Types of cancers treatedWe do our best to provide the best quality of life for animals suffering from cancer, achieve remission or cure from the disease, minimize the side effects of therapy, and offer palliative treatment.
The most common tumors treated are:
- Mast cell tumors
- Feline fibrosarcoma
- Soft tissue sarcoma
- Tumors of the mammary gland
Signs and symptoms of cancer
Since our pets cannot tell us when they’re in pain, it’s important to be aware of any behavioural changes. While some cancers can be detected through blood work, changes in behaviour and activity are important warning signs to pay attention to. If you notice your pet is acting different or abnormal in any way, it is time to seek veterinary attention. As in humans, early detection of cancer in pets is critical to ensuring the best possible treatment outcomes.
Symptoms of cancer in animals are similar to those in humans. Some of the most common early warning signs of cancer in pets are:
Abnormal swelling that persists or continues to grow
Regularly check your pet’s skin for lumps and bumps. Check behind the ears, in the mouth, and around the face. Cancer can move fast. If you find any abnormality, be sure to note it and measure it. If it changes shape and size, its time for a visit to the vet for the growth to be evaluated.
Sores that do not heal
If your pet has a lesion on the skin that is not going away or healing, it’s time to call the veterinarian.
Unexplained weight loss
Unless there has been a diet restriction or change, weight should remain stable throughout your pet’s life.
Loss of appetite
There are many reasons why your pet may have a loss in appetite, cancer being one of them. Seek veterinary advice if this is the case.
Healthy gums are a red-pink in colour. Pale or grey gums can be a sign of illness. If you notice your pet has pale, almost white, gums, seek veterinary assistance as soon as possible.
Other signs may include:
- Bleeding or discharge from any body opening such as the nose or mouth.
- Bad odour, especially from the mouth.
- Difficulty eating or swallowing.
- Reluctance to exercise or loss of stamina.
- Persistent lameness or stiffness.
- Difficulty breathing, urinating or defecating.
Surgery considerationsWhenever cancer surgery is being considered, you should discuss its costs and benefits with your veterinarian.
- Complete cure and a disease-free life
- Reduced pain
- Improved quality of life
- Prolonged life
- Potential complications of surgery, including infections, bleeding, recurrence of the cancer, and undesirable changes in appearance
- Short- or long-term pain and discomfort
- Loss of normal function in affected limbs or organs
Surgery is considered the cornerstone for treating most cancer and tumours in animals. It is one of the oldest forms of treatment and frequently the most effective one. Today, surgery may be combined with radiation therapy and/or chemotherapy, depending on the characteristics of the case.
When surgery is performed, the main goal is usually to remove all the cancerous cells in the animal’s body. Sometimes, if the cancer is detected early (before it grows too large or spreads to other parts of the body), surgery can completely cure the animal. Other goals of surgery can include removing an unsightly tumour to improve the animal’s appearance or comfort or removal of a tumour that is interfering with the animal’s normal body functions. These goals can improve the quality of life for the animal.
Surgery is most successful when the cancer involves a tumour that has not spread beyond its original location. Unfortunately, however, not all tumours can be surgically removed. Some are in inaccessible sites. And, there are times when the costs to the animal might outweigh the benefits. For example, removing a large tumour might require removing a vital organ or may cause a pet to lose a vital body function. If the cancer has spread to more than one location (metastasized), then surgery alone is not as likely to be an effective treatment.
A biopsy is a surgical procedure in which a piece of a tumour is removed for study and analysis by a pathologist. The pathologist’s report will provide important information such as the type of cancer and its characteristics. Combined with information about the size and location of the cancer, your veterinarian can develop the best treatment program for your pet.
Certain drugs (chemicals) destroy cancer cells. This type of treatment is called chemotherapy. It can be used to manage and treat several types of cancer. When it is used, the most common treatment goal is to shrink, stop the growth of, or destroy the cancer without longterm negative effects on the quality of life for the animal. Your veterinarian will prescribe chemotherapy based on the type of cancer to be treated, the stage of the cancer, the overall condition of the animal, and any financial constraints that may be present.
In an ideal situation, a chemotherapy drug would kill cancer cells in an animal’s body without harming normal healthy cells. Few such drugs have been found. Today, the drugs selected for chemotherapy have been designed to be more damaging to cancer cells than to normal cells. They specifically target cells that divide and grow rapidly. Normal cells will be affected to some extent by chemotherapy drugs, and sometimes the drugs can have adverse effects.
Chemotherapy drugs are delivered either by mouth or by injection. If injection is used, it can be into a vein (intravenous), muscle (intramuscular), or under the skin (subcutaneous). The delivery method will be selected with the comfort and quality of life for the pet in mind balanced against the goal of effective delivery of the drugs.
Chemotherapy alone usually cannot cure cancer in pets. It is used most often to control cancer and its spread. Thus, chemotherapy is often used to treat cancers that affect the whole body, such as cancer of the lymphatic system (lymphoma). In other cases, chemotherapy is used to fight the remaining cancer cells when a tumor cannot be completely removed with surgery. Chemotherapy is also used to fight types of cancer that spread around the body early in their development.
In all cases, your veterinarian must weigh the expected benefits of the drugs with possible adverse effects to select the most appropriate treatment for your pet. The veterinarian will carefully monitor your pet’s physical and behavioural response to the treatment and adjust the dosage to maximize the effect on the cancer while reducing the side effects.
Animals generally appear able to tolerate chemotherapy better than people, but treatment with some chemotherapy drugs may lead to vomiting or a lack of interest in food. This side effect can be treated with anti-nausea medicine. Intravenous fluids can be used to control such side effects as vomiting, diarrhea, and dehydration.
Dogs and cats receiving chemotherapy usually have good to excellent quality of life throughout the treatment program. Side effects, if any, are usually mild. The risk of life-threatening adverse effects is estimated at less than 5% for most types of chemotherapy. If your pet will be undergoing chemotherapy, you should discuss the treatment program with your veterinarian in advance. You need to come to a mutual understanding about what you can expect for your pet and the level of risk you are willing to accept.
The term combination therapy refers to the use of 2 or more treatment options in the fight against cancer. Today, combination therapy is the most frequently used approach to treat cancer in pets. It offers the best opportunity to cure the cancer while maintaining the best possible quality of life for the animal.
Combination chemotherapy offers many advantages over single drug treatment programs. For example, when multiple chemotherapy drugs are used, and each one uses a different mechanism to kill cancer cells, it is less likely that the cancer will become drug resistant. This improves the chances that the treatment will be successful.
There is no single best treatment for all cancers. For some cancers, the best approach is one that combines surgery, radiation therapy, and chemotherapy. Tumours and other cancers that are confined to a localized area are often best treated with surgery or radiation therapy. Chemotherapy has the advantage of treating cancer cells that have spread from their original location. In other cases, radiation or chemotherapy is used to shrink a tumour to a size that makes surgical removal possible or more likely to succeed. Radiation or chemotherapy may be used following surgery to kill any cancer cells that may remain.
The stage of cancer development is a factor in selecting the treatment, whether a single treatment mode or a combination of treatment methods. For animals with advanced cancers that cannot be treated with surgery or radiation therapy, combination chemotherapy can be used to reduce the signs of the disease and prolong life.