EVALUATION OF LASER-DOPPLER FLOWMETRY FOR MEASURING CORONARY BAND ANDLAMINAR MICROCIRCULATORY BLOOD-FLOW IN CLINICALLY NORMAL HORSES

Once daily for 3 days, laser Doppler flowmetry was used in 5 healthy, nonsedated adult horses to evaluate coronary band and laminar microcir culatory blood flow (MBF) in both forelimbs. The coronary band had sig nificantly (P < 0.05) higher MBF than did the laminae on the days eval uated. Significant variation in MBF was not found over the 3-day measu rement period in any one site. Significant (P < 0.05) variation was fo und in coronary band MBF among horses. This variation was not observed in laminar MBF. On occlusion of the digital arteries at the level of the fetlock, marked decrease in coronary band and laminar MBF was obse rved. Twenty minutes after rv administration of acetylpromazine, marke d increase in coronary band and laminar MBF was observed. The techniqu e was easily performed in standing nonsedated horses, did not inflict discomfort, lacked complications, and measurements were repeatable. Th is technique provides an index of digital MBF, either intermittently o r continuously, avoiding introduction of invasive variables associated with other techniques.