SWELLED LEGS. 295 



similar fluid within any one of the cavities of the body ; the 

 chest, belly, head, &c. Our present concern is with — 



EXTERNAL DROPSIES. 



Sometimes less correctly called local dropsies. I have 

 remarked, that, at the spring and fall of the year, when 

 horses are shedding their coats, and this disposition to serous 

 effusion is apparent ; any part which sustains injury, such as 

 any slight contusion, or even more than ordinary pres- 

 sure, is likely to become painfully swollen; hence arise 

 tumours under the belly near the girthing place, at these 

 seasons. These are comprehended under the technical ap- 

 pellations of anasarca and cedema : terms which are indis- 

 criminately apphed ; the former, however, strictly means a 

 sort oi general dropsy, though generally used to imply effusion 

 into a member only — as into a limb, or the head ; while the 

 latter denotes effusion in some particular place or part, and 

 commonly represents anasarca in a limited form, thus the 

 limb is affected with anasarca, but the leg is swollen with 

 cedema. The most common form of external dropsy in 

 horses, is — , 



SWELLED LEGS. 



When young horses first arrive, and are put into London 

 stables, they generally will have swelled legs. The changes 

 these animals have been suddenly subjected to, are such as 

 to disturb the powers of assimilation, and oedema may be 

 regarded as one of Nature's modes of relief. The disorder 

 is clearly inflammatory : it proceeds from causes which in 

 other cases produce colds, coughs, inflamed lungs, &c. At 

 the same time, the action of the absorbent vessels may be 

 diminished by the quiescent state of the animal. The legs 

 are the common seat of effusion, for two reasons : 1st, 

 being the most dependent parts of the body, whatever fluid 

 collects in the cellular membrane will naturally gravitate 

 into them. 2dly, being farthest removed from the heart, 

 its influence is comparatively weak in them ; consequently. 



