Although urinary bladder cancer is only a small percentage (~2%) of all malignancies reported in dogs, transitional cell carcinoma (TCC) is the most common form of canine urinary bladder cancer, by far. TCC is most often found in the trigone region of the bladder, which can lead to urinary tract obstruction. TCC may also occur initially in the urethra up to the renal pelvis or prostate, and local and distant metastasis is common. Common sites of distant metastases include lymph nodes, liver, and lungs. There is a strong breed predisposition in Scottish Terriers and to a lesser degree in several other breeds. Exposure to some lawn chemicals and older flea products has been associated with increased risk. A diet with vegetables included three times per week may decrease risk. Common clinical signs include hematuria, dysuria, and pollakiuria. Recurrent urinary tract infections are common. Cystocentesis should be avoided so as not to seed tumor cells into the abdomen or skin. Treatment plans may include surgery, radiation therapy, and/or chemotherapy (local or systemic). Depending on the stage of detection, prognosis is improving as new treatment options develop.
Links to sections in The MVM:
Neoplasia of the Urinary System in Small Animals
References
Fulkerson CM, Knapp DW. Management of transitional cell carcinoma of the urinary bladder in dogs: a review. Vet J. 2015 Aug;205(2):217-25. doi: 10.1016/j.tvjl.2015.01.017
Budreckis DM, byrne BA, Pollard RE, Rebuhn RB, Rodriguez CO Jr, Skorupski KA. Bacterial urinary tract infections associated with transitional cell carcinoma in dogs. J Vet Intern Med. 2015 May-Jun:29(3):828-833. doi: 10.1111/jvim.12578