Evaluation of hoof wall surface temperature as an index of digital vascular perfusion during the prodromal and acute phases of carbohydrate-induced laminitis in horses.

This is a study examining the use of surface temperature of a horse’s hoof wall as an indicator of blood flow in the hoof, particularly during the early stages of laminitis, a painful foot disorder that affects horses.

Research Methodology

• The study featured three experiments involving 30 adult horses that did not have any foot abnormalities.
• The first experiment involved two groups of horses, each acclimatized to either hot or cold conditions and thereafter exposed to cold ambient temperature. The surface temperature of their hoof walls was then measured.
• In the second experiment, the hoof wall surface temperature (HWST) in both forefeet of six horses was measured before and after a tourniquet was applied to one forefoot, causing vascular occlusion or blockage of blood flow.
• In the third experiment, HWST was recorded in 12 horses in the stages leading up to and during carbohydrate-induced laminitis.

Results

• In the first experiment, the HWST of the horses acclimatized to hot conditions and then exposed to cold ambient temperatures was significantly lower than that of the horses acclimatized to cold conditions.
• In the second experiment, the HWST significantly decreased during arterial occlusion, and then increased during reperfusion, the restoration of blood flow.
• In the third experiment, a decrease in HWST, indicating reduced blood flow, was observed during the prodromal phase, the period leading up to the development of carbohydrate-induced laminitis.

Conclusions

• The use of HWST is considered an effective method of evaluating blood flow in the hoof under controlled conditions in horses.
• The observation of decreased HWST during the prodromal phase of laminitis indicates decreased blood flow in the hoof and/or decreased metabolic activity, adding value to HWST as a diagnostic tool.
• If treatments that improve blood flow to the hoof are administered to horses during this prodromal phase, it might be possible to prevent the development of laminitis.