Vail Pet Talk column: Pet cancer statistics are alarming; know the warning signs for early detection |

Vail Pet Talk column: Pet cancer statistics are alarming; know the warning signs for early detection

Every October and November, to align with Breast Cancer Awareness Month, we do Pet Cancer Awareness Month here at Gypsum Animal Hospital. Our goal is to make you aware of the importance of checking for cancer in pets. My veterinary colleagues and I are amazed at the similarities in the diseases that both humans and pets suffer. Cancer is no different.

Just like in people, cancer is uncontrolled growth of cells that ultimately leads to a tumor formation. It can also occur in the blood cells and end up in a form of cancer such as leukemia. If this happens in the lymph system (i.e. lymph nodes), then it is called lymphoma.

Again, just like in people we do not know for certain the cause. Many things such as genetics, chemicals, toxins, ultraviolet radiation, environmental factors, viruses, hormone imbalances and a poorly functioning immune system can cause cancer.

Role of Genetics

Certain breeds of dogs and cats are more prone to certain cancers, which points toward genetics. This is one reason why your doctor asks you so many questions about diseases in your family. Boxers, Boston terriers and golden retrievers are among the breeds more prone to an often-deadly form of skin cancer called a mast cell tumor.

Golden retrievers and Bernese mountain dogs are two of the more cancer-prone breeds of dogs. Size seems to play a role in dogs, as well — smaller dogs suffering less cancer. According to the website PetMD, of the top nine breeds for cancer, only one, the Bichon Frise, is a small dog. The jury is still out on cancer and cat breeds, but many feel purebreds are at greater risk. Color in cats does play a role. White ear tipped cats are more susceptible to squamous cell carcinomas.

So, on to some statistics: Approximately 6 million dogs and an additional 6 million cats will be diagnosed with cancer this year. More than half of dogs older than 10 are likely to develop cancer in their lifetime. About 11 percent of a general practice veterinarian’s caseload is cancer; typically, we see one case of cancer for about every 10 medical cases we see.

Skin tumors are among the most common form of cancer in dogs and cats. In dogs, about 40 percent are malignant (cancerous), and in cats, the number soars to 60 percent. Mammary cancer is also very common; some stats suggest it is the second-leading cause of cancer in pets. Mammary cancer has its own special rule: the 50/50/50 rule: 50 percent are malignant and 50 percent are benign; of the malignant ones, 50 percent of dogs are cured by surgery and the other half eventually succumb to the disease.

We can almost eliminate breast cancer in dogs by early spaying or ovariohysterectomy. The incidence is 1 in 2,000 if we spay your dog before the heat and jumps up to 1 in 4 if we wait until after the second heat cycle. Those are crazy numbers.

Mortality Rate

OK, sigh, I needed to step away from this article for an appointment. It was to euthanize a patient suffering from cancer. According to a landmark 20-year retrospective study (i.e., looking back in time) by the University of Georgia, almost one out of three adult dogs died of cancer. Cancer was three times more likely to claim a dog’s life than the number two cause, trauma. The study looked at almost 75,000 animal records from 27 veterinary teaching hospitals over a 20-year period.

Other common forms of cancer in pets are bone cancer, or osteosarcoma in large breed dogs, lymphoma, oral cancers and abdominal cancers such as tumors of the spleen. According to a source of veterinary insurance, VPI, they processed more claims for lymphosarcoma in 2008.

Early Detection is Essential

Is there any good news or statistics out there? Well, maybe. Just like in people, early detection saves lives. Researchers are working on a melanoma vaccine and often share results with human researchers in a growing field called comparative oncology. Neutering male dogs is being looked at closely to see if either not neutering or just delaying it can ward of certain cancers.

I don’t want to just spout statistics here. I also want you to be aware of the warning signs of cancer in your pet; the more common are weight loss, abnormal swellings, loss of appetite, bad odors, bleeding or discharges from any body opening, weakness, limping or lameness, difficulty eating, breathing, urinating or defecating.

If you notice any of these signs in your dog, then please schedule an appointment with your veterinarian. To help and encourage you to visit a veterinarian, we will be offering free cancer screenings during October and November. In reality, though, an office visit expense with your current veterinarian is a very good investment in your pet’s health. If you have any doubts, then don’t wait.

Stephen Sheldon, DVM, practices at Gypsum Animal Hospital. Sheldon is a member of The Veterinary Cancer Society. He can be reached at 970-524-3647, or by visiting


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