ON CARPITIS. 
667 
with the sound leg, but which very quickness causes a shortening 
of the step : the effect of this is to give a horse a tendency to go 
round in a large circle, evinced by the horse bearing to the 
sound side ; and so early does this occasionally shew itself, that 
it will be often the first intimation of the existence of lameness. 
There is a tendency to drop the fore quarters, but not to the 
same extent as where both joints are affected. 
The characters are very much akin to those considered to belong 
to shoulder lameness, but from which it may be readily distin- 
guished ; first, by the circumductive manner in which the leg is 
thrown forwards, and the straight knee ; secondly, by the absence 
of the dragging or striking of the toe against the ground ; thirdly, 
by the stepping on the heels and the greater firmness on standing ; 
but, perhaps, one of the best guides in diagnosis is noting which- 
ever joint is attempted to be least brought into use. 
I have sufficiently pointed out the distinction between carpitis 
and naviculitis ; but there is one fact which I cannot clearly account 
for, that is the heat of the foot of the lame limb in carpitis : this at 
first I found a very considerable obstacle in diagnosis ; but I have 
noticed its presence in so many instances, that all doubt respecting 
its existence has ceased. 
There are, however, instances in which I have noticed its 
absence : whether this depends upon a particular part of the 
carpus being affected, I am not prepared to say, though I believe 
such to be the case. I suppose it to arise from a similar cause to 
that which produces in man pain in the knee joint from disease of 
the hip, from pressure applied to or irritation affecting the trunk 
of the nerve, and which is referred to its extremities. 
This heat of the foot was present in each of the cases before re- 
lated, the more particularly so in the second case ; and when the 
cause of lameness was removed the foot returned to the normal 
temperature, while the heat continued so long as the true cause re- 
mained unremoved, in despite of the means perseveringly applied 
locally to remove it. I have met with very many instances of the 
same fact. 
The second case is also illustrative of another point, — that is, the 
injurious effect of standing in wet clay; this arises from its tena- 
city holding down the foot, causing a straining of the joints, and 
as effectually adds to mischief as over-exertion in the opposite 
direction : so have I found, in riding horses lame from carpitis, in 
deep or tenacious ground, the same increase of lameness; and I 
am disposed to believe that such may be occasionally, if not a first 
cause, a disposer thereto; and from its being well known that the 
fetlock joint is often affected from this cause, it is strange that the 
knee joint should be considered to be exempt from its influence : 
