108 DR. LEGEAR'S STOCK BOOK. 



or scabies, iteh. etc-. It is transmissible from animal to animal, 

 and from one species to another. The parasites burrow down 

 into the flesh, and are found in the horse, man. sheep^ plus, 

 and cattle, and are also common to many other smaller animals. 

 Besides the sarcoptes, there is another kind called "dermato- 

 dectes," signifying "the skin," and "to prick." The dermato- 

 dectes do not burrow beneath the skin, but simply hold on to 

 and prick the skin. They are common to the ox, horse, and 

 sheep. Another variety is known as "symbiotes." They neither 

 burrow nor prick the skin, but cause considerable irritation, and 

 are common to the horse and ox. Certain conditions appear 

 favorable to the attack of the sarcoptic kind. A horse poorly 

 cared for, badly groomed, and in an unthrifty state generally, is 

 in a favorable condition for the reception of the disease. - The 

 attack of the sarcoptes is at first slow, but having once fairly 

 secure a start, they spread with great rapidity, irritating the 

 skin and sometimes destroying the animal. (Fig. 15.) 



The dermatodectes are far less troublesome than the sarcoptes. 

 The symbiotes are often found affecting the legs of horses, set- 

 ting up considerable irritation or itching, and causing the animal 

 to rub and scratch the parts. The parasites mentioned are those 

 causing mange, although of the three families named, the sar- 

 coptes is probably the one oftenest met with in mange, and most 

 certainly is the one causing the worst form of the disease; either 

 variety may be conveyed from one animal to another by means 

 of the harness, saddle, clothing, etc. The dermatodectes can in 

 some cases be easily detected by the naked eye, and either variety 

 can of course be readily discovered by the glass, an ordinary 

 magnifying glass in most cases being quite sufficient. During 

 t imes of war mange is usually quite common. As a general thing 

 the disease is not so very common on the American continent. 



Mange in every instance is caused by coming into contact with 

 affected animals, or infected clothing, harness, etc. At the same 

 time it should be remembered that dirty, badly groomed and 



