Dog cancer, like human cancer, refers to any type of malignant tumor or growth (neoplasia) that invades the surrounding tissues, spreads to other parts of the body via the bloodstream, is likely to recur after attempted removal, and can cause death unless it is adequately treated or removed. While cancer can occur at any age, the chances of getting cancer increases with age, and because pets are living longer, the incidence of cancer has been increasing accordingly.
There are many signs that can be associated with cancer. Abnormal swellings that persist or continue to grow, sores that do not heal, bleeding or discharge from any body opening, difficulty eating or swallowing, a persistent lameness, difficulty breathing, urinating, or defecating, or persistent coughing are examples of specific signs which may arise. Weight loss, fevers, decreased appetite, and loss of stamina, though vague and non-specific, may also be suggestive of cancer.
There are literally as many types of cancers as there are types of cells. It is not known why normal cells become cancerous and begin to divide and multiply out of control. Environmental factors, genetics, toxins, and other biological factors are all possible contributors.
Despite the poor prognosis that one normally associates with cancer, effective treat- ments are available for many types of cancer. Once a tumor has been detected, the eventual outcome can often be favorable if early detection is followed by timely intervention. A biopsy can usually determine what kind of cancer is involved and thus helping set the appropriate course of therapy.
Surgery is the treatment of choice with some cancers. A localized tumor can usually be effectively excised surgically and, when detected early, the procedure carries an excellent success rate. An attempt is made to determine if there has been any spread (or metastasis) to adjoining organs or tissues. Staging the disease helps to set the prognosis. If the growth turns out to be malignant, the veterinarian will suggest an appropriate course of action and will help you understand what might be expected in the future. In cases where a tumor proves to be inoperable and surgery is not curative, radiation, biological, or chemical therapies may be a viable alternative. During radiation therapy, the malignant cells are exposed to high levels of radiation to kill them. Similarly, chemotherapy utilizes medication to kill cancer cells while sparing normal healthy cells that are not dividing quickly. Sometimes a combination of therapies is prescribed such as surgery plus radiation. This is often the case when aggressive tumors are identified and this strategy helps to increase remission rates while reducing side effects.
Modern cancer management is much more than just the application of the above therapies. Nursing care advances such as nutritional support, pain management, grooming, soft bedding for comfort and ulcer prevention, physical therapy, and other supportive techniques have all contributed to improved expected outcomes, and the improved quality of life for a pet with cancer.
Treatment options should be discussed with your veterinarian and the average expected success rate of each option will be explained. In some cases, your veterinarian may refer your pet to an internist or a cancer specialist (oncologist) for further treatment. You are an important part of the care team when dealing with cancer, so make sure you understand what you can do to help the health care team at your practice optimize your pet's treatment.
For more information, please contact the National Canine Cancer Foundation