Thermographic evaluation of horses with podotrochlosis.

The distal forelimbs of 10 clinically normal horses with hair clipped on 1 limb were thermographically scanned before and after exercise. The thermal patterns, temperature distribution, and temperature changes after exercise were determined and compared with those of 8 horses with podotrochlosis. Clipping the hair did not cause changes in the thermal patterns, but the clipped limbs were warmer than the unclipped limbs. The temperature of the limbs of horses with podotrochlosis did not increase as much after exercise as did the limbs of normal horses. The failure of skin temperature increase correlated with the radiographic evidence of enlarged vascular foramina in the navicular bone. Because the failure to increase skin temperature after exercise is the result of low blood flow, the enlarged vascular foramen can be related to a state of low blood flow.