A 14-year-old, spayed female Beagle, presented to the Cornell University Hospital for Animals’ Oncology service for evaluation of a bladder mass. The patient had originally presented to her primary care veterinarian two months prior for signs of polyuria, pollakiuria, and hematuria. Urinalysis revealed an elevated number of cocci, white blood cells and red blood cells, consistent with a lower urinary tract infection, as well as many transitional cells in sheets. Following treatment of her urinary tract infection, a focused abdominal ultrasound was performed which revealed a mass near the trigone of the patient’s bladder. At that time, a transitional cell carcinoma was suspected, and the patient was referred to Cornell for further evaluation.