Question: If my horse has an injury, how do I know if I should use cold treatment (i.e., hosing) or heat treatment?
ANDY KANEPS, DVM, Diplomate, American College of Veterinary Surgeons and American College of Veterinary Sports Medicine and Rehabilitation
Answer: Thermal therapy—applying either hot or cold treatments—is one of the most accessible and time-tested remedies for injuries in horses. Cold therapy is generally used for recent injuries, within two to seven days of the occurrence. It is particularly effective during the first 24 to 48 hours after surgery or injuries such as sprains or strains of joints or tendons, bruises, cellulitis and lymphangitis. Cooling a horse’s tissue temperature below about 66 degrees Fahrenheit reduces pain, edema (swelling) and bleeding and slows down the inflammatory response. It also diminishes the severity of laminitis.
Even uninjured horses can benefit from cold therapy. After heavy exercise sessions, such as gallops or strenuous jump schools, ice treatments reduce low-grade inflammation, alleviate discomfort and prevent limb edema. Nearly every baseball pitcher undergoes a post-game ice bath on the pitching arm for the same reasons.
Heat therapy—warming tissue to between 104 and 113 degrees Fahrenheit—is more commonly used for chronic issues. In most cases, it should not be applied until after the acute inflammation has subsided, about seven days after an injury or surgery. It, too, decreases pain while also increasing local circulation, which may accelerate healing. Heat therapy is especially beneficial for wound healing. Horses experiencing strained back/topline muscles (who are usually hypersensitive to palpation of the area) enjoy the relief heat provides by reducing muscle spasms. When used in conjunction with careful stretching techniques, heat can increase joint mobility and improve tissue elasticity, which can be useful, for example, to elongate foals’ contracted tendons. Heat therapy also helps to soften the skin over an abscess to draw out fluid.
There are many different ways to apply thermal therapy. The most effective cold-therapy modalities surround the limb at the treatment site: for example by fully immersing a horse’s leg in an ice-water-filled bucket or commercial ice boot or by wrapping large, ice-slurry-filled plastic bags (such as used 5-liter medical/veterinary fluid bags) around the limb. Although not as effective as these immersion techniques, traditional cold hosing and cold packs are good for treating areas elsewhere in the body that are difficult to immerse. You can also freeze water in a paper cup, then peel some of the cup away and apply the ice directly to the injured area by hand.
Cold therapy is very safe; there is no way to harm tissue in a horse’s body or legs with ice, so don’t worry about over cooling. When cold therapy is used immediately after surgery, the wound can be protected with a water-impervious barrier.
Excessive heat, on the other hand, can be harmful. Temperatures above 113 degrees can result in pain and tissue damage. Before applying hot water through a hose, bucket or whirlpool/turbulator boot, test that you can comfortably tolerate the temperature on your hand. If you use a rechargeable hot pack made for humans (the type that starts as a clear gel and releases heat when manually activated), wrap it in a moist towel before applying it to prevent skin burns. I don’t recommend using electric heating pads on horses because the electrical cord presents a risk.
It takes about 10 minutes for any of these cold and hot therapies to bring the tissue to the target temperature, so apply them for 20 to 30 minutes per session. Repeat three to four times daily.
Two additional heat therapies, therapeutic ultrasound and leg sweats, should be administered only by trained horsepeople. Therapeutic ultrasound is useful for treating soft-tissue sprains and strains and to reduce scar tissue from a wound or surgery. It can also be applied in between shockwave therapy sessions to treat soft-tissue injuries. Leg sweats—using ointment, poultice or plastic wrap to trap heat against the skin—increase local blood circulation and reduce tissue fluid, commonly known as “stocking up.” Do not apply a sweat to a recent wound or infected leg. Ask your veterinarian or an experienced horseperson to show you how to apply either of these modalities safely.
One simple heat therapy that all horsepeople can administer easily is a thick fleece blanket or exercise rug. Putting this on a horse’s back before stretching exercises or riding will help to relax tight muscles.
Dr. Andy Kaneps is an equine surgeon and sports-medicine specialist. A former veterinary-school professor at Ohio State University, Oregon State University and the University of California-Davis, he has also completed extensive research on pathologies and therapies of horses and other animals. His prolific studies, which include experiments performed on the space shuttle, have been published extensively in multiple academic journals. In 2010, Dr. Kaneps cofounded a new veterinary specialty college called the American College of Veterinary Sports Medicine and Rehabilitation and teamed up with Dr. Steven Adair to develop a curriculum for a 102-hour certification course in equine therapy at the University of Tennessee College of Veterinary Medicine. A popular speaker at veterinary events around the country, Dr. Kaneps now bases his private practice, Kaneps Equine Sports Medicine and Surgery, in Beverly, Massachusetts.
This issue was originally published in the June 2018 issue of Practical Horseman.