Chapter 14

The acute form is generally ushered in very suddenly. Often a horse that is perfectly free from symptoms of the disease is found a few hours later so stiff and sore that he will scarcely move. They stand like they were riveted to the ground. If forced to move the evidence of pain subsides to some extent after they have gone a short distance, to return more severe than ever after they have been allowed to stand for a short time. If the disease is confined to the two front feet, the hind feet are placed well under the center of the body to support the weight and the front ones are advanced in front of a perpendicular line so as to lessen the weight they must bear. If they are made to move, the same position of the feet is maintained. If made to turn in a small circle, they do so by using the hind feet as a pivot, bringing the front parts around by placing as little weight on them as possible.

Placing the hind feet so far under the body, arches the back and often leads to errors in diagnosis, the condition sometimes being taken for diseases of the loins or kidneys.

If all four feet are involved, the animal stands in the usual position assumed in health, but if urged to move, the least effort to do so usually brings on chronic spasms of the entire body. In very severe cases, a slight touch of the hand will develop the spasms. At times they are so severe, and have such short intermissions, that the disease has been mistaken for tetanus. However, the clonic nature of the spasm should prevent such an error. If they are lying down, it is difficult to get them to arise, and if they do so, they show marked symptoms of pain for some time after rising.

If the disease is confined to the hind feet, they are placed well forward to relieve the strain on the toe caused by the downward pull of the perforans (deep flexor) tendon, but in place of the front feet being kept in front of a perpendicular line, as they are when the disease is confined to the front ones, they are placed far back under the body, so they will carry the maximum share of the body weight of which they are capable. The position of the feet is of great importance and offers symptoms that should not be overlooked.

When the subject is caused to walk, symptoms of excruciating pain are manifested in all acute cases of laminitis. In some cases where all four feet are affected, no reasonable amount of persuasion will cause the suffering animal to move from its tracks.

There is acceleration of the rate of heart action; the pulse is full and in some cases, bounding. As the affection progresses the pulse becomes rather weak and irregular. The character of the pulse in the region of the extremity is a reliable indicator; but one has to learn to make necessary discrimination because of the condition of the parts, as in some cases of lymphangitis or where the skin is abnormally thick. The characteristic throbbing pulse is, however, easily recognized in most cases. Temperature is variable, though usually elevated from one to four degrees above normal. This symptom varies with the type and stage of the affection. In a subject that has been down, unable to rise for several days, where there is a suppurative and sloughing condition of the laminae, the temperature is high. Whereas, in some other and less destructive cases there may be little thermic disturbance after the first few hours have lapsed.

A constant symptom in bilateral affections of acute laminitis is the difficulty with which the subject supports weight with one foot. It is this which causes the victim to stand as if "rooted to the ground" when all four feet are involved. If one attempts to take up one foot, thus causing the subject to stand on the other, there is much resistance and in many cases the animal refuses to give the foot.

When we consider that the sensitive parts of the foot are encased by a horny, unyielding box and that, when the laminae are congested, a great pressure is brought to bear upon the sensitive structures, it is easy to understand why the condition is so painful.

_Chronic laminitis_ is a sequel of acute inflammation of the sensitive laminae. It varies as to intensity and the exact manner of its manifestation depends upon preëxisting disturbances.

In some mild cases of laminitis there are recurrent attacks wherein no particular structural change exists, and diagnosis is established chiefly by noting the character of the pulse at the bifurcation of the large metacarpal (or metatarsal) artery just above the fetlock. The same manifestation of pain is present when weight is supported by one foot, though in a lesser degree. There is less local heat to be detected by palpation than in the acute cases.

Chronic laminitis as it occurs following acute attacks which have resulted in structural changes of the foot, present the same symptoms just described and, in addition, the peculiar alterations in structure exist. When, owing to acute inflammation of the sensitive laminae, there has resulted necrosis of this sensitive tissue together with infiltration between the anterior surface of the distal phalanx (os pedis) and the contacting hoof, the lower portion of the distal phalanx is turned downward and backward (rotated upon its transverse axis). Because of the traction which is exerted by the deep flexor tendon (perforans), as it attaches to the solar surface of the distal phalanx, this rotation is facilitated. With hyperplasia of lamina, at the anterior portion of the distal phalanx, there results a thick "white line." Rotation of the distal phalanx necessitates a descent of its apical portion and there occurs a "dropped sole."

In time, partly because of excessive wear of hoof at the heel, owing to an altered condition in the normal antagonistic relation between the flexor and extensor tendons, the toe makes an excessive growth, and the concavity of the anterior line is accentuated owing to this abnormal length of hoof. The hoof, because of recurrent inflammatory attacks, is corrugated--elevations of horn in parallel rings are usually present.

Animals that are so affected in traveling strike the heel first and the toe is later contacted with the ground surface. Rotation of the distal phalanx upon its transverse axis produces a condition, with respect to this peculiar impediment, that is equivalent to added and excessive length of the deep flexor tendon.

Where there occurs suppuration, by careful inspection of the coronary region, one may early recognize detachment of hoof. In such cases animals remain recumbent and, while the condition is not so painful at this stage, the practitioner must not overlook the real state of affairs. History, if obtainable, will be a helpful guide in such cases. Separation of hoof occurs as a rule in from four to ten days after the initial attack of acute laminitis. Needless to say these cases are hopeless, when the economic phase of handling subjects is considered.

Treatment.--Much depends upon the concomitant disturbances (or causes if one is justified in referring to them as such) as to the manner in which laminitis is to be treated. In all cases where digestive disturbances exist, the prompt unloading of the contents of the alimentary canal is certainly indicated. D.M. Campbell[31] in a discussion of laminitis has the following to say regarding the treatment of such cases:

Because superpurgation may be followed by laminitis, the advisability of using the active hypodermic cathartics is questioned. Neither arecolin nor eserin can cause superpurgation. The action of the former does not continue longer than an hour after administration and of the latter not more than eight hours. The action of either is mild after the first few minutes.

I do not think that anyone has recommended either arecolin or eserin where there is severe purgation. Where the intestinal canal is fairly well emptied and its contents fluid, I should be inclined to rely upon intestinal antiseptics to hold in check harmful bacterial growth.

The use of alum in the treatment of laminitis is held to be without reason other than the empirical one that it is beneficial. If laminitis is due chiefly to an autointoxication, good and sufficient reason for the administration of alum can be shown based upon its known physiological action. It is the most powerful intestinal astringent that I know of and has the fewest disadvantages. I have not noted constipation following its use nor diarrhea, nor a stopping of peristalsis, nor indigestion, and in any case its action lasts at most only a few hours, and if it did all these, it could not much matter. Quitman says, that it constricts the capillaries. If this is true, a thing of which I am not certain, is it not reasonable to suppose that as with other vaso-constrictors, e.g., digitalis, there is a selective action on the part of the capillaries (not of the drug) and those that need it most, i.e., those of the affected feet in laminitis, are constricted most? All body cells exert this selective action in the assimilation of food, the tissue needing most any particular kind of food circulating in the blood, gets it.

Our first consideration in laminitis should be to remove the cause--to stop the absorption of the toxin in the intestinal tract that is producing the condition. This we accomplish by partially unloading it by the use of the active hypodermic cathartics and stopping absorption by the surest and most harmless of intestinal astringents. Whether the astonishingly prompt and certain action of alum in this case is due wholly to its astringent action or whether alum combines with the harmful bacterial products chemically and forms an innocuous combination, I can only surmise, and it is unimportant. At any rate, when alum is administered, the onslaught of the disease is promptly stopped. Irreparable damage may already have been done if the case is a neglected one, but whether administered early or late in acute attacks, the progress of the disease is stopped immediately.

The same authority may be profitably quoted in the matter of handling all cases wherein the revulsive effect of agents which diminish vascular tension are chiefly indicated or necessary as adjuvants. In this connection, Campbell says:

The early and vigorous administration of aconitin in laminitis to its full physiological effect, is more logical. Assuming that laminitis is due to absorption of harmful products from the intestinal tract permitted through the deranged functioning of the organs of digestion, or assuming that it is due to an extension of the inflammation from the mucosa to the sensitive lamina, or that it is a reflex from a sudden chilling of the skin, we have in any of these conditions a disturbed circulation, and aconitin is the first and foremost of circulation "equalizers." Furthermore, in laminitis there is an elevation of the temperature, an almost invariable indication for aconitin. A speedy return of the temperature to normal, a very marked diminution of the pain and improved conditions generally, appear coincident with the symptoms of full physiological effect of aconitin when given in cases of laminitis, which constitutes assuredly an important part of its treatment.

Where lameness is not great as in cases wherein no marked structural change of the foot has occurred, proper shoeing is very beneficial. By keeping the heels as low as possible and shoeing without heel calks a more comfortable position is made possible. Thin rubber pads which do not elevate the heel are of service in diminishing concussion.

Dr. David W. Cochran of New York City has attained unusual success in cases of chronic laminitis with dropped sole by the use of a specially designed shoe.

Cochran claims that, not only are horses with dropped soles that would otherwise have to be put off the streets enabled to do a fair amount of work by means of this shoe, but that continually wearing it, meanwhile keeping the convexity of the front of the hoof rasped thin, in time brings about a marked improvement, and that after some months or years of use the animals are able to work with ordinary rubber-pad shoes, provided they are arranged to facilitate breaking over.

From having been successfully used on some race horses of high value, the Cochran shoe has attained considerable notoriety and is being used by a number of practitioners. A disadvantage, however, arises from the fact that few horseshoers other than Doctor Cochran seem able to make the shoe, the peculiar shape of which offers considerable difficulty in forging. Concerning the application of the shoe Cochran[32] says:

"The most important primary procedure is the preparation of the foot to receive the shoe. All excess of growth must be removed from the anterior face of the hoof. The outer face must be reduced at the toe (not shortened), but rasped down thin for the lighter the top of the foot is, the more chance the sole and coffin bone will have of resuming their former normal position. The pressure of the wall at the toe upon the exudate between wall and coffin bone, tends to force the coffin bone and sole out of their normal position. Leave the sole alone. You can lower the excess of growth at the heels.

"There are many designs of shoes to relieve this condition. A great deal depends on the judgment of the shoer to meet the conditions presented, depending on the degree of the convexity and strength of the sole. In some cases we use a shoe that admits of a large amount of sole room. Again, we shoe with a shoe of wide cover. In other cases a shoe with even pressure over the whole sole. In some cases a high, narrow shoe, resting only on the wall, or the ordinary plain shoe with side calks welded close to the outside edge and the shoe dished well from these as a foundation. Then we have the air cushion pad designed after the model of the bowl shoe."

In cases when slight and persistent lameness interferes sufficiently to prevent using an animal at any sort of work on hard roads, median neurectomy will relieve all lameness in most instances. This is a safe operation, moreover, in that no bad after effects are to be feared, even though lameness were to continue.

Calk Wounds. (Paronychia.)

Etiology and Occurrence.--Injuries of various kinds are inflicted upon the coronary region but usually they are due to the foot being trampled upon. When the foot that inflicts the injury happens to be unshod, a contusion of the injured member is occasioned, but in the majority of instances, wounds that demand attention are the result of shoe calks which have penetrated the tissues in the region of the coronary band. Often calk wounds are self-inflicted. When animals are excited and in turning crowd one another, they often perform dancing movements which frequently result in deep calk wounds of the coronet. Some horses have a habit of resting the heel of one hind foot upon the anterior coronary region of the other. While sleeping in this position, if they are suddenly awakened, the weight is abruptly shifted to the uppermost foot and the one underneath is (because of the pain attending its being wounded) quickly drawn out from under its fellow. In this way deep cuts may divide the coronary band and inflict extensive injury to the sensitive lamina as well.

An infectious type of coronary inflammation occurs in some localities during the winter months, wherein the condition is enzootic.

Symptomatology.--Depending upon the manner in which the injury has been produced, the appearance of the wound varies and likewise lameness is more or less pronounced. If the tissues are not divided and the wound is chiefly of the subsurface structures, there will not immediately occur pronounced local evidence of the existence of injury; but as soon as the lame animal is made to move, the peculiar character of the impediment (supporting-leg lameness with the affected foot kept well in advance of its normal position) directs attention to the extremity and all of the symptoms of acute inflammation are discovered.

Where a wound is inflicted which divides, in some manner, the surface structures (skin, coronary band, or the hoof wall) one's attention is at once called to the existence of the wound.

Because of the fact that there is every facility for the production of a sub-coronary and podophylous infection, these wounds should receive prompt attention. In some instances, the pastern joint is opened by calk wounds and then, of course, an infectious arthritis succeeds the injury.

Treatment.--In all contused wounds of the coronary region the parts need thorough cleansing; the hair, if long is clipped and a cataplasm is applied. Or preferably, an iodin-glycerin combination of one part of iodin to four parts of glycerin is poured on a layer of cotton, and this is confined in contact with the inflamed parts by means of a bandage.

Where normal resistance to infection obtains, the subject usually suffers no suppurative disturbance when the surface structures are not broken; and daily applications of the antiseptic lotion above referred to stimulates complete resolution. This may be expected in from four to ten days depending upon the extent of the injury.

If a calk wound has been inflicted, the adjoining surface structures are freed of hair and the parts cleansed in the usual manner, (which in wounds recently inflicted, should be done without employing quantities of water) and after painting the wound surface with tincture of iodin and saturating its depths with the same agent, the wound is cleansed, if it contains filth, by means of a small curette. By using a small and sharp curette, one is enabled to cleanse the average wound quickly and almost painlessly.

In such cases, equal parts of tincture of iodin and glycerin are employed. The wound is filled with this preparation and a quantity of it is poured upon a suitable piece of aseptic gauze or cotton and this is contacted with the wound. The extremity is carefully bandaged and this dressing is left in position for forty-eight hours unless there occurs, in the meanwhile, evidence of profuse suppuration--which is unusual.

One is to be guided as to the progress made by the degree of lameness present. If little or no lameness develops, it is reasonable to expect that infection has been checked; that the wound is dry and redressing every second day is sufficiently frequent.

Where cases progress favorably, recovery (unless infectious arthritis results) should occur in from ten days to three weeks. Where extensive sub-coronary fistulae result, either from lack of prompt or proper attention, the condition is then one requiring a radical operation to establish drainage and to disinfect if possible, the suppurating tissues.

Corns.

Etiology and Occurrence.--In horses, because of a tendency toward contraction of the heel in some subjects, together with work on hard roads and pavements, where the feet become dry and brittle, and because of neglect of the matter of shoeing, this affection is of frequent occurrence. Unshod horses are rarely affected. If conformation is faulty and too much weight is borne on the inner or the outer quarter, and the hoof wall at the quarter tends to turn inward, corns are usually present. They occur more frequently on the inner quarters of the front feet, though the outer quarters are occasionally also affected and in rare instances corns are found at the toes. They do not often affect the hind feet.

As soon as injury by pressure, such as is supposed to cause the formation of corns, is brought to bear on the sensitive sole, an extravasation of blood occurs. In time when the cause remains active, this discoloration is evident in the substance of the insensitive sole and consists in a red or yellowish spot which varies in size--this is ordinarily termed dry corn.

In some cases where infection of this extravasation of blood and serum occurs, instead of desiccation and discoloration of the insensitive parts, there is, in time, manifested a circumscribed area of destruction of the insensitive sole and the abscess may, where no provision for drainage exists, burrow between sensitive and insensitive laminae and perforate the tissues at the coronet. If the suppurative material discharges readily by way of the sole, no disturbance of the heel or quarters occurs above the hoof.

Symptomatology.--A supporting-leg-lameness characterizes this condition; and this lameness in most instances varies in degree with the amount of distress which is occasioned by pressure upon the inflamed parts. By an examination of the sole after having removed all dirt, and exposed the horny sole to view, no difficulty is encountered in locating the cause of the trouble.

Treatment.--Before suppuration has taken place and in the cases where suppuration does not occur, the horse-shoer's method of paring out the diseased tissue affords a means of temporary relief; but unless frequently done, in many cases, lameness results within about three weeks after such treatment has been given. In other instances temporary relief is not to be gotten in this manner for any great length of time or until a more rational mode of treatment becomes necessary so that the subject may experience a cessation of the inconvenience or distress.

The general plan which meets with the approval of most practitioners consists in careful leveling of the foot and removing enough of the wall and sole at the quarters to make possible frog pressure by means of a bar shoe. With frog pressure, expansion of the heel follows in time, and permanent relief is obtainable in this manner. Thinning the wall of the quarter is advocated by many practitioners and is undoubtedly beneficial in chronic cases where marked contraction has taken place. The wall must be thinned with a rasp until it is readily flexible by compressing with the thumbs.

There are instances, however, where corns and contraction of the heel have existed so long that they do not yield to treatment. Such cases are found in old light-harness or saddle-horses that have been more or less lame for years and where there exists marked contraction of the heels, rough hoof walls, and hard and atrophied frogs.

Suppurating corns require surgical attention in the way of removal of the purulent necrotic mass and making provision for drainage. Dry dressings, such as equal parts of zinc sulphate and boric acid, may be employed to pack the cavity. After the infectious condition has been controlled, and the wound is dry, the same plan of treatment is indicated that is employed in the non-suppurating corn. Ample time is allowed, however, for the surgically invaded tissues to granulate and, if the subject is to be put in service, a leather pad, under which there has been packed oakum and tar, affords good protection.

Quittor.