ExoticRx · exoticrx.com/drugs/warfarin
US brand names:Coumadin, Jantoven
Warfarin is dosed at 0.05–0.2 mg/kg PO q24h in dogs, per Winter RL, Sedacca CD, Adams A, Orton EC. Aortic thrombosis in dogs: presentation, therapy, and outcome in 26 cases. J Vet Cardiol. 2012;14(2):333-342. doi:10.1016/j.jvc.2012.02.008; Smith SA. Antithrombotic therapy. Top Companion Anim Med. 2012;27(2):88-94.; Arai S, Callan MB. Warfarin therapy in a dog with acute arterial thrombosis and pyometra. Can Vet J. 2014;55(11):1066-1068.; Usechak PJ, Bright JM, Day TK. Thrombotic complications associated with atrial fibrillation in three dogs. J Vet Cardiol. 2012;14(3):453-458. doi:10.1016/j.jvc.2012.04.003 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.1345 (2026-08-01).. Verify against current literature before clinical use.
Inhibits vitamin K epoxide reductase, blocking synthesis of vitamin K-dependent clotting factors (II, VII, IX, X).
Narrow therapeutic index. Frequent PT/INR monitoring required. Numerous drug and dietary interactions. Hemorrhage is the main risk.
Species references:All Cat (Domestic) drugsAll Dog (Domestic) drugs
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A dog/cat sample is shown here. Cited dosing for all 2 species — reptiles, birds, pocket pets, livestock, and equine — is free on the per-species pages above. Pro adds the weight-based calculator for every species.
| Species | Route | Dose | Frequency | Evidence | Source |
|---|---|---|---|---|---|
| Dog (Domestic) | PO | 0.05–0.2 mg/kg | q24h | Moderate | Winter RL, Sedacca CD, Adams A, Orton EC. Aortic thrombosis in dogs: presentation, therapy, and outcome in 26 cases. J Vet Cardiol. 2012;14(2):333-342. doi:10.1016/j.jvc.2012.02.008; Smith SA. Antithrombotic therapy. Top Companion Anim Med. 2012;27(2):88-94.; Arai S, Callan MB. Warfarin therapy in a dog with acute arterial thrombosis and pyometra. Can Vet J. 2014;55(11):1066-1068.; Usechak PJ, Bright JM, Day TK. Thrombotic complications associated with atrial fibrillation in three dogs. J Vet Cardiol. 2012;14(3):453-458. doi:10.1016/j.jvc.2012.04.003 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.1345 (2026-08-01). |
| Cat (Domestic) | PO | 0.06–0.09 mg/kg | q24h |
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View PlansSource citations and evidence levels available on the live page. Reference only — verify against current literature before clinical use.
| Plumb's Veterinary Drug Handbook, 9th Ed |