The new ice age

The new ice age

Are you ready to offer your clients advice about the range of cold-therapy options available?
Aug 01, 2008

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.
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.

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?

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.
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.

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.

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.
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 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.)
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.