An atypical presentation of anticoagulant rodenticide toxicosis in a dog.

A 5-month-old intact female Australian shepherd dog was referred to our clinic for neurologic signs including ataxia, a head tilt, and altered mentation following consumption of an unidentified rodenticide several days prior to developing clinical signs. A provisional diagnosis of bromethalin toxicosis had been made, given the neurologic signs seen and the general increased use of bromethalin-containing rodenticide products. However, on physical examination, the dog was noted to have scleral hemorrhage and bleeding at the venipuncture sites, which was inconsistent with bromethalin toxicosis. Coagulation testing was supportive of anticoagulant rodenticide toxicosis and the rodenticide was later identified as the first-generation anticoagulant rodenticide diphacinone. The neurologic signs seen were attributed to a coagulopathy causing multifocal hemorrhage into the central nervous system. Neurologic signs rapidly resolved following treatment with a frozen plasma transfusion and vitamin K1. This atypical presentation of an anticoagulant rodenticide toxicosis highlights the need for accurate product identification, if available, and thorough patient examination and laboratory testing. An atypical presentation of anticoagulant rodenticide toxicosis should be considered when neurologic signs are present with clinical bleeding, especially if the type of rodenticide is unknown, or even if it was not thought to have an anticoagulant as the active ingredient. Key clinical message: Given the change in commercially available rodenticide products, this case highlights the need for accurate product identification in cases of suspected toxicosis, and the variable clinical signs that can be seen following anticoagulant rodenticide toxicosis.