BOG SPAVIN/BOGGY HOCK/CAPPED HOCK/THOROUGHPIN
QUESTION: My 14-year-old mare injured her hock somehow. It is swollen and she is slightly lame in it. The attending Vet said it is the Synovial Joint, kind of like a sprain type injury as opposed to an external concussion. What does this mean and how should I treat it?
ANSWER: I tend to agree with your Vet. But you do not say exactly where the injury is. Inside of hock and also slightly to the front, Synovial swelling, is Bog Spavin. Whole Joint, Synovial swelling, is Boggy Hock. Back of hock, Synovial swelling, is Capped Hock. Inside/outside of the hock, Synovial swelling is Thoroughpin.
The swelling is caused by: Synovia fluid that is discharged by Synovial membranes, which line the inside of joints. In addition, they line the sheaths which fit around the tendons and also numerous small pockets or sacs in various parts of the body. Sacs that are called "Bursae."
If, for any reason the Synovial Membrane becomes inflamed in part or in whole, then it will discharge more than the normal quantity of fluid to the joint, tendon sheath or bursa and a swelling will result. Such a swelling is known as a Synovial Distension.
This is Synovial fluid buildup, Mother Nature’s way of trying to heal and protect.
Although applying cold packs when it first happens, then "perhaps" trying heat later on, plus wrapping to dispense the swelling MAY be of some help, many times the swelling will remain to some degree, especially in a mature equine. The best thing for these is total rest, often for several weeks.
Depending on just exactly which one of the above it is and if any lameness present, will determine whether the injury will constitute permanent unsoundness. Generally speaking, Bog Spavin and Boggy Hock is considered a permanent unsoundness. While Capped Hock and Thoroughpin are not.