Effect of heparin administration on urine protein excretion during the developmental stage of experimentally induced laminitis in horses

Abstract

Objective - To investigate the effects of heparin administration on urine protein excretion during the developmental stages of experimentally induced laminitis in horses. Animals - 13 horses. Procedures - Horses received unfractionated heparin (80 U/kg, SC, q 8 h; n = 7) or no treatment (control group; 6) beginning 3 days prior to induction of laminitis. All horses were given 3 oligofructose loading doses (1 g/kg each) at 24-hour intervals and a laminitis induction dose (10 g of oligofructose/kg) 24 hours following the final loading dose (designated as 0 hours) via nasogastric tube. Serum glucose and insulin concentrations were measured before administration of the first loading dose (baseline) and at 0 and 24 hours; urine protein-to-creatinine (UP:C) ratio was determined at 0 hours and every 4 hours thereafter. Lameness was evaluated every 6 hours, and horses were euthanized when Obel grade 2 lameness was observed. Results - Mean ± SD time until euthanasia did not differ significantly between the heparintreated (28.9 ± 6.5 hours) and control (29.0 ± 6.9 hours) horses. The UP:C ratio was significantly increased from baseline at 20 to 28 hours after induction of laminitis (ie, 4 ± 4 hours before lameness was evident) in control horses but did not change significantly from baseline in heparin-treated horses. Serum glucose or insulin concentration did not change significantly from baseline in either group. Conclusions and Clinical Relevance - Urine protein excretion increased during the developmental stages of carbohydrate-induced laminitis in horses; administration of heparin prevented that increase, but did not delay onset or decrease severity of lameness.