Understanding Transitional Cell Carcinoma in Dogs and Cats

When your pet is straining to urinate or you notice blood in their urine, it’s natural to worry about an infection. But sometimes, the cause is more serious. Transitional Cell Carcinoma (TCC)—also called urothelial carcinoma—is a type of bladder cancer seen in both dogs and cats. Although not common, it can be an aggressive and challenging condition to treat, so early recognition and compassionate care are key.

What Is Transitional Cell Carcinoma?

The bladder is lined with special “transitional” cells that stretch and protect against the acidity of urine. When these cells grow uncontrollably, they can form tumors, most often near the neck of the bladder (where urine exits into the urethra). Because of this location, surgery is often difficult, and in many cases, the tumor can block urine flow.

Dogs—especially Scottish Terriers, West Highland White Terriers, Beagles, and Shelties—are more commonly affected, with the average age of diagnosis around 11 years. In cats, the disease is rarer, typically diagnosed around age 15.

What Causes It?

Like many cancers, there’s no single cause, but several factors may increase risk:

• Repeated exposure to carcinogens that are filtered through urine
• Female dogs tend to be at higher risk (possibly due to less frequent urination)
• In cats, males seem more affected
• Environmental exposures such as herbicide-treated lawns have been linked to increased risk in some breeds
• A study even suggested that feeding leafy green or yellow-orange vegetables several times a week may lower the risk in Scottish Terriers

Recognizing the Signs

Common symptoms can mimic a bladder infection, so it’s important not to dismiss them:

• Blood in the urine
• Straining to urinate
• Frequent urination or accidents
• Difficulty passing urine
• Lethargy or discomfort

Because urinary infections often occur alongside tumors, the two can look similar. If symptoms persist despite antibiotic treatment, your veterinarian will recommend further testing.

How We Diagnose TCC

At Grace Animal Hospital, we approach diagnosis step by step, beginning with the least invasive options.

1. Urinalysis and Culture:
We check for infection, inflammation, or abnormal cells. About one-third of TCC cases shed tumor cells detectable under the microscope.

2. Imaging:
If infection isn’t the cause, we use ultrasound or X-rays to look for bladder stones or growths. Ultrasound is especially helpful for seeing soft tissue masses.

3. BRAF Gene Test (for Dogs):
A newer, non-invasive urine test can detect a mutation seen in most canine TCC cases. It’s a valuable tool for breeds at risk or dogs showing symptoms.

4. Cystoscopy or Biopsy:
For a definitive diagnosis, we may recommend a referral to collect tissue samples using a small camera or surgical biopsy. This allows us to determine the exact type and extent of the tumor safely.

Treatment Options

TCC is a serious cancer, but several treatments can improve quality of life and, in some cases, extend survival. Treatment focuses on comfort, maintaining normal urination, and controlling tumor growth.

Surgery:
If caught early and located favorably, surgical removal of part or all of the bladder may be possible. However, because these tumors often occur near the bladder neck, full removal is usually not an option.

Chemotherapy & Anti-Inflammatory Medications:
Medications such as piroxicam, deracoxib, or mitoxantrone may slow tumor growth and relieve inflammation. Some dogs respond well to combinations of these drugs, with survival times ranging from several months to a year or more.

Laser Therapy or Stenting:
These minimally invasive options help open the urinary passage and reduce symptoms when surgery isn’t feasible. While not a cure, they can make daily life far more comfortable.

Radiation Therapy:
With modern imaging, radiation can target tumors more precisely, helping control growth while minimizing side effects.

Living with a Pet Diagnosed with TCC

A diagnosis like this is heartbreaking, but you’re not alone. Our team will help you navigate options that fit your pet’s needs and your family’s comfort level. Some pets live happily for months to over a year with supportive care and medication.

We may recommend working with a veterinary oncologist for advanced treatments or enrollment in clinical studies when appropriate.

Supporting Your Pet at Home

• Encourage hydration with fresh, clean water at all times
• Offer regular potty breaks to avoid bladder irritation
• Follow medication schedules carefully
• Keep track of appetite, energy, and bathroom habits—and let us know about changes

At Grace Animal Hospital, we know your pets are family. Our goal is to guide you through each step with clarity, empathy, and the highest level of care. If you’ve noticed changes in your dog’s or cat’s urinary habits, contact our team today. Early intervention can make all the difference.

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