290 PEINCIPLES OF YETEEINAEY SUBGEKY 



found an infiltrated, swollen surface, from which, more or less 

 serum exudes, its watery parts evaporate and a crust remains 

 behind. Now the stadium crustosum is reached. On removal 

 of the crust, a raw, red, oozing surface is seen. Proper treat- 

 ment at this time is followed by loosening of the crusts, the 

 surface desquamates (stadium squamosum) and the destroyed 

 epidermis is replaced. Should the animal not receive the con- 

 sideration which it should, especially when kept at work, this 

 ■ regular course of healing does not take place and the skin be- 

 comes fissured. In these cases chronic connective tissue 

 changes are a sequel, giving rise to the formation of keloids. , 

 3. Dermatitis gangrenosa : This variety of dermatitis 

 may arise independently 'as a spontaneous skin necrosis, or 

 naay follow in the wake of a neglected and infected eczema- 

 tons dermatitis, especially when the skin is fissured and the 

 animal worked in slushy.and very cold weather. In gangren- 

 ous dermatitis setting in spontaneously, intense and sudden 

 lameness is observed. The animal, most likely, was put away 

 the night before in good health and in the following morning 

 walks upon three legs ; a part of the leg, or the greater por- 

 tion of it, may be swollen, the diseased skin is soft and has 

 a soapy feel, a reddish liquid oozing from it. In two to five 

 days the necrotic, gray, soft piece of skin becomes loose, the 

 defect being eventually covered with granulations, unless the 

 septic process invaded adjacent structures, as the lateral carti- 

 lage, tendon sheath, etc., when symptoms peculiar to these 

 conditions predominate. 



4. Dermatitis chronica verrucosa : Usually affects the , 

 hindlegs of long-haired horses, starting at some place in the , 

 region of the fetlock, from where it may spread. 



The hair has dropped out, more or less, and the surface is 

 covered with a gray, smeary mass, smelling badly. This 



