Thoroughpin in Horses

Updated June 27, 2023

What is Thoroughpin in Horses?

Thoroughpin is a cosmetic blemish of the hock area that is similar to windpuffs of the ankles (fetlocks). Specifically, thoroughpin is swelling of the tendon sheath around the deep digital flexor tendon as it passes over the hock. This swelling is not accompanied by heat or pain, and it does not usually cause lameness.

Causes of Thoroughpin in Horses

Any horse with poor conformation in the hock region may be at risk for developing thoroughpin. In addition, a young horse just starting work as well as a horse in heavy work may also be at risk due to the added stress on the horse’s legs.

Diagnosis and Treatment

It’s always a good idea to have a veterinarian examine any changes in horse, especially new swellings in the hock area. In addition to a regular physical examination, your vet may also perform a lameness exam and image the area to rule other conditions that may cause a swollen hock, such as bog spavin or capped hock.

X-rays will show changes in joints and bones while ultrasound will show changes in soft tissues such as tendons and ligaments. Generally, no treatment is necessary or recommended for routine cases of thoroughpin.

Prevention and Management

While thoroughpin is not the same as arthritis, many of the same activities and conformation flaws that lead to thoroughpin 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/shoeing, arena footing, conditioning program, and work schedule to help keep your horse healthy and happy and avoid problems in the future.

Supplements That May Lend Support

The right supplement can help support a normal inflammatory response in your horse’s body.