GREASE. 921 



skin, though it is often confined to certain regions or even to one, and 

 runs a comparatively simple, benign course, leading to recovery. When 

 affecting the mucous membrane of the mouth and lips it constitutes the 

 above-mentioned stomatitis pustulosa contagiosa. 



Leblanc in 1850 made microscopical examinations of the diseased 

 skin, and regarded the condition as a simple hypertrophy. He 

 found the hair follicles, and sebaceous glands enlarged. In another 

 section it has been pointed out how closely this process resembles 

 canker. Either disease may extend to new structures, giving rise 

 to the other ; thus grease may produce canker, and canker grease. 



The disease is more frequent in the hind limbs, particularly in 

 hairy-legged horses ; sometimes it seizes on several legs, one after 

 another. Whether a specific organism is the causative agent remains 

 for the present undecided, though such an explanation appears 

 probable. Sometimes the disease originates from the eczematous 

 form of dermatitis ; not infrequently it is due to slight grazes or 

 scratches. 



Moller saw many outbreaks of this form of grease in certain 

 stables ; indeed, there seems to be some ground for referring them to 

 direct infection. In large establishments animals in hospital were 

 often attacked after being rested for some time, and in one case the 

 horse-keeper suffered from an eczematous disease on the hands. 

 Every practitioner has noticed how the disease is transferred from the 

 affected leg to the sound one by rubbing. The local appearances 

 and gradual spread of the disease point to infection, though its 

 immediate cause is yet unknown. The variations in its method of 

 outbreak and course suggest that it may be due to more than one 

 cause. 



Prognosis. Spontaneous recovery is very rare. As with canker, 

 careful and often prolonged treatment is required. The greater 

 the extent of the disease, the more active the proliferation and 

 consequent thickening, and the further the growth has penetrated 

 the papillary layer of the skin the greater the difficulty in treatment. 

 The dry form is most hopeful. When the papillae have attained a 

 considerable size, and folds exist in the skin, much less can be done, 

 Treatment. The condition being unquestionably a local skin 

 affection, internal treatment is of little value, and the chief indications 

 are to cleanse, and keep clean, the diseased skin, rapidly to remove 

 decomposing secretions, or to prevent decomposition occurring. 

 When the process is confined to one small spot, the parts may be 

 cleansed, a white-hot firing-iron passed several times over the diseased 

 surface and a disinfectant applied. In more extensive attacks the 



