Transitional cell carcinoma is a malignant tumor of the
transitional epithelium layer of the urinary tract. It commonly
affects the bladder but involvement of other parts of the urinary
system is also possible. The tumor spreads and causes thickening of
the bladder or tract wall resulting in function loss and possible
lumen obstruction. Spreading to other sites (lymph nods, lungs) in
the body is common. This tumor carries a grave prognosis with only
about four to six month survival time.
Older and middle aged dogs are at high risk, while cats are
rarely affected. The tumor is more common in females and has a
predilection for small breeds such as Scottish terrier, West
Highland white terrier, Shetland sheepdog, Eskimo dog and dachshund.
Signs may not be obvious at the beginning and include blood in
the urine, frequent and difficult urination, urinary incontinence
and house soiling. Treatment with antibiotics for presumed urinary
tract infection may be temporarily effective.
Diagnosis can be made by x-rays, ultrasound and bladder cytology.
Treatment is mainly medical. Local radiation treatment may prolong life but often result in bladder deformity and dysfunction. This tumor is prone to shed cancerous cells and surgery might increase metastasis (spreading to other parts) unless done under special precautions. Post surgical recurrence is also very likely. Effective medications include Piroxicam and Cisplastin.
Close monitoring of patients is necessary, as chemotherapy side
effects and tumor progression need to be addressed.