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A horse with a spavin, as Percivall said, is especially lame on stepping out 
of the stable, on the day following after a heavy day’s work. Dragging of 
the toe is sometimes noticed, on riding a horse down a. steep hill; and, in this 
manner, spavin has been not unfrequently detected. Percivall was the first 
authority to whom we are indebted for accurate descriptions of spavin. 
Regarding the actual position generally taken by spavin, we cannot do 
better than quote his words. “It is precisely the interval between the 
prominence where the hock ceases, and the canon-bone begins, that is the 
site of spavin. A small round tumour interrupts the natural declivity from 
the hock to the canon bone, and in a moment catches the eye of the 
experienced observer. In cases where the tumour being small, or flat, or 
diffuse, is indistinct to the eye, the observer will not make up his mind 
concerning it, until he has narrowly compared the suspected, with the sound 
hock.” a 
In some severe cases, the lameness of spavin is characterised by a kind 
of spasmodic jerking up of the limb, at the instant the heel comes into 
contact with the ground. Sometimes there may be no lameness ; but, when 
active change is going on in the bones, this is rarely or never absent. In 
all cases the examiner should feel both hocks, when he wishes to compare 
them with the view of noticing any difference of conformation. It is 
customary to examine the near hock with the right hand, and the off one 
with the left. Often a spavin can be felt, when it is too small to be observed ‘ 
with the eye. Animals with spavin should not be used for breeding 
purposes, unless, indeed, the disease be due to some external cause, such 
as a sprain,’ 
In those cases of lameness from spavin, which are seen in the very early 
stages, a purgative should be given in the first instance, and the animal 
should be rested, and shod with a high-heeled shoe. Locally, a blister of 
ointment of biniodide of mercury may then be applied. If ineffectual, 
setoning or firing will then be necessary. Unless the spavin gives rise to 
lameness, treatment is seldom carried out. Firing is commonly adopted in 
_those chronic cases which have resisted the milder remedies, such as 
blistering, or the douching with cold water, practised by some. In applying 
the actual cautery, the horizontal lines should not be made too closely 
together, but they should be pretty deeply burned in, in order to act more 
effectually. After firing, a rest of six or seven weeks or more is necessary, 
" before the animal is again fit for work. Prick firing we frequently advise, 
as it often proves more valuable than stripe firing. The prick iron we use 
is different from the one commonly in use; the prick at the extremity being 
only about one-sixth of an inch in length. This is heated red-hot, and is 
then thrust in in several places (see page 208). We'do not recommend 
setoning in cases of spavin. 
If it be decided to pass a seton, it is best to have the animal cast, and 
one must take care not to injure the large vein, which runs over the inner 
and front portions of the hock. The seton is passed vertically exactly over 
the growth, or we may insert two smaller ones on each side of it. After 
