The Effects of Glucosamine on Equine and Canine Platelet Aggregation

Glucosamine supplementation is a commonly administered therapy in horses and dogs, but has been shown to inhibit platelet aggregation in humans and guinea pigs. The aim of this study was to determine the in vitro effects of glucosamine on equine and canine platelet aggregation. Platelet-rich plasma, created from blood from eight healthy horses and eight healthy dogs, was incubated for 5 minutes at room temperature with four glucosamine concentrations: 0 μg/ml, 1 μg/ml, 10 μg/ml, and 100 μg/ml. Platelet aggregation was measured, using ADP (40 uM) and collagen (10 ug/ml) as agonists. In horses, there was no change in the mean maximum aggregation at any glucosamine concentration for either ADP (p=0.096) or collagen (p=0.86). In dogs, there was an increase in maximum aggregation for the 100 μg/ml samples compared to the 0 μg/ml (p=0.0013) and 1 μg/mL (p=0.0244) samples when ADP was used as an agonist. There was no change (p=0.2925) in maximum aggregation when collagen was used as an agonist. Our study suggests that glucosamine does not exert an in vitro anti-platelet effect on equine and canine platelet aggregation.