Treatment. In all cases the cause must be done away with, whether filthy stalls, reeking dunghills, septic pools, work in irritating road mud, or melting snow, washing the heels with caustic soaps, drying them in cold draughts, pricking with stubble or clipped hairs, and all the causes of stocking of the limbs. If heels are washed, use pure tepid water, and, if necessary, the best Castile soap, and rub them dry at once. If this cannot be done bandage them rather than leave them in a cold draught.
Give rest in a clean stall and thoroughly clean the affected heel, then wrap in a bandage wet with an acetate of lead or sulphate of zinc lotion (1 ∶ 50), or apply benzoated oxide of zinc, or cream of glycerine and salicylic acid.
When chaps have formed they will often promptly heal under standard solution of sulphurous acid 1, glycerine 1, and water 1. This is applied on soft cotton and covered by a rubber bandage to confine the acid. The sulphurous acid solution should be recently prepared, since it will prove injurious if it has oxidized into sulphuric acid. To one or other of these preparations the addition of a little carbolic acid, creolin, pyoktannin, or lysol will often prove useful. When the cracks have healed, zinc ointment, chrysarobin ointment, chrysophanic acid 1, vaseline 15, or other soothing and antiseptic agent may be employed till all inflammation has subsided, and the animal must not be returned to work until the skin has been restored to its former healthy and elastic condition.
It may be desirable to greatly restrict the grain during treatment and even to giving cooling laxatives or diuretics. With a constitutional diathesis arsenic or other alterative may be tried, and any internal disease must be attended to. For stocking, use careful bandaging, hand-rubbing and exercise.
With the formation of the deeper fissures the same antiseptic agents may be employed, or salol, iodoform, glutol, aristol, or some tincture of iodine, or iodide of starch may be used. A weak solution of copper sulphate has often an excellent effect. The measures advised below for grease will usually apply in this condition.
SEBORRHŒA OF THE DIGITAL REGION: DIGITAL IMPETIGO, GREASE: STREPTOCOCCIC DERMATITIS IN HORSES.
A sequel of erythema or cracked heels. Causes: constitutional predisposition in lymphatic draught horses, rare in ass and mule, anatomical conditions, wet damp regions, digestive disorder, overfeeding and lack of exercise, diseases of liver or kidney, change to stable life, cold water, slush, mud, salted snow, steaming manure, urine in mares, infection, streptococcus pyogenes. Symptoms: swelling, heat, and tenderness of pastern hollow, itching, hairs erect, unctuous exudate, vesicles, excoriations, discharge opaque, grayish, sticky, fœtid, chaps, knuckling, resting on toe, kicking: in severe cases discharge purulent, more opaque, sloughs, excessive granulations, “grapes,” extensions forward, upward, downward, canker, quittor, sand crack, etc. Lesions: first, congestion of derma, hair follicles full, hairs loose, connective tissue infiltrated, or thickened, ligaments: and bones involved, grapes in superposed clusters pediculated. Diagnosis: from horsepox. Treatment: remove causes, secure cleanliness, laxative, diuretics, moderate grain ration, or tonic regimen; locally, soothing antiphlogistic, antiseptic treatment, lead, zinc, phenol, creolin, lysol; when advanced, antiseptic dusting powders, calomel, salicylic acid, iodine, zinc oxide, salol, or solutions, zinc chloride, tar. Value of changes. For “grapes” actual cautery, excision, ligature.
This may develop as an advanced condition of the erythema or cracked heels already described. Yet it is so distinctive in its habit of profuse secretion, the eruption of vesicles or pustules and the abundant, fœtid sebaceous discharge that it deserves a special consideration.
Causes. Something depends on constitutional predisposition. This is preëminently a disease of the heavy, lymphatic, draught horse, being rare in racers and trotters, with fine sinewy limbs, no long hair on the fetlock, delicate skins, and less abundant sebaceous glands. It is almost, though not quite, unknown in the spare limbs of ass and mule, and though claimed by Reynal as attacking cattle its occurrence is equally rare in them. Much of this may be attributed to conformation. The limb of the draught horse is so much thicker and coarser, with a great excess of connective tissue and lymph plexus which become readily gorged in idleness, inducing stocking, congestion and debility of the whole limb. This same condition operates as a powerful predisposition to lymphangitis. Again the great length and profusion of the long hairs, entails the necessary compliment of an excessive development of the sebaceous glands which become over-stimulated by congestion, and afford a much more open and favorable infection atrium for the pus microbes. These structural conditions are much more marked in the draught horses of wet regions as in Ireland, the western counties of Great Britain, Belgium, Holland, and the Atlantic provinces of France, and in these the affection is remarkably prevalent. In our Eastern States and on the Plains, where the progeny of imported draught horses lose their digital hair, the malady is comparatively rare. A similar immunity has long been noticed in the horses of Spain and Africa. Disturbances of the digestion in heavily fed horses, subjected to transient confinement in the stall, and diseases of the liver and kidneys, must be recognized as further predisposing causes. The age of five and six when many horses change hands, and are subjected to extreme changes of stabling, feed and work, has furnished the greatest number of cases.
External causes we find in all those conditions already enumerated which favor chapped heels. Wet, mud, gritty masses, irritant fumes of manure, cold, heat, filth are potent factors. In connection with these are the pus and septic microbes that are always present in stables, farm yards, manure, street dust, etc. No one of these can be adduced as the constant and exclusive cause, and it is inevitable that a complex infection should be present, yet the propagation and persistence of the disease may often be connected with the streptococcus pyogenes.