This is from Trail Blazer, July/Aug 95. BEATING THE HEAT, by
Nancy Loving, DVM:
One of the big problems presented by a hot and humid climate
is that often the water temperature is very close to the air tem-
perature. In an insufferable hot climate, keep in mind that if the
water has been sitting around a long time in a bucket, you may have
to add ice to cool it to a potentially useful temperature before
sponging the horse. The addition of ice cubes or frozen plastic
water bottles ("Bullets") to buckets of water will acheive some
temperature differentiation to improve conduction and evaporative
cooling. This does not mean you should pour ice water on your
horse. Please note that using ice water on a long-distance horse
is a poor idea in any situation, even in heat and humidity. If
water applied to a horses skin is TOO cold, then the superficial
blood vessles will reflexively constrict and pull away from the
skins surface. Instead of continuing to release heat, the blood
vessls suck back into the deeper confines of the muscles. The
result is a rise in muscle and body temperature quite the opposite
of the effect you were trying to accomplish. And worse, muscles
may stiffen or cramp in response. Heart rate will remain elevated
due to high body temperature and/or muscle cramping. This will
certainly not help you get through a vet check in good speed.
(Presently studies are underway on the use of ice water to cool
event horses. The work effort of event horses involves both aerobic
and anerobic exercise. Ideally, an endurance horse works primarily
in the aerobic range, and at relatively slower speeds than a
galloping and jumping event horse. The differences in exercise
intensity between the two sports may make it difficult to draw
correlations from up-comming research. Be cautious in extrapolating
from the ice water data that is directed towards the 1996 Atlanta
Olympics.)
Karen
To: ENDURANCE@MOSCOW.COM