Page 113 - 2021 Barrel Stallion Register

“With the lower joints, sometimes we can palpate thickening of the joint capsule, but you cannot palpably detect an in-
crease in joint fluid. It’s more of a clinical assessment, especially if we are not doing blocks. In cases of under-performance, we might look at a horse and see that it is a little bit short-strided in both hind limbs and a bit worse on the inside versus the outside of a circle, and positive to flexion. We might have a discussion with the owner about medicating the joint as a diagnostic therapeutic, which is essentially a treatment trial to see if the horse improves. Bilateral hindlimb asymmetry is most common
in an arthritis type of presentation versus something acute, where you might detect pronounced soft tissue swelling. In those sit- uations, we often see a unilateral lameness, meaning only one limb is affected.” One hock may have suffered traumatic injury.
“Between the talus and the calcaneus, within the high-motion tarsocrural joint, there is another articulation called the talocalcaneal joint. This is a low-motion articulation that can also develop arthritis. When this occurs, the pain can be quite debilitating and extremely difficult to manage, but this is also relatively rare,” says Mills.
Duncan Peters DVM, DACVSMR, IS- ELP Certified Member, East-West Equine Sports Medicine, Lexington, Kentucky, says we often see hock soreness in perfor- mance horses due to strain and stress. “In young horses (weanlings, yearlings) we may see Developmental Orthopedic Disease (DOD), such as OCD or bone cysts, in the hock joints. These defects are usually dis- covered early on, and many are taken care of surgically. Occasionally some of those
are not evident until the young horse starts training and then gets a little osteochon- dral fragment (usually in the tibial tarsal joint) and associated swelling and lameness within the joint,” he says.
“Most of those chips in the joint occur early on in training or when they start racing. The horse has to stop training and have the chip removed surgically. Some
of those horses can get back to work and training within 90 days or so and don’t miss very much time,” says Peters. If the problem is discovered early and taken care of, the outcome is usually good.
“More commonly, the hock problems we see in young horses are just a soreness.
EQUINE HEALTH
The talocalcaneal joint is a low-motion articulation that can develop arthritis.
When this occurs, the pain can be quite debilitating and extremely difficult to manage.
As the horse starts working and asked to do more, the hock joints get sore, just because of the mechanics of that area of the leg. The hock is unique because the upper joint is a high-motion joint and the lower joints are low-motion but must endure a lot of concussion. Those lower joints are held together with many small ligaments— holding those two rows of small bones together.” The hock has seven bones and is similar to the human ankle.
If there is too much strain on the hock, there will be inflammation associated with the ligaments holding those small bones together, as well as inflammation within the joint itself--which causes syno- vitis in the joint. “Depending on what we find, it may require a different course of treatment,” says Peters.
“The other thing we might see in some of those young horses coming into racing is some bone soreness related to concussion in the lower joints. This may depend on the surfaces they are working on, the level of activity, and the maturity and quality
of the bone.” Some of these horses will get some bone bruising and bone soreness.
Dr. Mark Cassells, Homestead Veteri- nary Hospital, Villa Ridge, Missouri, says his practice deals with a lot of sport horses and in these disciplines he doesn’t see many hock problems in young horses, compared to what might be seen in racehorses, be- cause horses in these other disciplines don’t start training as young and are not asked to
Lameness exams include flexion and palpation.
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