160 NON-PARASITIC SKIN DISEASES. 



The best preventive measures are to allow the mud and dirt to 

 remain on the legs until they are thoroughly dry — say, till next 

 morning — and then brush the dust off; and to refrain from washing 

 or clipping the legs. 



Surfeit (Urticaria or Nettle-rash) 



is the term applied to an eruption of small irregular lumps or boils 

 which are more or less painful to the touch, and which break out 

 suddenly, as a rule, on the horse's body and neck, and in rare cases 

 on his limbs. A favourite seat of this eruption in saddle-horses 

 is the bearing surface of the saddle on the upper part of the 

 back, and especially under the cantle ; probably because there 

 is more motion at the cantle than at the pommel, on account 

 of the forward position of the girths. Sometimes, after two 

 or three days, the lumps form scabs, which usually fall of? 

 during the course of a week, and leave behind a hairless 

 and more or less round patch of skin, of, say, a quarter 

 of an inch in diameter. These spots generally remain as 

 permanent marks on the coat. If the inflammation has been sufH- 

 ciently severe to destroy, in a dark-skinned horse, the layer of 

 pigment in the skin of the part, the spots will be white, with, 

 usually, white hairs in them. The destruction of a portion of the 

 pigmentary layer need not necessarily involve that of the contained 

 hair follicles. On a grey or white horse which has a dark skin, a 

 slight attack of surfeit may leave a number of black spots showing 

 through the light-coloured coat. The presence of these painful 

 lumps on the back of a saddle-horse may become known to the 

 rider by the fact of the animal acting, when he is being mounted, 

 as if he had a sore back. 



The usual cause of surfeit is supposed to be the consumption 

 of food which upsets the animal's digestive organs; for the skin 

 being continuous with the mucous membrane of the intestinal canal, 

 a disturbance of the one structure is readily communicated to the 

 other. Apparently owing to the extremely dry nature of the forage 

 during the greater part of the year in South Africa; the horses of 

 that part of the world frequently suffer from surfeit. In men, " the 

 formation of wheals is the special characteristic of urticaria " 

 (^Bristoive). From a consideration of the nature of the attack and 

 course of the disease, I cannot help thinking that surfeit is often 

 of parasitic origin. 



TRExA.TMENT. — Usually, I have had good results from smearing 

 over the lumps and sores with mercurial (blue) ointment. Some- 

 times, putting the affected horse on carrots or green food and giving 



