Updated: Jun 14
Lameness in the hock is a fairly common problem in the performance horse. For the most part, ailments in this area represent chronic or long-lasting lesions that become more and more incapacitating as the years go by. Almost any section of the hock can become diseased, but certain areas are more common than others.
Other than the feet, the hock is probably the most important structure in the performance horse. It is a complex joint, comparable to the ankle of a human, and is an area of enormous torque in a horse traveling at full speed. The hock is the pivotal part of the hindquarters that propels the horse forward at speed and, as such, is a point where the power of the huge muscles of the rump is transferred down the leg to drive it forward from the surface.
Hock lameness usually demonstrates the most pain in the jack region (cunean bursa). Simple palpation in this area will usually cause the animal to flinch if a problem is present. At times the pressure in the front of the hock will also produce a marked response. The shoe of the horse should be examined. The majority of horses will wear the toe and outside of the shoe excessively.
The most common, as well the most successful way to treat a hock problem is by injecting the whirlbone and jack cords. When a hock lameness is present, the animal will alter its gait. This change in movement quite readily causes the whirlbone to be inflamed. Although other hind-end lameness can cause inflammation to the whirlbone, it is primarily the hock that is involved. It is rare, if not inexistent for the whirlbone to become inflamed on its own. They are always secondary to a problem further down the leg.
Injection of the whirlbone involves the use of a long ( 3-1/2") needle. Usually, an irritating substance like iodine is injected into the area. Cortisone can be used as well with little or no side effects. For the odd animal, this technique will be sufficient to sound him up completely, but the results will be short-lived. Since the primary problem is in the hock, the lameness will quickly return.
Treating the jack cords will usually give the best response. The majority of horses with hock lameness begin as a jack problem. If untreated, the condition usually expands to involve the hock joints as well. It is important, therefore, to treat the jacks first without tampering with the joints. If therapy proves to be unsuccessful, then a joint injection may be necessary. Whenever one jack is treated, the other is as well. Although the animal may only demonstrate right-hock lameness, experience has shown that the same problem is likely brewing on the other side.