CHAPTER II.
DISEASES OF THE FOOT.
CONGESTION OF THE CLAWS.
Congestion of the claws is not infrequently confused with contusion of the sole. It is, however, essentially different, and presents closer analogies with laminitis. The condition is characterised by congestion of the entire vascular system of the claw and principally of the velvety tissue. Like laminitis, it affects all four limbs; in rare cases the two front or two hind.
Congestion of the claw results almost exclusively from enforced movement on hard, dry and hot ground. It is commoner in animals unaccustomed to walking, and in heavy beasts which have been travelled considerable distances to attend fairs or markets. It is commonest in the bovine and porcine species, and less common in sheep.
The symptoms appear after animals return from a long journey by road. They are characterised by unwillingness to bear weight on the feet and difficulty in movement. Standing is painful, and the animals resist being moved; as soon as released they lie down.
Diagnosis presents no difficulty, though the condition is sometimes mistaken for slight laminitis.
Prognosis is favourable.
Absolute and prolonged rest is always followed by recovery, no internal medication being necessary, though this result is promoted by enveloping the claws in wet compresses or by using cold foot baths, etc.
CONTUSIONS OF THE SOLE.
Contusions of the sole are only seen in animals which work without shoes or in such as are badly shod.
Work on rocky ground, movement over newly metalled roads, and wounds produced by sharp stones, are the principal causes of
contusion of the sole. Badly applied shoes, flat or slightly convex on their upper surfaces, may also produce bruising in the region of the sole. The anterior angle of the claw is rarely affected.
Lameness is the first symptom to attract attention. It is slightly marked, unless the bruising has been overlooked until suppuration has set in. It affects only one or two limbs, and is rarely accompanied by general disturbance, such as loss of appetite, fever, exhaustion during work, etc.
Locally the claw or claws affected are abnormally sensitive to percussion of the wall, and particularly to compression of the sole.
The parts are hot to the hand, and thinning the sole with a knife shows little perforations, irregular points and crevices in the horn. One may also find softening, infiltration and hæmorrhage within the horn similar to those of corn in the horse, undermining of the sole over limited areas, and sometimes suppuration, if the animals have been forced to work when lame.
Complications like necrosis of the velvety tissue or of the bone, though comparatively common in the horse, are rare in oxen.
Diagnosis is not difficult provided the history of the case is known. Confusion with laminitis is scarcely possible, for the gait of this lameness and the local symptoms are all different. Examination of the sole will usually dispel any remaining doubt.
Prognosis. The prognosis is favourable. When the horn is simply softened and a blackish liquid transudes, the lesion is trifling; if the discharge is reddish grey the lesion is graver, and implicates all the velvety tissue; finally, separation of the horn from the secreting membrane and the discharge of true pus point to death of the keratogenous tissue or of the bone.
Treatment should be commenced by carefully thinning the sole around the wound and applying moist antiseptic dressings or cold affusions. Removal of loose portions of horn hastens repair by allowing discharge, which has accumulated between the living tissues and the horn itself, to escape freely. The extirpation of necrotic tissue and the application of surgical dressings are only called for in specially grave cases.
This treatment usually gives good results. The acute complications which are so common and so dangerous in the horse seldom occur in
Most of these operations can be performed without casting, provided the animal is placed in a trevis or is sufficiently secured.
LAMINITIS.
Laminitis is characterised by congestion, followed by inflammation of the horn-secreting tissues of the foot. It is now rare in oxen and very seldom assumes an acute form. The slow pace at which animals of the bovine species move may sufficiently explain this rarity; nevertheless, prolonged travel on stony roads with heavy vehicles, rapid and repeated marches to towns or important fairs, are sufficient to produce attacks. Before the days of railways, and for some time after their introduction, in Britain cattle were travelled by road, and laminitis was common.
Long journeys in crowded railway trucks may also produce the disease, although the animal has not been forced to walk. Persons engaged in exhibiting cattle at shows are well aware of this. Prolonged maintenance of the standing position will produce the trouble, to which the joltings of the railway journey may also contribute their share. Prolonged standing on board ship may induce laminitis.
“Show condition” and the consumption of highly nitrogenous, and particularly of farinaceous, foods favour the occurrence of laminitis.
Breed is also considered to have some influence, and laminitis is said to occur more frequently in animals raised in flat districts, because in their case the space between the digits is larger than in mountain-bred cattle. In this connection the body weight may perhaps play a certain part.
The symptoms vary somewhat, depending on whether laminitis is general and affects all four feet, or restricted to the two front or the two hind feet.
The internal claws always seem more severely affected and more sensitive than the external. In very rare cases the animal remains standing, but usually it lies down, and will only rise under strong compulsion.
When standing, the symptoms are similar to those noted in the horse; the animal appears as though absolutely incapable of moving. If all four feet are affected the animal assumes a position as though just about to rise; if the front feet alone are affected the animal kneels in front whilst it stands on its hind legs, a very unusual position for the ox to assume; finally, if the hind feet alone are affected, the animal seems to prefer a position with the feet under the body both in front and behind. (See Veterinarian, 1894, case by Bayley, and note by Nunn.)
It is always difficult to make the animal move. Walking seems painful, and most weight is thrown on the heels. The body swings from side to side as the limbs are advanced, and each limb is moved with a kind of general bodily effort.
The claws are hot, sensitive to the slightest touch, and painful on percussion.
Throughout the development of laminitis the general symptoms are very marked. The appetite falls off early, fever soon appears, and in grave cases the temperature rises to 105° or to 106° Fahr. Thirst is marked, and the animal seems to prefer cold drinks. The muzzle is dry, the face anxious and expressive of pain. Wasting is rapid.
The ordinary termination is in resolution, which occurs between the eighth and fifteenth day, provided the patient has been suitably treated. The disease rarely becomes chronic. On the other hand, the claw occasionally separates, as a consequence of hæmorrhage or suppuration, between the horn proper and its secreting membrane. Should this complication threaten, the pastern becomes greatly swollen, the extremities become intensely congested, and separation commences at the coronet. Loss of the claws, however, like suppuration, is rare.
Diagnosis. Congestion of the sole, the early stage of infectious rheumatism and osseous cachexia may, at certain periods of their development, be confused with laminitis; but the history and the method of development of the above-mentioned diseases always allow of easy differentiation.
It should, however, be added that, in certain exceptional conditions (suppurating echinococosis, producing chronic intoxication, tumours of the liver, and tumours of the pericardium
and mediastinum), symptoms may be shown that suggest the existence of laminitis, although it is not really present. In these cases pain may possibly be felt in the bones of the extremities.
The prognosis is usually favourable, but necessarily depends on the intensity of the disease. Fat stock always suffer severely.
The treatment varies in no important particular from that prescribed for the horse, and is usually followed by rapid improvement. The chief indications are free bleeding from the jugular, the application of a mustard plaster over the chest, and the administration of a smart purgative (1 to 2 lbs. of sulphate of soda, according to the size of the animal) at first, followed by laxatives. This treatment may be completed by giving salicylate of soda per os in doses of 5 to 8 drams, or arecoline in subcutaneous injection, 1 to 1½ grains. Local treatment consists in cold affusions or poultices to the feet.
Failing cold baths, clay plasters applied to the feet are useful. To ensure success all these methods should be utilised simultaneously. In cases of separation of the claw, antiseptic dressings, with a thick pad of tow placed under the sole, become necessary.
Chronic laminitis may perhaps occur in the ox as in the horse, but, as a rule, oxen are slaughtered before the disease can assume this form. In dealing with fat, or even with fairly well-nourished, oxen it would clearly be more economical to slaughter early, and so prevent wasting and the resulting loss from disease.
SAND CRACK.
Sand crack—that is to say, the occurrence of vertical fissures in the wall of the claw—is not absolutely rare in bovines. It is commonest in working oxen drawing heavy loads, though in very exceptional cases it affects animals which have never worked. (Moussu describes one case in a young ox where four sand cracks existed simultaneously.) It may also result from injuries to the coronet. In contrast to the case of the horse, and owing to the different conditions under which the ox performs its work, the disease is commoner in front than in hind feet. In drawing, the ox’s front limbs play the principal part, and the animal pivots, so to speak, on the claws of the front limbs.
The position of the crack may vary. It is commonest on the inner surface of the claw, rare at the toe, and still rarer at the quarter. It is often superficial and complete, extending throughout the entire height of the claw, but not throughout its thickness; sometimes it is complete and profound, the fissure then extending to the podophyllous tissue.
The symptoms are purely local in the case of superficial lesions. When the injury is deep seated, or when it originates in a wound of the coronet, lameness is present. Intense lameness, swelling of the coronet, and blood-stained or purulent discharge point to grave injury and probable complications.
Diagnosis is easy. The prognosis naturally varies with the symptoms. It is favourable when the fissure is merely superficial, but becomes grave when it is deep seated and the animal is exclusively used for heavy draught.
Treatment. When the lesion is superficial and unaccompanied by lameness, no surgical interference is necessary. Rest or very light work is alone required. As soon as lameness appears, rest is obligatory. The application of antiseptic poultices, containing 2½ to 3 per cent. of carbolic acid, creolin, etc., usually alleviates pain in a short time, and facilitates healing in the depth of the fissure.
In exceptional cases, where complications have occurred in consequence of suppuration beneath the fissure, suppuration in the coronary region, or necrosis of the podophyllous tissues, an operation becomes necessary, and is of exactly similar character to that performed under like circumstances in the horse.
Over a space of 1 to 1½ inches on either side of the fissure the horn is thinned “to the blood,” and the subjacent dead tissue removed. The claw is then thoroughly cleansed with some antiseptic solution, the wound freely dusted with equal parts of iodoform, tannin and boric acid, and covered with pads of tow or cotton wool, fixed in position by appropriate bandages. After such operations a long rest is essential for complete recovery, during which, however, the animal may be fattened.
The object of operation is to prevent complications, like chronic suppuration and necrosis, which would endanger the animal’s life,
rather than to effect perfect restoration of usefulness for the work previously done.
PRICKS AND STABS IN SHOEING.
The wall of the ox’s claw is so thin that shoeing is always somewhat difficult, more especially as nails can only be inserted in the external wall. Moreover, as very fine nails must be used, they are apt to bend, penetrate the podophyllous tissue, and cause injuries of varying importance. The ox is often very restless when being shod, and, even though firmly fixed, usually contrives to move the foot every time the nail is struck. The farrier, therefore, may easily overlook the injury which he has just caused, and by proceeding and ignoring it may transform a simple stab into a much more dangerous wound.
Symptoms. In most cases lameness appears immediately the animal leaves the trevis, but, although this is more difficult to explain, lameness is sometimes deferred until the day after, or even two days after, shoeing. Though little marked at first, lameness may become so severe that the animal cannot bear the pain caused by the foot touching the ground. When this stage is reached general disturbance becomes marked, fever sets in, rumination stops, and appetite is lost.
These symptoms point to the occurrence of suppuration. The pus, confined within the horny covering of the foot, causes very acute suffering and sometimes grave general disturbance; later it burrows in various directions, separating the podophyllous tissue from the horn, and ends by breaking through “between hair and hoof” in the region of the coronet. In exceptional cases, complications such as necrosis of the podophyllous tissue extending to the bone, and suppuration of its spongy tissue, may be observed.
Diagnosis. When the farrier suspects he has pricked an animal the immediate withdrawal of the nail will remove any doubt, because bleeding usually follows. If the condition is only detected at a later stage, the early lameness having been misinterpreted, examination of the claw and tapping the clenches of the nails will cause the animal to show pain at a given point, thus indicating the penetration of the nail. Removal of the offending nail is painful, and is often followed
by discharge of pus or blood-stained fluid, which clearly points to the character of the injury. In obscure cases the shoe should not be reapplied.
When the horn wall is separated from the sensitive structures, there is marked general disturbance, and pus is discharging at the coronet, it is practically impossible to err in diagnosis.
Prognosis. In cases of simple nail puncture the prognosis is hopeful, provided that the condition is at once diagnosed. The longer it remains unrecognised, particularly if complication like necrosis has occurred, the graver becomes the outlook.
Treatment. In cases of simple puncture the nail should immediately be withdrawn and the animal placed on a perfectly clean bed to prevent the wound becoming soiled or infected. If lameness appear and become aggravated, the shoe should be removed and antiseptic poultices applied. In the majority of cases the lameness will then diminish, and in a few days completely disappear.
In cases of discovery within the first few days the same treatment is applicable, and is often sufficient. If, on the contrary, pus is discharging at the coronet, if lameness is intense and the general symptoms marked, it may be needful to operate.
The stages of operation comprise: thorough thinning of the horn in the shape of an inverted V over the affected portion of the wall, removal of the loose necrosed parts, disinfection of the wound, and the application of a surgical dressing covering the entire claw.
PICKED-UP NAILS, Etc. (“GATHERED NAIL.”)
Penetrating wounds of the plantar region are, as in the horse, usually included under the heading of “Picked-up Nails.” They are only seen in oxen or cows which are not shod. Pointed objects, like nails, harrow teeth, sharp fragments of wood or glass, etc., may produce injuries of the character of that now in question.
In considering the position of such wounds we may for convenience divide the plantar region into two zones, one extending from the toe of the claw to the point of insertion of the perforans tendon, the other comprising the region between this insertion and the bulb of the heel.
Symptoms. Lameness occurs immediately, and varies with the intensity of the existing pain. If the offending body has not remained fixed in the wound, this lameness may in a few moments disappear, either for good or merely for a time. The recurrence of lameness on the following day or a couple of days later marks the commencement of inflammatory changes in the deeper seated tissues. This lameness in many instances is accompanied by a movement suggestive of stringhalt, the foot being kept on the ground only for a very short time, or sometimes not being brought into contact with the ground at all.
The depth to which the offending object has penetrated, and the direction it has taken, may sometimes be discovered by a mere casual examination of the sole. In other cases only the orifice by which it has penetrated can be found. If the injury has existed for several days, the discharge from the puncture will be thin and blackish, purulent, or blood-stained, according to the case. Fever and general systemic disturbance suggest an injury of a grave character.
Diagnosis. The diagnosis is easy, inasmuch as the lameness almost directs examination to the foot.
Prognosis is rarely grave. The direction, the situation and mode of insertion of the flexor tendon, which forms the plantar aponeurosis, ensure this aponeurosis being rarely injured by objects penetrating from without. The points of the offending bodies usually pass either forwards to the phalanx or backwards in the direction of the plantar cushion.
Treatment. The first stage in treatment consists in removing the foreign body and thoroughly thinning the neighbouring horn. An antiseptic poultice consisting of linseed meal saturated with 3 per cent. carbolic acid or creolin solution is then applied. Considerable and progressive improvement usually takes place in a few hours. If lameness persists, surgical interference becomes necessary; in the anterior zone it is confined to removing any dead portions of the velvety tissue and to extirpating the fragment of bone which has undergone necrosis. In the posterior zone the sinus must be probed and laid open, so that all the diseased parts can be treated as an open wound.
If, as happens in exceptional cases, the plantar aponeurosis is found to be severely injured, the complete operation for picked-up
nail, as practised in the horse, may be performed, or the claw may be amputated. In the former operation the horn covering the sole is first thinned “to the blood.”
The stages of operation are as follows:—
(1.) Ablation of the anterior portion of the plantar cushion. Transverse vertical incision at a distance of 1¼ inches in front of the heel; excision of the anterior flap.
(2.) Transverse incision and ablation of the plantar aponeurosis by the same method.
(3.) Curettage of the point of implantation of the aponeurosis into the bone.
(4.) Antiseptic dressing of the claw.
Finally, if the primary lesion, wherever it may have started, has become complicated by arthritis of the inter-phalangeal joint, it will be necessary to remove the claw, or, better still, to remove the two last phalanges, the latter operation being easier than the former, and providing flaps of more regular shape and better adapted for the production of a satisfactory stump.
INFLAMMATION OF THE INTERDIGITAL SPACE.
(CONDYLOMATA.)
Condylomata result from chronic inflammation of the skin covering the interdigital ligament. Any injury to this region causing even superficial damage may result in chronic inflammation of the skin and hypertrophy of the papillæ, the first stage in the production of condylomata.
Injuries produced by cords slipped into the interdigital space for the purpose of lifting the feet when shoeing working oxen are also fruitful causes.
Inflammation of the interdigital space is also a common complication of aphthous eruptions around the claws and in the space between them. Continual contact with litter, dung and urine favour infection of superficial or deep wounds, and by causing exuberant granulation lead to hypertrophy of the papillary layer of the skin. When the animal stands on the foot the claws separate
under the pressure of the body weight and the condylomata are relieved of pressure. When, however, the limbs are rested, the claws mutually approach, compress the abnormal vegetations, flatten, excoriate, and irritate them, thus favouring their further development.
F . 16. Condylomata of the interdigital space and sidebones.
The symptoms are easy to detect. The animals appear in perfect health, but have difficulty in walking, and show pain. They walk as though on sharp, rough ground, and lameness is sometimes severe. Locally, the anterior surface of the claws and the interdigital space are markedly congested and sensitive, or painful on pressure. The growths are of varying size, isolated or confluent, bleeding, excoriated, or covered with horn, and are visible between the claws when the animal stands on the limb. In many cases they form a perfect cast of the vertical interspace. When the superficial layers have undergone conversion into a horn-like material, lameness diminishes or disappears.
Diagnosis presents no difficulty.
Prognosis is only grave in so far as the condition interferes with animals working, but it may render working oxen entirely useless.
Treatment in the early stages is of a preventive character, and consists in placing animals which have been accidentally injured or attacked with foot-and-mouth disease on a perfectly clean bed.
Surgical treatment is the only reliable method in cases where hypertrophy of the papillary layer is well marked, and is extremely simple.
The animal should be fixed in the trevis, the foot to be operated on separately secured, and the growths completely removed with sharp scissors or with a bistoury and forceps. When bleeding has subsided the wound is covered with a mixture of equal parts of iodoform, tannin, and powdered boric acid, and an interdigital dressing is applied. The dressing is removed after five to ten days, according to circumstances. If the cicatrix shows signs of exuberant growth it is dusted with powdered burnt alum, and the parts are treated as an open wound. When the growths are covered with horn and no longer painful it is not desirable to interfere with them.
CANKER.
Canker—i.e., chronic suppurative inflammation of the podophyllous or velvety tissue—is accompanied by hypertrophy of the papillæ and progressive separation of the horn of the sole. It is much rarer in the ox than in the horse, although it occasionally occurs.
Prolonged retention in dirty stables, where the bedding is mixed with manure and continually moistened with urine, is the principal cause of the disease. Individual predisposition and the action of some specific organism may also have some influence.
Canker in oxen, like the same disease in horses, is recognised by softening and separation of the horn of the sole, and by progressive extension of the process towards neighbouring parts. The usual course consists in invasion of the podophyllous tissue, separation of the wall and of the heels, and pathological hypertrophy of the hornforming tissues, producing condylomata.
The new growths do not attain the same dimensions as in the horse, but, on the other hand, the disease very frequently takes a progressive course, involving the whole of the claw. A trifling
accidental injury may be followed by infection of the subungual tissues, and thus become the point of origin for canker.
Canker may attack only one claw; on the other hand, it may extend to both claws of one foot, or to the claws of more than one foot in the same animal.
Diagnosis. Diagnosis is easy. The separation of the horn, the presence of a caseous, greyish-yellow and offensive discharge between the separated parts and the horn-secreting tissues, the appearance of the exposed living tissues, etc., leave no room for doubt.
Prognosis. The prognosis is grave; for, as in the horse, the disease is obstinate.
Treatment consists in scrupulously removing all separated horn, so as fully to expose the tissues attacked by the disease. The parts should then be thoroughly disinfected with a liquid antiseptic, and a protective pressure dressing applied.
As a rule, cauterisation with nitric acid, followed by applications of tar or of mixtures of tannin and iodoform, iodoform and powdered burnt alum, etc., effect healing, without such free use of the knife as has been recommended in the horse during the last few years.
GREASE.
Grease in the ox seems only to have been described by Morot and Cadéac, and even in these cases the descriptions appear rather to apply to elephantiasis or fibrous thickening of the skin than to grease proper. The descriptions are not sufficiently clear, and the symptoms described differ too much from the classical type seen in the horse to convince us without further confirmation of the occurrence of the disease.
Any injury in the interdigital space or flexure of the pastern may, under unfavourable circumstances, be complicated by death of the skin, necrosis of the interdigital ligament, of the fibro-fatty cushion
PANARITIUM FELON WHITLOW.
in the flexure of the pastern, and of the terminal portions of the tendons.
These lesions are sometimes regarded as panaritium. In reality, they correspond exactly to what, in the horse, are known as “cracked heels” and “quittor.” The primary injury becomes infected with organisms which rapidly cause death of the skin or the formation of a deep-seated abscess and necrosis of the invaded tissues.
Causation. Neglect of sanitary precautions and filthy stables constitute favouring conditions, the feet being continually soiled and irritated by the manure and urine. Animals reared on plains, and having broad, flat, widely-separated claws, are more predisposed than animals from mountainous regions, in which the interdigital ligament is stronger and the separation of the claws less marked. Any injury, abrasion, or cut may serve as a point of origin for such complications.
Panaritium may even occur as an enzootic with all the characters noted in isolated cases. In Germany it has received the name of “contagious foot disease.” These enzootic outbreaks of panaritium follow epizootics of foot-and-mouth disease, with lesions about the claws. Through the superficial aphthous lesions the parts become inoculated with bacteria, and the severity of the resulting injury is in some measure an indication of the virulence of the infecting organism.
Symptoms. The first important symptom consists in intense local pain, rapidly followed by marked lameness. The affected region soon becomes swollen; the coronary band appears congested; the skin of the interdigital space projects both in front and behind; the claws are separated, and all the lower portion of the limb appears congested and œdematous. The engorgement usually extends as high as the fetlock, and the parts are hard and extremely sensitive. The patient is feverish, loses appetite, and commences to waste. After five to ten days sloughing occurs at some point—if the ligament is affected, in the interdigital space; if the tendons, or the fibro-fatty cushions, the slough appears in the flexure of the pastern. The dead tissue may separate and fall away, or remain in position macerated in pus. Separation is generally slow, requiring from twelve to fifteen days, and, unless precautions are taken, complications occur. If only the interdigital ligament or fibro-fatty cushion be necrotic, recovery may
be hoped for; but, on the other hand, if the tendons, tendon sheaths, ligaments, or bones are affected, complications like suppurating synovitis, suppurating ostitis, arthritis, etc., supervene, with fatal results. Death may occur from purulent infection, unless the animal is slaughtered early.
The diagnosis is easy. The intensity of the lameness, separation of the claws, swelling of the pastern region, sensitiveness of the swollen parts, and absence of lesions in the ungual region sufficiently indicate the nature of the condition.
The prognosis is grave, for complications may result, in spite of proper treatment.
Treatment. Treatment consists, first of all, in thoroughly cleansing the affected limb and placing the animal on a very clean bed. The parts are next subjected to antiseptic baths containing carbolic acid, creolin, sulphate of zinc, or sulphate of copper. It is often more convenient, and quite as efficacious, to apply antiseptic poultices to the foot and pastern, and to allow them to remain for some days, being moistened several times daily with one of the solutions indicated. The effects are: rapid diminution of the pain, delimitation of the necrotic tissues is hastened, and the abscess is more readily opened.
Many practitioners recommend early intervention in the form of deep scarification in the interdigital space or pastern region. The local bleeding, and the drainage which takes place through the wounds so made, is said to hasten recovery or to prevent complications.
When the abscess has opened, and the dead tissue separated, the abscess cavity or wound should be regularly washed out with a disinfecting solution, to prevent complications, in case fragments of necrotic tissue have been retained. If, however, complications have occurred, no hesitation should be felt in freely incising the parts, and, if necessary, in removing one or both phalanges. When both joints of one foot are affected, and arthritis threatens to or has set in, there is no object in treating the animal, and early slaughter is to be recommended.
In cases where the disease follows foot-and-mouth disease, and threatens to become enzootic, it can generally be prevented
spreading by keeping the foot-and-mouth subjects on very clean beds, and frequently washing the feet with antiseptic solutions. Disinfection of the sheds is also very desirable.
FOOT ROT.
Foot rot is a disease of sheep, and, like canker, is confined to the claws.
Thanks to the progress of hygiene, it tends to become rarer, but is still seen in the enzootic form in some portions of England and Scotland, in the mountains of Vivarais, the Cévennes, and the Pyrenees.
It affects large numbers of animals at once, animals belonging to one flock or to neighbouring flocks in one locality, and when it invades a sheep farm, all the animals may successively be attacked at intervals, according to the local conditions.
Symptoms. The disease develops rather insidiously, and the patients always retain an excellent appetite. It begins with lameness, which is at first slight, later becomes accentuated, and in the last periods is very intense. On examination, the coronet and lower part of the limb as high as the fetlock are found to be swollen. Palpation reveals exaggerated sensibility, and on direct examination, a fœtid discharge is discovered in the interdigital space. This discharge, which is peculiar to the onset of the disease, only continues for a week or two, and is succeeded by a caseous exudate which is always offensive, which moistens and macerates the horn, the skin, the tissues in the interdigital space, and the region of the heels. From the 20th to the 30th day after onset the claw separates above in the interdigital space. The separation extends towards the heel, then to the toe, exposing ulceration of the subjacent podophyllous tissue.
From this time the patients experience very severe pain, and, as in other diseases of the feet, remain lying for long periods. Movement becomes extremely painful, and the animals frequently walk on the knees. The subungual lesions become aggravated, separation of the claw extends, necrosis of the podophyllous tissue and of subjacent tissue becomes more extensive, and the inter-phalangeal ligaments and the extensor or flexor tendons become involved. Finally, the
