LAMENESS IN HORSES. 
129 
be content to dismiss the subject with the remark, that it would 
appear as though the bulging of the capsule of the hock-joint had 
been confounded with the distention of the vein, or, in other words, 
that the tumour was thought to arise from the latter; and that this 
supposition would the more readily be entertained from the cir¬ 
cumstance of blood, and not joint-oil, being found to issue whenever 
puncture was made at the place where naturally it would be made, 
to let out the contents of the swelling, viz. the most prominent or 
pointing part of the “ enlargement.” 
Thorough-Pin. 
A Thorough-pin may be defined to be, a windgall running 
from side to side through the upper and back part of the hock. 
The Name of “Thorough-pin” owes its derivation to this 
“ running through” or thorough; it being originally taken from the 
French vessignon cheville , which means precisely the same thing 
as our through or thorough-pin . 
The Site of Thorough-pin is notorious enough. It occupies 
the floor of the hollow interval at the supero-posterior part of the 
hock, between the joint in front and the tendo Achillis behind; 
reposing, as it were, after the manner of a cushion placed trans¬ 
versely, upon the joint beneath. 
Felt on either side, it has all the sensible characters of 
windgall; and the fluid it contains is readily made, by pressure or 
pulsation with the fingers, to fluctuate from one tumour to the other, 
shewing that free communication exists between them. In fact, to 
external examination the swellings appear as though an oblong 
bladder or windgall had become formed here, and that it was com¬ 
pressed or nipped together in the middle by some narrow pass it 
had to permeate. 
This is the ordinary but not invariable seat of thorough-pin ; 
for, on occasions, the tumours exhibit a more spread-out aspect, 
and are broad or even diffuse instead of being spheroid or ovoid 
and circumscribed, and so extend downward upon the sides of the 
hock; though this latter is a remark more applicable to the tume¬ 
faction upon the outer side. 
The Tumour is not necessarily Thorough, or cheville. 
Sometimes it is confined to one side; and more frequently, we 
believe, in this single form, will the swelling be found outward 
than inward. Such cannot, strictly speaking, be called thorough - 
pin, although in nature the tumour nothing differs from it. When 
true thorough-pin is present, however, the inner tumour is gene¬ 
rally the larger or the more prominent of the two. 
True Thorough-pin is rarely or never seen without 
