ner of treatment has its favorers.
Advocates of tenotomies, likewise, are to be found. Consequently, one
may summarize thus: Spring-halt is a disease of unknown origin--the
exact cause has not been determined; therefore, all treatment is, in a
way, experimental. The recommendation of any given procedure in handling
cases must then be a matter of opinion based either upon practical
experience or knowledge of the experiences of others. Divisions of the
lateral digital extensor (peroneus) below the tarsus near its point of
insertion to the extensor of the digit is recommended here because it is
followed by a percentage of recoveries that is as large as in any other
method of treatment and the operation is not difficult to perform nor
is its performance fraught with any dangerous complications. In selected
subjects about fifty per cent of cases recover in from two to six weeks
following this operation.

[Illustration: Fig. 53--Lateral (external) view of tarsus showing
effects of generalized tarsitis.]

Open Tarsal Joint.

Like the tibia the hock is exposed to frequent injuries and in some
cases wounds perforate the joint capsule. When due to calk wounds where
horses are kicked, the injury is often on the side of the tarsus (medial
or lateral) and such wounds not infrequently result in infectious
arthritis. Horses sometimes jump over wire fences and wounds are
inflicted which constitute extensive laceration of the joint capsule. In
firing for bone spavin, where a deep puncture is made very near the
tibial tarsal (tibioastragular) joint if infection gains entrance,
serious and generalized infection of the open joint cavity supervenes in
some cases.

Symptomatology.--There is no marked difference in the constitutional
disturbances which are occasioned in this condition and those
encountered in other cases of septic arthritis (previously considered
herein) except that there is a difference in the degree of resultant
derangement and local tissue changes. Chiefly, because of the difficulty
encountered in keeping the hock joint in an aseptic condition or
securely bandaged, open tarsal joint constitutes a more serious
condition than a similar affection of the fetlock. Otherwise, a very
similar condition obtains and the same diagnostic principles serve here
that have been described on page 110 in considering open fetlock joint.

Treatment.--The same plan that is described in detail for treatment of
similar conditions affecti