600 
LAMENESS IN HORSES. 
“ work” or “ hard work,” we find to be very commonly succeeded 
by the appearance of windgall, either in the form of what is 
usually so called, or in that of bog spavin , thorough-pin, &c. So 
connected are the two, as cause and effect, that whenever a horse 
presents himself exhibiting windgalls, we at once pronounce him 
to have “ done work.” And yet, by no means infrequently are 
brought before us young horses — horses that have never been 
broken or backed even — having bursal swellings, not so much in 
their fetlocks as in their hocks : bog spavins being any thing but 
rare occurrences among them. And these have manifestly arisen 
in the absence of work. 
In the young or unworked Horse bursal swellings are said 
to arise from “ weakness.” The interpretation of which appears 
to be, that the joints — with which the bursae are so generally con- 
nected, and with which in some parts they make common cavities, 
are in many a growing animal physically too “ weak” even to 
support the weight of its body ; and the consequence is, they 
bulge , i. e. the capsular ligament becomes distended and stretched, 
and ultimately has its cavity considerably enlarged in consequence 
of communications being established with the tumefied bursa or 
bursse in its immediate vicinity. This is what happens in bog 
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 
provocation 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 
from lax ness 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 
