VVINDGALL. 277 



stretched, and ultimately has its cavity considerably enlarged in 

 consequence of such pouching ; or, as happens in some cases, in 

 consequence of communications with the bursse in its imme- 

 diate vicinity. This is the case in hog spavin; the form of 

 windgall to which young horses are especially subject. To this 

 may be added, as another link in the causation, the manifest 

 disposition existing in the constitution of the young subject to 

 augmentation of secretion as well as to effusion. His capillary 

 system seems ever exuberant — ever ready on the slightest pro- 

 vocation to relieve itself of the plethora natural to it at this 

 season of life, in the emission of either serous fluid or synovial 

 secretion or coagulable lymph, dependent on the nature of the ex- 

 citing cause, and the part on which it is operating. For instance, 

 if there exist a general plethora of the system, or a disposition 

 fromlaxness or " weakness" of the capillaries generally, to effusion 

 or secretion, the legs and sheath, being the lowest or most depend- 

 ent parts, will tumefy and become enlarged; on the other hand, 

 if the joints or bursal cavities receive weight or motion beyond 

 their powers to withstand, or which becomes the source of any in- 

 creased arterial or hypertrophic action in them, then will the syno- 

 vial secretion become augmented, and bog spavin or some other 

 form of windgall be the result. But 



In old or worked Horses what causes Windgall ] If 

 weakness of fibre in the young animal be a local cause of windgall, 

 overstretch or strain, from intensity of force or repetition of motion 

 beyond the powers of the parts, may occasion the same thing in the 

 adult or perfectly formed animal. Work tells upon no parts more 

 than it does upon the joints. We witness this in the trembling knees 

 and knuckling-over hind fetlocks of aged horses, and horses that 

 have performed a good deal of hard work, as well as in the sham- 

 bling, shuffling, bone-setting gait they in consequence get into ; 

 and we see what are generally received as unerring signs of it in 

 the windgalls upon their fetlock joints, upon the fore less often 

 than upon the hind legs, in consequence of the nature of the work 

 they have been doing being more likely to have called the one 

 rather than the other into excessive action. 



But distended and enlarged bursse exist in situations where 

 there are no joints, where the bursa; can have no connection 



