Anticoagulant rodenticide toxicity in dogs: A retrospective study of 349 confirmed cases in Saskatchewan.

OBJECTIVE: To evaluate the signalment and clinical, laboratory, treatment, and outcome features of dogs diagnosed with anticoagulant rodenticide (AR) intoxication in Saskatchewan.

ANIMALS: We studied 349 dogs.

PROCEDURE: Medical records from the Veterinary Medical Centre (Saskatoon, Saskatchewan) between 1999 and 2022 were reviewed. Cases were included if they met at least 1 of the following criteria: owner witnessed the dog ingesting an AR; AR was seen in the vomitus when emesis was induced; the dog had clinical signs of coagulopathy, with elevation of PT ± aPTT that normalized after vitamin K1 therapy, in the presence of appropriate clinical and paraclinical data and the absence of other causes of hypocoagulable state determined by the primary clinician.

RESULTS: Fifty-three percent of cases were seen between July and October. Most dogs (61%) came from an urban setting. Ninety-two percent of dogs ingested a 2nd-generation AR and the most frequent toxin was bromadiolone. Clinical signs were reported in 30% of AR intoxications and included lethargy (86%), dyspnea (55%), and evidence of external hemorrhage (44%). The most common site of hemorrhage was the pleural space, accounting for 43% of hemorrhage sites. Consumptive thrombocytopenia was reported in 24% of dogs with evidence of AR-induced hemorrhage, with moderate (platelet count < 60 K/μL) and marked (< 30 K/μL) thrombocytopenia in 7/12 and 2/12 dogs, respectively. Blood products were administered to 84% of dogs with AR-induced hemorrhage; the most common product administered was fresh frozen plasma (56% of cases). Among dogs with AR-induced hemorrhage, those that received blood products were more likely to survive to discharge (81%) compared to those that did not (19%) ( P = 0.017). Eighty-six percent of dogs with AR-induced hemorrhage survived to discharge.

CONCLUSION AND CLINICAL RELEVANCE: The pleural space was the most common site of hemorrhage. Moderate thrombocytopenia was a common finding. Eighty-six percent of dogs with AR-induced hemorrhage survived to discharge.