138 VETERINARY STUDIES 



days. Treat all horses that have been exposed to infection, and 

 watch closely for reappearance of the disease. 



If the horses are halter broken and conditions permit, clip 

 the hair and burn it. Soften the scabs and crusts by a thor- 

 ough application of soft soap well rubbed in over the affected 

 surface. The soap is left on for two or three hours and then 

 washed off. The scab should then be very easy to remove. Allow 

 the skin to dry and apply one of the following treatments. 



Cattle Mange (Barn Itch) 



This is the same general disease as horse mange and sheep 

 scab. Mange causes serious trouble and losses in range cattle 

 and is occasionally a source of serious trouble among farm 

 herds. Breeding herds seem most apt to become affected on 

 account of the most frequent opportunities for introducing it 

 by the purchase of new breeding stock. This disease is rarely 

 fatal in cattle that are well kept; but is a source of financial 

 losses by reason of unthrift. In farm herds it is a serious 

 nuisance, and should not be neglected or ignored. 



Cause. — In cattle there are four types due to Swrcoptes, 

 Psoroptes, and Chorioptes and Demodex. 



The Swrcoptes (burrowing) affect especially the inside of the 

 thigh, root of tail, under surface of the neck and the brisket. 

 The Chorioptes affect chiefly the tail and legs. This form is 

 slow, local and much less important than Psoroptes. Demodex 

 causes small lumps on neck and shoulders from millet to pea 

 size. It is rare and practically incurable. The Psoroptes is 

 most common. This form affects the general body surface, and 

 spreads rapidly. It lives upon the surface of the body and can 

 move about rather freely ; hence the disease spreads more rapidly 

 than the common mange and is easier to cure. The skin irrita- 

 tion and inflammation is due to punctures which the mites 

 make in order to suck their nourishment. 



Symptoms. — Symptoms of cattle mange are similar in a gen- 

 eral way to those shown in sheep scab and mange of horses. 

 With cattle, the disease usually appears first on the neck or 

 shoulder or near the tail, and from these places is spread over 

 other portions of the body. The skin becomes bald, thickened 

 and wrinkled and perhaps badly scratched and sore as a result 

 of rubbing. 



