Acute kidney injury from presumptive intramural ureteral hemorrhage secondary to diphacinone rodenticide exposure in a dog

Objective To describe the clinical features and outcome of a dog with anticoagulant rodenticide (diphacinone) exposure, which was subsequently diagnosed with a coagulopathy characterized by hemoperitoneum, and presumptive ureteral wall hemorrhage contributing to acute kidney injury (AKI). Case Summary A 4‐year‐old, female neutered Australian Cattle Dog was evaluated for an acute onset of lethargy, decreased appetite, and a mild right thoracic limb lameness. Radiographs and point of care ultrasound demonstrated retroperitoneal and peritoneal effusion. Diagnostic abdominocentesis confirmed hemorrhagic effusion. Complete blood count, biochemistry, and coagulation profile showed a regenerative anemia (PCV 32%), thrombocytopenia (platelets 96 × 109/L [96 × 103/µl]), azotemia (BUN 38.9 mmol/L [109 mg/dl], creatinine 512.8 µmol/L [5.8 mg/dl]), and coagulopathy (prothrombin time >100 s, activated partial thromboplastin time >42.3 s). The client reported access to anticoagulant rodenticide up to 72 hours prior to presentation. Ultrasonographic examination revealed bilateral pyelectasia and hydroureter with thickened distal ureteral walls at the level of the ureteral–vesicular junctions. The ultrasonographic conclusion was presumptive intramural ureteral hemorrhage resulting in ureteral obstruction. The patient was diagnosed with AKI with likely prerenal, renal, and postrenal components. Treatment included vitamin K and frozen plasma transfusion. The patient recovered fully and was discharged 3 days after presentation. Two days after discharge, the patient had improvement in azotemia (BUN 10.7 mmol/L [30 mg/dl], creatinine 176.6 µmol/L [2.0 mg/dl]). Gas chromatography–mass spectrometry confirmed presence of diphacinone in the blood. Repeat ultrasound and biochemistry 60 and 210 days, respectively, after discharge showed resolution of ureteral wall thickening, hydroureter, pyelectasia, and recovery of kidney parameters. New or Unique Information Although nephropathies secondary to anticoagulant therapy have been described in people, the authors believe this is the first report of diphacinone anticoagulant rodenticide exposure contributing to an AKI secondary to obstruction from ureteral wall hemorrhage in the veterinary literature.