328 DISEASES OF CATTLE. 



cattle rub the root of the tail and buttocks until the flesh was worn 

 off down to the bones. 



Another cause is found in affections of the liver and of the kidneys, 

 when an increase of effete material has to be thrown off by the skin. 

 Morbid materials circulating in the blood may produce a tickling or 

 smarting sensation of the skin in their passage from the blood to the 

 free surface of the skin. Certain irritating substances when eaten may 

 be excreted by the skin, and coming thus in direct contact with the 

 sensory nerves produce itching. In another class of cases the pruritis 

 may be due to an atrophy, contraction, or hardening of the skin, when 

 the nerves become irritated by the pressure. These conditions may be 

 so slightly marked in a thick skin like that of the ox that they can not 

 be recognized. It is frequently noticed that cattle will rub themselves 

 as soon as they pass from the stable into the open air changing from 

 a warm to a cold atmosphere. Again, we may find an animal which 

 does all its rubbing in the stall. We may look for lice, but fail to find 

 them. These conditions are generally attributable to high feeding and 

 to too close confinement. They may be associated with inflammatory 

 irritation or not certainly we fail to discover any morbid changes in 

 the skin. There is to some extent a delightful sensation produced by 

 rubbing, and it may partly become a habit of pleasure. 



Treatment. We must place our chief reliance upon a change of food, 

 plenty of exercise, and in most cases the administration of an active 

 cathartic 1 to li pounds of Epsom salts, a handful of common salt, a 

 tablespoonful of ginger or pepper, mixed with 2 quarts of water, all 

 of which is to be given at one dose. Afterward half an ounce of hypo- 

 sulphite of soda may be given twice a day for a week, mixed with the 

 feed. For an external application, when the skin is abraded or thick- 

 ened from rubbing, a solution of borax, 4 ounces to the quart of water, 

 may be used. Carbolic acid, ounce to a quart of water, will give 

 relief in some cases. 



INFLAMMATORY DISEASES OF THE SKIN. 

 ERYTHEMA. 



This is the simplest form of inflammation of the skin. It consists of 

 an increased redness, which may occur in patches or involve consider- 

 able surface. The red coloration disappears when pressed upon by the 

 finger, but soon returns again after the pressure is removed. There is 

 seldom much swelling of the affected part, though often a glutinous 

 discharge may be noticed, which dries and mats the hair or forms a 

 thin scale upon the skin. In simple erythema the epidermis alone is 

 affected; when it becomes chronic, fissures form, which extend into the 

 coriuni or true skin. 



Erythema is divided into Erythema simplex, E. chronicum, and E. 

 intertrigo. 



