It's very traumatic when a family member is diagnosed with cancer. You may be surprised to know that often that family member is your dog or cat. Unfortunately, cancer is very common in companion animals, but thanks to advanced veterinary medicine, many of these animals are surviving while continuing to have a wonderful quality of life. Although a cancer diagnosis can be frightening, the American College of Veterinary Internal Medicine Foundation (the “ACVIM Foundation”) and Tails of Hope Foundation have compiled the following information to help you get the best treatment possible for your beloved family member:
What are the common signs of cancer in companion animals?
As in human cancer, detection is the first step to recovery. Knowing what to look for could save your companion animal's life. According to the American Veterinary Medical Association, common signs of cancer include:Abnormal swellings that persist or continue to grow
Sores that do not heal
Loss of appetite
Bleeding or discharge from any body opening
Difficulty eating or swallowing
Hesitation to exercise or loss of stamina
Persistent lameness or stiffness
Difficulty breathing, urinating, or defecating
My companion animal has been diagnosed with cancer. This seems very scary! What does this mean? Cancer is a very general term that means that a normal tissue in your companion animal's body is no longer behaving in a normal manner, and is growing and developing outside of the body's usual regulation and control. Depending on the type of cancer, your veterinarian may also tell you that your companion animal has a "tumor" or a "mass". These are very nonspecific terms and do not indicate whether or not the disease is easily treatable. Cancer causes problems in the body by affecting local structures, or by spreading to other organs (metastasis). Who treats cancer in companion animals? There are several types of Board-certified Veterinary Specialists who work together to treat cancer. Specialists are veterinarians who, after graduating from veterinary school, seek additional focused training in certain areas. This training usually lasts an additional 3-4 years (one year of internship, and 2-3 years of residency, depending on the specialty). At the end of this training, the Specialist must pass a certifying exam.
The types of Board-certified Veterinary Specialists who treat cancer are:
A veterinary medical oncologist is a veterinarian who specializes in the overall diagnosis and treatment of cancer, and will usually administer chemotherapy. Medical oncologists are Board-certified by the American College of Veterinary Internal Medicine (ACVIM). Their credentials will usually read "Diplomate ACVIM - Oncology". For more information, including a searchable database, please visit www.ACVIM.org.
A veterinary radiation oncologist is a veterinarian who specializes in the treatment of cancer with radiation therapy. Radiation oncologists are Board-certified by the American College of Veterinary Radiology (ACVR). Their credentials will usually read "Diplomate ACVR (RO)". For more information, including a searchable database, please visit www.acvr.org.
A veterinary surgeon is a veterinarian who specializes in surgery. Veterinary surgeons are Board-certified by the American College of Veterinary Surgeons (ACVS). Their credentials will usually read "Diplomate ACVS". Some surgeons have a special interest in surgical oncology, however there is currently no formal certification for surgical oncology as a subfield. For more information, including a searchable database, please visit www.acvs.org.
After a cancer diagnosis, your medical oncologist can suggest, based on your companion animal's condition, what the best treatment protocol is, which may include surgery, chemotherapy, and/or radiation, as discussed below.
How do I find appropriate treatment for my companion animal? Your first resource is your family veterinarian (general practitioner) who knows you and your companion animal well. Your family veterinarian can:
Help obtain the diagnosis; help inform you about the disease; and offer treatment options and/or referral to the appropriate Board-certified Veterinary Specialist.
You are encouraged to obtain a referral to a Board-certified Veterinary Specialist from your family veterinarian whenever possible. This ensures the proper transfer of medical information and is beneficial to the Veterinary Specialist, and will help your companion animal receive the best care possible.
Is cancer treatable? What kind of treatments can I expect?
Advances in veterinary care have made many cancers treatable and capable of being put into remission, or possibly cured, while preserving the animal's quality of life. Not all cancers are curable, and different types of cancer respond to different treatments in different ways and with different levels of success. There are many different options, depending on the type of cancer, where it is located, and how advanced it is. Some cancers are quite benign and easily treated. Others are locally aggressive but do not tend to spread to other parts of the body. Others are systemically aggressive and spread to other organs.
Depending on your companion animal's condition, diagnostic testing or management may be needed including:
Advanced laboratory testing of various blood or tissue samples
Biopsies and tissue analysis
Cancer vaccines for certain types of cancer (e.g., melanoma)
A friend of mine was treated for cancer and seemed very tired and sick most of the time. Is it fair to put my companion animal through that? Dogs and cats seem to tolerate anesthesia, surgery, radiation, and chemotherapy more easily than people. Also there are many different treatment options used for your companion animal with cancer. The goal is always to cure the cancer if possible, but in many veterinary patients, a complete cure may not be possible at the time the disease is diagnosed. In this case, the goal of treatment is to put the cancer into remission and lengthen your companion animal's life while providing a good quality of life. Companion animals' lives are too short to allow them to feel poorly for any length of time before we switch to another treatment protocol. There certainly can be complications associated with surgery, chemotherapy or radiation therapy, but many are mild and self-limiting, and most companion animals tolerate the process well. The specific things you might expect your companion animal to experience vary with the treatment and any underlying conditions your companion animal might have, and should be discussed in advance with your veterinary oncologist. Don't allow your friend's experience to prevent you from at least learning what your options are, and how your veterinary oncologist thinks your companion animal would respond! You may be surprised at how good your companion animal feels during the treatment. What is the role of surgery and what should I expect if surgery is recommended for my pet? Surgery is important for the removal of "gross" or solid/visible disease, and is most useful in the treatment of a single, discrete mass. The goal of cancer surgery is usually to remove not only the visible mass, but a rim of normal tissue around it — this amount varies with the type of cancer. The reason for this is that some tumors will extend microscopic "fingers" of cancer into the normal tissue which cannot be seen with the naked eye. Therefore, the incision that is made to remove the tumor is often larger than you might expect. The successful removal of a tumor may be limited by the presence of nearby anatomic structures that have important function and cannot be damaged. In order to perform surgery the patient must be anesthetized. There are certain risks associated with surgery and anesthesia, therefore it is important to test for and discuss other, unrelated, underlying medical problems that may exist so that the safest protocols may be chosen. The tissue that is removed is submitted for histopathologic analysis, so that important information including the type of tumor, a prediction of its biologic behavior, and the "margins" of the surgical resection (how close the tumor extends to the surgical incision, and therefore the likelihood that any microscopic cells were left behind) are known. How does chemotherapy work and what should I expect if chemotherapy is recommended for my companion animal?Chemotherapy is important in treating systemic or metastatic cancer and works best when disease is microscopic. Alone, it is not very useful for treating solid masses or tumors. Most chemotherapeutic agents work by inhibiting cancer cells which divide and reproduce in an uncontrolled manner. However certain other normal cells in the body are also rapidly dividing, which is why some chemotherapy protocols are associated with side effects involving the bone marrow (and infection-fighting cells) or the gastrointestinal tract, for example. When is radiation therapy indicated, and what should I expect if radiation therapy is recommended for my companion animal? Radiation therapy is best utilized for treatment of local microscopic disease in a specific area after a discrete mass is removed with incomplete margins (meaning that tumor cells remain in the surrounding tissue). It is helpful for treating microscopic disease that is left behind because of anatomy limitations, or because the disease was more extensive than could be detected preoperatively. However some tumors can be treated by radiation therapy without surgery, and sometimes "palliative radiation therapy" may be indicated if surgery is not possible. "Palliative radiation" will not cure the disease but it may slow progression or relieve discomfort associated with the cancer. There are many different protocols, which can involve few treatments of a relatively large radiation dose, or many treatments of a much smaller radiation dose. Side effects are possible, but vary according to the protocol recommended, and the area of the body being treated, and should be discussed with your radiation oncologist. It is very important that the patient be positioned exactly the same way when receiving radiation treatments, and that he or she does not move during the treatment, so a very short anesthetic episode is typically necessary for each treatment.
What kinds of payment plans are available for cancer-related care?
We encourage you to discuss the likely cost of treatment for your companion animal upfront with your veterinarian. Many payment options are available for veterinary treatment including veterinary payment plans, veterinary financial aid programs, or assistance programs, including the Sponsor-a-PetSM Program provided by Tails of Hope Foundation.
Special thanks to Michele Steffey, DVM, DACVS; Philip Bergman, DVM, MS, PhD, DACVIM (Oncology); Carolyn Henry, DVM, MS, DACVIM (Oncology); and Sandy Willis, DVM, DACVIM (Small Animal Internal Medicine) for preparing this information.
For more information about cancer in companion animals or for more information about the campaign, visit or