146 HEALTH AND DISEASE 



animal is heated, or the sudden movement of an animal from a hot stable 

 to a cold, wet atmosphere. The form of urticaria which arises from 

 dietetic errors is distinguished as urticaria ad ingestis. 



The eruption in this affection occurs very suddenly in the form of 

 flattened, more or less rounded elevations, diftering much in size, the 

 majority of them being something from an inch to two inches in diameter. 

 They commonly occur on the neck, and frequently over a considerable 

 part of the body, and sometimes the head also. The lumps appear very 



quickly, and may be so closely 



^ packed as to run together into 

 ; a single patch the size of a 



|y^'',; : dinner- plate. Sometimes when 



the eruption is scattered, and 

 the lumps are not much larger 

 than a shilling, the disease 

 assumes a chronic form, and 

 is attended with loss of hair 

 from the raised patches. It 

 is curious that the new hair is 

 1 always lighter in colour than 

 the rest of the coat. The 

 \ treatment of the disease con- 

 sists in the administration of 

 i a mild laxative, to be fol- 

 ! lowed by small repeated doses 

 ! of bicarbonate of soda and 

 cliloride of sodium in the food 

 ' iiiiiht and morning. 



Liquor arsenicalis, in doses 

 of an ounce to an ounce and 

 a half, given in the food night and morning, may also be tried Avhere 

 the disease proves obstinate, and failing with this, some vegetable tonic, 

 as gentian and columba root, or quinine, deserve a trial. 



If there is much irritation, a little Goulard water may be applied to 

 the seat of eruption, or a liniment of glycerine and oxide of zinc. 



CATARRHAL INFLAMMATION 



Eczema is the most common disease occurring in the horse, typical 

 of the catarrhal condition of the skin. It consists, in the first instance, 

 of inflammation of the superficial layers of the true skin, with an eruption 



Fis-. 265.— Urticaria 



