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Classificaton of Wounds


Wounds may be classified into: (a) Closed wounds or contusions; (b) open wounds.

(a) Contusions. - A contusion may be defined as a subcutaneous wound or injury due to external violence. The skin is not broken although it may be severely bruised in some instances, and in mild cases the connective tissue only is lacerated. In severe instances deeper structures are involved, such as muscles, tendons, nerves, or even bones. A familiar example of a mild type of contusion is the soft swelling resulting from a kick in the vicinity of the buttock, in which a cavity is formed by the laceration of the tissues, and contains serous fluid and blood-clots. As an example of the severe form we may mention the lesion resulting from an injury to the abdominal wall, in which the skin is intact but the underlying muscle is ruptured, constituting a ventral hernia. Another example of contusion is speedy-cut, found on the inner and lower aspect of the knee and produced when a horse strikes this part with the shoe of the opposite foot. The injury produced varies in degree from a soft swelling containing a blood - stained serous fluid to an acute, painful, inflammatory condition, asso ciated with tense swelling, lameness, and some times considerable damage to the skin of the part, so that sloughing may follow.

It must be remembered that a contusion may be accompanied by an irregular wound of the skin and subcutaneous tissue, such as occurs when the wheel of a heavy vehicle passes over a horse's coronet. Also a wound may be of the type known as"contused and lacerated"when, in addition to the injuries of the mus cular structures, the parts are also more or less bruised. A wound caused by the penetration of a shaft during a collision and one resulting from injury caused by a cow's horn are examples of contused-lacerated type. This type will be con sidered under"Lacerated Wounds." Treatment. - This will depend on the extent of the injury. In the case of simple bruising of the tissues all that is necessary is rest and the frequent application of a lotion composed of equal parts of Goulard's extract and water. If the contusion occurs on a part to which a band age can be affixed, a layer of cotton-wool soaked in the lotion may be applied.

In severe cases accompanied by pain and inflammation the best application is a thick layer of paste composed of kaolin and glycer ine, or one of the patent preparations of this nature, such as thermofuge. The preparation is heated to a proper temperature before being applied, and the part is then covered with a layer of cotton-wool. Care should be taken not to continue this treatment too long, else disorgan ization of the skin may result.

In ordinary contusions the skin should never be incised except under special conditions, such as the presence of a large hematoma, or when a large artery has ruptured subcutaneously. In the case of a hematoma a free incision should be made at the lowest point so that efficient drain age may be secured. The contents of the sac are then carefully removed, and the cavity washed out with an antiseptic solution, and a tampon of double cyanide gauze inserted. Daily dressing is necessary. In spite of all precautions sup puration is likely to occur, and eventually healing takes place by granulation. Unless the procedure indicated be adopted a conspicuous permanent blemish is likely to result.

In some instances suppuration may ensue in a hematoma, probably from an invasion of bacteria through a minute lesion of the skin. This is observed in bumped knee and in some cases of"speedy-cut."A free incision should be made as early as possible, and the pus evacuated. The part is then treated on ordinary surgical principles.

Repeated contusions, such as result from long continued"speedy-cutting"in horses with faulty action or formation of limbs, are likely to be followed by serious consequences. The skin covering the inside of the flexor tendons may undergo necrosis and sloughing, the sub cutaneous tissue also being involved. In such cases prompt surgical treatment is essential, consisting of free incisions and frequent irriga tion with an antiseptic solution.

When a large artery has been ruptured in hematoma a careful incision should be made through the skin, the blood-clots are then removed, and the vessel sought for and ligatured.

(b) Open Wounds. - In these the skin and sub cutaneous tissue are severed, and, according to the extent and depth of the injury, other struc tures may also be involved. Open wounds are classified according to their mode of production and the nature of the injury as follows: (1) Incised; (2) lacerated; (3) lacerated and con tused; (4) punctured; (5) poisoned; (6) gun shot or war wounds.

According to their condition as regards in fection, wounds may be divided into (a) aseptic; (b) infected.

These various types require special technique as regards treatment, although the general prin ciples already mentioned apply equally to all of them.

(1) Incised Wounds.

- An incised wound is one caused by a sharp instrument or any article having a sharp edge. The tissues involved are cleanly divided, and bruising of the margins of the incision is absent. An incised wound varies in extent and depth according to the form or shape of the object producing it, the amount of force employed, and the nature of the tissues. Although a stone possessing a sharp edge may inflict an incised wound on a limb of a hunter while jumping a fence, such an injury is accom panied by a considerable degree of contusion, hence it does not properly come under the present heading.

In a deep incised wound various structures may be divided, such as muscles, blood-vessels, nerves, tendons, etc. Owing to arteries being cleanly divided, free haemorrhage often occurs.

In operative surgery the wounds made by the surgeon are of the incised type. As regards the classification into aseptic and infected, every attempt is made to render surgical wounds free from infection at the time of operation and to maintain them in this condition. Obviously wounds caused by accident become more or less infected at their inception, owing to bacteria being conveyed by the object causing the injury.

Treatment. - In the treatment of incised wounds an attempt should be made to bring about primary union. This can only be accom plished by rendering the parts aseptic and suturing the edges of the wound. We have already pointed out the difficulties in connection with securing asepsis in the treatment of wounds in animals, and at the same time have shown that attempts in this direction are likely to be bene ficial, as by enforcing surgical cleanliness as far as possible we shall avoid adding to the existing infection. We have also indicated the neces sity for the judicious employment of antiseptics in general practice, owing to the difficulty, if not impossibility, of adopting aseptic methods with success.

The following remarks apply chiefly to acci dental wounds, the after-treatment of surgical wounds being considered under a special section, viz."Surgical Technique." We will assume that the case is brought for treatment early, before any attempts at amateur surgery have been made. If severe bleeding is taking place, measures must be taken to arrest it at once. If the blood comes from a large vessel the latter must be secured by means of artery-forceps and a ligature applied. If the vessel is small, by simply twisting it with the forceps bleeding may be stopped. It is of im portance to prevent bleeding, as the presence of blood in a wound forms a nidus for the develop ment of bacteria.

The next step is to clip or, preferably, shave the hair closely around the edges of the wound and for some distance beyond it. This area is then painted with tincture of iodine.

The cleansing and disinfection of the interior of the wound is next carried out. A careful search should be made for foreign bodies, and if these are present they should be removed by means of dressing-forceps.

The initial disinfection of the wound is of vast importance, and any extra trouble involved by the technique will be amply repaid by the results. All accidental wounds are more or less infected, hence the necessity for thorough irriga tion by means of a syringe and a suitable anti septic solution. As regards the selection of an antiseptic, we have already drawn attention to the value of Dakin's solution. But a large number of agents are available for this purpose, and the selection is generally a matter of choice on the part of the practitioner.

The time-honoured carbolic acid (1 part to 40 of water) is still employed by some practi tioners. Agents such as klondol and lysol are more reliable germicides and may be used in solution of 1 to 2 per cent.

After careful disinfection of the wound has been carried out, the application of sutures will be necessary.

Although the technique of suturing is regarded by the owners of animals as a very simple matter, yet in reality it is an art, and in order that favourable results may be obtained from its employment it is essential to direct attention to certain details. The various forms of sutures, their application and uses, will be described further on. Here we shall only refer to the uses of sutures in a general manner. In veterinary practice the chief use of sutures is to bring the edges of an incised wound into apposition, so that, if possible, healing by primary union may be brought about. Even when such a satis factory result does not take place, the judicious employment of sutures assists healing by bring ing the edges of the wound together, and also lessens the chance of blemishing But there are four important points to be considered in connection with suturing: (1) Be fore sutures are applied it is essential to disinfect the interior of the wound as thoroughly as pos sible. We quite admit that in ordinary condi tions of practice it is rarely possible to render accidental wounds aseptic, but experience teaches that the more carefully the disinfection of wounds is carried out the less likely are unfortunate complications to result from the entrance of virulent bacteria. We are also confident that unless thorough disinfection is practised sutures do more harm than good, as they simply favour the development of micro organisms by retaining the discharges; besides, they only retain their hold in the tissues for a very limited time, and by favouring sloughing of the edges of the wound they increase the chances of a resulting blemish.

(2) In large incised wounds when, owing to the mode of their production and the patient's surroundings, infection is tolerably certain, it is advisable, when circumstances permit, not to suture for some days or until thorough dis infection can be carried out. A prevalent idea exists that unless suturing is practised im mediately it is of no value, but we know from experience that in a deeply infected wound it is of more importance to combat infection than to rely on early suturing.

(3) In suturing wounds efficient drainage should be provided. Neglect of this precaution gives rise to very unfortunate complications.

(4) Wounds in certain regions of the body, such as those of the head or the orbit, require great discrimination as regards the employment of sutures, and the most thorough disinfection is necessary. Not infrequently virulent micro organisms seem to make such regions a seat of predilection, as exemplified by the occurrence of erysipelas or malignant oedema in connection with wounds which appear to be trivial in extent. Generally speaking, it is preferable to avoid employing sutures in such cases, more especially when unskilled attendants have to be entrusted with the after-treatment.

As we shall point out later, lacerated and punctured wounds should seldom be sutured, and the same warning applies to wounds caused by bites. In the after-treatment of an incised wound that has been sutured, beyond making certain that sufficient drainage has been pro vided, nothing further is necessary. If, how ever, suppuration occurs and the edges of the wound become inflamed, it is essential to remove some of the sutures and to wash out the wound daily with an antiseptic solution.

As regards the application of surgical dressings and bandages, these are necessary in the case of wounds of the limbs, joints, etc. For in formation on this point the reader is referred to the article on"Surgical Technique." Various forms of sutures. A few words on suture materials will be necessary before con sidering the technique of suturing. These may be classified into (a) absorbable and (b) non absorbable. Of absorbable material catgut is the most familiar. When embedded in the tissues it is absorbed by the living body. Special preparation is necessary in order to render cat gut sterile. The most reliable is known as Formalin Catgut, as it can be boiled without diminution of its tensile strength. Catgut may be employed for buried sutures and for super ficial sutures when for any reason we wish to avoid subsequent removal. It is also suitable for suturing nerves, tendons, and muscles.

Non-absorbable material. Of this silk, in the form of twisted and braided silk is extensively employed for sutures.

Various substitutes for silk are on the market, and being soft in texture and sufficiently strong they form efficient suture materials. It is necessary to sterilize silk or its substitutes; this can be done by boiling for twenty minutes and then placing the material in an antiseptic solution, from which it can be taken as required. A suitable antiseptic solution is composed of one part of biniodide of mercury in 1000 parts of a 90 per cent alcohol, with the addition of 5 per cent of glycerine.

Silver wire was at one time a favourite material for suturing the skin, but it possesses no advantages over silk.

Silkworm gut, when sterilized by boiling, forms a very useful material for suturing wounds of the eyelids, etc.

Celluloid thread consists of fine linen fibres coated with celluloid. It is very useful for suturing small wounds and in canine surgery.

Linen thread may be employed for sutures in emergency cases when silk or other materials are not available. It is apt, however, to cut through the tissues.

Fine tape forms a very efficient suture material in the case of extensive wounds of the hip, back, etc., in horses and cattle.

For full details on the subject of suture material the reader is referred to the article on"Surgical Technique." Here we may repeat that every precaution should be taken to avoid introducing infection during the suturing of wounds. The amateur does not recognize the importance of this point, and imagines that the chief aim should be to bring the edges of the wound together as quickly as possible, no attention being directed to the surgical cleanliness of the suture material, the needle, or the hands of the operator.

The Ordinary Interrupted Suture. - This is the form of suture most commonly employed. A number of distinct stitches are made, each separately fastened and complete in itself, and placed at intervals along the direction of the wound. Each suture is passed once through the divided structures and then tied so that the knot lies well to one side of the incision. One or more of the sutures can, if necessary, be removed without disturbing the remainder. In tying interrupted sutures care should be taken to avoid unnecessary tension. Although from the popular point of view the insertion of sutures is regarded as a very simple procedure, it is in reality one that requires skill and dis crimination; neglect of technical details exerts a very unfavourable influence on the healing. The attempts of the amateur at suturing in dicate that he does not appreciate the import ance of providing proper drainage and of avoiding tension on the edges of the wound.

In inserting sutures it is essential to intro duce the needle at a proper distance from the edge of the wound in order to secure a sufficient hold of the skin. The distance selected should vary according to the extent and depth of the wound. In small wounds the needle should be inserted close to the edges, while in those of large extent a firmer"hold"of the skin should be taken. The edges of the wound should be brought together accurately, so that no spaces will result, but it is of prime importance to arrange the sutures with a view to providing efficient drainage. The size and strength of the selected suture material should depend on the extent of the wound, the thickness of the skin, and the amount of strain to which the part is likely to be subjected. In extensive wounds in the region of the hip or quarter the material should be strong, and at the same time soft in texture so that it may not cut through the skin. A needle-holder is necessary in cases where the skin is tough and thick. Each suture may be tied as it is inserted, but in the case of wounds having a straight direc tion all the sutures may be first inserted and then tied. Care should be taken to see that the edges of the wound are not inverted at any point. In inserting sutures it is advisable to guard against infection from contamination of material by its coming into contact with the surrounding skin, etc. It is desirable to soak the suture material in a solution of biniodide of mercury.

With regard to the length of time that should elapse before sutures should be removed, this will depend on the condition of the wound. In the case of wounds that heal by primary union the suture may be removed about the seventh day. When, however, any sutures cut through one edge of the wound they should be removed without delay. The same remark applies when a wound suppurates, as sutures then do more harm than good. In removing sutures care should be taken to avoid drawing the outside part through the needle-track, as this would introduce infection. By means of a tissue-forceps each suture should be raised from the surface, cut with scissors, and then drawn outwards. In the case of vicious horses or unhandled animals, when large incised wounds have to be dealt with in the region of the quarter or hip, it may be necessary to cast the patient in order to apply sutures in a satisfactory manner. Not infrequently it proves the safest and most expeditious method for such cases and, besides, enables the practitioner to cleanse the wound thoroughly.

Sutures of Relaxation, or Tension Sutures, are useful in cases of wounds where there is considerable gaping or loss of substance, and some difficulty exists in bringing the edges of the wound together. The object is to transfer the tension from the healing margin to tissues further away, and thus relax the strain on the superficial sutures. Relaxation sutures are in serted at some distance from the margins of the wound and carried deeply through all the divided tissues, and emerging at points in the opposite side corresponding to the apertures of entry. Care should be taken not to draw them too tight. They are generally removed at the end of three or four days. Relaxation sutures are of special value in closing wounds of the abdominal region.

The Quilled Suture is seldom employed. A quill or a fine metal rod is passed through the loops on one side of the wound, the ends of the stitches being tied over a rod on the opposite side.

The Mattress Suture is a form of inter rupted suture made by passing the needle transversely across the wound, and recrossing it at a short distance so as to leave a loop at one side and two ends at the other. The ends are then tied together.

The Twisted or Pin Suture is convenient in cases of emergency when needles and suture material are not at hand. It is formed by passing a pin deeply through the tissues and transfixing both sides of the wound. The margins are then brought together by twisting a piece of thread in a figure-of-eight form around the projecting ends of the pin. The pin is then shortened by cutting off the point with scissors. A pin-director is useful in making a pin-suture.

Continuous or Uninterrupted Sutures are those in which a single thread is employed for the purpose of making a series of consecutive stitches. They are seldom employed for sutur ing the skin, but are used in the form of buried sutures for uniting deeper structures and also for wounds of the hollow viscera. For a description or these sutures the reader is referred to the article on"Surgical Technique."One form of continuous suture, however, is worthy of mention here, namely the subcuti cular suture, as it is especially useful in canine practice.

A fine straight needle and Fine silkworm gut are employed. A grain of perforated shot is fixed on the tail of the suture close to its end to prevent its drawing through. The needle and suture are passed through the epidermis (or outer layer of skin) close to one end of the incision, and then traverse the corium (or deep layer of the skin) on each side alternately, and finally emerge through the epidermis at the other end of the wound. When the suture is drawn sufficiently tight the margins of the skin are approximated, and by means of another grain of perforated shot this end of the suture is also prevented from becoming loose. If perforated shot is not at hand, the ends of the suture may be fixed by means of a figure-of eight knot. Of course, this suture is only suitable for aseptic wounds.' (2) Lacerated or Wounds. - A lacerated wound may be described as one which is produced by a more or less blunt object, consequently the tissues are torn, includ ing the skin. Not infrequently a pointed object may cause a lacerated wound if an animal rushes against it and then endeavours to free itself. A cow's horn is capable of causing an extensive laceration, while a sharp-pointed object, like a large hook, when caught in the tissues, may pro duce a very deep and lengthy wound. Again, it must be remembered that a wound in the vicinity of the shoulder or quarter caused by the shaft of a light car in a collision may give the ' For illustrations of the various forms of suture the reader is referred to the article on"Surgical Technique." appearance of a punctured wound externally, but there may be extensive laceration of the muscles in the deeper parts. Kicks, especially when inflicted by a horse shod with calkins, may in some cases cause extensive laceration, while barbed wire is capable of producing extra ordinary damage to the tissues. Lacerated wounds are always associated with more or less contusion of the parts, a complication which adds materially to the gravity of such injuries; as sloughing of the tissues is apt to follow, and this increases the risk of septicaemia.

A very serious form of lacerated and contused wound is met with as the result of the wheel of a heavy vehicle passing over the coronet of a horse. In the hunting-field lacerated and con tused wounds of the horse's limbs are of very common occurrence, more especially in a country like Ireland where ditches and loose stone-walls largely exist as fences. Cases arising from this cause will be considered later under the treat ment of wounds according to their position.

Amongst the more serious and often fatal lacerated wounds are those caused by the shaft of a car or cart during a collision, as owing to the force of the impact the shaft may penetrate the thoracic or abdominal cavity, or may rupture a large blood-vessel, and cause death from hematoma in a very short time.

Treatment. - Here it is advisable to discuss general principles of treatment as applied to lacerated and contused wounds. The special measures to be adopted will be considered under wounds of the various regions of the body.

Suppression of Hcemorrhage. - In lacerated wounds of moderate extent haemorrhage, as a rule, is slight, because the blood-vessels are torn instead of being cut as in incised wounds. In the case of extensive lacerated wounds, however, may be profuse, and if large blood: vessels be severed immediate surgical interven tion is essential. Not infrequently in the case of deep wounds considerable difficulty will be experienced in locating and ligating the bleeding vessel. If the patient be unhandled, or a nervous, well-bred animal, the difficulty is in creased, more especially in cases where it is necessary to enlarge the opening of the wound in order to secure the vessel. When the haemo rrhage comes from a wound in the vicinity of a fore or hind limb, the application of a tourniquet above the wound will control the bleeding until the artery can be secured. In an emergency an improvised tourniquet can be made by knotting a handkerchief around the limb, and inserting a stick between them and giving it a series of twists. Of course, a tourniquet can only be regarded as a temporary expedient, and must be released when the vessel is secured. Although firm plugging of the wound with pledgets of carbolized tow, soaked in a styptic such as corn pound tincture of benzoin, will succeed in the case of bleeding from vessels of moderate size, this treatment cannot be relied upon when it arises from a large artery, as there is consider able risk of recurrent hemorrhage. Experience teaches that in such an instance, if owing to the opposition offered by the patient the vessel cannot be secured, the most advisable course is to insert provisionally a tampon of tow, then cast and secure the animal and take up the artery. With the horse in the recumbent position the procedure is greatly facilitated, and, if necessary, the opening of the wound can be enlarged in a safe manner. In the case of a deep-seated vessel it may be impossible to apply a ligature, especially when the tissues are of a dense character and the artery retracts. Under such conditions a large artery forceps is required, and when a good grip of the vessel is obtained the instrument can be left in situ for twenty-four hours or longer. For this purpose a most useful instrument is Schoemaker's artery-forceps or"Ligature Carrier,"which carries the loop of the ligature in a groove on the point of one of the blades. When the vessel is secured the ligature can be tied with facility, and the operator can be certain that it does not enclose the point of the forceps. In the case of a large artery it is advisable to ligature both ends of the divided vessel, as owing to collateral circulation bleeding may take place from the proximal end.

When hemorrhage has been controlled by plugging the wound with tow, care should be taken that the tampon is not removed too soon, as otherwise recurrent hemorrhage may follow and prove serious. If the tampon be antiseptic, it can be allowed to remain in place for about twenty-four hours, the length of time depending on the serious character or otherwise of the bleeding.

Having succeeded in arresting hemorrhage, we next make a careful examination of the wound and proceed to Cleansing, Disinfecting, and providing effi cient Drainage. - On these details successful

results depend to a large extent. The extra time occupied in this part of treatment will be repaid by the prevention of complications, more rapid healing, and considerable limitation of blemishing.

The first step is to remove all necrotic or bruised tissue. This can be effected by means of a tissue forceps and sharp scissors. The wound is then irrigated with an antiseptic solution, and a careful search made for foreign bodies, which, if found, should be removed. In wounds of certain regions portions of bone may be detected, and should be extracted at once.

Neglect to search for foreign bodies is often responsible for unsatisfactory results such as sinus formation. Without doubt the presence of a foreign body in a wound renders the animal more liable to become infected with tetanus.

The next step is to provide proper drainage, and in the case of extensive wounds, such as those caused by a cart shaft, considerable ingenuity will be required in order to render this procedure effective. By observing the course and direction taken by the fluid injected into the wound a fair idea will be gained of the position for making the necessary counter openings. Diligent search should be made for"pockets"in any part of the wound, and if present these must be laid open, as otherwise they would act as reservoirs for pus. Similar remarks apply to torn fasciae resulting in the formation of a cul - de - sac. Not infrequently there may be considerable difficulty in securing efficient drainage owing to the direction of the wound, and in making the necessary counter openings a marked degree of surgical skill is required. It is generally necessary to cast nervous or vicious horses in order to carry out the procedure with safety and efficiency. It is important to point out that, unless proper drainage be provided, the most assiduous irriga tion is likely to fail in preventing serious com plications. For irrigation of extensive wounds the most suitable apparatus is a continuous flow pump provided with rubber tubing. In summer time the ordinary hose-pipe and cold-water tap prove efficient for the preliminary daily flushing, and the irrigation is completed by washing out with an antiseptic solution. But in winter weather cold - water flushing is not advisable. Recent experience has proved that the most suitable antiseptic agent is Dakin's solution.

In irrigating a wound care should be taken not to injure the tissues by rough manipulation, nor to make fresh openings between healthy muscles, as such irrational handling would start new centres of infection. In amateur treatment errors of this kind are not infrequently com mitted, especially when the irrigating tube is furnished with a metal or wooden nozzle.

Sutures. - In the majority of lacerated wounds sutures are not required. Cases occur, however, in which sutures employed with discretion assist in promoting healing by bringing the edges of the wound together at its two extremities, when the tissues are widely separated. Thus in large wounds in the vicinity of the hip and quarter, the insertion of a few interrupted sutures is often indicated. Care should be taken, how ever, to ensure that drainage is not interfered with, and if there be evidence that pus is prevented from escaping, the sutures should be removed. In most instances suturing lacerated wounds can only be relied on to keep the parts together for a short time, as under ordinary conditions suppuration is inevitable and the stitches slough out. The common mistake made by amateurs in connection with wounds of this nature is to apply sutures in a similar manner to that adopted for incised wounds. The neces sity for drainage is not appreciated, and serious complications are apt to result from preventing the escape of discharges.

As regards the after-treatment of lacerated wounds, one must be guided by the progress attained and the occurrence or not of complica tions. Irrigation must be practised as long as the discharge of pus continues, and during the course of treatment it may be necessary to provide additional drainage. Complications will be considered under a separate heading.

In country practice the difficulties in the way of ensuring ordinary cleanliness are enormous, hence it is usually necessary to prescribe a dressing which is likely to overcome the inevit able infection resulting from the manipulations of the attendant, and from the patient's sur roundings. A useful all-round dressing is com posed of creosote 3ij., oil of turpentine iv., and olive oil Oj. This possesses the advantage of warding flies from the wound - a most important point during warm weather.

(3) Punctured Wounds. -Wounds of this type are very common in veterinary practice. They may be caused by any form of sharp or blunt pointed body, and are characterized by an insignificant surface opening and considerable depth, so that the serious nature of the lesion is apt to be overlooked by the layman. Much damage may be caused to deep-seated tissues, and, owing to the fact that often efficient drainage is difficult to provide, serious complica tions are likely to ensue. As examples of this type of wound may be mentioned punctures of the foot due to gathered nails, punctures of the limbs in hunters due to thorns, sharp projecting spicules of stone or sharp branches of furze (gorse), and a stab of the fetlock or pastern from a stable fork. Punctured wounds of joints or of the chest or abdominal cavity are especially dangerous, and will be discussed under"Wounds of Special Regions." Another important feature in connection with punctured wounds is the frequency with which a foreign body may be present without being detected. Such an occurrence prevents the wound healing, and not infrequently leads to the formation of a sinus. Again, owing to the injury inflicted on deep-seated structures, a portion of necrosed tissue may be imprisoned in the depth of the wound and induce a chronic discharge of pus.

Treatment. - The general principles of treat ment will be considered here. In cases where a blood-vessel has been punctured the first indica tion is to arrest the bleeding. Owing to the small size of the orifice of the wound it may be necessary to enlarge it in order to take up the vessel and apply a ligature. When the artery is of small size, haemorrhage can be controlled by inserting a plug of tow soaked in compound tincture of benzoin.

The next step is to ascertain the direction and depth of the wound by the careful use of a probe, and also by the finger. Efficient drainage must then be provided by enlarging the wound and making a dependent orifice. If the direction of the wound be downwards there may be considerable difficulty in carrying out this procedure, but by acting on mechani cal principles, and observing the manner in which fluid injected into the wound escapes therefrom, suitable drainage can generally be provided.

A careful search for foreign bodies must next be made; neglect of this precaution has on very many occasions been responsible for unfortunate results. A thorn, a splinter of wood, a spicule of bone or a bit of flint may easily be overlooked, hence the importance of thorough exploration. Irrigation with an anti septic solution is then carried out, and the wound is treated in a similar manner to that advised for lacerated wounds.

In the case of a very deep wound it is advis able to plug loosely with double cyanide gauze soaked in Dakin's solution, and to remove this daily. Not infrequently there is a tendency for healing to proceed in the superficial part of the wound, while the deep region continues to suppurate. By the judicious use of gauze plugging such an undesirable condition can be avoided, and the orifice can be kept patent until healing by granulation has occurred in the deep part of the wound.

As punctured wounds are most liable to be followed by tetanus, it is always advisable to administer a dose of antitetanic serum as early as possible.

In valuable animals, when there is a suspicion of the existence in a wound of a foreign body which cannot be detected by the probe or the finger it is advisable to bring radiography to our assistance.

Poisoned Wounds. - Under this 'reading some authors describe various wounds, including those infected by virulent micro-organisms. The latter will be dealt with in the section entitled"Wound Complications." Bites inflicted by a dog may be included with poisoned wounds, as unless early surgical treatment is adopted a serious septic condition is likely to result. Usually another dog is the victim, but occasionally a vicious dog attacks a horse and inflicts wounds of the lips or of the limbs. In the case of a large dog the canine teeth may cause deep punctured wounds, which in the limbs may infect tendon sheaths and lead to extensive sloughing of the skin and underlying structures. In the treatment of such wounds sutures must on no account be employed; efficient drainage should be provided by the judicious use of the knife, and the part should be thoroughly irrigated with an antiseptic solution, and a cataplasm of thermofuge applied thick and hot.

If septicemia is threatening it is advisable to administer a dose of polyvalent anti-strepto coccic serum subcutaneously; this is a valuable auxiliary to surgical treatment.

Stings of insects, such as bees or wasps, may cause serious results if an animal be attacked by a swarm of these and the part involved be the region of the throat, as extensive swelling of the pharynx or tongue may result and also cedema of the glottis. In such a case a tracheo tomy tube must be inserted at once so as to prevent asphyxia. In milder cases an alkaline lotion, such as a solution of bicarbonate of soda in water or a very dilute solution of liquor ammoniae, may be applied. Certain flies capable of biting may after feeding on putrid material cause a serious form of septic inflammation in the bitten part. The treatment consists in applying a cataplasm of thermofuge, and when evidence of pus formation is manifested, a free incision should be made into the part.

Snake Bites are not encountered in the British Isles, as the only venomous reptile met with is the common adder, and the poison which it is capable of conveying with its bite is not of sufficient virulence to prove serious.

But in India and other countries where poisonous snakes are found, fatalities are common. In the treatment of such cases, if the bite be situated on a limb, a tight ligature should be applied above the wound so as to prevent absorption of the virus. The part should be laid open with a knife, the tissues excised, and permanganate of potash applied. If available, Fraser's antivenene should be in jected subcutaneously. Collapse is to be com bated by the administration of stimulants and hypodermic injections of strychnine Gunshot Wounds. - In civil practice this type of wound is rarely met with except in dogs, as the result of accidents during shooting or of the act of malicious persons. In the case of wounds occurring in warfare, when treatment is deemed to give a fair prospect of a return to utility, the principles are similar to those advised in connection with lacerated and con tused or punctured wounds. The arrest of haemorrhage is the first consideration, then the removal of foreign bodies if present and of all bruised and loose tissues; the provision of drainage, followed by frequent irrigation with Dakin's solution. The question of applying dressings of gauze and cotton-wool, etc., must be left to the discretion of the surgeon.

In the dog the damage caused by shot will depend on the range at which the gun is fired. If discharged close to the animal extensive destruction of tissues will result, and probably render the case hopeless. If at long range, the shot is scattered and may enter the skin and subcutaneous tissue and can be detected by palpation. If not interfered with, the grains of shot gradually find their way to the surface of the skin and can be removed with facility. Not uncommonly they reach the surface a long distance from the seat of entrance.

Here we may remark that in the case of either bullet or shot, if no important structures are injured, the foreign body may remain in situ indefinitely without inducing suppuration.

Complications or Segueice of Wounds. - These are of great importance, not only from the thera peutic aspect but also from the preventive point of view. As infection is responsible for the majority of these unfortunate occurrences, the necessity for attention to surgical cleanliness and to the judicious employment of antiseptics will be readily understood.

Recurrent, Intermediate or Reactionary Hce morrhage. - We have already referred to the suppression of haemorrhage as the primary step in the treatment of all wounds associated with bleeding. Here attention must be directed to haemorrhage which recurs within twenty four hours after the infliction of a wound, and this is termed recurrent, intermediate, or reactionary, and occurs subsequent to primary treatment.

Various factors are responsible for this un fortunate occurrence, such as (a) the slipping or loosening of a ligature owing to defective application, such as tying a"granny instead of a"reef"or"surgical"knot, or from including within the grasp of the ligature other structures as well as the artery; (b) in cases where plugging of the wound has been resorted to, too early removal of the material, i.e. before the coagula in the divided vessels have become sufficiently firm to withstand the blood- pressure; (c) exercise or excitement subsequent to the cessation of haemorrhage may, by increasing blood-pressure, disturb the coagula in vessels which have not been ligatured.

Secondary Hcemorrhage. - This term is applied to bleeding from wounds after the lapse of twenty-four hours. The following factors may be responsible: (a) Infection of the obstructing coagula, which break down under the influence of bacterial action, an ulcerative form of arteritis which may bring about softening of an absorbable ligature with weakening of the vessel wall, and thus contribute to the produc tion of secondary (b) the liga For a description and illustration of these knots the reader is referred to the article on"Surgical Technique." ture may be composed of material which is too readily absorbed; (c) a vessel may be exposed m its continuity and, owing to tension on its walls due to movements of the animal, it may rupture.

Treatment. - This form of haemorrhage is more difficult to control than the recurrent, as the walls of the vessels may be in an unhealthy condition and tend to rupture while being secured. In bleeding from a large artery every effort should be made to apply a ligature to the vessel, as plugging the wound is seldom satisfactory. The prevention of secondary haemorrhage consists in careful attention to the suppression of primary bleeding, and in apply ing proper ligatures to every artery within reach. When a vessel exposed in a wound is likely to be subjected to tension it should be ligatured. Plugging a wound with tow or cotton-wool cannot be relied on in haemorrhage from large vessels, and should only be practised when it is impossible to secure them with artery forceps.

In cases where collapse seems imminent owing to loss of blood, stimulants are indicated. The hypodermic injection of two drachms of solu tion of adrenalin (1 to 1000), with half a grain of atropine sulphate, often gives excellent results. The patient should be warmly clothed, and bandages applied to the limbs.

Cellulitis is a spreading inflammation of the subcutaneous or cellular connective tissues, with a tendency to terminate in suppuration and necrosis. It varies in degree and extent, and originates from the presence of various bacteria in the wound. The more severe types of cellulitis are caused by the Streptococcus pyogenes, and not infrequently the lesions pro duced resemble those of erysipelas. The milder forms depend on Staphylococcus pyogenes aureus or albus.

The symptoms observed vary according to the severity of the attack and the virulence of the causative micro-organisms. The lips of the wound and the tissues in the vicinity become swollen, hot, and painful. If occurring in a limb the swelling extends upwards, the super ficial lymphatic vessels become prominent, and marked lameness is observed.

In severe cases constitutional symptoms are present, such as fever, depression, loss of appetite, etc., due to absorption of toxins by the general circulation. Suppuration occurs under the skin, with sloughing of the cellular tissue. The skin in parts becomes softened and gives way, so that a number of openings are produced. In severe cases associated with deep wounds the pus may extend between the muscles, and necrosis of the muscular tissue may result. General septicaemia may set in unless prompt surgical treatment be adopted.

Treatment. - In mild cases, attention to efficient drainage of the wound and thorough irrigation with an antiseptic solution will usually prove successful. If severe pain be present a hot cataplasm of thermofuge may be applied for a few days, but discretion is necessary, as such applications tend to produce softening and disintegration of the skin. In severe cases free incisions should be made into the tense tissues, in addition to providing proper drainage for the wound. Polyvalent anti - streptococcic serum administered by subcutaneous injection gives excellent results in some cases, and the injection may be repeated every second day until improvement occurs. When suppuration is observed in the vicinity of the wound, free incisions should be made and the parts thoroughly irrigated with antiseptic solutions.

Erysipelas. - As already remarked, the border line between severe cellulitis and erysipelas is not clearly defined in many cases. The causal micro-organism of erysipelas according to some authorities is the Streptococcus erysipelatus, but it is admitted that its microscopical characters cannot be differentiated from those of ordinary Streptococcus pyogenes occurring in cellulitis. The infective nature of erysipelas makes, how ever, a striking difference between the two affections.

Erysipelas cannot be described as common in animals, but its serious nature, especially when associated with wounds in the vicinity of the head or orbit, must be pointed out. Erysipelas is characterized by a spreading inflammation of the skin and subcutaneous tissue, with the local formation of toxins, which being absorbed are to a large extent the cause of the marked constitutional disturbance and fever which accompany this disease. The streptococci re sponsible for the affection are widely distributed and may become attached to litter, the walls of buildings in which affected animals are housed, and may be carried by the hands or clothes of attendants, and thus infect wounds or abrasions.

The alterations produced in a wound infected with erysipelas are as follows: Marked swelling of the structures in the vicinity of the wound and extending to a considerable distance beyond it. As the swelling extends it is limited by a broad, sharply defined, slightly raised and infiltrated margin of skin. The discharge from the wound is amber-coloured in some cases. In others, diffuse suppuration occurs; areas of skin lose their vitality and fall off by sloughing and there is a discharge of watery sanguineous pus containing shreds of lymph and debris of broken-down tissues. Serious constitutional disturbance is present, and may be accompanied by extensive necrosis of the skin and under lying tissues. Death may follow from exhaus tion, septicaemia, or other complications.

Treatment. - Patients that are in high condi tion (sthenic) should be given a moderate dose of purgative medicine. The judicious administra tion of aconite is indicated when pain and marked constitutional disturbance are present. Atten tion should be directed to the condition of the wound and free drainage provided. Thorough irrigation with an antiseptic solution should be carried out.

When there is evidence of suppuration under the skin, free incisions should be made. Ichthyol ointment combined with extract of belladonna and glycerine should be applied around the wound.

A polyvalent anti-streptococcic serum should be administered subcutaneously on the appear ance of the first evidence of the disease and repeated daily until improvement takes place.

Malignant Cedema

is also known as spread ing traumatic gangrene, and is one of the most serious and fatal of wound complications. The micro-organism on which it depends is the bacillus of malignant oedema. Although not a common condition in animals, yet it occurs sufficiently frequently to merit brief considera tion here. The symptoms produced are a very acute cellulitis accompanied by general septi caemia. The surface of the wound becomes covered with sloughs, the tissues in the vicinity are much swollen, and the skin crepitates on pressure, owing to the presence of gases in the underlying structures. The process spreads rapidly and extensive gangrene of the tissues supervenes. Death occurs from general blood poisoning.

The majority of cases prove fatal. If the patient be seen early, free incisions into the affected tissues should be made, and constant irrigation with an antiseptic solution carried out. For further details see"Malignant (Edema." Irritative Fever.- This term is sometimes applied to the acute febrile condition associated with septic wounds of joints or tendons, or any surgical lesion of the limb or foot accompanied by great pain. The symptoms, which depend on infection, nerve irritation, and probably absorption of toxins, consist of elevation of temperature, quick pulse, accelerated respira tion, loss of appetite, sweating, constant move ment of the affected limb, which is unable to bea r weight; after some time emaciation sets in and gradual exhaustion; in some instances the animal goes down and struggles in a convulsive manner. Unless early and successful treatment of the lesion is possible, such cases usually terminate fatally, or are destroyed as incurable. If treatment be attempted, the indications are to relieve pain and to quiet the irritability of the nervous system. These are accomplished by prescribing chloral hydrate.

Tetanus is one of the most serious com plications of wounds. For full information the reader is referred to the special article on the subject. Here we may point out that tetanus arises from infection of the wound with the Bacillus tetani, and that since antiseptic treat ment has become general the disease is not so frequently encountered in surgical practice. The prevention of the affection by the adminis tration of antitetanic serum is well known, and in treating wounds in valuable horses the practitioner should administer this serum as early as possible. Moreover, the very high mortality of tetanus accentuates the necessity for the timeous employment of this serum.

Sinus Formation. - In deep punctured wounds, more especially in certain regions such as the area between the forearm and the sternum, the ribs, the shoulder, the anterior tibial region and the coronet, sinus formation is a very troublesome sequel. A sinus is a narrow track with a smooth lining and extending deeply into the tissues. The orifice is often depressed and continuous with the skin, and there is a constant discharge of pus, so that healing cannot take place until surgical treatment is adopted. On exploration considerable tension is present, and if a tampon of gauze be inserted it is forced outwards after a short time.

In favourable cases the walls of the sinus are lined with granulation, and if sufficient drainage be provided healing takes place under ordinary antiseptic treatment. But there are certain causes which are responsible for the non closure of a sinus. These include the presence of a foreign body in the depth of the wound, such as a ligature, a fragment of diseased cartilage or bone, a splinter of wood, a thorn, or a piece of stone or iron. Insufficient drainage associated with tension in the wound also tends to produce sinus formation. Constant move ment of the part is also a causative factor, as it prevents healing, as happens with wounds situ ated between the fore extremity and the trunk.

Treatment. - In dealing with a sinus the first essential is to enlarge the opening so as to enable a search to be made for a foreign body, and also to provide drainage. The next procedure is to examine the walls of the sinus, and if lined by a smooth membrane this should be removed by careful scraping with a sharp curette.

Daily irrigation with an antiseptic solution is then carried out, followed by plugging with anti septic gauze, and healing not infrequently results within a reasonable time.

But cases occur in which, owing to the direc tion of the sinus or its situation, it is impossible to reach its limit, or to provide proper drainage. In such instances success is often obtained by injecting daily a strong solution of sulphate of zinc (1 part of zinc sulphate to 4 parts of water): This causes a removal of the lining of the sinus, and healing then takes place through out the track of the sinus.

For sinuses which do not extend deeply the application of a blister to the part will often succeed in bringing about closure.

wound, sutures, skin, treatment and tissues