296 CLINICAL VETERINARY MEDICINE AND SURGERY. 



charge, by staring of the hair, and by verrucous growths due to hyper- 

 trophy of the papillary layer. Chronic vegetating dermatitis of the 

 foot — canker — produces similar hypertrophic changes in the horn- 

 secreting structures of the sole, principally in the velvety tissue, at the 

 same time destroying a greater or less area of the horny sole. Chronic 

 dermatitis of the coronet — inflammation of the perioplic ring — pro- 

 duces disturbance in the secretion of periople and increases and 

 hardens the superficial layers of skin around the coronet. 



Whilst the latter disease is principally seen in plethoric or nervous 

 patients, the two former (whose development is favoured by the local 

 action of moisture and of urine, etc.) are almost always confined to 

 lymphatic animals, and may be regarded as special morbid conditions 

 having a distant connection with the usual forms of eczema. 



The prognosis of the various forms of eczema in the horse is 

 favourable. In the acute forms recovery is easy and almost always 

 rapid. The chronic forms generally yield to suitable local and general 

 treatment. Mallenders and sallenders, which may also involve lame- 

 ness, are the most obstinate complications. 



In acute eczema the first indication is to thoroughly cleanse and 

 protect the diseased surfaces from irritation. If secretion is abundant, 

 absorbent powders, like simple starch powder, or starch powder with 

 the addition of a little bismuth or oxide of zinc, may be used. Gly- 

 cerine, iodine-glycerine, more or less strong antiseptic solutions, and a 

 large number of ointments have also been successfully employed. 

 The good results obtained from all these agents are easy to explain, 

 inasmuch as we know that in acute eczema recovery occurs spontane- 

 ously in a period seldom exceeding three weeks to a month. Where 

 itching is very severe, ointments or glycerina containing i per cent, 

 of carbolic acid, or analgesic preparations like solutions of cocain may 

 be tried, though the latter require frequent application. 



If the attack is prolonged or recurrent, internal treatment becomes 

 necessary. Arsenious acid. Fowler's solution, alkalies, or even iodide 

 of potassium may be used. In certain cases the diet requires to be 

 changed. 



In chronic eczema the diseased surfaces must first be cleansed, 

 either with water alone or with soap and water, and the process 

 repeated sufficiently often to keep the skin perfectly clean. After 

 drying, the parts may be dressed with vaseline, containing carbolic acid 

 or creolin, or with one of the liniments recommended for the dog. 

 Occasionally it is very useful to apply a surgical dressing for several 



