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.
OBJECTIVE
To evaluate the use of hoof wall surface temperature (HWST) as an indirect indicator of digital perfusion and to describe HWST patterns during the prodromal and acute phases of carbohydrate-induced laminitis in horses.


METHODS
30 adult horses without foot abnormalities.


METHODS
Three experiments were performed. In the first, HWST was measured in 2 groups of horses acclimatized to hot (n = 6), or cold (6) environments and exposed to cold (15 C) ambient temperature. In the second experiment, HWST were measured in both forefeet of 6 horses before and after application of a tourniquet to 1 forefoot to induce vascular occlusion. In the third experiment, HWST were recorded in 12 horses before and during the prodromal and acute phases of carbohydrate-induced laminitis.


RESULTS
Mean HWST of hot-acclimatized cold-challenged horses was significantly less than that of cold-acclimatized cold-challenged horses at all times. Transient episodes of high HWST were observed during prolonged cold-induced vasoconstriction. Hoof wall surface temperature significantly decreased during arterial occlusion and increased during reperfusion. Digital hypothermia was observed during the prodromal phase of carbohydrate-induced laminitis.


CONCLUSIONS
Determination of HWST is a valid technique to evaluate digital perfusion under appropriate controlled conditions in horses. Digital hypothermia detected during the prodromal phase of laminitis is consistent with decreased digital vascular perfusion or metabolic activity. If administered to horses during the prodromal phase, agents that enhance digital perfusion may prevent development of laminitis.
Hood
D M
DM
Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine, Texas A&M University, College Station 77840-4466, USA.
Wagner
I P
IP
Brumbaugh
G W
GW
D000818:Animals; D001831:Body Temperature / Q000502:physiology; D003080:Cold Temperature; D005534:Foot Diseases / Q000503:physiopathology / Q000662:veterinary*; D005552:Forelimb / Q000098:blood supply; D006724:Hoof and Claw / Q000098:blood supply* / Q000502:physiology; D006734:Horse Diseases / Q000503:physiopathology*; D006736:Horses; D006358:Hot Temperature