FR
ENWhat is transitional cell carcinoma?
Transitional cell carcinoma (TCC) is a malignant, invasive cancer of the urinary system arising from the lining cells of the bladder. It is the most frequently reported urinary tract tumor in cats. Unlike dogs (where the tumor often sits near the trigone), in cats it tends to form at the apex of the bladder, potentially leaving more surgical options.
Vesical TCC (apex of the bladder)
The most common location in cats. The tumor develops at the top or on the walls of the bladder, progressively invading muscle layers and disrupting normal bladder filling and emptying.
TCC of the urethra or ureters
TCC can also occur in the urethra, ureters, or kidneys. Urethral involvement significantly increases the risk of complete urinary obstruction: a life-threatening emergency.
Invasive TCC (muscle wall invasion)
TCC can penetrate the deep muscle layers of the bladder wall. This local invasion reduces surgical options and worsens prognosis, making complete resection more difficult.
Metastatic TCC
Approximately 20% of cats already have metastases at the time of diagnosis, primarily to regional lymph nodes, lungs, or other organs. The presence of metastases considerably worsens prognosis.
Risk factors include advanced age, male sex, and prior environmental exposures (older pesticides, insecticides, previous-generation flea products). Symptoms often closely resemble a urinary infection or FLUTD; thorough investigation is essential when standard treatments fail to resolve the issue.
Signs and symptoms
TCC signs closely resemble those of a urinary infection or feline lower urinary tract disease (FLUTD). A cat treated for these conditions without lasting improvement should have a more thorough workup to rule out TCC.
Early stage
- •Difficulty urinating (straining), prolonged efforts
- •Pink or bloody urine (hematuria)
- •Excessive licking of the genital area
- •Hunched posture during urination
- •Abdominal pain on palpation
- •Lethargy, prolonged sleeping, less engagement
Intermediate stage
- •Progressive weight loss
- •Very frequent urination, often in very small amounts
- •Increased thirst (polydipsia)
- •Recurrent urinary infections despite treatment
- •Eliminating outside the litter box (discomfort during urination)
Advanced stage
- •Isolation, withdrawal, loss of interest in surroundings
- •Anorexia, nausea, vomiting
- •Diarrhea or constipation
- •Over-grooming of the abdomen and genital area (pain)
- •Skin lesions from urine irritation
When to seek immediate help?
Some signs constitute a life-threatening emergency. Go immediately to a veterinarian or emergency clinic if you observe:
- Complete inability to urinate, absolute emergency (risk of bladder rupture and fatal toxicity within hours)
- Respiratory distress: intense panting, open-mouth breathing
- Bluish or very pale gums (cyanosis or severe anemia)
- Sudden collapse or inability to stand
- Uncontrollable vomiting or diarrhea
- Intense pain: abnormal vocalizations, very rigid abdomen
How is the diagnosis made?
TCC diagnosis requires several steps, as symptoms resemble other urinary conditions. Early diagnosis improves the therapeutic options available.
Clinical examination and tests
Abdominal palpation and complete symptom history. Full blood and urine analysis (urinalysis, culture, cytology, crystal evaluation). A mass may sometimes be palpated in the abdomen.
Imaging
Abdominal X-rays and bladder ultrasound to visualize a mass, assess its extent, and detect involvement of lymph nodes or adjacent organs. CT scan provides a more precise staging assessment.
Biopsy and staging
Biopsy via endoscopy (cystoscopy) or exploratory surgery to confirm TCC and establish tumor grade. Chest X-rays and advanced imaging to detect potential distant metastases.
Treatment and management: multimodal approach
TCC treatment aims to control tumor growth, relieve symptoms, and maintain quality of life. No single approach definitively cures TCC; the goal is long-term control.
- NSAIDs (piroxicam, meloxicam): certain anti-inflammatory drugs show direct anti-tumor activity on TCC cells. Regular kidney function monitoring is essential for long-term use.
- Chemotherapy: IV or oral protocols (metronomic low-dose daily regimens) to improve remission or stabilize the tumor. Often combined with NSAIDs.
- Infection control: regular urine cultures and analyses, appropriate antibiotics to treat frequent secondary urinary infections.
- Surgery: tumor removal if localized and sufficient resection is possible. Apex location (common in cats) sometimes allows a more complete resection than in dogs.
- Radiation therapy: effective for local mass control. Can cause side effects (inflammation, ulcers) - tolerance varies between cats.
- Laser ablation: endoscopically guided reduction of tumor mass to relieve obstruction and improve quality of life without open surgery.
- Urinary stent: small tube placed in the urethra or ureter to bypass the tumor and allow urine flow in cases of partial or complete obstruction.
- Cystostomy tube: tube directly connecting the bladder to the abdominal wall for severe obstruction cases not correctable otherwise.
- Diet and hydration: wet food to maximize fluid intake, filtered water or water fountain to encourage drinking and dilute urine.
What to expect long-term?
Prognosis depends on the precise location of the tumor, degree of local invasion, presence or absence of metastases, and response to treatment.
Consultation with a veterinary oncologist is strongly recommended to develop the most appropriate treatment plan for your cat's specific situation.
Home management tips
To implement
- Strictly follow the medication protocol (NSAIDs, chemotherapy, antibiotics)
- Place multiple low-sided litter boxes in strategic locations
- Clean litter boxes frequently to encourage regular urination
- Prioritize wet food to maximize fluid intake
- Provide fresh filtered water or a water fountain
- Monitor appetite, weight, urination frequency and appearance daily
- Keep the cat indoors to better observe urinary habits
- Keep a journal of 'good' and 'bad' days to track progression
- Trim fur around the genital area if needed for hygiene
- Minimize stress with pheromones (Feliway®) and a calm environment
Never do
- Ignore a cat that has not produced urine for more than 12–24 hours : life-threatening emergency
- Adjust medication doses without veterinary guidance (kidney risk with NSAIDs)
- Give human pain medications (acetaminophen is toxic to cats)
- Wait for symptoms to worsen before consulting
Always
- Maintain regular veterinary follow-up with urine and blood tests
- Report any behavioral change or urinary change to the veterinarian
- Consult a veterinary oncologist for complex therapeutic decisions
Frequently asked questions
Is TCC curable in cats?
How can TCC be distinguished from a simple urinary infection?
Do anti-inflammatory drugs (NSAIDs) really work against cancer?
Is my cat suffering? How do I assess quality of life?
Is it essential to see a veterinary oncologist?
This guide is provided for informational and educational purposes only. It does not constitute veterinary medical advice and is not a substitute for a consultation with a qualified veterinarian. Every animal is unique and their health must be evaluated individually. If you have concerns about your pet's health, contact our clinic or consult a veterinarian promptly.
Is your cat showing concerning urinary signs?
Our veterinary team can evaluate your cat and direct you toward the appropriate diagnostic tests and specialists for optimal management.