120 NON-SPECIFIC OR GENERAL DISEASES 



In this chapter parasitic skin diseases produced by insects will 

 not be discussed. 



Falling Out of the Hair and Feathers. — Falling out of the 

 hair and feathers frequently occurs independent of parasitic 

 diseases. This condition does not occur as an independent dis- 

 order, but as a secondary affection. It is due to faulty nutrition, 

 and irritation to the skin. Intestinal diseases, insufficient feed 

 and feed of bad quality are common causes. Animals that are 

 fed a heavy ration, or that lie on dirty, wet bedding frequently 

 lose large patches of hair. Sheep that are dipped in late fall 

 and early winter, or exposed to wet, cold weather may lose 

 a i)art of their fleece. It is not uncommon for animals toward 

 the latter period of pregnancy, or that sweat freely, to lose patches 

 of hair. 



Falling out of the hair heals of itself within a few weeks. 



The 'preventive measures are of special importance in sheep 

 and horses. This consists in avoiding conditions that may lead 

 to alopecia and in correcting the diet. In horses the regions of 

 the mane and tail should be washed with soap, or rubbed with 

 alcohol and spirits of camphor, equal parts. Treatment should 

 be persisted in for a long period if necessary. 



Urticaria, " Nettlerash." — Urticaria is characterized by 

 roundish elevations that appear quickly and become scattered 

 over a part or the whole surface of the skin. They are caused 

 by an inflammatory infiltration of the deeper layers of the skin. 

 Horses and hogs are most frequently affected. 



The causes of urticaria are irritating juices of certain plants, 

 secretions of flies, ants and some caterpillars, irritating drugs, 

 scratching, sweating and the action of cold on a warm skin. It 

 has been observed in connection with the feeding of certain legii- 

 minous feeds and digestive disturbances. Horses that are fat, or 

 putting on flesh rapidly, seem to be predisposed to this disorder. 

 Urticaria may occur in certain infectious diseases. 



The characteristic symptom is the formation on the skin of 



