What is the treatment algorithm for anticoagulant rodenticide toxicity in a dog including Vitamin K dosing duration?

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Anticoagulant rodenticide (AR) toxicity in dogs is treated in two phases: immediate stabilization with clotting factor replacement and vitamin K₁, followed by prolonged oral vitamin K₁ supplementation for a minimum of 28 days. Survival with adequate treatment is 98.7%, and 86% of dogs with AR-induced hemorrhage survive to discharge. 47 For the clinically bleeding dog, stabilization takes priority. Fresh frozen plasma (FFP) is the most commonly administered blood product and is the first-line source of clotting factor replacement. 7 Cryosupernatant (CS) is an alternative to FFP for clotting factor replacement; at a median dose of 11.0 mL/kg IV, CS reduces prothrombin time (PT) from a median of 697% above the control reference range to 98% above it, with resolution of clinical hemorrhage in 6 of 7 dogs treated. CS contains lower factor IX activity than FFP and is therefore a secondary option. 10 Crystalloid support with lactated Ringer's solution at 10 mL/kg IV bolus is appropriate for volume resuscitation. 1 Vitamin K₁ (phytonadione) is the definitive antidote. The standard subcutaneous loading dose is 2.5–5 mg/kg/day SC or PO. 6 One published case used a loading dose of 2.58 mg/kg SC followed by 1.29 mg/kg SC q12h the next day, then transitioned to 3 mg/kg PO q24h at discharge. 1 In life-threatening emergencies, intravenous vitamin K₁ at 10 mg/kg is appropriate as initial therapy. 5 Intravenous mixed-micelle phytomenadione (MMP) is a safe alternative to traditional blood product therapy — no adverse reactions were recorded in dogs receiving MMP, and dogs treated with MMP had significantly shorter hospitalization times compared to those receiving traditional therapy, with no difference in survival to discharge. 8 One case of severe hemopericardium used IV vitamin K₁ at 5 mg/kg BID with complete echocardiographic resolution of pericardial effusion and thickening within 12 hours. 9 Oral vitamin K₁ supplementation must continue for a minimum of 28 days after exposure to