Causes: friction, inside thighs, side of scrotum or mammæ, inner side of elbow, between digits on clipped heels, under harness. Dried sebum, sweat, dust, clay. Pricks with stubble. Symptoms: lameness on starting, abduction, straddling, knuckling, steps on toe. Treatment: abate cause, cleanse, rest, dusting powders, zinc, lycopodium, magnesia, starch, bismuth, alum, lead, morphia, surgeon’s cotton. Carron oil, vaseline, antiseptics.

This occurs where the folds of skin come in contact and rub on each other as between the thighs or beside the scrotum, sheath or mammæ in fat horses and other animals, on inner side of the elbow, between the digits in ruminants, on clipped heels in horses, and under harness. Irritant perspiration and sebaceous matter dried on, and mixed with more or less gritty or septic road dust contribute to it. Drying of clay and mud in the cleft of the frog, or in the interdigital space of ruminants is a common cause, also pricking with stubble.

Symptoms. These are most marked when the animal has been standing with the raw surfaces partially dried and adherent. After moving for some time, and when the surface has been moistened by the exudate there may be little lameness. Until then he moves hesitatingly and stiffly, with the legs abducted or in case of the hind ones straddling. With intertrigo of the pastern or frog, the horse stands on the toe or with the fetlock knuckled forward, and avoids as far as possible a full extension. The same is true of cattle with interdigital intertrigo.

The affected part is hot, perhaps swollen, red, damp and exceedingly tender. Under renewed work, lameness disappears, but becomes worse on standing, and an extensive exudation may occur subcutaneously. If this becomes infected it may result in severe and even destructive lesions, but it usually remains simple and proves readily responsive to soothing and protective treatment. It is most amenable to treatment in dogs and meat producing animals of which no work is required. On the contrary the latter when travelled long distances on foot may suffer severely.

Treatment. First abate the cause. With castile soap wash from the affected part the dried accumulations of sweat, sebum, dust and other matters, remove clay from frog, interdigital space or heels. Rest until the congestion and tenderness subside. Drying applications in the form of dusting powders are usually best: zinc oxide, lycopodium, magnesia oxide, may be dusted in freely after the affected part has been thoroughly exposed and dried. In the absence of these use gloss starch, corn starch, farina or white bismuth. To one or other of these may be added a little alum, lead acetate or morphia. The addition of a layer of surgeons’ cotton is useful, if in a place where it will be retained. Of liquid applications the veterinarians white lotion (zinc sulphate and lead acetate, of each 1 oz. water 1 qt.) is one of the best, being at once sedative and astringent. It may be applied on cotton. Astringent preparations with glycerine are useful but glycerine has the serious drawback of attracting moisture and increasing the secretion when drying is desirable. Carron oil (equal parts of lime water and linseed oil) is most effective and free from this objection. Vaseline alone or medicated with zinc oxide, lead acetate, alum or tannic acid may be resorted to when dusting powders fail. Morphia and camphor have been added when itching is violent.

In intertrigo of the frog or interdigital space the danger of infection from the floor or road is so great that the demand for antisepsis must overcome other considerations. Calomel freely applied to the surface, previously cleansed and dried, is most successful. It may be bound in place by a pledget of cotton and bandage. In other cases alum 5 parts, copper sulphate 1 part, or carbolic acid and tar may be bound to the part.