Vet oncologists talk feline cancer

Photo by Darby Leigh

Photo by Darby Leigh

We asked Dr. Valerie MacDonald, DVM DACVIM (oncology), Associate Professor at Western College of Veterinary Medicine in Saskatoon and her resident, Dr. Charlotte Johnston to answer the following questions about feline cancers. Below are their answers.

  1. How common is cancer in cats? What are some of the more common cancers found in cats?

The prevalence of cancer in cats is increasing. The increase is due to a variety of reasons — cats are living longer, increasing care given by owners and advancing veterinary care. Cancer remains a major cause of morbidity and mortality in cats.

Some of the most common cancers seen in cats include:

  • Lymphoma: Cancer arising from lymphoid tissue. Infection with feline leukemia virus increases their risk of developing lymphoma.
  • Mammary cancer: Spaying cats before their first heat can decrease the risk of developing mammary cancer.
  • Squamous cell carcinoma (SCC): Most commonly affects the skin and mouth. Sun exposure increases their risk of developing skin SCC and it most commonly involves light or unpigmented areas of skin.
  • Injection site sarcomas

2. What are some of the symptoms of feline cancers?

There is no single symptom that can confirm cancer in cats. Cats are also hard to evaluate, as they tend to hide their disease well. In general any cat that is not feeling well should be examined by a veterinarian.

Some symptoms to monitor for include:

  • Lumps
  • Persistent sores or skin infections
  • Abnormal discharge from any area of the body
  • Sudden lameness or lameness that is not improving
  • Weight loss
  • Decreased appetite
  • Vomiting, diarrhea, coughing or sneezing
  • Changes in behaviour
  • Difficulty breathing
  • Bad breath

3. What are some of the causes of feline cancers?

In general there is no single cause for cancer in cats. There are hereditary and environmental factors than can contribute to the development of cancer in cats. Cats that receive excessive exposure to sunlight are at risk for skin cancer. Feline leukemia virus has also been linked to the development of the malignant cancer lymphoma in cats. Injections into the muscle and subcutaneous tissue have been linked to the development of injection site sarcomas at a later date.

4. What are some of the more common treatments for cats with cancer? Are there any new treatments or advanced technologies for the treatment of feline cancers?

There are three main types of treatments that we use for cancer — surgery, chemotherapy and radiation therapy. Surgery is the most common treatment that is used to remove tumours that are found. For localized tumours surgery may be the only treatment needed. Chemotherapy is used to treat systemic cancers (such as lymphoma) and also cancers that have a high chance of spreading. Radiation therapy can be used to treat tumours in locations not amenable to surgery (for example the nasal cavity) or where surgical removal is unachievable.

There is research being done constantly to try and identify advancements in radiation therapy, new and novel chemotherapy protocols and new surgical approaches.

5. How much does it typically cost to treat a cat with cancer?

The cost to treat various different cancers in cats by a specialist depends on a number of different factors including type and location of the cancer, the treatment that is recommended (surgery, chemotherapy, radiation therapy) and ultimately where you live.

6. If treated, what’s the cure rate for cats with cancer?

It is very difficult to comment on a cure rate. However, on a whole it is going to be very low. It will depend on the type of tumour, the location, when it was found and how it is treated.

7. What are some of the preventive measures we can take to help keep our cats cancer free? 

It is often hard to suggest a number of preventative measures when we do not know the underlying cause of most cancers. Early detection and prompt treatment are the most effective approaches for the best outcome. Having your cat spayed early can reduce the chance of mammary cancer. Avoiding excessive sunlight exposure and sunburn can help reduce the chance of certain skin cancers. Vaccinating for feline leukemia can prevent the development of the disease. There has been no links of feeding certain foods or using a particular cat litter to the development of cancer. Feeding a well-balanced diet and getting regular exercise can help your cat stay healthy with a good body condition score to reduce the risk of a number of health related diseases, not just cancer.