Veterinarians often are called upon to help their clients sort out all of the commercial choices available when equine products
are being purchased. Equine nutritional products (primarily feeds), vitamin, mineral and other performance supplements and
joint-protection products tend to be the three areas where client confusion abounds and veterinary clarification is sought.
Photo 1: This thermography scan shows the temperature of regular ice cubes at 19.2 degrees. Though bulky and sometimes uncomfortable
to horses, it is difficult to improve on the cooling effects of ice.
Now, because of innovations and new products and technologies, you can add cold-therapy devices to the list of products that
likely will get you a call from a client seeking advice and information. Should the client looking for a means of cooling
lower-leg tendons and ligaments post-exercise purchase a soaker hose system, new gel wraps, chemical ice products, one of
the more expensive coolant-compression machines or a more traditional but updated ice boot or wrap?
An understanding of what is known about cold therapy in horses and a review of current research into different methods of
cold application will help equine practitioners intelligently and effectively respond to questions.
Photo 2: A thermography scan of a standard commercial chemical ice pack shows that it is bulky, does not conform to a horse's
leg and it is not as cold as regular ice.
The use of cold therapy (cryotherapy) is not a recent medical development. Greek and Roman physicians described the use of
cold therapy as a means of controlling pain and inflammation as early as the 4th century B.C.
A good deal also is known about what cold application does to tissue. First, it reduces inflammation. It is thought that cold
acts by causing local vasoconstriction. The constriction of small vessels on the body's surface may help reduce hemorrhage
and edema. Reduction of edema allows for better cellular oxygenation to tendons and ligaments and a reduction in the release
of cytokines such as prostaglandins and histamines.
Photo 3: The small circular air port in this chemical ice pack allows it to freeze completely but continue to be pliable and
to conform well to the horse's body. This pack will maintain its cooling effects for nearly two hours.
It must be noted, though, that following initial vasoconstriction from cold therapy, a reflex vasodilatation also occurs,
which appears to be a protective mechanism designed to maintain the health of body tissues at low temperature by allowing
periodic tissue reperfusion. It is this secondary dilation that determines the amount of time that cold is currently applied
to humans, and by extension, to horses.
Photo 4: Cold hosing or immersion in a cold-water tub has long been the industry standard for cold therapy. It is time-consuming,
labor-intensive, requires a relatively compliant horse and, as this thermography scan shows, cannot cool down the horse's
legs any more than the temperature of the water source. In this case, cooling can only achieve a temperature of 70 degrees,
although regular ice usually registers closer to 30 degrees. (Note the pool of water on the ground at the horse's foot that
shows the same temperature as the leg.)