MANGE. 



573 



scales are detached in great abundance, and the hairs fall out, 

 forming extensive bare blotches. The skin itself becomes thickened, 

 wrinkled, and cracked, and more or less deeply creviced. These 

 cutaneous alterations are accompanied by an intense pruritus, which 

 becomes intolerable in hot stables or near the fire, also after various 

 kinds of excitement and exertion. In order to reduce it, the ani- 

 mals scratch themselves constantly; rubbing performed with the 

 fingers upon the diseased regions gives them a relief which they 

 show by moving one of their hind legs, the movements of which are 

 synchronous with those of the hand. When the trouble is old and 

 generalized the dogs lose flesh. Weak subjects may succumb. 



Diagnosis. The most important diagnostic symptoms are : 

 intense itching, localization of the disease upon the head, its rapid 

 extension, its transmissibility to other species and to man, wrin- 

 kling of the skin and depilations, also the accumulation of squamae 

 and formation of scabs, the tendency of the eruption to settle on 

 the ears, the lower pectoral region, the belly, elbows, the inner 

 aspect of the thighs, etc. Here again, however, the only charac- 

 teristic symptom is finding the sarcoptes, by microscopical exam- 

 ination, in the product which is taken from the affected regions. 

 This is quite difficult ; as a rule, the parasites are located deeply in 

 the skin, and in order to reach these we must not only remove the 

 scabs, but also the superficial layers of the integument. It has to 

 be scratched by means of a very sharp bistoury till the appearance 

 of blood, or we may make superficial cuts upon it with a pair of 

 scissors. The movements of the acari may also be influenced; 

 they may be attracted upon the surface of the skin through heat ; 

 to effect this the animals may be placed near a fire, in addition 

 being covered with a woollen blanket, etc. In some cases, espe- 

 cially when thick scabby blotches have formed, the parasites are 

 easily found. As a last diagnostic method, we may try the appli- 

 cation of scabs upon a man's arm. (The sarcoptes are easily found 

 on a dead animal.) 



Differential diagnosis. Sarcoptic mange may be confounded 

 with follicular mange. Both are contagious and are marked by an 

 eruption of pimples, falling out of hair, and abundant epidermic 

 exfoliation, etc. The main differences are : the intensity of the 

 pruritus and the rapidity of healing in sarcoptic mange ; a par- 

 ticular pustulous character and an extremely easy recognition of 

 Demodex in follicular mange. 



