One of the most common causes of lameness in horses is arthritis of the lower hock joints. Almost all hard-working horses over the age of 5 will have some pathology in these joints. If you have heard horse owners say they have had their horse's hocks injected, these are the joints I am talking about. There are many different treatments for hock arthritis including injecting the joints with cortisone and hyaluronic acid. Also, sometimes people ride horses while the horse is on anti-inflammatories like bute, and many of them are on oral joints supplements with glucosamine. However, some of these horses are so severely affected that many of these treatments are ineffective or at least do not last very long.
The next step in treatment is to arthrodese the joints, or destroy the joints so that the bones grow together. This decreases the pain in the area because if there is no longer a joint then there is no arthritis pain. In the past, destroying the joint was a surgical procedure accomplished with a laser or by drilling out the cartilage in the joint. These are expensive procedures and the veterinarians at the Western College of Veterinary Medicine performed a study on another method of destroying the joints by injecting ethyl alcohol into the joints. Ethyl alcohol is injected after making sure only the lower hock joints would be affected. Of the 16 horses in the study, all 16 were pain free after 6 months. So if you have a performance horse that routinely has the hocks injected but are still having problems, ask your vet about ethyl alcohol injection.