168 



VETERINAKY MEDICINE AND SURGERY. 



means of drying the legs, care should be taken that they also cover the 

 heels. 



The common practice of clipping the hair off the back part of the 

 fetlock and heels is another frequent cause. A moderate amount of hair 

 is needed as a protection to the skin against chill, cold, wet, dirt, and 

 sand, and also against excessive evaporation, especially in those breeds to 

 which such long hair is natural. 



The disease is sometimes associated with febrile disturbance. In 

 some instances, swelling of the limb or limbs affected may precede the 

 eruption; whilst in others, the eruption precedes the swelling. The 

 hind limbs are more frequently affected than the fore ones. The dis- 

 charge is sometimes very profuse, and it is said that it is capable of in- 



FiG. 78. 



Fig. 79. 

 Different Stages of Grease. 



Fig. 80. 



ducing an eruption in cows and human beings similar to that of vari- 

 ola; on this account it has been termed equine lymph. 



The discharge from the pustules and vesicles of grease irritates the 

 surface over which it flows ; and the skin of the heels — which in health 

 is peculiarly soft and pliable — becomes rigid; the natural sebaceous se- 

 cretion of its follicles is arrested, and, as a consequence, the movements 

 of the limb cause the skin to crack, and to become a mass of soreness, 

 ulceration, and fungus, accompanied by heat, pain, and lameness. When 

 the disease is of this type, it is very apt to assume a chronic character. 



