GREASE. 773 



ance of coarse hair iij)on tlieir limbs, all tending to favour local 

 congestions. Disturbance of the digestive functions, marked 

 augmentation of nutrition through forced supplies of food, 

 particularly when connected with want of sufficient exercise in 

 animals otherwise disposed through temperament, are liable to 

 be followed by an appearance of ' grease.' 



No doubt local changes and adverse influences operate 

 largely in the production of this disease ; still it does not 

 appear that these are either all-powerful, or even as powerful as 

 others which must ever be regarded as operating from within. 



Of external influences, we may observe that the heels and 

 fetlocks of horses — particularly the hind ones — the situations 

 where this disease is most common, are very liable to be acted 

 upon unfavourably as to equilibrium of circulation and direct 

 irritation, from their exposure, both within and without the 

 stable, to cold, moisture, and the direct contact of foul and 

 irritating materials. In short, whatever tends to sluggishness of 

 circulation, to general or local debility, and all direct irritation, 

 seems to favour the congestive and inflammatory condition of 

 skin-glands and true skin-tissue in the heels of horses, de- 

 veloping into this erysipelatous impetigo, ordinarily known as 

 ' grease.' 



Symptoms. — In the simpler form of merely increased or even 

 perverted secretion, there may be only a trifling amount of 

 swelling of the parts where the follicular disease usually 

 appears — i.e., in the hollow of the pasterns and posterior parts 

 of the lower extremities of the metacarpus and metatarsus. 

 Shortly after this swelling, the characteristic dampness becomes 

 evident, and the hair is somewhat matted, while the parts, 

 when manipulated, impart a soapy feeling and disagreeable 

 smell to the fingers. For long this feature of increased and 

 perverted secretion may be the only abnormal feature. When, 

 however, it is abundant, and much changed, it will collect in 

 cakes or crusts, beneath Avhich pus accumulates; this crustaceous 

 state causing stiffness in movement, or distinct lameness, par- 

 ticularly in starting from the stable. 



Often the perifoUicular, suppurative, and cutaneous changes 

 will result in shedding of the hair, leaving a slightly reddened 

 and moist surface ; while when the suppuration extends, and 

 the cceneral cutaneous tissues become raw and ulcerated, swell- 



