448 IOWA DEPARTMENT OF AGRICULTURE 
pose with, the toe pointing forward, the heel raised, and the hock flexed. 
Some little heat and a considerable amount of inflammation soon appear. 
The slight lameness which appears when backing out of the stall ceases 
to be noticeable after a short distance of travel. 
A minute examination of the hock may then reveal the existence of a 
bony enlargement which may be detected just at the junction of the hock 
and the cannon bone, on the inside and a little in front, and tangible 
both to sight and touch. This enlargement, or bone spavin, grows rap- 
idly and persistently and soon acquires dimensions which render it im- 
possible to doubt any longer its existence or its nature. Once established, 
its development continues under conditions of progress similar to those 
to which we have before alluded in speaking of other like affections. The 
argument advanced by some that because these bony deposits are fre- 
quently found on both hocks they are not confined to a single point. 
The characteristic lameness of bone spavin, as it affects the motion 
of the hock joint, presents two aspects. In one class of cases it is most 
pronounced when the horse is cool, in the other when he is at work. 
The first is characterized by the fact that when the L^nimal travels the 
toe first touches the ground, and the heel decends more slowly, the mo- 
tion of flexion, at the hock taking place stiffly, and accompanied by a 
dropping of the hip on the opposite side. In the other case the peculiarity 
is that the lameness increases as the horse travels; that when he stops 
he seeks to faver the lame leg, and when he resumes his work soon after 
he steps much on his toe, as in the first variety. 
As with sidebones, though for a somewhat different reason, the dimen- 
sions of the spavin and the degree of the lameness do not seem to bear 
any determinate relation, the most pronounced symptoms at times accom- 
panying a very diminutive growth. But the distinction between the two 
varieties of cool and warm may easily be determined by remembering the 
fact that in a majority of cases the first, or cool, is due to a simple 
exostosis, while the second is generally connected with disease of the 
articulation, such as ulceration of the articular surface — a condition 
which, as we proceed further, will meet our attention when we reach the 
subject of stringhalt. 
An excellent test for spavin lameness, which may be readily applied 
consists in lifting the affected leg off the ground for one or two minutes 
and holding the foot high so as to flex all the joints. An assistnat, with 
the halter strap in his hand, quickly starts the animal off in a trot, 
when, if the hock joint is affected, the lameness will be so greatly inten- 
sified as to readily lead to a diagnosis. 
Prognosis. — Having thus fully considered the history of bone spavin 
we are prepared to give due weight to the reasons which exist for the 
adverse prognosis which we must usually feel compelled to pronounce when 
encountering it in practice, as well as to realize the importance of early 
discovery. It is but seldom, however, that the necessary advantage of 
this early knowledge can be secured, and when the true nature of the 
trouble has become apparent it is usually too late to resort to the reme- 
dial measures which, if duly forewarned, a skillful practitioner might 
have employed. We are fully persuaded that but for the loss of the 
