940 Scabies. 



the body which are covered with long hair, and also the flexor 

 surfaces of the joints. This scab usually begins under the fore- 

 lock, at the back of the poll, under the mane, at the root of the 

 tail, in the intermaxillary space, in the inguinal region, also 

 on the sheath and udder, exceptionally also in the saddle re- 

 gion or on the croup, and from these places it may spread 

 further on to the body and extremities. 



Apart from its varying localization, the symptoms and skin 

 changes correspond with those of sarcoptic scab, and especially 

 in severe cases the two forms of mange are so similar that the 

 differentiation is only possible by a careful examination of the 

 mites. Still the diseased parts of the skin generally appear 

 more sharply circumscribed than in sarcoptic scab (Schin- 

 delka), and the scabs are generally larger. In this disease 

 also emaciation and cachexia make their appearance. 



The development and course of dermatocoptic scab are 

 also similar to those of sarcoptic mange ; its prognosis, on the 

 contrary is generally more favorable, for the mites living on 

 the surface of the skin are more easily and certainly destroyed ; 

 appropriate treatment leads more promptly to recovery, at 

 least in cases which are not excessively severe. 



3. Dermatophagus Scab. The disease known as foot scab 

 always begins on the extremities, and only very exceptionally 

 attacks the trunk or the whole surface of the body (Fambach). 

 It mostly attacks the hind feet, less often the fore feet in the 

 fetlock and pastern joints, whence it spreads up to the hock 

 and knee, and sometimes even further, so that finally the thigh 

 and leg, the shoulder and the neck may be attacked. Long fet- 

 lock hairs and also neglect of skin hygiene favor the localiza- 

 tion of the mites. 



Itching is the first symptom also in this disease; the ani- 

 mals stamp their feet, kick, rub the shin l)one and fetlock re- 

 gion of one leg with the edge of the hoof of the opposite one 

 and gnaw accessible parts. The itching and the unrest caused 

 by it are noticeable especially at night in a warm stable and 

 are frequently considered as a vicious habit. 



The disease of the skin begins wdtli exfoliation and desqua- 

 mation of the epidermis, which gradually leads to the fornuition 

 of large crusts and finally, after months, to hypertrophy of 

 cutaneous tissue ; large transverse folds form on the pillar- 

 shaped ends of the legs, and in exceptional cases horny and 

 papillous growths may be present. 



This form of scab develops very slowly and becomes — in 

 contrast to otlier forms of mange — ^more intense in winter, while 

 in sunnner time it generally improves, of its own accord, to a 

 remarkable degree; with the onset of winter, however, it again 

 assumes a severe form. This is possibly due to the fact that 

 during the cold and damp time of the year a large amount of 

 damp dirt collects on the skin above tlie hoofs which of itself 



