Oncology resources for pet owners

Cancer is the process where normal cells in the body undergo excessive or unrestrained growth. Cancer can occur in any bodily organ and can travel from one part of the body to another distant part by the blood or lymph system. There are more than 100 different types of cancer that can affect our pet companions.

Cancer is usually more common in older animals, and is the cause of death in almost half the pet population over 10 years of age.

Most often, a pet’s caregiver will notice a mass on the body, or possibly enlarged lymph nodes. Sometimes the animal may have a reduced appetite and less energy. There may be changes in bowel movements, or there may be an unusual odour from the mouth of a pet with mouth cancer. While the initial lump or cancer is often the most obvious to a caregiver, other organs of the body may become affected (metastasis), and the function of normal cells may be compromised. For example, liver damage may occur because of the expanding tumour cell population in the liver, and decreased exercise tolerance may happen when the lungs are affected. Normally the bone marrow produces the majority of the blood cells. Tumour cells in the bone marrow can cause fewer normal cells which aid in blood-clotting and infection-fighting to be available. The pet is then susceptible to bleeding and infection.

The affected pet may develop what are called “paraneoplastic syndromes” or tumour-associated conditions. For example, there may be abnormal proteins or too much calcium in the blood due to secondary effects of the cancer. These syndromes themselves can cause acute, life-threatening problems; this is why careful monitoring by the veterinarian is important. Many of these signs are non-specific, indicating problems other than cancer, and a visit to the primary care veterinarian is always the first step when you suspect cancer in your pet. If a diagnosis of cancer is confirmed, your veterinarian may suggest a biopsy, lymph node evaluation, chest and abdominal radiographs, and standard blood tests and urinalysis, but they may also discuss more complicated procedures.

Cancer is caused by a variety of factors, potentially involving viruses, genetic components, exposure to carcinogens, and other unknown factors. In this respect cancer in pets is the same as in any other animal, including humans. Some cancers are preventable in pets, such as breast (mammary) cancer in dogs which rarely occurs after early neutering.

Particularly when seeing a veterinarian for the first time, it’s important to give a complete picture of the health status of your pet. If your pet has several health problems or a long history with one, be sure to provide a history of events, recurrences, treatments, medications, and outcomes associated with the condition. A written list can save time and ensure completeness.

Primary care is a term for the branch of medicine concerned with your pet’s overall, general well being. It is important to have a veterinarian who is familiar with your pet’s medical history and who can serve as their “care ambassador”.

Although your primary care veterinarian is an integral part of the cancer care for your pet, often you may need to visit an expert in a specific area of veterinary science. These veterinarians have undertaken further training and have achieved certification by various veterinary Colleges. They are often called Specialists.