Canine transitional cell carcinoma (TCC), also known as urothelial carcinoma (UC), is the most common cancer of the canine urinary tract (1). Across all breeds the cancer represents an estimated 1-2% of all canine cancer, and with over 4-6 million cancers diagnosed in pet dogs each year in the US, the number of canine TCCs/UCs is estimated to exceed 50,000. However a group of 13 breeds, including the Beagle, has a much higher chance of developing the cancer. The cancer is generally a disease of mid to late life, with over 95% of cases occurring in dogs age 6 years and older. TCC/UC affects the bladder, urethra, and kidneys of male and female dogs and also the prostate of males. Clinical presentation of advancing TCC/UC is shared with other much more common urinary tract disorders, including cystitis and prostatitis. These may include one or more of the following: straining to urinate; repeated frequent attempts to urinate; blood in the urine; and bacterial infection.