Related Experiment Video
Updated: Apr 8, 2026
Ferric Chloride-induced Canine Carotid Artery Thrombosis: A Large Animal Model of Vascular Injury
Published on: September 7, 2018
Effects of dipyrone, meloxicam, or the combination on hemostasis in conscious dogs
Felipe S Zanuzzo1, Francisco J Teixeira-Neto2, Camila M Thomazini3
1Department of Anesthesiology, Faculdade de Medicina, Universidade Estadual Paulista (UNESP), CEP 18618-970, Botucatu, Brazil.
Objective:
To compare the effects of dipyrone, meloxicam, and of the combination of these drugs on hemostasis in dogs.
Design:
Prospective, blinded, randomized crossover study.
Setting:
Research laboratory at a veterinary teaching hospital.
Animals:
Six adult dogs.
Interventions:
Animals received 4 intravenous treatments with 15-day washout intervals: control (physiological saline, 0.1 mL/kg), meloxicam (0.2 mg/kg), dipyrone (25 mg/kg), and dipyrone-meloxicam (25 and 0.2 mg/kg, respectively). A jugular catheter was placed for drug injection and for collecting samples for whole blood platelet aggregation (WBPA) and thromboelastometry assays at baseline, 1, 2, 3, 5, and 8 hours after treatment administration. The percent change from baseline of lag time and of the area under the curve (AUC) of impedance changes in response to collagen-induced platelet activation were recorded during WBPA. Thromboelastometry-derived parameters included clotting time, clot formation time, alpha-angle, and maximum clot firmness. The buccal mucosal bleeding time was evaluated by a blinded observer at baseline, 1, 3, and 5 hours after treatment injection.
Measurements And Main Results:
No significant changes in WBPA and thromboelastometry were recorded in the control treatment. Dipyrone significantly (P < 0.05) increased the lag time for 2 hours and decreased the AUC for 3 hours after injection. Meloxicam did not alter WBPA. Dipyrone-meloxicam significantly increased lag time for 2 hours and decreased the AUC for 5 hours after treatment injection. Experimental treatments did not differ from the control treatment for thromboelastometry and buccal mucosal bleeding time.
Conclusions:
While meloxicam does not alter hemostasis by the methods evaluated, dipyrone inhibits platelet aggregation for up to 3 hours. Meloxicam-dipyrone combination causes more prolonged inhibition of platelet function than dipyrone alone. Decreased platelet aggregation induced by dipyrone and dipyrone-meloxicam does not appear to impact the viscoelastic properties of the blood clot nor increase the risk of bleeding in dogs without preexisting hemostatic disorders.
