460 THE HORSE. 
fig. 5, 3. There may or may not be lameness, but if bone is thrown out the 
disease is established. In recent cases whenever the horse is worked he 
will after rest limp in his action, but the lameness soon goes off, and does 
not show itself again until the part has been suffered to become stiff by a 
rest of an hour or two. The lameness is very remarkable, and differs 
greatly from that shown in any other disease. The leg is drawn up with 
a quick catch, and yet there is a dragging of the limb, indicating not only 
pain in the joint, but a want of action in it. In the early stages the 
latter is not clearly developed, but afterwards it is so well marked that a 
spavin may be pronounced to exist without an examination of the joint. 
Where lameness is not established, great care should be exercised in pro- 
nouncing on the existence of spavin, for some hocks are naturally formed 
with prominent heads of the internal metatarsal bones, and the mexpe- 
rienced eye and hand are very apt to mistake these for exostosis. In such 
cases, by comparing the two hocks it will generally be seen that they are 
both exactly alike, while in spavin, although both joints may be the seat 
of mischief, yet they will seldom manifest the disease to the same extent. 
The treatment should be directed to the abatement of the inflammation 
which gives rise to the pain, and also to promote absorption of the new 
growth. Veterinary surgeons are very apt to assert that the disease 
cannot be cured, and that a spavined horse will always remain the subject 
of it, and therefore unsound. But practically it is known that many a 
hock which has been the seat of undoubted spavin loses all external 
enlargement, and no lameness is shown in it, although tried most severely 
through a series of years. Still on dissection after death, the ligaments will 
not show their natural white and glistening structure, and the tarsal bones 
will be to a certain extent united by anchylosis. In very bad cases there 
will be also caries of the articulatory surfaces, and with it inflammation 
of the synovial membranes, which may and often does exist without the 
caries. Now as these are much more formidable diseases than exostosis, and 
far more difficult either to cure or palliate, it follows that although certain 
remedies will be generally successful with genuine bone spavin (exostosis), 
yet they will fail when the above complication exists. The treatment 
must therefore be adapted to the exact nature and extent of the disease. 
Prior to the adoption of any plan the joint should be rested, the outer heel 
of the shoe should be lowered, the corn should be taken away, and the system 
cooled by appropriate treatment. After these precautions are taken, the 
next thing is to decide upon the remedies which will be suited to the case. 
They consist in 1. Blisters, which have a tendency to cause absorption ; 
2. Firing; 3. Setons, with or without subcutaneous scarification ; 4. Division 
of the nerve. If there is simply aslight exostosis, with little lameness, and 
no evidence of the joint being implicated, the biniodide of mercury may be 
applied as described at page 456. Repeated dressings will be necessary, 
and the joint must have at least two months’ absolute rest, the horse 
being placed in a loose box. This remedy is often successful, but it will 
fail utterly where the exostosis is extensive, or there is caries, or even 
severe inflammation of the synovial membrane. Arsenic, sulphuric acid 
(which is the basis of Major’s British Remedy), and other caustic appl- 
cations, have been counted as infallible cures; but while they are just as 
certain to produce a blemish as firing, the extent to which the inflam- 
mation and sloughing, caused by them, go is far more completely beyond 
our control. Arsenic has been known to destroy the joint, by producing 
a slough of the synovial membrane, and it is said that the British 
Remedy, which, however, is often very successful, has had a similar 
