Effect of ambient temperature upon the surface temperature of the equine limb.

Ten clinically healthy adult horses were examined with the portable infrared thermometer at ambient temperatures of 5, 15, and 25 C to evaluate the thermal response of limbs of the horse to variations of ambient temperature. Limb surface temperature varied in direct proportion to changes in the ambient temperature, with considerable variation occurring among individual horses, especially at the lower temperatures. Areas of proximal parts of the limbs were more resistant to temperature variation than were distal parts. Ambient temperature had a statistically significant, but clinically unimportant, effect upon the bilateral symmetry (right side/left side) of limb surface temperature. At all ambient temperatures, the mean variation between left side and right side target areas was less than 1 degree C.