OBSERVATIONS ON THOROUGH-PIN. 
2*21 
thorough-pin, the effect of bog-spavin, its presence in some cases not 
only depends upon the bulging of the capsular ligament of the hock- 
joint, but is also due to the latter, causing the bursa of the flexor 
pedis to become displaced to a greater or less degree: and to make 
up for this error loci, nature appears to bring about an increased 
secretion of synovia in the bursa, which makes “the tumours ex¬ 
hibit a more spread-out aspect, and are broad or even diffuse, in¬ 
stead of being spheroid or ovoid and circumscribed, and so extend 
downward upon the sides of the hock.” 
Tt is curious to notice how well aware Mr. Percivall seems to 
be of the different appearances and forms in which thorough-pin 
presents itself; yet at the same time it is equally singular that he 
should not have hit on the true causes of these different anormal 
conditions: but, then, we are led to suppose that he has not had 
the opportunity of dissecting or seeing specimens of these diseases; 
for he states, “ we must ask those who have had opportunities of 
dissecting thorough-pinned hocks to what extent such changes of 
structure have gone or may go.” 
In reference to the latter part of the extract, I may, at a future 
period, have some observations to make; but, at the present time, 
I fear I cannot afford a good reason why I should further lengthen 
the subject, being afraid that I have already trespassed too much on 
the pages of The VETERINARIAN : but, before bringing the present 
observations to a conclusion, I must crave permission to add a few 
remarks regarding the treatment of thorough-pin; for I am unable 
to state, with Mr. Percivall, that “of lameness from pure thorough- 
pin we know of no example on record; treatment, therefore, will 
hardly be called for.” And this inability on my part cannot be 
owing to any difference between our kinds of practice, from which 
we have respectively gleaned experience; for what little practical 
experience I have hitherto gained has been chiefly through army 
practice, to which I believe Mr. Percivall, during a long profes¬ 
sional career, has devoted strict attention. 
Suffice it to state that I have seen a case of lameness arising 
from “ pure thorough-pin.” I say a case, for it was one that 1 
have well in remembrance, and will presently mention it. It is 
unnecessary to observe that it is quite a common occurrence to 
have lameness from bog-spavin and thorough-pin combined ; and 
I also imagine that I have seen more cases than one in which 
thorough-pin existed per se, and lameness arising from its presence. 
It may be proper to hint that the symptoms induced in lameness, 
the result of bog-spavin or thorough-pin, are much the same—a 
stiffness of the hock, which, in some cases, amounts to a total in¬ 
flexibility of the joint; dragging of the toe; more or less tume¬ 
faction and heat in the vicinity of the tarsus, &c. But to return 
VOL. .XXII. Gg 
