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). — Plumb's 10th ed (held) printed p.1318, Warfarin monograph spanning p.1317-1318; page located 2026-08-05 from the book's own running heads, and carries this exact dose under the matching species heading. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207. 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
Each ExoticRx dose rule is graded by the strength of its primary evidence — see the editorial process.
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). — Plumb's 10th ed (held) printed p.1318, Warfarin monograph spanning p.1317-1318; page located 2026-08-05 from the book's own running heads, and carries this exact dose under the matching species heading. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207 |
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View PlansSource citations and evidence levels available on the live page. Reference only — verify against current literature before clinical use.
| Cat (Domestic) |
| PO |
| 0.06–0.09 mg/kg |
| q24h |
| Weak |
| Papich MG. Saunders Handbook of Veterinary Drugs, Warfarin Sodium, printed p.848-849 - "Initial doses in cats have ranged from 0.06-0.09 mg/kg (0.25-0.5 mg/cat/day)" with the dosage table at printed p.849 giving "Cats - Start with 0.25-0.5 mg/cat/day". WARN - Plumb's 10th ed printed p.1317-1318 prints NO feline warfarin dose and states "Use in cats is not recommended" and "an increased mortality rate and a high rate of significant adverse events, including fatal hemorrhage". |