What Is Transitional Cell Carcinoma?
Transitional cell carcinoma (TCC), also called urothelial carcinoma, is a cancer of the cells lining the urinary tract and the most common bladder cancer in dogs. It usually affects older dogs, around 9 to 11 years of age, and is somewhat more common in females. The tumor often grows near the neck of the bladder, where urine flows out, and can extend into the urethra and, in males, the prostate.
Scottish Terriers have by far the highest risk, and West Highland White Terriers, Shetland Sheepdogs, Beagles, and Wire Fox Terriers are also overrepresented. Studies have linked exposure to certain lawn herbicides and older-generation flea dips, along with obesity, to a higher risk. TCC is locally invasive and can spread to lymph nodes, lungs, and bones.
Why it matters
TCC signs look just like a urinary tract infection, and they may improve briefly on antibiotics. Repeated or stubborn urinary signs in an older dog are a reason to look further.
Signs Owners Notice
- Blood in the urine
- Straining to urinate, passing small amounts often, or dribbling
- Accidents in the house in a previously house-trained dog
- Urinary signs that keep coming back after treatment for a UTI; compare dog UTI symptoms
- Later: weight loss, lethargy, limping, or coughing if the cancer has spread
Diagnosis
Your vet will start with a urinalysis, urine culture, and bloodwork, then use ultrasound to look at the bladder, which also helps rule out bladder stones. A urine test that looks for a BRAF gene mutation found in most canine TCC can support the diagnosis. Confirming the cancer usually needs a tissue sample collected with a catheter or a camera (cystoscopy). Needle sampling through the belly wall is generally avoided because it can spread tumor cells. Chest X-rays and abdominal imaging help with staging.
Treatment and Outlook
- Anti-inflammatory medicine: certain NSAIDs, such as piroxicam, have a direct anti-tumor effect and improve comfort for many dogs.
- Chemotherapy: often combined with an NSAID to slow tumor growth.
- Radiation therapy: used in some cases to control the tumor and relieve signs.
- Surgery: rarely able to remove the tumor completely because of its location, but may be possible for tumors away from the bladder neck.
- Urethral stent: a tube that keeps urine flowing if the tumor blocks the outflow.
TCC is rarely curable, but treatment can keep many dogs comfortable with good quality of life for months to a year or more. Dogs on an NSAID alone often have shorter survival than those also receiving chemotherapy. Costs for imaging, cystoscopy, and chemotherapy can add up, so ask for an itemized estimate and check pet insurance for cancer treatment before diagnosis if you own a high-risk breed.
Practical Tips for US Pet Owners
- If you own a Scottish Terrier or other high-risk breed, ask your vet about periodic urine screening from about age 6.
- Keep dogs off lawns recently treated with herbicides, and keep your dog lean.
- Review general dog cancer warning signs with your family.
- Find a nearby practice through veterinary clinic listings.
When to see a vet
Book a visit for blood in the urine or straining that lasts more than a day or two. Go to an emergency clinic right away if your dog is straining but passing little or no urine.
Key Takeaways
- TCC is the most common bladder cancer in dogs, mostly in seniors.
- Scottish Terriers and several other breeds have a much higher risk.
- NSAIDs, chemotherapy, and stents can control signs and extend quality time.
FAQ
Is blood in my dog’s urine always cancer?
No. Infections and stones are more common causes, but signs that keep returning should be investigated.
Can cats get transitional cell carcinoma?
It is rare in cats. Bloody urine in cats is usually caused by cystitis, crystals, or stones.
What is the BRAF urine test?
It detects a gene change found in most canine bladder TCC and can help support a diagnosis, sometimes before a mass is visible.