested by: (a)"Quidding"hard food like oats and hay, that is, partially chewing it and letting it drop out of the mouth saturated with saliva. (b) Salivation, character ized by foaming at the mouth, and by the escape of saliva therefrom during feeding, the manger and the food being moistened by the fluid.

(c) Imperfect grinding, recognized by the absence of the normal grinding sound during mastication, and by cautious, limited movement of the jaws.

(d) Holding the head to one side when chewing.

(e) Food collecting between the teeth and the cheek in the intervals between feeding.

(2) The presence of the sharp borders on the teeth detected on manual examination.

(3) Wounds of the cheeks or tongue, or both, due to laceration by the sharp edges.

(4) Loss of condition, due to indigestion and defective nutrition following imperfect masti cation.

There are degrees and varieties of the con dition, the foregoing symptoms being those of a typical case.

Treatment. Remove the sharp borders of the teeth by means of the tooth-rasp or float. Have the horse backed into a corner, securely held by a halter with the nose-band slack. Have the tongue taken out at the opposite side of the mouth and apply the rasp to the outer edge of the upper and to the inner edge of the lower molars. Having filed all the teeth, pass the hand into the mouth with or without the aid of the oral speculum, and feel the teeth to ascertain if all the sharpness has been removed.

II. Overlapping Molars. The upper and lower molars overlap each other like the blades of a shears. The condition is an aggravated form of sharp teeth and is brought about in the same way. It occurs in old horses. The upper molars may be so long that they wound the gum of the lower jaw next the cheek, and the lower ones may reach to and injure the palate. As a rule, little can be done in the way of remedy. Repeated use of the rasp may have some effect. When there are projections here and there they can be cut with the tooth-shears before using the rasp.

III. Irregularities affecting Single Teeth.

Frequently the first superior molar overhangs the corresponding lower molar in front, and the last inferior molar projects behind the last superior molar, so that a hook or projection forms on each of these teeth due to their entire table surfaces not undergoing wear. The pro jecting portion may be so sharp that it wounds the tongue or cheek. The remedy for this con dition is to remove the projection with a tooth shears or tooth-chisel. Holding the end of a flat bar of iron against the abnormal portion of the tooth and striking it with a hammer or mallet will break it off. It is often difficult to apply the shears at the anterior or posterior extremity of the dental arch. Any remaining sharp edge is removed with the rasp.

These single irregularities are not confined to the terminal teeth of the rows. Occasionally one of those towards the centre of the row is affected.

IV. Undulating Molar Tables. - -In

this condi tion the lower row of molars is concave, and the upper row is convex in its centre. Otherwise the teeth are normal. This abnormal configura tion is only serious when the fourth inferior molar, which is usually the lowest tooth of the row, becomes worn below the level of the gum, allowing the entrance into the alveolus of alimentary matter and infection which set up alveolar periostitis. The corresponding superior tooth, which is the longest of its row, may then wound the gum opposite. Nothing can be done to improve the condition except to treat alveolar periostitis if it supervenes as a com plication, and shorten or extract the offending upper molar.

V. Step-formed Tables. Here

neighbouring teeth are of unequal height, being up and down like steps of a stairs. This condition interferes more or less with mastication.

Treatment. Cut the long teeth with the tooth shears, and smooth the cut surfaces with the rasp.

When the condition is due to the absence of an opposing tooth the overgrown one must be shortened periodically, not being subjected to wear.

VI. Smooth Teeth. The

tables of the molar teeth are smooth like the keys of a piano, and are useless for grinding.

The smoothness is due to equal wearing of the enamel and dentine of the teeth, and, in very old horses, to the crowns being completely worn away. If only a few teeth are involved the abnormality is of little or no consequence, but if the majority of the teeth are affected the patient's health suffers through indigestion from imperfect mastication.

3. Alterations in the Substance of the Teeth. Fractures. Fractures of teeth are fairly common in the horse, especially of the incisor teeth, and they result from direct violence usually caused by falls.

The teeth may be broken right across, or fissured, or splintered, and the fracture may involve the crown only or extend to the fang and open the pulp cavity, exposing it to infec tion which sets up alveolar periostitis. In the molar teeth the fissure or fracture is usually caused by some hard substance in the food, a nail or a bit of flint which the animal unex pectedly chews.

Difficult mastication may result from wound ing of the soft tissues by the sharp teeth.

The accident may not be noticed in the case of the molars until alveolar periostitis super venes.

Treatment. If the fracture be partial, in volving only a portion of the crown, smooth the rough surface left with the rasp. If the fang is affected the tooth must be extracted.

Dental Tartar. Dental

tartar is a greyish yellow deposit on the teeth formed from the fluids of the mouth and composed of carbonate and phosphate of lime, magnesium carbonate, and organic matter, comprising bacteria and mucus.

Etiology. The condition is very common in old pampered house dogs, receiving little exercise and getting food that requires no tearing or gnawing which tends to keep the teeth clean.

It is rare in herbivore and when present is of no consequence. It is less frequently met with in the cat than in the dog.

Symptoms in the Dog. In the early stages of the affection the only symptom is the appear ance of the deposit on the teeth. It forms on the incisors, canines, and molars, mostly at the base of the teeth and on their outer aspect. After a while it tends to encroach on the fangs, causing inflammation of the gum and separating it from the teeth, thus opening the alveoli and allowing alimentary matter with organisms to gain entrance thereto and set up alveolar peri ostitis, which is usually present, affecting one or more teeth, when the patient is brought for treatment.

In a well - established case the following symptoms are observed: (1) Salivation, the saliva escaping from the mouth, especially during feeding. (2) An offensive odour from the mouth, which is very pronounced. (3) Difficulty in eating hard food, which hurts the inflamed gums, the animal whining when attempting to gnaw a bone. (4) Inflammation and redness of the gums, which are very tender and bleed easily on being touched. They may be ulcerated. (5) Looseness of some of the teeth due to alveolar periostitis. (6) The presence of the tartar, which is usually found on the majority if not all of the teeth. (7) Resent ment of the patient to handling of the mouth, which causes pain and makes the animal cry. Similar symptoms occur in the cat.

Prevention consists in keeping dogs under more natural conditions, restricting their diet, giving them plenty of exercise, allowing them to gnaw bones or crusts of bread with a view to keeping the teeth clean, examining the mouth occasionally, and if the teeth show a deposit, scraping it off and brushing them with chalk or some dentrifice.

Treatment. The procedure may be as follows: (1) Have the dog well controlled, with a tape muzzle applied if necessary. The latter will allow access to most of the teeth for the removal of the tartar.

(2) Scrape off the tartar by means of scalers for the purpose or by one of the limbs of an ordinary dissecting forceps, applying the force from the gum towards the table of the tooth.

(3) The teeth may be brushed with powdered chalk or pumice-stone to remove all trace of the tartar.

(4) Wash out the mouth with a solution of alum (2 in 100), or potass. permanganate (1 in 1000), or thymol (1 in 1000), etc., and if the gums are ulcerated paint the ulcers with tincture of iodine.

(5) Remove loose teeth.

Caries.Caries of the teeth is rare in animals but less so in herbivora than in carnivora, and is practically confined to the molars. It may be defined as a molecular destruction of the cement and dentine of the tooth, the enamel being, com paratively speaking, intact.

The disease is apparently due to bacteria, and is favoured by food lodging and decom posing in spaces between the teeth or in depres sions on the tables of the latter. Ordinarily the enamel on the tooth becomes more or less filled with a cement substance, but occasionally it is absent and then a cavity exists in which alimentary debris collects and may have the effect mentioned. Micro-organisms are said to have been found in the dentine tubules.

The disease may extend into the pulp cavity and give rise to alveolar periostitis.

Symptoms. The condition may be long in existence before being detected.

It is only when mastication is interfered with that attention is drawn to the affection by the usual symptoms of trouble in the mouth already described (Irregularities of Wear), and by an offensive odour from the cavity. On ex amination of the mouth the lesion is discovered as a black spot on the tooth in the early stage of the disease, and as a cavity therein when it is more advanced. The decomposed food material in the hollow of the tooth has a very fcetid odour which is communicated to the finger after digital examination of the diseased part. The tooth may have fractured or the caries may be complicated by disease of the dental alveolus when the case is brought for treatment.

Treatment. If the case is seen early, before the tooth is deeply excavated, curetting the diseased spot, disinfecting it, and shaping it to enable filling to be retained, and stopping the cavity with cement or amalgam may pre serve the tooth. As a rule, the case is too far gone to allow this to be done successfully and the tooth must then be removed.

4. Affections of the Alveolar Periosteurn. Alveolar Periostitis. Alveolar periostitis or peri odontitis, inflammation of the periosteum lining the dental alveolus, is probably the most common disease of the teeth in our animals.

Etiology. Anything which causes injury and infection of the alveolar periosteum acts as a cause of the condition, such as: (1) Alimentary matter insinuating itself between the gum and the tooth, opening the alveolus and allowing foreign matter and bacteria to enter it. (2) Fissures or caries of the tooth extending into the pulp cavity. (3) 'A tumour on the jaw causing separa tion of the gum from the tooth. (4) A com pound fracture of the jaw involving the alveolus. (5) Tartar on the teeth in the dog, the chief cause of it in this animal and in the cat, but rarely acting as such in the large animals.

Symptoms. The gum in the affected region is red, swollen, painful to the touch and receding from the tooth, which is more or less loose. The bone in the vicinity may become affected with purulent osteomyelitis, causing a large in flammatory swelling on the jaw at the level of the affected tooth. When the disease is in connection with the posterior upper molars it usually gives rise to pus in the sinuses, and when the anterior molars above are involved there may be perforation of the floor of the nasal cavity. When an abscess bursts on the surface of the jaw a dental fistula develops there.

In a chronic case of alveolar periostitis an odontoma may form on the root of the tooth.

Treatment. Once the disease is established the tooth must be removed. Complications, e.g. pus in the sinus and dental fistula, are treated according to their nature.

After extraction of the affected tooth or teeth, prescribe a mouth-wash to be used until healing takes place.

Dental Fistula. A dental fistula is a suppurat ing tract abutting on the fang of a tooth and opening on the surface of the jaw or into the maxillary sinus or nasal cavity.

It is a common condition in the horse and is also frequently met with in the dog, but is rare in other animals.

Etiology. The cause of the condition may be: (1) Alveolar periostitis, the bone in the vicinity becoming affected with necrosis and suppura tion extending until the skin ulcerates or the cavity of the nose or sinus is perforated. (2) External injury and infection causing necrosis of the bone and involving the alveolus of a tooth. Occurring in this way it is most com monly situated on the posterior border of the lower jaw at the level of the first or second molar, where it is caused by striking the jaw against the manger or some fixed object.

In the dog the condition is due to ulceration of one or more of the fangs of the upper car nassial tooth (fourth molar), which causes the accumulation of pus in the antrum. The pus causes destruction of the overlying bone and escapes by bringing about ulceration and per foration of the skin a little below the lower eyelid towards the nasal canthus.

Symptoms. The fistula is easily recognized when it opens on the face, where it appears as a weeping orifice surrounded by a variable degree of inflammatory swelling of the bone, which is more or less tender to the touch. A probe passed into the fistula may encounter loose pieces of bone and comes into contact with the root of the tooth, and if there be an oral orifice, which is frequently the case, the instrument can be passed into the mouth.

When alveolar periostitis is absent there may be no hindrance to mastication, and nothing abnormal may be noticed on examination of the mouth.

There may, however, be some redness of the gum at the level of the tooth whose fang is involved, and if an oral fistula be present its opening may be seen. When periodontitis is present its symptoms are manifested as described. When the fistula communicates with the sinus or nasal cavity there is a unilateral, foetid, purulent nasal discharge.

Treatment. Dental fistula is treated by extraction of the affected tooth, which is acting as a septic foreign body. When due to injury, dental fistula is dealt with as described on p. 806, extraction of the tooth not being necessary as there is no diffuse inflammation of the alveolar periosteum.

Tumours. — Dental tumours comprise: (1) Cysts; and (2) solid tumours.

1. Cysts may develop along with the teeth or form after the development of the latter. They have been considered in connection with affections of the cranium and of the jaws.

2. Solid tumours are of two varieties, viz.: (a) odontomata, having the same histological structure as tooth; and (b) pseudo-odonto mata exostoses, caused by injury of the fang of a tooth or a slight but chronic alveolar periostitis.

Symptoms. Sometimes these solid tumours cause no symptoms, but usually they interfere with mastication, and consequently with diges tion, and produce loss of condition and vigour. There is a swelling on the jaw at the level of the affected tooth.

On examination of the mouth the gum may be found swollen and tender in the vicinity of the tooth involved. It is usually the superior molars that are affected. There may be a dis charge from the corresponding nostril.

Treatment. — Extract the affected tooth. Operation is generally very difficult and fre quently involves fracture of the wall of the alveolus. It may be impossible to remove the tooth with the forceps, repulsion being neces sary. Although partial fracture of the jaw may occur during the procedure by either method of removal, the cavity in the jaw usually heals without complications.

Several cases of successful treatment of the condition in the horse have been recorded.

It may be necessary after exposing a large tumour to fracture it with the chisel and mallet to remove it in sections and facilitate extrac tion or repulsion of the tooth to which it was attached.

Dental Operations. Dental operations com prise: (1) Filing of teeth; (2) section of teeth; (3) extraction of teeth; (4) repulsion of teeth.

1. Filing of Teeth. Indications. The opera tion is practically confined to the horse for the purpose of removing sharp edges or corners on the molar teeth and for shortening overgrown incisors.

Operations on the Molars. Control. — Have the horse backed into a corner or a stall with plenty of light in front and held with a slip or head-collar with the nose-band sufficiently slack to permit of the mouth being opened widely. A twitch on the upper lip lower jaw or on the ear is seldom necessary. A mouth speculum is useful to keep the jaws apart during examination of the teeth, but is rather a dis advantage during the operation and may often have to be dispensed with altogether on account of its making the horse restive.

Instruments. There are various patterns of tooth-rasps, including a small one which can be used with one hand, a very convenient instru ment and especially suitable for young or srial] horses and for restive subjects; a larger one requiring the use of both hands; and a power rasp on the same principle as the power clip ping machine, the rasp being spherical and working with a rotary movement. It is very useful for applying to a single tooth, but for general purposes the ordinary hand rasp is pre ferable. A pail of water is necessary to immerse the hand-file in occasionally to remove the filings from the grooves of the instrument.

Operation. Let an assistant take the tongue out at the opposite side of the mouth with one hand and steady the head with the other hand placed on the face. Keeping the instrument under control to avoid wounding the gums or soft structures, apply it vigorously to the outer edge of the upper and the inner edge of the lower row of molars until the sharpness is removed.

Incisor Teeth. In order to reduce overgrown incisors with the rasp it is necessary to have the horse cast and the jaws separated by a gag applied behind the teeth. The most suitable instrument for the purpose is a farrier's rasp, the file surface being employed.

2. Section of Teeth.Indications.Section is indicated for the removal of isolated promin ences on the teeth and for shortening teeth that are too long.

Molar Teeth. Control the horse as in No. 1. If the subject is restive, cast him or put him in stocks.

Instruments. A speculum is necessary to keep the jaws separated during the operation. The instruments used for cutting the teeth or removing projections include: (1) The tooth-shears, a powerful instrument made of steel whose handles are about two and a half feet in length. Power is brought to bear on its jaws by leverage through a series of joints as in"Squair's Tooth Shears,"or by the handles being brought together by a screw as in Thomp son's instrument. The former is an excellent forceps, but the latter is probably more con venient when great force is required, being less laborious to employ.

(2) The Tooth-screw. This is in the form of a chisel whose blade is guarded by a frame to prevent injury to the sensitive tissues from slipping of the instrument. It is worked by the aid of a screw which is capable of exerting great pressure on the tooth. It is not much used, the forceps being a more suitable instru ment.

(3) The Tooth-chisel. — In the form of an ordinary long cold-chisel, which is struck by a mallet after placing its edge against the part to be removed. Or a chisel guarded by a frame which surrounds the part to be cut may be used in the same way. The former is more generally useful as the frame of the latter often prevents the blade being applied at the most desirable point. The chisel should not have a keen edge. A farrier's rasp with one end placed against the tooth and the other struck by a mallet or hammer answers the purpose admir ably in many cases. The chisel is necessary for projections which cannot be grasped by the shears.

(4) The Tooth-plane. This is an instrument on the principle of a carpenter's plane, with a short, strong edge projecting beyond the level of the plane of the surface or frame on which it is fixed. It is useful for removing slight pro minences before employing the rasp. It is not much in vogue.

Operation. Using the Shears. Having the tongue held out of the mouth and the gag in serted, simply apply the shears in the required place, taking care to follow the movements of the animal with the instrument to avoid injury to the mouth from its displacement. When it is only a portion of a tooth that is to be cut it gives way quickly, but if a whole tooth is to be severed great force is required. When section occurs a report is heard due to the frac ture of the structure. The separate portion must be removed from the mouth at once, if it does not drop out, to prevent its being swal lowed or possibly falling into the larynx.

In an old horse the force required to cut an entire tooth sometimes causes it to separate from its alveolus and come away in the jaws of the shears.

When the projection on a tooth is very oblique the shears may fail to grasp it, and then the chisel or a piece of iron must be used to knock it off.

It is difficult to apply the shears at either extremity of the row of teeth, and here again the chisel proves more useful.

Using the Chisel. The method of employing this has already been indicated. Great care must be taken lest by displacement it should wound the soft tissues.

Incisor Teeth. Section of the incisor teeth is seldom performed. They are very apt to break irregularly when an attempt is made to cut them with a shears.

When they require to be shortened the farrier's file is the best instrument for the purpose.

3. Extraction of Teeth.Indications.Ex traction of teeth is indicated in the following conditions: alveolar periostitis, caries, fracture involving the fangs of the teeth, odontomata and pseudo-odontomata, dental fistula which fails to respond to other measures or is due to disease of the alveolus, and persisting temporary teeth causing masticatory trouble.

teeth, bone, treatment, mouth and nasal