Bladder Cancer in Dogs: Vet-Verified Causes, Symptoms, and Treatments

Bladder cancer in dogs is a rare condition (2% of cases) compared to other cancers that develop in other areas of the body.

Symptoms of bladder cancer in dogs may include sudden weight loss, bloody urine, discolored urine, and recurrent urinary infections.

This type of cancer occurs frequently in males compared to females. Some dog breeds are more prone to this type of cancer (e.g., Scottish Terrier, Beagle, Fox Terrier). Several factors can contribute to the development of bladder cancer in dogs, such as pollution, chemical substances, genetic predisposition, or sex.

The most commonly used treatment for bladder cancer is chemotherapy, although surgery is a great option when the tumor is reachable.

What Is Bladder Cancer in Dogs?

The urinary bladder is an organ like a balloon. It is found in the lower part of the abdomen and has the role of storing urine. The structure of the urinary bladder is made up of a muscular wall that allows it to stretch to store more urine. The bladder is covered by a mucous membrane. Urine is produced by the kidneys, which, together with the urinary bladder, help eliminate toxins from your pet's body.

Bladder cancer occurs when cells multiply without control. The most common form of bladder cancer is located in the muscle layer.

How Common Is Bladder Cancer in Dogs?

About 2% of all tumors in dogs are bladder tumors; therefore, it is a rare cancer. The most common form of bladder cancer in dogs is called transitional cell carcinoma (TCC) – in 90-95% of cases. This form of cancer can have an intermediate to high grade. Tumor grading refers to describing tumor cells under a microscope – whether they appear normal or abnormal. The more abnormal they are, the higher the grading and the worse the prognosis (chance of survival/recovery or recurrence).

TCC is a malignant cancer (i.e., it metastasizes at a distance – it spreads to the other organs and tissues of the body). This cancer develops in the mucous layer (from the transition cells in this layer). Unlike humans, TCC in dogs is invasive and can grow and spread quickly throughout their body. In dogs, TCC can also invade the muscular layer of the urinary bladder. The bigger the bladder tumor, the more it can block the urine flow.

Although this type of cancer is most often found in the bladder, TCC can also occur in the kidneys, urethra, ureters, or prostate.

Understanding Transitional Cell Carcinoma vs. Other Bladder Tumors

As mentioned earlier, TCC is the most common bladder cancer in dogs. It develops in the transitional epithelial cells that line the inside of the bladder wall, forming a protective barrier between the urine and the bladder wall. In the case of TCC, these cells begin to grow uncontrollably and chaotically, which leads to the formation of an invasive tumor that penetrates the muscular wall of the bladder.

TCC is an aggressive cancer that grows quickly. In addition, it has a tendency to spread throughout the body to other organs (e.g., urethra, lungs, liver, or in rare cases, to the bone).

The most common treatment for TCC is chemotherapy. Surgical treatment is often difficult, especially when the tumor develops in the trigone of the urinary bladder (formed by the two ureteric orifices and the internal urethral orifice). However, most of the time the life expectancy of dogs diagnosed with TCC is low.

Another type of bladder cancer in dogs is leiomyosarcoma. This is a rare type of bladder cancer that originates in the smooth muscle lining the bladder wall – it usually occurs in the gastrointestinal tract.
Leiomyosarcoma grows more slowly than TCC and has a lower rate of metastasis. If surgical treatment is elected, it can sometimes be curative if the cancer is detected early.

Fibrosarcoma is another rare type of bladder tumor. It develops from within the bladder wall, which can lead to thickening and obstructions.

Rhabdomyosarcoma is usually seen in young dogs, originating from immature muscle cells. It has an unpredictable growth pattern.

There are also benign bladder tumors, such as papillomas or polyps. These are usually not cancerous and can cause clinical signs such as blood in the urine and straining to urinate. In some cases, they can turn into malignant tumors if left untreated.

What Causes Bladder Cancer in Dogs?

The exact causes of bladder cancer in dogs are not known. In general, several factors contribute to the occurrence of bladder cancer, such as: genetic predisposition, environmental, physical, and chemical factors, sex, recurrent infections, or polyps.

1. Genetic Predisposition

Certain breeds are more prone to bladder cancer: Scottish Terriers (have an 18-20 times higher risk), Beagles, Westies, Fox Terriers, American Eskimo Dogs, Australian Cattle Dogs and Shepherds, Border Collies, Russel Terriers, and their half-breeds.

2. Environmental Factors

Examples for environmental factors are pollution, pesticides, insecticides, or second-hand smoke. Recent studies show that Scottish Terrier dogs that came from an environment where smoking was involved developed bladder cancers. Also, in this breed, a link was found between exposure to herbicides and pesticides and an increased risk of TCC – dogs exposed to these substances with which the lawn is treated had a significantly higher risk of developing transitional cell carcinoma. The conclusion would be that this breed should be restricted from treated lawns to reduce the risk of developing TCC.

3. Chemical Factors

Chlorine in drinking water and some drugs can lead in time to bladder cancer in dogs.

4. Physical Factors

Physical factors such as bladder stones (urolithiasis) have a local mechanical-irritating action, which in time can lead to the development of bladder tumors.

5. Sex

Males predominantly develop this type of cancer; the ratio being 3:1, compared to females.

6. Persistent Urinary Tract Infections

Although it is not exactly known if persistent urinary infections lead to bladder cancer, there is a possibility that these recurrent infections increase the risk of developing this type of cancer. In humans, studies show that people with persistent urinary infections developed bladder cancer over time (being more prevalent in men).

Symptoms of Bladder Cancer in Dogs

Bladder cancer in dogs used to occur in pets aged 7-8 years old. However, new data shows that the age of appearance of this type of cancer has dropped to 3-4 years.

Early signs of bladder cancer in dogs may include the following:

• Frequent urination with small amounts of urine
  
• Difficulty urinating
• Urinary accidents in the house
• Other clinical signs of bladder cancer in dogs may include:
• Low appetite
• Weight loss
• Bloody urine (hematuria)
• Lethargy

Remember that the clinical signs of bladder cancer in dogs can also occur in other non-cancerous conditions. These symptoms are usually common with those of urinary tract infections. So, it is vital to go with your dog to the vet's office for a proper diagnosis and treatment.

Early Warning Signs Owners Often Miss

Early signs of bladder cancer in dogs can be overlooked or mistaken for milder medical conditions, such as urinary tract infections or bladder stones. As a result, in the early stages of bladder cancer, dogs may try to urinate more frequently or appear uncomfortable when urinating. Sometimes these may be seen as “accidents” by their owners.

Another clinical sign that may occur in the early stages is straining to urinate (dysuria). Dogs may appear to be “struggling” to urinate – they may also show signs of discomfort. In some cases, only small amounts of urine may be produced or not at all. Urination may be painful – dogs may whine or show discomfort during or after urination. This sign can easily be mistaken for urinary tract irritation.

Blood in the urine may also be noticeable at times. It can appear very subtly, giving the urine a pinkish color, or it can appear as spots. It can be easily overlooked if the urine is not carefully checked.

Dogs that are trained to urinate only outside may start having accidents inside. Often, their owners may attribute these accidents to behavioral problems or aging.

Affected dogs may lick their genital area excessively, trying to soothe irritation or discomfort.

Decreased appetite and/or lethargy are common signs of many conditions, including bladder cancer. They appear especially as the disease progresses. However, they can also start subtly early on.

Here is why these signs can be easily overlooked:

• They resemble common urinary tract infections or bladder stones.
• Dogs are good at masking pain and discomfort.
• Symptoms may be intermittent or mild at first.
• Owners may delay veterinary visits, hoping that the clinical signs will resolve on their own.
  

If you notice these clinical signs, seek prompt veterinary evaluation and ask for a urinalysis, urine culture, and abdominal ultrasound. Early diagnosis can improve treatment options and prognosis.

What Are the Final Stages of Bladder Cancer in Dogs?

The disease can progress so much that it will end up affecting other tissues or organs. The final stages of bladder cancer in dogs may include the following clinical signs:

• Shortness of breath (when the cancer spread to the lungs)
• Lameness and sitting and walking issues (when the cancer spread to the bones)
• Constant pacing
• Vomiting
• Refusal of food (anorexia)
• Further weight loss
• Painful abdomen
• Behavioral changes
  

Bladder cancer in dogs can cause pain when your pet is straining to urinate or when it spreads to the bones. So, it is best to talk to a vet or an oncologist about pain management.

Bladder Cancer in Dogs: When to Euthanize?

When bladder cancer in dogs reaches the final stages, euthanasia is required in order not to let your pet suffer. If the surgery to remove the tumor is not possible and it completely blocks the passage of urine, the dog can die in 1-2 days. To end the pet's suffering, human euthanasia should be considered.

Bladder Cancer in Dogs: When to Contact the Vet?

You should contact the vet when you notice changes in your dog's routine. For example, go to the vet when your pet starts straining when urinating, when accidents happen around the house, when they have difficulty breathing, when they vomit or stop eating, etc. It is important to take your dog to the vet in order to be able to diagnose the disease and treat it properly. In addition, early detection of bladder cancer in dogs can increase their chances of recovery and survival.

How Is Bladder Cancer in Dogs Diagnosed?

Bladder cancer, as well as prostate cancer, are among the most aggressive and most difficult to detect. To detect this type of cancer, a series of tests and exams are necessary, such as:

1. Clinical examination of the animal – The physical examination will highlight various changes (presence of pain, color of mucous membranes, coat's aspect, proprioception, lameness, etc.)
2. Abdominal ultrasound – It is easily done when there is a satisfactory urine volume in the bladder. The ultrasound allows the identification of abnormal growths; the tumors presence is accompanied by localized changes in the bladder wall.
3. Urinary cytological examination – This exam evaluates the cell types that are found in the urine. In the case of cancer, cancerous cells will be found in the urine; in this way the cancer can also be diagnosed (what type of cancer it is).
4. Cystoscopy – The purpose of this exam is to evaluate the bladder’s mucosa for possible growths.
5. CADET BRAF testing – A diagnostic DNA test that detects the presence of a single mutation present in 85% of confirmed TCC cases.
6. Tumor biopsy – Through this exam, the pathologist can tell what kind of cancer it is (its type) and whether it is low-grade or high-grade.
7. Blood tests, especially blood biochemistry
8. Urine summary

Prognosis for Dogs with Bladder Cancer

Unfortunately, high-grade cancers are aggressive and can grow and spread quickly. As a result, the prognosis for this type of cancer is poor. Dogs that do not receive treatment can survive 4-6 months from diagnosis, while those that receive treatment can survive 6-12 months from diagnosis.

How Is Bladder Cancer in Dogs Treated?

Regarding the treatment of bladder cancer in dogs, the therapy can be local, general, or a combination of them.

Local therapy involves the surgical removal of the tumor from the urinary bladder in cases where this is possible. Not all urinary tumors are operable - sometimes, due to the location of the tumor, its complete removal may be impossible and, then, partial removal will be resorted to relieve your dog's symptoms. Keep in mind that the tumor will grow back after a while if it is partially removed. Local therapy can also involve radiation therapy – this therapy is successfully used to control transitional cell carcinoma in dogs.

General therapy includes cytostatic drugs (ifosfamide, carboplatin, vinblastine, mitoxantrone). Also, certain NSAIDs (non-steroidal anti-inflammatory drugs), such as Meloxicam and Piroxicam, have proven to be effective in the treatment of transitional cell carcinoma in dogs. However, these NSAIDs have a better effect when they are administered in combination with some chemotherapy drugs.

Combined therapy can include all of them – Initially the tumor is surgically removed, then radiotherapy and chemotherapy are resorted to.

Alternative Treatment – Can Bladder Cancer in Dogs Be Treated Naturally?

Did your vet find that your dog has bladder cancer? If you are against conventional treatments, consider natural products. These can support your pet's health and help fight bladder cancer.

Turkey Tail Mushrooms (Coriolus versicolor)

Turkey tail mushrooms can stimulate the immune system and inhibit tumor growth through their content in beta-glucans, a type of polysaccharide (polysaccharide-k – PSK). These mushrooms are often used in oncology therapy as an adjuvant treatment.

Zumalka’s Coriolus formula is a natural supplement designed to support cellular health and restore your dog’s immune system. It helps maintain a balanced intestinal microbiome, which promotes stronger immunity and supports the recovery process. At the same time, the product is a valuable source of antioxidants and essential compounds, supporting the general well-being and vitality of your pet.

Shiitake Mushrooms (Lentinus edodes)

Shiitake mushrooms are rich in beta-glucans and are known for their anti-cancer and immune-boosting effects, promoting the natural process of apoptosis (cancer cell death), similar to turkey tail mushrooms. In addition, they contain a valuable compound, lentinan, which has been scientifically proven to support patients in their fight against cancer. SHIITAKE from Zumalka helps strengthen the immune system and maintain healthy liver function in pets. The formula is rich in essential nutrients, including vitamins B2 and B12, which can support your dog's natural resistance and help them cope better with environmental stressors.

Reishi Mushrooms (Ganoderma lucidum)

Reishi mushrooms are known for their medicinal properties, with the potential to support health and help fight against cancer. Human research has shown that these mushrooms can slow tumor growth by reducing protein synthesis in cancer cells and by influencing cell signaling pathways involved in their survival and multiplication. Reishi mushrooms represents a promising natural option for both breast cancer and other types of cancer in humans. In addition to its direct effects on cancer cells, Reishi also contributes to stimulating the immune system, providing important support in slowing the progression of the disease. Zumalka's Reishi formula is a natural supplement rich in antioxidants. It helps dogs cope better with cancer, promotes liver health, and strengthens the body's natural defense mechanisms, including during periods of harsh oncological treatments, such as chemotherapy. In this way, Reishi becomes a valuable support in your pet's daily care routine.

Birch Polypore

Another exceptional product for supporting your dog’s health is PIPTOPET. This powerful formula offers a range of benefits, especially for dogs dealing with serious health challenges like cancer. The key ingredient in PIPTOPET is the medicinal mushroom Fomitopsis betulina.  PIPTOPET’S key benefits include its anti-inflammatory, anti-tumoral, antibacterial, and antiviral properties.

PIPTOPET helps reduce oxidative stress, promotes antioxidant function, and supports vital detoxification systems, all of which are crucial in slowing tumor growth and supporting the body’s natural healing processes. When combined with traditional treatments like surgery or chemotherapy, PIPTOPET can enhance these treatments and potentially improve your dog’s life expectancy. By boosting the immune system, PIPTOPET helps your pets lead healthier, more vibrant lives, even when faced with serious illnesses.

CBD Oil

CBD oil (cannabidiol) is another supplement you can give your dog with bladder cancer. Studies show that CBD oil reduced cell viability and induced cell death. Combinations of CBD oil with some chemotherapeutics (vinblastine and mitoxantrone) led to even better results.

Bladder cancer and urinary issues can significantly impact your pet’s health and quality of life. In homeopathy, we focus on treating the whole body by addressing the symptoms, following the principle of “like cures like.” This means that a substance causing symptoms in a healthy body can, in small, diluted amounts, help treat those same symptoms in a sick body. By observing the symptoms your pet is experiencing, we can use homeopathic remedies to support healing in a gentle, holistic way.

One such remedy is URINARY TRACT SUPPORT, which is specifically designed to help pets dealing with urinary system issues, including symptoms of bladder cancer. This natural product is designed to support bladder and kidney health, helping to maintain comfort, promote balance in the urinary tract, and encourage normal urinary function.

The effectiveness of Urinary Tract Support lies in its combination of powerful homeopathic ingredients. Ingredients in the product and how they can help with symptoms:

• Berberis 30k: Traditionally used in homeopathy to support kidney and bladder balance and promote overall urinary comfort.
• Cantharis 30k: Often recommended in homeopathy to help ease urinary discomfort and support bladder health.
  
• Nitricum Acidum 30k: Known in homeopathic practice for supporting urinary tract wellness and maintaining tissue balance.
  
• Pareira Brava 30k: Used in homeopathy to encourage natural urinary flow and ease occasional discomfort.
  

What Supportive Care Is Recommended for a Dog With Bladder Cancer?

Unfortunately, dogs suffering from transitional cell carcinoma present a higher risk of urinary tract infections. These infections are sometimes difficult to diagnose because bloody urine is a clinical sign that can be found in both conditions. Cystocentesis (urine collection by puncture) is contraindicated in such cases because there is a risk of seeding the tumor with bacteria. As a result, it is recommended to administer antibiotics when your dog's urine has an unpleasant smell. In addition, the vet may recommend cranberry supplementation, which could reduce the incidence of infections at this level.

Post-operative Care in Dogs With Bladder Cancer

Post-operative care may include the following:

• Limit your dog's activity - no running, jumping, playing, swimming, or other strenuous activities.
• Keep your pet clean and dry. Therefore, do not bathe your dog or let them swim during the recovery period.
• Keep the incision clean and dry to reduce the risk of infection.

In general, these restrictions apply for 10-14 days, but your veterinarian will recommend what is best for your dog depending on its condition.

How Do I Make My Dog Comfortable With Bladder Cancer?

Here's what you can do for your dog to make their life better if they suffer from bladder cancer:

• Access to water and food should be done with ease.
  
• Create a comfortable place for them to rest.
  
• Administer your pet’s medication when it is the right time.
  
• Monitor their state of health: urination, appetite, energy level, vomiting, pain, hydration, etc.
  
• Contact the veterinarian if your dog's condition worsens.
  

Frequently Asked Questions

What is the life expectancy of a dog with bladder cancer?

On average, dogs live 6–12 months with treatment. Without treatment, survival is a few months. The prognosis depends on the stage and response to therapy.

How aggressive is bladder cancer in dogs?

Bladder cancer in dogs can be very aggressive, especially transitional cell carcinoma. This type of cancer grows quickly, obstructs the bladder, and metastasizes frequently, making the prognosis difficult, even with treatment.

Are dogs in pain with bladder cancer?

Yes, cancer causes discomfort and pain, especially when urinating. The tumor irritates the bladder and favors infections. Treatment can improve symptoms, but pain remains common.

How do you know when it's time to put a dog down that has cancer?

When your dog is no longer eating, urinating normally, is in constant pain, and the quality of life is compromised, euthanasia can be seen as a humane option.

Should I euthanize my dog with bladder cancer?

If the symptoms can no longer be controlled and life becomes difficult, euthanasia can be taken into consideration. The decision is made together with the veterinarian.

How long will a dog live with bladder cancer?

The duration varies: a few months without treatment and up to a year or more with therapy. The evolution of bladder cancer in dogs depends on the response to treatment and the extent of the disease.

How do vets check for bladder cancer?

Ultrasounds, urine tests (including BRAF), cystoscopy, and biopsies are used. These confirm the diagnosis and establish a treatment plan adapted to each case.

What is the average age of bladder cancer in dogs?

Bladder cancer occurs most often in dogs 7–11 years old. It is rare in young dogs. Breeds such as Scottish Terriers and Beagles are more genetically predisposed to this disease.

What is the main cause of bladder cancer?

Causes include genetic predisposition, exposure to pesticides, chemicals, and secondhand smoke. There is no single factor, but a combination of environment and genetics.

Has a dog ever survived bladder cancer?

Complete remission is rare, but some dogs have lived up to 18–24 months with treatment. Most survive less than a year, but quality of life can be maintained.

About the author

Dr. Iuliana Mihai, DVM, MSc, PhD

Iuliana Mihai, DVM, MSc, PhD, is a Bucharest-based veterinary expert specializing in internal medicine and oncology.

Her work has been published in reputable publications such as Veterinary Medicine Journal, Catster.com, Dogster.com, Hepper.com, Meowiz.com, Springnaturals.com, Petkeen.com, and Wilderharrier.com.

She is a malpractice and negligence veterinary consultant and a graduate of The University of Agronomic Sciences and Veterinary Medicine and The Romanian Academy.

Read the complete profile of Dr. Iuliana Mihai, DVM, MSc, PhD (Veterinarian) here.