A 14-month-old female dog presented with a 7-month history of pollakiuria, hematuria, and stranguria. The dog had been treated with various antibiotics, under the assumption that the problem was recurring urinary tract infections, but only partial improvement of clinical signs was noted. The urinary bladder wall felt thickened. An ultrasonographic examination of the abdomen was performed, using a 5-8-MHz linear transducer. Multilobulated masses were seen in the area of the ureteral papillae. These masses were heterogeneous and hypoechoic in relation to the bladder wall and bulged into the lumen of the bladder. The bladder neck wall was irregularly thickened, the lumen of the bladder neck was narrowed secondary to the protruding masses, and thickening of the urethral wall was noted. Because this was a long-standing clinical problem, the dog was taken to surgery rather than attempting an ultrasound-guided biopsy. A multilobulated mass with multiple cystic lesions was attached to the mucosal surface of the urinary bladder, affecting the entire circumference of the bladder neck. The mass was extirpated with forceps. The histopathologic diagnosis was fibrosarcomas in the lamina propria of the urinary bladder wall. The dog did poorly after surgery and was euthanized. On postmortem examination, multiple metastatic masses were found in the liver and lungs. Fibrosarcomas of the bladder are unusual in dogs and extremely rare in dogs this age.

COMMENTARY: Although tumors of the urinary bladder are rare in dogs, this case demonstrates the importance of looking for reasons for chronic or recurrent urinary tract infections.

A urinary bladder fibrosarcoma in a young dog. Olausson A, Stieger SM, Loefgren S, Gillingstam M. VET RADIOL ULTRASOUND 46:135-138, 2005.