Bladder Cancer in Dogs

Bladder Cancer in Dogs

Bladder Cancer in Dogs

Bladder cancer in dogs is difficult to determine and, without a test, may be confused with less serious conditions or infection. Some breeds, especially Terriers, are genetically predisposed to this type of cancer. 

This article equips you with valuable knowledge for the health of your pet, such as the causes and the most reliable test for bladder cancer. It aims to raise awareness that you need to catch the disease early, plus explores options for dog owners in case curative treatment is no longer possible.

Key Takeaways

  • Canine bladder cancers are aggressive—they may spread to the urinary tract and later to the lymph nodes or lungs. It is essential to know the signs before the disease spreads to other areas in the body.
  • There is a clear link between bladder cancers and specific breeds. Be vigilant to the symptoms if you are an owner of Terriers, Scottish Terriers, or Shetland Sheepdogs.
  • Urinary tract infections have similar symptoms to early-stage tumors in the bladder and ureters. It is better not to assume a harmless infection. Take your dog to a veterinarian for a test if they show any symptoms, especially blood in the urine.

Types of Bladder Cancer in Dogs

Bladder cancers usually come in one of three types of cell mutation: Transitional Cell Carcinoma (TCC), Fibrosarcoma, or Leiomyosarcoma. See below for information on each type.

Transitional Cell Carcinoma 

Transitional Cell Carcinoma (TCC) is a malignant, aggressive form of cancer that metastasizes (spreads) quickly. Although bladder cancer is rare compared with other places in the body, TCC is the most common form of urinary tract tumor in dogs [1]

Pets can also develop the disease in other parts of the urinary system. The kidneys, ureters, urethra, prostate, or vagina are other locations where TCC may appear. Unfortunately, at later stages, dogs with TCC may have also developed TCC in the lungs, lymph nodes, bones, or other organs, and many dogs with TCC have metastases by the time they are diagnosed [2]

bladder cancer in dogs Percentage of papillary infiltrative tumors caused by Transitional Cell Carcinoma that is grade 2 or 3
By the time of diagnosis, about 81% of the dogs had progressed to a grade 2, and 16% were already at grade 3
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3095172/

Fibrosarcoma 

Fibrosarcoma is a less common type of malignant cancer with cells that usually develop on muscles and connective tissues. As the bladder has muscle tissue, in some cases, it can develop there or in the urinary system. In humans, this type of cancer does not often spread to the lymph nodes; however, dogs often present the cancer at a later stage.  

Leiomyosarcoma 

Leiomyosarcoma is a rare type of cancer that develops on the lining of major organs that have cavities, such as the uterus or bladder. Due to the cancer cells sticking to the walls of the bladder, it is notoriously difficult to remove via surgery, and usually, radiation therapy would be required.

Signs of Bladder Cancer in Dogs

Dogs with urinary tract infections and tumors within the bladder, prostate, kidneys, or urethra may present with similar symptoms:

  • Straining to urinate.
  • Bloody urine.
  • Increased water consumption.
  • Strong odor to the urine.
  • Increased urination or incontinence.
  • Fever.
  • Lethargy.
  • Vomiting.
  • Severe back pain.
  • Licking around the opening of the urethra.
  • Redness and swelling around the opening of the urethra.
  • Abdominal pain.

The most common signs of urological disease in pets are blood in the urine, pain in the abdomen, and changes in urine flow, causing either accidents in the house or painful urination. More general signs are not to be confused with other symptoms of cancer in dogs

What Are the Symptoms of Late Stage Bladder Cancer in Dogs?

Later stage symptoms of urinary bladder cancer in dogs include:

  • Vomiting.
  • Blood in the urine.
  • Severe abdominal pain.
  • Anti-social behavior.
  • Inability to exercise.
  • Pain when sitting or moving.
  • Constant pacing.
  • Constipation as a result of dehydration.
  • Loss of appetite and weight loss.

If your pets have abdominal pain or are straining to urinate, this is not to be ignored—seek veterinary advice. Straining to urinate and being unable to pass urine for more than 24 hours is a medical emergency. Consider arranging for the dog to have a test for cancer cells if you notice blood in the urine.

What Causes Bladder Cancer in Dogs? 

Risk factors of cell mutation include the breed of dog, the sex (females are more prone), and age, as well as environmental factors. The use of pesticides and insecticides has been shown to correlate with the risk of developing TCC, especially in older veterinarian studies when less advanced veterinary parasite treatments were being used. 

Further research in the veterinary field is needed to determine the possible relationship between dogs with TCC and secondhand smoke, as in humans, cigarette smoking is the most common risk factor.

What Breeds of Dogs Get Bladder Cancer?

Several breeds, in particular Terriers, are more likely to develop bladder cancer. Owners of Scottish Terriers should be aware the breed has an 18 fold higher chance of being diagnosed with TCC than other dogs [3].

bladder cancer in dogs Risk of urothelial carcinoma (UC) in Scottish terrier compared to non-risk breeds
It was showed that Scottish terriers are more likely to develop bladder cancer than other breeds
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6036476/

Shetland Sheepdogs, Beagles, West Highland White Terriers, and Wire Hair Fox Terriers are also more at risk of developing TCC than other breeds. It is unclear why these breeds are prone to urinary tract cancer, although these breeds are less resilient to TCC and other urinary tract mutations, therefore the bloodlines of these dogs have significance.

Dog Bladder Cancer Diagnosis

The diagnosis of bladder cancer in dogs requires a series of diagnostic tests:

  • A urine test and analysis.
  • A smear test of cells present in the urine sediment.
  • A bladder tumor antigen test, assessing the proteins in a urine sample.
  • Ultrasound of the urinary system, ureters, and urethra.
  • Biopsy (but not in all cases).
  • Cadet BRAF test: a urine sample to test DNA mutation.

Most of these tests are straightforward checks with minimal harm to your pet; however, traditional biopsy is slightly more invasive with possible risk involved (more information on biopsy is below).

Cadet BRAF

Cadet BRAF is the trademark of the newest diagnostic test for detecting transitional cell carcinoma (TCC) in dog’s bladders. The rate of diagnoses has been high: up to 95% of confirmed cases are being diagnosed with the Cadet BRAF test, and it is less invasive than biopsy because it requires a urine sample only [4].

Ultrasound or Other Imaging Tests

Imaging tests usually involve X-ray, CT scanning, or ultrasound in the abdominal area to get a picture of the bladder tumor(s). The ureters, kidneys, and bladder can all be pictured with ultrasound. This test tends to be more accurate at a later stage when tumors are more visible. 

Biopsy

Biopsy is when a sample of a tumor is taken from the affected area and examined under a microscope. It can help with diagnosis as it may determine exactly what type of cell mutations are present in the tissue sample (TCC or other). 

Normally pets would have to be under general anesthetic for the test, as an endoscope would be inserted into the urinary tract to be able to see the bladder and remove cells. It is also used for screening abnormalities in the lungs. There is a chance of this procedure causing infection and slight bleeding, as well the risks associated with general anesthetic in dogs. 

Dog Bladder Cancer Treatment

Veterinary bladder cancer treatment has scientific importance because canine outcomes help doctors to develop better treatment for humans. As a result, hopeful new therapies for TCC are emerging; however, alongside other therapies, full or partial cystectomy (urinary bladder surgery) is still usually required [5].

Surgical Excision

The surgical removal of bladder tumors has been the cornerstone of treatment for bladder cancer in dogs. Radical cystectomy involves the complete removal of the bladder; surgery to remove tumors within the bladder is generally not possible with this type of cancer. 

Because of the high rate of metastization of bladder tumors in dogs, surgery alone does not have good treatment success levels, and radiation or chemotherapy may also be required. 

Radiotherapy

Radiation therapy is a targeted intervention that uses high-energy X-rays to destroy cancer or reduce mutation and growth of the harmful cells. It can be used to reduce the size of the tumor prior to surgery or used after surgery to kill any cancer cells that may remain in the bladder.

If surgical removal is no longer an option, or you choose not to have your pet operated on, your veterinarian may recommend a higher dose of radiation to shrink the tumor and increase the life expectancy of your dog.

NSAIDs or Cox Inhibitors

Non-steroidal anti-inflammatory drugs (NSAIDs), also known as Cox Inhibitors, are a choice treatment for cancer suffering dogs due to their analgesic properties. There are both human and veterinary versions and have qualities that are similar to aspirin [6]. They would likely be used during bladder cancer therapy to reduce some of the abdominal pain caused.

Chemotherapy and NSAIDs

Chemotherapy is toxic and can have severe side effects. In dogs, adverse effects are nausea, diarrhea, vomiting, and in some cases, further irritation of the bladder. NSAIDs may be used in conjunction with chemotherapy to reduce some of the discomfort by keeping your pet pain-free.

Chemotherapy 

TCC is both difficult to remove with surgery and responds poorly to chemotherapy. However, chemotherapy is a generalized treatment, which means it is designed to kill cancer cells where they have spread. It could be recommended if the bladder cancer has spread to the lymph nodes, lungs, or beyond. It can also be used before or after surgery.

Metronomic Chemotherapy 

Metronomic chemotherapy is the gradual but consistent use of a lower dose of cancer drugs. It takes a longer period of time than regular chemotherapy, but the side effects are less severe. 

Dog Bladder Cancer Clinical Trials

There is a close similarity between TCC in dogs and high-grade invasive bladder tumors in humans; therefore, canine bladder cancer is an area of research interest for doctors and veterinarians alike [7]. As such, you may be asked if you would like your dog to be part of a veterinary clinical trial, which can give you access to experimental treatments that are otherwise unavailable. 

Dog Bladder Cancer: What to Expect

Look out for these common symptoms, especially if you are the owner of Scottish Terriers or Shetland Sheepdogs:

bladder cancer in dogs

  • Bloody urine
  • Accidents in the house
  • Painful urination or other urinary tract infection signs.
  • Abdominal pain.

When you seek veterinary help, expect that your veterinarian may recommend a urinary catheter to help your pet relieve themselves, should they be suffering from a blocked urinary tract. 

Ask your vet if they believe there is a harmless urinary infection, and consider a Cadet BRAF test if there are suspicions of a serious disease.

If the Cadet BRAF and other urinary tests determine cancer cells are present, talk to your veterinarian about a biopsy and ultrasound. This will ensure your dog is fully diagnosed by assessing if the bladder tumors have spread to the lymph nodes, the lungs, the kidneys, or the urinary tract. 

With advanced bladder tumors, expect that chemotherapy may be recommended, which can have nasty side effects for your dog. Consider ways of making your pet as comfortable as you can.

Preventing UTIs in Dogs with Bladder Cancer

Urinary tract infections are caused by bacteria in the urethra. Therefore, cleanliness of the dog’s mouth and urethra can help prevent urinary tract infections. Herbal remedies can be used to treat and relieve, such as organic cranberry extract powder, which has antibacterial properties when ingested.

Bladder Cancer in Dogs Stages

Staging is a way to measure the primary tumor with X-rays or ultrasound to see how far the cancer may have spread and assess what level of risk there is to the dog. 

Following the staging tests, your veterinarian may grade the tumor as low, intermediate, or high risk, depending on what stage it has reached. Unfortunately, most dogs with bladder tumors have intermediate to high-grade invasive TCC, which is high risk and difficult to treat.

Dog Bladder Cancer Life Expectancy 

Veterinary research shows that without diagnosis or TCC treatment, the life expectancy of dogs with bladder cancer is four to six months. With treatment, approximately 75% of dogs respond well and can continue for up to a year or more with good quality of life [8].

FAQ

Can TCC In Dogs Be Cured?

Yes, but sadly that is not the norm with this cancer type. If your dog has successful surgery on the primary bladder tumor(s), it could be curative.

How Long Can a Dog Live with a Bladder Tumor?

Usually around six months without treatment and around a year with treatment.

bladder cancer in dogs The prognosis for dogs with TCC (with or without treatment)
Even with treatment, dogs with TCC rarely live longer than 12 months
Source: https://bluepearlvet.com/medical-articles-for-pet-owners/bladder-cancer-in-dogs/#:~:text=Prognosis,6%2D12%20months%20with%20treatment.

How Do Dogs with Bladder Cancer Die?

The cause of death from this type of cancer is usually kidney failure, following blockage of the urinary tract. Other reasons for death are secondary, as a result of the cancer spreading to the lungs or lymph nodes. 

What Is the Most Common Bladder Tumor in Dogs?

Transitional cell carcinoma (TCC) is the most common form of urinary bladder cancer in dogs, which is aggressive and spreads easily around the body.

Conclusion

As pet owners, our dogs are important to us, as is having all the right information. Cancer in dogs can be severe, and if your pet has a serious disease, it is difficult to know what to do. 

Try to ensure that you holistically take into account what their life will now be like. Do they have any other illnesses or kidney problems? What is the safest and most pain-free option for them? Although there are no perfect answers, these are the factors that may impact your dog’s overall comfort and help you make the best decision for your dog. 

References:

  1. DW;, Mutsaers AJ;Widmer WR;Knapp. “Canine Transitional Cell Carcinoma.” Journal of Veterinary Internal Medicine, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/12683611/. 
  2. Mutsaers, Anthony J., et al. “Canine Transitional Cell Carcinoma.” Journal of Veterinary Internal Medicine, vol. 17, no. 2, 2003, pp. 136–144., doi:10.1111/j.1939-1676.2003.tb02424.x. 
  3. Urinary Bladder Cancer Research, Purdue Comparative Oncology Program, https://www.vet.purdue.edu/pcop/urinary-bladder-cancer-research.php
  4. Sniffing Out Cancer in Canines — And Humans, Too, NC State University, https://news.ncsu.edu/2019/11/canine-bladder-cancer-cadet-braf/
  5. Bradbury ML;Mullin CM;Gillian SD;Weisse C;Bergman PJ;Morges MA;May LR;Vail DM;Clifford CA; “Clinical Outcomes of Dogs with Transitional Cell Carcinoma Receiving Medical Therapy, with and without Partial Cystectomy.” The Canadian Veterinary Journal = La Revue Veterinaire Canadienne, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/33542551/.
  6. Zarghi, Afshin, and Sara Arfaei. “Selective COX-2 Inhibitors: A Review of Their Structure-Activity Relationships.” Iranian Journal of Pharmaceutical Research : IJPR, Shaheed Beheshti University of Medical Sciences, 2011, www.ncbi.nlm.nih.gov/pmc/articles/PMC3813081/. 
  7. Knapp DW;Ramos-Vara JA;Moore GE;Dhawan D;Bonney PL;Young KE; “Urinary Bladder Cancer in Dogs, a Naturally Occurring Model for Cancer Biology and Drug Development.” ILAR Journal, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/24936033/. 
  8. DW;, Fulkerson CM;Knapp. “Management of Transitional Cell Carcinoma of the Urinary Bladder in Dogs: a Review.” Veterinary Journal (London, England : 1997), U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/25747698/.