Cancer is a general term for a group of diseases that involve abnormal growth of cells within the body. These cells often grow rapidly, taking over normal cells and even invading organs. Cancer may originate in one area of the body (usually in the form of a tumor) or can be throughout the body (such as in the lymphatic system). Cancer is seen in a great number of forms, some of which can be treated.

Sadly, many types of cancer are ultimately fatal.

Causes of Cancer in Dogs

There is not a known cause of cancer in dogs, but there are risk factors. Genetics play a role in the development of cancer for some dogs. Breeds such as Boxers, Golden Retrievers and Great Danes may be genetically predisposed to certain types of cancer. In addition, unaltered dogs have a greater risk of cancer in the reproductive organs than dogs that have been spayed or neutered. In general, older dogs are much more likely to develop cancer than younger dogs. Some experts believe that poor nutrition and other environmental/lifestyle factors may contribute to a dog’s risk of cancer.

Signs of Canine Cancer

The signs of cancer can range from subtle to dramatic. They can also mimic the signs of common illnesses or other serious diseases. Some signs of cancer in dogs may include the following:

• Lumps/bumps/tumors/growths on the body
• Weight loss
• Loss of appetite
• Lethargy and/or Depression
• Trouble breathing and/or coughing and/or shortness of breath

• Distended abdomen (bloated appearance)
• Evidence of pain in any area of the body
• Persistent lameness
• Pale gums or other mucus membranes
• Bleeding or discharge from any part of the body (not due to known injury)
• Yellow-colored gums, skin and whites of the eyes (jaundice)
• Vomiting and/or Diarrhea (especially when chronic)
• Difficulty urinating and/or defecating
• Trouble eating or swallowing
• Strong odor from mouth and/or excessive drooling (especially if dental disease is not present)

If your pet exhibits any of these or other signs of illness, it is important to contact your veterinarian. Remember that these signs do not necessarily mean your dog has cancer. However, your vet should be the one to determine this. Early diagnosis of cancer (and other diseases) usually makes them easier to treat successfully. Communication with your vet is key when it comes to your pet's health.

Diagnosing Cancer in Dogs

There are several different ways to diagnose cancer in dogs. First, veterinarians look at a dog's medical history and current signs. Next, a physical examination is performed. If a lump (may also be called a mass or growth) is found, the vet may decide to obtain a sample via needle aspirate or biopsy. Sometimes, surgery is recommended to remove the mass. Other common diagnostics include blood tests, urinalysis and X-rays. There is no blood test for cancer, but abnormalities in blood work and urinalysis can help vets make a diagnosis. X-rays will sometimes show evidence of tumors or metastasis (spreading of cancer) inside the body.

Next: Cancer Treatment Options for Dogs