SPAVIN. 
725 
such as sprain, &c., may lead even experts into error. Such mistakes 
often lead to doubts being cast on the value of treatment. 
The lameness accompanying spavin is scarcely ever sufficiently 
distinctive to alone determine the diagnosis, but must be considered 
along with the anatomical changes in the hock-joint. 
Even Knoblock, when speaking of it, says: “ If one detects no swell¬ 
ing, how is one to know that a spavin will come?” One must not be 
understood to say that the character of the lameness does not afford 
valuable information, but the kind of lameness is less important than 
the manner of its appearance and its after-course, and, finally, than the 
absence of visible pathological changes, to which the lameness could 
otherwise be referred. 
The onset and course of the lameness is, then, of greatest value ; the 
style of movement, which varies greatly according to the position and 
extent of the inflammation and to other circumstances, much less so. 
In the greater number of cases the limb is incompletely extended. The 
last phase of the stride, while weight is still carried by the limb, is 
relatively shortened, apparently on account of the pain due to extension 
of the hock-joint. Immediately the hoof leaves the ground the limb is 
drawn rapidly forward. This sudden movement often resembles string- 
halt, and is best seen during the first few steps, or when turning in a 
small circle. 
A further consequence of the incomplete extension of the limb is an 
exaggerated hip-action, which is seldom absent. The shortening of the 
last part of the stride is compensated by extra movement of the quarter. 
Sometimes the limb is abducted, especially in double-sided spavin, in 
which the turning out of the limbs is often well marked. In other cases 
the fetlock becomes upright, in consequence of the incomplete extension 
of the hock causing the animal when moving over uneven ground to 
walk on the toe. In almost all fully-developed cases the horse wears the 
toe of the shoe excessively. 
As a rule, lameness develops very gradually. At first it disappears 
after a few steps, and in many cases all that can be observed is a catch 
in the movement of the affected limb, resembling stringhalt, when turn¬ 
ing round in the stall towards the sound side. This usually disappears 
with work. The disappearance of lameness during movement, and its 
regular recurrence after rest, form one of the most important peculiari¬ 
ties of the disease. The fact that turning towards the sound side seems 
more painful than towards the diseased is explained by the pressure on 
the inner part of the hock being then greater. Occasionally, however, 
lameness persists during movement, and may, indeed, become more 
severe, especially if it were previously well marked or of old standing. 
The increase in lameness when turning in small circles is clearly due 
