156 NON-PARASITIC SKIN DISEASES. 



on this disease; for when the animal is kept in a state of enforced 

 rest, the blood in his feet and lower jDortion of his legs is liable to, 

 more or less, stagnate, on account of the habit the horse usually 

 has of standing up. While this partial congestion exists, the health 

 and vitality of the living structures involved in it, become more or 

 less impaired, and the secretion of oil to lubricate the cuticle (outer 

 skin) becomes proportionately reduced. High feeding, will also 

 predispose the animal to inflammatory attacks of the skin, as 

 well as of other parts. 



Hand-rubbing the pasterns of stabled horses, by stimulating the 

 local circulation, reduces the liability of the part to contract eczema ; 

 though it would probably be of no benefit to horses kept in the 

 open. It is evident, however, that if the skin of the pasterns has 

 become accustomed to it, and its practice is suddenly discontinued, 

 the skin, before it regains its usual working efficiency, will be more 

 subject to this form of inflammation, than it would be, had such 

 stimulation never been applied. 



As the hair at the back of the pastern forms a protection to the 

 part, its removal often induces cracked heels and predisposes the 

 animal to grease. It is probable that old horses, from their 

 lower vitality, are more susceptible to eczema of the pastern than 

 are young ones. 



Injury, such as that caused by hobbles or ropes, sometimes gives 

 rise to cracked heels ; because it exposes the true skin to influences 

 that are likely to give rise to this complaint. 



The great predisposing cause of cracked heels is the senseless 

 practice of washing the feet, which is popular among grooms ; 

 because it saves trouble for the time being. It is a significant fact 

 that cracked heels are as rare among horses whose legs and feet 

 are never washed, as they are common among animals whose legs 

 and feet enjoy the supposed benefit of being cleansed with water, 

 no matter how carefully they may be afterwards dried. 



VARIETIES.-^The degrees of severity in this disease are (I) 

 when it is characterised only by redness and a little heat and swell- 

 ing (erythematous eczema); (2) when vesicles form (vesicular ec- 

 zema) ; (3) when there is a discharge of pus from the skin (pustular 

 eczema) ; and (4) when there are " grapes " or warty excrescences 

 on the skin (warty eczema), which are accompanied by more or less 

 infiltration of the skin. We may roughly class (1) and (2) as 

 cracked heels ; and (3) and (4) as grease. 



SYMPTOMS. — When inflammation is set up in the part, the 

 secretion of oil is interfered with, and cracks usually occur in the 

 places where the skin becomes wrinkled when the pastern joints 



