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

The research focuses on the impact of weight bearing and non-weight bearing on the arterial blood flow in horses’ feet, using Doppler sonographic measurements. No significant relationship was found between blood velocities and variables like time of the day, resting heart rate, age, or hoof angle, but a significant increase in blood-flow velocities was observed when the horse’s limb was non-weight bearing.

Methodology

• The study involved six normal adult horses. Pulsed-wave Doppler sonographic inspections were made on their left and right lateral palmar proper digital artery (LPPDA) of each thoracic limb.
• The research was conducted using a two-period, crossover design with repeated measures. This means that each LPPDA was inspected four times throughout the day in a time span of 7 hours.
• Each inspection took into account whether the limb was weight bearing (supporting the horse’s weight) or non-weight bearing.

Findings

• The study found that there were significant increases in blood-flow velocities when the limb was non-weight bearing. This suggests that the weight or pressure exerted on the limb directly influences the speed at which blood travels through the arteries.
• There was no correlation found between blood velocities (the speed at which blood travels through the arteries) and the time of the day, the order in which the inspections were made, resting heart rate, age of the horse, or hoof angle. This means these factors do not significantly affect the blood flow in horses’ feet.
• In both the weight bearing and non-weight bearing scenarios, the Doppler waveform demonstrated a systolic peak (highest point of pressure in the arteries), followed by at least two diastolic peaks (lowest points of pressure in the arteries) and an end-diastolic plateau. This likely is a normal arterial blood flow pattern in horses’ feet.
• It was also noted that horses that moved least during the sonographic inspections had the lowest coefficients of variation, which signifies more consistent or stable results.

Conclusion:

• This study provides a better understanding of arterial blood flow in horses’ feet and how it is influenced by weight bearing. Such findings can be beneficial in designing more effective treatments or management strategies for equine foot disorders.