Circular 338, U. S. Department of Agriculture 



scrapings should be softened b}' soaking in a solution of caustic soda 

 or caustic potash for half an hour or more, the strong solutions 

 acting more rapidly than weak ones, and then placed on a glass slide 

 under a cover glass and examined with the low powers of the micro- 

 scope. Whenever possible this examination should be made by a 

 competent veterinarian or zoologist, as these mites are frequently 

 difficult tO' detect. The finding of the mites is sufficient to confirm 

 the diagnosis of mange, but failure to find mites, while it establishes 

 a presmnption that the disease is not mange, does not prove the 

 case, as the mites may be overlooked or not reached by the scraping. 

 Symptoms. — Sarcoptic mange affects dogs of all ages and all 

 breeds. It usually begins about the head and may spread over the 



entire body in the course of a 

 month. It appears first in the 

 form of red points which soon 

 become papules or vesicles, most 

 easily seen where the skin is 

 thin and without pigment, as 

 on the abdomen. As the mite 

 burrows into the skin it causes 

 irritation and there is an exu- 

 date of serum. As this con- 

 stant flow of serum dries it 

 forms the characteristic scab. 

 Simultaneously this irritation 

 gives rise to itching, which be- 

 comes intense in the presence 

 of heat or after exercise, and 

 the animal scratches and rubs 

 the affected portions of the 

 body. In doing so it rubs off 

 the scabs and opens up sores. 

 Bacterial infection of these 

 areas may add to the inflam- 

 mation and injury resulting 

 from the presence of the mite 

 mSiuremSftJ? ^^d the scratching. The hair 

 also may become matted and 

 fall out. There is evidently 

 more or less toxic absorption 

 from the mites or from the diseased skin, as shown by a blood 

 reaction in the form of an eosinophilia, a condition frequently 

 associated with parasitism, and the presence of the toxins and the 

 loss of nervous energy due to constant itcliing and irritation cause 

 the animal to become Aveak and thin. The skin may show large 

 sores, and the mang}^ or " mousy " odor becomes A^ery pronounced. 

 A general impairment of digestion and other body activities follows 

 and if the disease goes unchecked tlie animal dies, usually in two 

 or three months under conditions favorable to the disease. The 

 term "mangy dog" as an expression of reproach shows the general 

 appreciation of the extremely ])itiable condition and apparent Avorth- 

 lessness of such an animal. 



Treatment, — A great aid in the treatment of mange is the use of 

 such measures as Avill build up the general health and resistance of 



Fig. 1. — The canine sarcoptic mange mite 

 kiurcoptes scabiei canis. A'entral view. Fe 

 male. Enlarged. From 

 Flierstenberg. (Micron 



Male, 100 to 250 long by 140 to 180 wide 

 female, 290 to 450 long by 230 to 350 

 wide.) 



