The innocuous-sounding blemishes called “windpuffs” (or windgalls) are balloon-like fluid swellings of the deep digital flexor tendon sheath near the back of the fetlocks that makes the joint appear puffy in a concentrated area. Similar to thoroughpins in the hocks, these swellings do not emit heat or cause pain or lameness, but a soundness examination and possibly x-rays or an ultrasound by a veterinarian are often recommended, as windpuffs could signal changes in bones, joints, or soft tissues such as tendons and ligaments. They most commonly appear in the hind legs, but can also affect the forelegs, and usually indicate that the sheath or related structures have been injured, or stretched due to over-exertion, creating the extra fluid.

While treatment for windpuffs is not usually necessary, they should be closely watched. If they are caused by conformation flaws or intense activity levels, they may signal that arthritis, tendonitis, or other lameness issues may be on the horizon. Careful management of the horse’s work schedule, the footing on which he is trained, his conditioning program, even his shoeing, should be examined and adjusted to keep him sound and prevent future lameness issues.

If the windpuffs suddenly increase in size, are very firm, are asymmetrical (i.e., one leg is larger than the other), or exude heat and the horse appears lame, it indicates a fresh injury that requires treatment.