658 
LAMENESS IN HORSES. 
idiopathic affection, i. e., as a disease — if disease it is to be called — 
independent of the joint to which it may be contiguous. Since, 
however, the bursae, particularly the large ones, have either from 
the time of birth, or as a consequence of work — occasioning rub- 
bing and pressure upon them — communication with the cavities of 
the joints, any distention the joint itself, from over-secretion of 
synovia, will of course produce distention and enlargement of the 
bursae in communication with the joint; a case in which the pa- 
thology of windgali becomes identified with articular disease or 
derangement. 
Once filled to distention, there is not much likelihood of absorp- 
tion of the effused fluid taking place ; though in young and un- 
worked horses bursal swellings do now and then, in the course of 
the animal’s growth, disappear. In adult and worked horses, how- 
ever, windgalls rarely vanish of their own accord. Once formed they 
become chronic ; for months, years perhaps, remain in statu quo. 
At length, slowly, gradually, the parietes of the bursa, from 
being simply stretched, become thickened in substance, as well 
as enlarged in caliber ; and the increase of growth, to which such 
alterations are to be ascribed, may go on to render that which was 
originally no larger than a marble of the size of an orange, and in 
some instances a great deal larger. It is probable also that, while 
such changes are going on in the size and substance of the bursa, 
alterations in its contents will become manifest. The synovial 
fluid, by degrees, acquires a deeper hue : instead of remaining a 
pale straw-colour, it comes to exhibit an amber or golden tinge. 
Flocculi of lymph may also appear in it, a layer of the same 
constituting the lining of the enlarged and now probably inflamed 
bursa. Indeed, in the course of time, by increase of this lymphy 
deposit, the bursa, instead of being a sac containing a liquid, be- 
comes the inclosure of solid substance, or of matters partly solid and 
partly liquid. The tumour now, instead of being soft and elastic 
as it was before, is solid, hard to the feel ; evidently, indeed, has 
undergone an established change of structure, out of the reach of 
all remedy, supposing its removal or diminution should be called 
for. This is the state in which we commonly find windgalls of the 
fetlock joints in old and hard- worked horses; a state in which 
they remain for years ; nay, out of which it is but in compara- 
tively few instances that they ever emerge, to change for one of a 
still more obstinate character, and one that may prove annoying 
or painful in a manner we shall hereafter point out. Of such tu- 
mours, that which was originally but membranous tissue, with the 
addition of no more than a lining of coagulable lymph, is converted 
into a fibrous structure, and from that into scirrhus. Even here, 
however, conversion does not stop. The scirrhus, in time, changes 
