Darlene Norris is a long-time pet lover. She has worked as a vet assistant and draws on this experience when she writes her articles.
Does Your Cat Have Feline Cancer?
Feline Cancer Diagnosis: What Happens Next?
A diagnosis of cancer is devastating for any cat owner, but it's important to keep a clear head so you can make the best decisions for your cat and also for yourself. Your vet will need to know two things about the cancer: the stage and the grade. This information is essential in making treatment decisions.
Staging Determines If a Tumor Has Spread
How does your vet stage a tumor? Some types of cancer are more likely to spread or metastasize than others. Your vet may rely on his own experience in treating a certain type of cancer. A benign tumor won't spread, while bone cancer metastasizes quickly.
Chest x-rays are recommended to determine if the cancer has spread to the lungs. A cat scan can show smaller masses in the lungs that an x-ray might miss. For tumors in the belly area, an ultrasound allows your vet to examine the whole area.
Cancer in the mouth can spread to nearby lymph nodes, so your vet will look for lumps in the nodes as well.
Grading Shows How Likely the Tumor Is to Spread
Your vet will probably do a biopsy and send the sample to a pathologist, who will examine the tumor under the microscope. There are three grades:
- Grade 1: Localized cancer that is unlikely to spread
- Grade 2: This tumor may or may not spread
- Grade 3: An aggressive tumor that is likely to metastasize
Once your vet knows the stage and grade of the tumor, a treatment plan can be finalized. Your vet will explain your pet's prognosis (what you can expect as the disease progresses), the treatments available, and the treatment goals.
Three Cancer Treatment Options for Cats
Your vet will choose from surgery, radiation, and chemotherapy, or a combination of these three treatments. The option your vet recommends is dependent on where the tumor is located, what kind of cancer it is, and the stage or grade of cancer.
You may choose to work with a veterinary oncologist. These vets specialize in cancer treatments for pets. They often have access to newer or specialty treatments that may not available at your regular vet's practice.
The end goal is to get rid of the cancer. This isn't always possible, but it may be possible to extend your pet's life while keeping her free from pain.
Treatment for Feline Cancer: Surgery Is Often the First Step
Completely removing the cancerous tumor is the goal for surgery. If the vet is able to remove the whole tumor, that may be all that's needed to cure your pet. However, the tumor may be too large to remove, or it may be attached to a vital organ. In that case, the vet may remove as much of it as possible in an effort to slow the tumor's growth.
Sometimes, a vet may remove a tumor that is causing disfigurement or discomfort, even if he or she can't get the whole thing. Improving the quality of your pet's life is the aim. If the cancer has already metastasized, surgery alone probably won't help.
Surgery: A Treatment Option for Cancer in Cats
Radiation Therapy for Cancer in Cats
Your vet may recommend radiation therapy for your cat with cancer. This therapy may be used to shrink a tumor so it can be removed surgically, or it may be done along with chemotherapy. Radiation is often used for cancerous masses in the head and neck area, including the nose and the brain, and for cancers of the spine or pelvis.
How does radiation therapy work? It targets cells that divide quickly, especially cancer cells. Normal cells can recover from radiation damage, but cancer cells can't. The radiologist will fine-tune the radiation dose so that there is just enough to damage or destroy the cancer cells, to keep them from spreading.
Your pet will need several radiation treatments over a period of time. Spacing the treatments out allows the normal cells to recover from radiation exposure, while the cancer cells die off. Sometimes, normal cells that divide quickly but are in the targeted area are damaged by radiation. Bone marrow, hair follicles, and cells that line the digestive tract may be affected.
How many radiation treatments will your pet need? It depends on what kind of feline cancer your pet has, the stage and grade of the tumor, how your kitty responds to treatment, and what the goal of treatment is. Your cat will need different size radiation doses if the goal is to shrink the tumor so it can be removed surgically, versus killing the cancer off completely. Usually, five doses a week over four to six weeks are recommended.
Are there adverse effects from radiation therapy? It depends on what area is being treated. Radiation can irritate the skin on the head or neck, and it can cause inflammation in the mouth. Your pet may need a feeding tube if her mouth is too sore for her to eat. She may also develop dry eyes due to damage to the eyelids. This may be a permanent condition, but eye drops can help.
Radiation therapy in the abdominal area may cause nausea, diarrhea, and a lack of appetite. Your vet may recommend a change of diet during treatment.
Unfortunately, radiation doesn't work on all types of cancers. This therapy is not a cure-all, as some cancers are not affected by radiation at all.
Dr. Lafer Discusses Cancer Treatment for Her Cat
Chemotherapy for Cats May Be a Treatment Option
Chemotherapy uses drugs to treat cancer. The same drugs used to treat human cancer patients are used in cats too, only in smaller doses. These drugs by themselves can't cure cancer, but they do work to keep the cancer from growing and spreading.
Chemotherapy is useful in treating types of cancer that affect the whole body, including lymphoma. It's also used to destroy cancer cells left after surgery. The goal of this treatment is to eradicate the cancer without permanently damaging your cat's body. Your vet will decide what drugs to use by evaluating what kind of cancer your pet has, the stage and grade, and your cat's health. Financial considerations come into play here as well. Chemotherapy works best when cancer is caught in its early stages, before it has spread throughout the body.
Your cat may be able to take anti-cancer drugs by mouth. These drugs can also be injected in one of three ways:
- Subcutaneously under the skin
- Intravenously into a vein
- Intramuscularly into a muscle
Your vet will choose the most effective way for the drug to reach your cat's tumor.
Do Cats Experience Side Effects From Chemotherapy?
It would be great if the drug treatment targeted only the cancer cells and left the normal cells alone, but this isn't possible. Most of the cells in your cat's body will be affected. Your vet needs to consider the potential benefits of treatment against the possible drawbacks.
Animals seem to do better with chemotherapy than people do, but there can be some side effects:
- Nausea, vomiting, diarrhea, dehydration
- Anemia due to lower numbers of red blood cells
- Leukopenia (lower numbers of white blood cells)
- More susceptibility to infection
- Bleeding problems due to lower numbers of platelets in the blood
Hair loss usually isn't an issue for cats, although some have been known to lose their whiskers during treatment.
Combining Cancer Treatment Therapies
Cancer in Cats May Be Treated With a Combination of Therapies
There is no one treatment that is best for all cancers. Your vet will more than likely choose the best combination of feline cancer treatments while considering your cat's quality of life.
A combination of treatments is usually more effective than using just one type. For example, doses of several different chemotherapy drugs make it less likely that your cat's cancer will become resistant to one drug. It's also possible to target different places in the body where the cancer may have spread.
Your vet may use surgery and radiation to treat cancer that is localized to one place in your cat's body. Chemotherapy and radiation are often used to shrink tumors so they can be removed surgically. Or these two therapies may be used after surgery to kill any cancer cells that couldn't be removed.
Cost of Cancer Treatment for Cats
Cancer treatment is expensive for both humans and pets. Once the cancer is diagnosed, staging and grading the cancer can be expensive. When the costs of surgery, radiation, and chemotherapy are added in, the cost of treating feline cancer can run into the thousands of dollars.
Not all owners decide to have their cats treated for cancer. Besides the expense, the endless trips to the vet's office for treatment eat up a lot of time too. In some cases, the treatment must be continued for the rest of your pet's life.
You may not be able to afford treatment, or you may not think it's worth putting your cat through treatment to extend her life for a few more months. Only you can make this decision.
When it comes to cancer in cats, there aren't any easy answers. Knowing your options will help you make wise decisions for both your cat and yourself.
Conversations on Cancer in Cats
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- Cancer and Tumors - Merck Veterinary Manual
This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.