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DISEASES OE THE HOCK. 
(5) Tendinitis and tendovaginitis of the flexor pedis lead, in the hind 
limb, to pronounced lameness when weight is thrown on the limb 
(supporting leg lameness), and can be detected by careful palpation. 
(6) Curb is less likely to be mistaken for spavin, because it seldom 
produces lameness, unless when accompanying the latter. 
(7) Spavin lameness is more difficult to differentiate from that due to 
ring-bone and sprain of the coronet-joint. It should be remembered, 
however, that, in a hind limb, ring-bone is less frequently followed 
by lameness, whilst sprain is usually distinguished by the pain (due 
to rotation of the joint) which occurs when the animal is sharply 
turned round. 
(8) The absence of foot lameness is proved by a careful examination 
of the hoof. In laminitis there is marked pulsation of the metatarsal 
arteries. 
(9) Double-sided spavin is sometimes difficult to distinguish from 
mere stiffness. In “worn” horses, which, as a rule, show no real 
lameness, too much importance should not be attached to the results 
of the spavin test, nor to the stiff movement. 
Course and prognosis. The nature of the disease explains its chronic 
course. It is rarely caused by mechanical violence, but as a rule results 
from slight, continually repeated strain, and, therefore, develops slowly. 
The first symptom is usually slight sensitiveness, soon followed by lame¬ 
ness, though at this stage no anatomical change can be detected in the 
joint. Sometimes, however, disease processes are so gradual that lame¬ 
ness is entirely absent during the first stage, and before it develops, 
boi W growth can be detected on the joint. In this respect spavin 
lesembles a number of other diseases—for example, contracted hoof. 
When it develops slowly, contraction may become well marked, without 
causing lameness; whereas in cases of rapid development, the walls of 
the hoof exert painful pressure on the soft parts, and soon interfere with 
movement. 
As a rule, the appearance of the exostosis is preceded for two to four 
weeks by lameness, which gradually increases in severity in proportion 
as disease processes become more pronounced. In cases where at first 
it was only noticeable during the first few steps, it afterwards becomes 
continuous. Considering the nature of the pathological process, it is 
scarcely surprising that lameness appears periodically, is sometimes lost 
and then returns, or that in certain exceptional cases recovery takes place 
without treatment of any kind except complete and prolonged rest. 
Thom a puiely theoretical standpoint there is no reason why the lesions 
m the joint may not disappear and the parts recover in every respect 
the status quo ante, but, in point of fact, this termination is very rare. 
As a rule, recovery is only relative, and is followed by obliteration of 
