Influence of long-term furosemide use on bone mineral content, bone metabolism markers, and weight loss in horses

Furosemide is a diuretic commonly used to reduce the incidence of exercise induced pulmonary hemorrhage (EIPH) in racehorses. Previous research suggests furosemide negatively influences calcium balance and may have long-term implications for bone health. In this study, furosemide use was evaluated over 56d for effect on bone mineral content (BMC), bone metabolism markers osteocalcin (OC) and pyridinoline cross-links (PYD) and weight loss post administration. No treatment effects were observed for BMC, but there was a period effect across all bone cortices (p<0.0001). OC showed no difference between groups (P=0.26) or days (P=0.25). PYD tended to be lower in FUR (P=0.0584) and exhibited a day effect (P<0.0001). Body weight change indicated day by time (P=0.0001), treatment by time (P<0.0001), and day by treatment (P<0.0001) interactions. While there was no treatment effect on BMC, the trend toward lower PYD in FUR may warrant further investigation with different times and imaging techniques.