90 DISKASaS OST DOGS. 



more difficult, as the parasites are hard to reach. This mite is 

 identical with a parasite found in the human skin causing some 

 disfiguration of the face, but further than that it does no harm 

 until transferred to the dog, when it causes a most repulsive 

 disease, and one very difficult to eradicate. 



Some few years ago Mr. Wm. Hunting, F.R.C.V.S., in con- 

 junction with Professor Duguid, made a series of investigations 

 and experiments in elucidation of this disease, and the following 

 description of symptoms and the diagnosis are from an article by 

 the former gentleman, which appeared in the Veterinary Journal, 

 and afterwards in pamphlet form : 



" The symptoms of the disease are seldom seen in the first stages ; 

 they consist merely of circumscribed spots from which the hair falls, 

 and upon which are noticeable a few small pimples. These patches 

 extend rapidly, and fresh ones appear on other parts. Any portion 

 of the skin may be affiscted, but the head, legs, belly, and sides, are 

 usually the seat of the disease. The affected places are almost 

 hairless, and what hair remains is easily puUed out ; small pimples 

 and pustules stud the surface, the latter varying in size from a pin's 

 head to that of a pea. The confluence of the pustules, and the 

 discharge of their contents, give rise to scabs; these crack and 

 bleed, and so produce a most repulsive appearance. In white-haired 

 dogs the skin is red ; in all it is extremely hot, and emits an un- 

 pleasant odour. The irritation does not excite much scratching, 

 but the dog frequently shakes himself. More pain than itching 

 seems to accompany the disease. In cases where the whole body 

 is affected, loss of condition is most marked ; and in cold weather 

 the almost total loss of hair may cause death, if the animal be not 

 kept in a warm place. This stage, too, is always accompanied by 

 ravenous appetite, due, probably, to the rapid loss of animal heat. 



" Diagnosis. — In white dogs the colour of the skin may cause the 

 disease to be mistaken for ' Red Mange ' or ' Eczema. ' The 

 circumscribed spots in the first stages may be confounded with some 

 forms of Tinea ; and the loss of hair and the presence of scabs seen 

 in the fully developed disease may easily be mistaken for ordinary 

 scabies. The pustules, the heat of the skin, and the comparatively 

 slight itchiness shown, are, however nearly diagnostic. Positive 

 diagnosis can only be made by the aid of the microscope and the 

 detection of the parasite. 11 we puncture one of the pustules, and 

 mix its contents on a slide with a little water, the acari are easily 

 discovered. I have found as many as thirty to one pustule. 

 Sometimes we may detect them on the root of a hair removed from 

 an affected spot. With a low power, the parasites scmewhat 

 resemble sprats or minnows, but a higher power shows them to 



