294 CLINICAL VETERINARY MEDICINE AND SURGERY, 



present. Trifling suppuration occurs, raising and detaching the crusts, 

 which carry with them a portion of the hairs covering the skin at that 

 point, and thus produce the bare surfaces seen during the final stage 

 of the eruption. The crusts having fallen suppuration ceases, the 

 dermis again becomes covered with a thin dry layer, under which the 

 epidermis re-forms, and the skin gradually resumes its normal ap- 

 pearance. 



Some weeks ago you saw in an eight-year-old cart-horse a remark- 

 able outbreak of generalised eczema. The skin of the trunk was dotted 

 over with small greyish circular crusts a few millimetres in thickness, 

 over which the hairs were glued together in tufts. The disease had 

 appeared about ten or twelve days before. This horse first showed 

 loss of appetite and depression, followed by the sudden eruption of 

 vesicles over a wide surface. When brought here we noted nothing 

 abnormal save the cutaneous disease ; neither the animal's general 

 health nor the various functions were in the smallest degree disturbed ; 

 not even the mucous membranes showed anything unusual. 



Successive attacks of an acute or subacute character may develop, 

 a fresh eruption occurring before the disappearance of the preceding, 

 so that lesions of varying age are often associated and combined, 

 forming a complex polymorphic clinical picture. In some cases the 

 skin finally becomes almost entirely covered with crusts. 



Instead of thus extending, eczema may be limited to certain 

 regions. It is commonest in those exposed to mechanical irritation, 

 like the head, withers, front of the shoulders, back, croup, and girth, 

 where the different portions of the harness exercise pressure and 

 continual friction ; behind the elbow, or in the groin, where the folds 

 of skin, which are frequently covered with sweat, produce mutual 

 friction during movement ; on the flexion surfaces of the joints of limbs, 

 especially the lower joints, where the skin forms- folds and is ex- 

 posed to the action of wet or mud, or is covered with scurf, dust, or 

 manure ; on surfaces covered with long hair, such as the upper margin 

 of the neck and tail (parts specially aff"ected by parasites, like lice and 

 trichodectes), and at points where the skin is kept moist, or is not 

 cleaned. Circumscribed eczematous patches show the same features 

 as the generalised form. Once the vesicles rupture, the skin, as in 

 exudative dermatitis, is seen to be swollen and discharging, while the 

 margins of the inflamed areas still exhibit a few vesicles. 



Instead of terminating in recovery eczema may assume the chronic 

 form. The skin becomes thickened, wrinkled, irregular, and squamous ; 

 sometimes it is covered with thick crusts, or shows superficial cracks. 



