Influence of weight bearing and hoof position on Doppler evaluation of lateral palmar digital arteries in healthy horses.

The research investigates how the blood flow in the lateral palmar digital arteries in horses is affected by varying degrees of weight bearing and hoof position, using pulsed-wave Doppler. It concluded that the horse’s posture significantly alters the Doppler tracing, calling for a standardized posture for repeatable data acquisition.

Research Methodology

• The study involved 17 healthy Saddlebred horses. It primarily used pulsed-wave Doppler examinations of left and right lateral palmar digital arteries.
• Examinations were conducted under multiple conditions with varying weight distribution and hoof positions. These included, BED position (horse standing squarely with weight equally distributed among all limbs), non-weight-bearing (NWB position), full weight-bearing (FWB position), and a position with hyperextension of the distal interphalangeal joint (HE position).
• For each position, various blood flow parameters were assessed, namely, systolic peak velocity, first and second diastolic peak velocity, end-diastolic velocity, mean velocity, and resistive index.

Results of the Study

• The findings revealed no significant differences in the measured flow parameters between the left and right forelimbs, suggesting symmetry in blood flow between both sides.
• However, significant differences in the first diastolic velocity, second diastolic velocity, mean velocity, and resistive index were observed when comparing the NWB and FWB positions. These differences indicate that the amount of weight borne by the limbs can significantly influence these blood flow parameters.
• The study also found that the end-diastolic velocity in the NWB position was significantly different from the velocity measured in the HE position, suggesting that the hoof position can impact blood flow as well.

Conclusions

• As blood flow in horses’ lateral palmar digital arteries is significantly influenced by both the weight bearing and hoof position, the study underscores the importance of using a standardized posture for obtaining consistent and repeatable Doppler data.
• This research can have valuable implications in clinical settings, sports medicine, and overall horse health management, by improving the precision and repeatability of Doppler measurements used to diagnose or monitor various circulatory conditions in horses.