670 DISEASES OF THE SKIN. 



Treatment. — If very slight, little or no treatment is necessar}''. 

 The parts may be covered over with the lead liniment, and a 

 diuretic given ; but when the vesicles are large, the base in- 

 flamed, and the animal disposed to rub himself, a smart cathartic 

 is to be administered, the parts bathed with the acetate of lead 

 lotion, and should there be excoriations, an ointment of nitrate 

 of silver, ten grains to the ounce of lard, should be used. If the 

 eruption be associated with debility, as is commonly the case 

 in young horses which have passed through an attack of a de- 

 bilitating disease, tonics and good food are to be prescribed. Mr. 

 Erasmus Wilson recommends that when herpes has become 

 chronic, a blister should be applied. 



(3.) URTICAEIA — NETTLE-RASH — SURFEIT. 



This is a frequent form of skin disease in the horse, and con- 

 sists of an eruption of elastic eminences, roundish or oblong in 

 shape, and attended with itching. 



The lumps rise quickly, and upon the greater part of the body, 

 generally beginning upon the neck, and frequently disappearing 

 as suddenly as they come. They are unequal in size ; some like 

 hemp-seed, others as large as beans, and flattened upon their 

 surface. 



The peculiarity of this form of eruption is its suddenness. I 

 have often seen the lumps appear upon all parts of the body in 

 the course of a few minutes. It is caused by some disorder of 

 the digestive apparatus, and is sometimes preceded by colic and 

 diarrhoea. 



A sudden change of diet wdll frequently produce it, and it is 

 not at all uncommon when horses are first fed on grass. It is 

 supposed that poisonous herbs, a draught of cold water when the 

 animal is heated, sudden exposure to cold and damp, and calculi 

 or worms in the intestines, are causes of it. 



Treatment. — As a rule, this is a very simple matter, a mild 

 j)urgative being all that is necessary. Should there be much 

 itchiness — the animal rubbing itself — the skin must be bathed 

 with warm water, dressed with the acetate of lead lotion, and 

 low diet prescribed for a few days. 



Dr. Maclagan reports the analysis of the urine in a case of 

 mticaria, in which there was deficiency of urea and uric acid, 



