Bog Spavin in Horses - Hock Joint Swelling

Updated July 30, 2024 | By: Dr. Lydia Gray
A chestnut horse's back legs

What is Bog Spavin in Horses?

Bog spavin is a cosmetic blemish or swelling of the hock joint area that is similar in appearance to windpuffs and thoroughpin. Specifically, fluid accumulation of one of the joint capsules of the hock causes the hock joint to appear swollen. This swelling is not accompanied by heat or pain, and it does not usually cause lameness.

Horses with osteochondrosis (OCD) are predisposed to developing bog spavin. In addition, poor hindlimb conformation, poor shoeing, poor trimming, poor footing, heavy training, or any trauma can also lead to bog spavin.

Treatment for Bog Spavin in Horses

It’s always a good idea to have a veterinarian examine any changes in your horse, especially new swellings in the hock area. A lameness examination will most likely include imaging such as x-rays or ultrasound to determine the exact cause of the problem and extent of the damage. Your veterinarian may also perform a joint “tap,” where a needle is inserted into the joint to remove a small amount of fluid for examination.

Surgery may be necessary if bog spavin occurs as a result of an OCD chip or other OCD lesion.

In some situations, your vet may recommend joint injections or intramuscular or intravenous injections with prescription medications such as Adequan® or Legend® to help improve joint heath.

Prevention and Management of Bog Spavin

While bog spavin is not the same thing as arthritis, many of the same activities and conformation flaws that lead to bog spavin may also lead to arthritis, tendinitis, and other lameness.

For this reason, you may want to reevaluate certain aspects of your horse’s management, including trimming or shoeing, arena footing, exercise conditioning program, and work schedule to help keep your horse healthy and happy, and avoid problems in the future.

In addition to modifying some of your management practices, now may also be a good time to start your horse on a joint supplement. The right joint supplement can provide the building blocks of healthy joint tissue and fluid as well as support normal inflammatory processes.

Ask the Vet Video on Bone vs Bog Spavin

In this Ask the Vet video, Dr. Andy Kaneps of Kaneps Equine explains the difference between bone spavin and bog spavin in horses. He defines each condition, treatment options, and strategies to prevent hock swelling.


SmartPak strongly encourages you to consult your veterinarian regarding specific questions about your horse's health. This information is not intended to diagnose or treat any disease, and is purely educational.