The term "wind puffs" is commonly used to describe any puffiness in the area of the horse's ankle. The two structures that can fill with fluid in the horse's ankle are the fetlock joint capsule and the flexor tendon sheath. It's important to learn to distinguish between the two and determine the exact cause of wind puffs in your horse's ankle before you can decide what to do about it.
Filling in the joint capsule will appear as a discrete, rounded "puff," about the diameter of a quarter, located just behind the cannon bone and under the end of the splint bone. The more fluid that's present, the tighter it will feel and more under pressure it will be.
Swellings in the flexor tendon sheath are located between the suspensory ligament and the back of the leg, above the sesamoid bones. Less discrete puffiness that can't be clearly localized to one area only may be related to swelling or thickening of the annular ligament of the fetlock, a band of tissue that encircles the ankle like a cuff.
Many horses can develop some swelling in the area of the tendons and suspensory ligament after a particularly long or hard work, or when first being put in work. This isn't necessarily a reason to panic, but it does require your attention.
Stall rest for a day, followed by light walking only, and aggressive cold-water hosing and ice wraps should take care of minor strains related to heavy work within one to three days. If the problem persists, an ultrasound of the tendons, the suspensory and the annular ligament area is indicated.
Swelling that involves the jont itself is potentially more serious and warrants a visit from your veterinarian for X-rays.
If the joint looks clean, synovitis is the most likely cause. A course of aggressive anti-inflammatory therapy with icing is indicated. At your veterinarian's discretion, a short course of anti-inflammatory drugs may also be called for. Use of injectable or oral hyaluronic acid can also be used to quiet the inflammation.
Your veterinarian will make specific exercise recommendations after evaluating your horse's individual case, but in general a short period of stall rest followed by low level exercise for two to four weeks is usually recommended. Resume more demanding work slowly and keep an eye out for return of the joint swelling.