Vitamin K therapy improves hemostasis in Vitamin K deficient patients. It is often initiated pending test results, but maintenance of vitamin K is not indicated for patients having diagnoses of thrombocytopenia, hereditary factor deficiencies, or DIC.
Anticoagulant rodenticide toxicities are the most common cause of severe vitamin K deficiency in dogs and cats. Vitamin K reverses the anticoagulant effect of rodenticides over a period of 24 to 48 hours from initiation of therapy. Other vitamin K deficient states include: biliary obstruction, intrahepatic cholestasis, intestinal malabsorption and chronic oral antibiotic administration.
Warfarin is a relatively short-acting rodenticide, and treatment for a total of 1 week usually is adequate.
To treat toxicity from second-generation, or long-acting rodenticides (bromadiolone, brodifacoum, or diphacinone, pindone):
Vitamin K for preoperative prophylaxis should be given at 1.1 mg/kg SQ q. 12 h for 1 to 2 days before surgery.
Subcutaneous injection of Vitamin K1 is the preferred parenteral route of administration because intravenous Vitamin K1 can cause anaphylaxis, and hematomas may form at intramuscular sites. Vitamin K3 (Synkayvite, Roche) is not effective for treating rodenticide toxicity due to its delayed onset of action.