We have all heard dramatic stories about people who have fallen through ice and weren?t recovered from the water for prolonged periods of time but lived. Doctors also sometimes use hypothermia therapy on heart-attack victims to help protect the brain tissue. These are extreme examples, but they illustrate how cooling drastically lowers the metabolic demands of a tissue, allowing it to survive with very low levels of oxygen and nutrients. You can use this same technique to help prevent or heal inflammation in your horse.
Cold is an effective way to control or prevent low-level inflammation in arthritic joints or areas of previous injury. These tissues often never completely return to normal, even when symptoms aren?t obvious, and we recommend routinely icing these areas after exercise.
Studies have shown that the most reliable and efficient way of lowering tissue temperature is by conduction, which is a movement of heat to an adjacent area that is cooler. An example of conduction is use of an ice pack. Immersion in ice water is the most effective conduction method. Heat can also be dissipated by evaporation of water from the surface or by convection, loss of heat into surrounding air that is cooler. In other words, contrary to common belief and some advertisements, cold does not go into the tissues ? heat comes out. The skin cools quickly, then heat begins to move from the deeper tissues out toward the cooled skin.
When To Cool.
A common-sense rule of thumb will cover most instances where cold therapy is indicated: If it feels hot to the touch, cool it. This covers all lameness problems where your hand can detect excessive heat. However, inflammation may be going on at deeper levels that you can't feel.
Because of their poor blood supply, tendons and ligaments are especially vulnerable to heat damage. In fact, damage to the middle of the flexor tendons in their center/core is common and is believed to be caused by the buildup of heat in this area. Rapid cooling of the lower legs after exercise assists in rapidly eliminating heat and turning off the chemical signals that can lead to inflammation. Since joint cartilage has no blood supply to help with the elimination of heat, cooling helps protect joints as well.
In the case of fresh injuries ? like kicks, falls or twists or stings ? start cooling before the area becomes hot and swollen. If you get to it quickly, the heat, swelling and pain can be greatly reduced or even eliminated.
The old-time treatment for laminitis was to stand the horse in a running stream. This is a very effective way to cool by conduction and is still valid today. Cold therapy has also been proven to prevent laminitis caused by carbohydrate overload in an experimental setting. This would apply to situations like ?horse broke into the grain room? or an insulin-resistant horse getting access to pasture (especially spring or fall pasture).
However, it is unknown if trying to prevent laminitis with cold would be beneficial or harmful in laminitis caused by systemic infections like Potomac horse fever, strangles or colitis, so You'll need to discuss this with your vet.
The movement of heat out of an area will be quickest when the difference between skin and tissue temperature and the outside is great. Ice will cool quicker than cool water. For best control of inflammation, start with the lowest temperatures possible.
Studies have also found that cooling is most effective when the cooling material is undergoing a phase change, such as melting ice to water. This is why standing the horse in an ice water bath is the most efficient cooling method. If using a cooling wrap, wet the skin under it first for easier transfer of heat.
there's a lot of confusion about how long to cool and whether to alternate cooling with heat. When treating an active problem, cooling is the preferred therapy for the first 72 hours. This gets you the best control of the inflammation.
Continuous cooling is ideal, but once deep tissues have been cooled, they can take an hour or longer to come back to even normal body temperature so it's not absolutely necessary to change wraps as soon as they begin to warm up.
With active injuries and things like arthritis flares, the most effective approach we have found is to ice for 30 to 60 minutes at least three times a day, using another cooling method in between and overnight. This can be one of the evaporative-cooling products in our trial (see chart), cold alcohol or witch-hazel wraps or a chilled poultice. After the first 72 hours, ice as necessary for heat and swelling, or try alternating icing and heating.
When icing after exercise to prevent problems, a 30- to 60-minute treatment is adequate. As a rule of thumb, continue icing until the horse's whole body has cooled out. If you're going to be wrapping the legs after icing, wait about an hour after icing to take advantage of the prolonged cooling of deep tissues that occurs after treatment.
We conducted our trial during the peak of summer heat and humidity in the Northeast, temperatures 85 to 100° F and humidity 75 to 95%.
Most of the products in our trial used conduction as the cooling method. These are the cooling wraps that use liquid or gel cooling inserts, and we found them to be the most effective.
Two products ? BSI Coldflex wraps and Equi-N-Ice ? relied on evaporation rather than conduction. However, in our trials, both were slower to cool than conduction methods. We found that Equi-N-Ice cooled better, possibly because of its mixture of alcohols rather than water. The Coldflex wraps performed better when chilled before use.
Several manufacturers offer neck-and/or-head cooling wraps. These are most indicated for reviving horses that have been worked too hard in the heat. They should be used in conjunction with aggressive cooling of the rest of the body.
Our top two performers were the Dura-Kold Pro-Kold wraps and the MacKinnon Ice Horse wraps. Both conform extremely well and cooled for 45 minutes to an hour even under extreme heat. Top pick goes to MacKinnon, as the inserts can be heated. EZ Ice earns Best Buy.
Honorable mentions go to the Equi-Gel Wrap for ease-of-use and to Equi-N-Ice for best on-the-road cold therapy.
One innovative product really impressed us: the ReCover Therapeutic Blanket. it's expensive, at $289, but can be used to treat chest, shoulders, rump, back, stifles and anywhere else along the body using cold/heat packs that adhere by Velcro to anywhere you desire on the interior of the blanket.
Article by Dr. Eleanor Kellon, our Veterinary Editor.