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. Journal of the…+1

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. Canadian Veteri… 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. Journal of Vete… Crystalloid support with lactated Ringer's solution at 10 mL/kg IV bolus is appropriate for volume resuscitation. Journal of the…

Vitamin K₁ (phytonadione) is the definitive antidote. The standard subcutaneous loading dose is 2.5–5 mg/kg/day SC or PO. Journal of Vete… 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. Journal of the… In life-threatening emergencies, intravenous vitamin K₁ at 10 mg/kg is appropriate as initial therapy. Tieraerztliche… 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. Australian Vete… 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. Open Veterinary…

Oral vitamin K₁ supplementation must continue for a minimum of 28 days after exposure to a second-generation AR (e.g., brodifacoum, bromadiolone, diphacinone). This duration applies even when the specific AR compound has not been identified. Journal of the… The oral maintenance dose is 3 mg/kg PO q24h. Journal of the… Coagulation times should be reassessed 48–72 hours after cessation of vitamin K₁ therapy to confirm that toxic concentrations of the compound are no longer present and that continued supplementation is not required. Journal of Vete…

Coagulation testing guides diagnosis and monitoring. PT is the most sensitive early marker of AR coagulopathy; both PT and activated partial thromboplastin time (aPTT) are markedly prolonged in most dogs with clinically significant hemorrhage. Journal of Vete… An activated clotting time (ACT) above 125 seconds (reference range 60–125 seconds) supports the diagnosis in the absence of full coagulation panel access. Journal of the… Blood AR concentrations do not correlate with PT prolongation or clinical severity and should not be used to guide treatment intensity. Journal of the… Predisposing factors that enhance AR toxicity include concurrent use of sulfonamides, phenylbutazone, aspirin, or chloramphenicol, as well as hypoalbuminemia, liver disease, and renal disease. Journal of the…

Hemorrhage distribution is broad — do not anchor on a single site. The most common hemorrhage locations are the pleural space (37–43%), pulmonary parenchyma (24%), abdomen (24%), skin/subcutaneous tissue (21%), and gastrointestinal tract (18%). Canadian Veteri…+1 Upper airway obstruction from pharyngeal, laryngeal, or tracheal hemorrhage is a rare but recognized presentation requiring prompt coagulopathy treatment. Journal of the… Neurologic signs from intracranial or spinal hemorrhage can mimic bromethalin toxicosis and should prompt coagulation testing when scleral hemorrhage or venipuncture site bleeding is present. Canadian Veteri…+1 Pericardial effusion with tamponade is a described but uncommon presentation. Open Veterinary…

Would you like guidance on how to manage the dog that re-presents with recurrent coagulopathy after completing a 28-day vitamin K₁ course?