GANGRENOUS DERMATITIS. 919 



In the neighbourhood of the coronet, the process may extend to the 

 coronary band, and produce severe inflammation, followed by 

 separation of the hoof. 



Prognosis depends on the extent, position, and character of the 

 disease. The larger the necrotic piece of skin, the greater the 

 difficulty of treatment, and the danger to deeper-lying structures. 

 Necrosis near the coronet threatens the pedal-point, in the pastern 

 the sheath of the flexor tendons. Implication of tendon sheaths 

 at once renders prognosis unfavourable. The same is true of a 

 complication like septicaemia ; in this case the swelling rapidly extends 

 upwards, often to the elbow or stifle, becomes very painful, and is 

 accompanied by high fever. The continuance of great pain after 

 the necrotic portion of skin has separated is an ominous symptom. 



Treatment. As a preventive measure, the pasterns in winter, 

 and especially during thaws, should be kept as dry as possible, and 

 care taken to protect them from the street mud, which macerates 

 the epithelium, and favours infection and necrosis. The hair on 

 the fetlock, and especially on the back of the pastern, may be 

 anointed with a neutral fat like vaseline or lanolin, so as to keep off 

 mud and water. This precaution can be strongly recommended. 

 For a similar reason, the feet should be carefully cleansed after work, 

 and if possible dried. As urine and stable manure also have a very 

 injurious action, cleanliness in the stable should be insisted on, and 

 after the floor has been swept a dry disinfectant powder should be 

 used. Holes in the floors, in which urine accumulates, must be 

 filled up. If horses with injuries like cracks or fissures of the heels are 

 kept at work, the wounds should be carefully cleansed and smeared 

 with tar or creolin ; and if the external temperature be below the 

 freezing-point, a dressing may be applied. 



If necrosis has already set in, its further progress may be prevented 

 or checked by placing the parts in a lukewarm bath of sublimate, 

 iodine, or carbolic solution, with which the affected spot may be 

 frequently washed. At night a bandage should be used, moistened 

 with camphor, or 10 per cent, chloride of zinc solution. Moller 

 had excellent results from applying 1 to 3 per cent, solution of 

 pyoktanin to the diseased spot by means of a mass of tow, fixed in 

 position by a bandage. 



It is of importance to hasten separation of the necrotic piece of 

 skin ; and if the entire piece cannot immediately be removed, loose 

 portions at least should be cut off with scissors. The granulations are 

 generally very abundant, and, being irritated by movements of the 

 limb, are apt to become excessive and irregular. In such cases 



