Doppler sonographic measurements of arterial blood flow and their repeatability in the equine foot during weight bearing and non-weight bearing

In six normal adult horses. pulsed-wave Doppler sonographic inspections were made of the left and right lateral palmar proper digital artery (LPPDA) of each thoracic limb, Using a two-period. crossover design with repeated measures, each LPPDA was inspected on four occasions throughout the day over a 7 hour period and, on each occasion, with the limb weight bearing and non-weight bearing. In comparison with the observations made during weight bearing, there were significant increases (P < 0.001) in bloodflow velocities when the I imb was non-weight bearing. There was no relationship between blood velocities and the time of day, the order in which the inspections were made, resting heart rate, age of the horse, or hoof angle. In both weight bearing and non-weight bearing. the Doppler waveform demonstrated a systolic peak followed by at least two diastolic peaks and an end diastolic plateau. Horses that moved least during sonographic inspections had the lowest co-efficients of variation. (C) 2001 Harcout Publishers Ltd.