Chemotherapy for Cats

Feebee cat in blue chair

While cancer in cats is not as common as it in dogs, it is still one of the leading causes of death in older cats. According to the Animal Cancer Foundation, 6 million cats will be diagnosed with cancer in the United States along. And because cats are masters at masking illness, it is often harder to detect.

Cancer used to be a death sentence for cats, but recent advances in feline cancer research have made treatment possible in many cases. Just like with human cancers, early detection is key to successful treatment.

Treatment options for cats are almost as varied as treatment options for human cancers, and will depend on the type of cancer. Surgery is the most common treatment for any lumps or growths that need to be removed. In some cases, surgery can be curative. Other cancers may require chemotherapy or radiation.

How chemotherapy works

Chemotherapy uses drugs with the objective to kill cancer cells with the least possible amount of damage to normal, healthy cells. In human medicine, the goal of chemotherapy is to achieve a cure. In cats, chemotherapy is aimed at controlling the disease and achieving a period of remission for the cat. Chemotherapy is typically used for cancers that affect multiple sites. Lymphoma is the most common form of feline cancer that is treated with chemotherapy. The drugs used in veterinary chemotherapy are frequently the same drugs used in human medicine.

Most cats tolerate chemotherapy well

Most cats tolerate chemotherapy well. Some cats may experience side effects such as vomiting, diarrhea or poor appetite, but these side effects are usually mild and can be managed with supportive care. Only a very small number of cats on chemotherapy will require hospitalization due to the side effects of chemotherapy. Unlike humans, cats will not lose all their hair. Most cats will lose their whiskers, and shaved hair will be slow to grow back, but substantial hair loss is uncommon.

Support your cat’s immune system

It is important to support your cat’s immune system while she is undergoing chemotherapy. One of the foundations of a healthy immune system is diet. Typically, veterinarians recommend a high protein, low carb, moderate fat diet for pets with cancer. A high quality grain-free canned diet will probably be your best choice for your feline cancer patient.

Even though I’m a proponent of raw feeding, I’m on the fence as to whether raw diets are appropriate for cats with cancer. On the one hand, there are numerous anecdotal reports of miracle cures when pets with cancer were fed a raw diet, on the other hand, I don’t know whether feeding a raw diet to an immunocompromised pet is necessarily a good idea. Check with a veterinarian who is familiar with raw feeding whether a raw diet is appropriate for your cat while she is undergoing chemotherapy.

Supplements and herbs

Supplements and herbs can provide immune system support during treatment. Probiotics not only help maintain a healthy gut flora, but also boost the immune system. Anti-oxidants and increased amounts of omega-3-fatty acids may also be indicated. Check with your veterinarian to determine which supplements are indicated for your cat.

Supportive therapies such as acupuncture, Reiki or other forms of energy healing can support your cat through her treatment. These therapies will not interfere with conventional medical treatment.

How will you know whether chemotherapy was successful?

A cat in remission doesn’t look any different from a cancer-free cat. Typically, a successful remission means that lymphnodes will go down to normal size, and if there were any signs of illness that were related to the cancer, they will disappear. Remission can last anywhere from weeks to months, and for some lucky cats, even several years.

My personal experience with feline cancer

My first cat, Feebee, was diagnosed with intestinal lymphoma when he was 15 years old. He tolerated his chemotherapy protocol of a combination of Vincristine injections and oral Cytoxan and prednisone well. He would be a little subdued for about 24 hours following treatment. His appetite wasn’t that great during that period, and he slept a lot more than usual, but the rest of the time, his quality of life was good.

After seven months, he stopped responding to the chemotherapy. My vet gave me the option of continuing with more aggressive drugs with the potential for more severe side effects. I elected euthanasia. My little man confirmed that I made the right decision: he died in my arms while my vet was on the way to my house.

Being faced with a cancer diagnosis is a devastating blow for cat parents. Making a decision about treatment is as individual as the affected cat and her human. There are no hard and fast rules. The ultimate goal of any decision is to provide good quality of life for the cat for as long as possible.

Have any of your cats undergone chemotherapy? What was your experience?

Photo ©Ingrid King

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842 Comments on Chemotherapy for Cats

  1. Kim
    May 8, 2019 at 7:51 pm (2 weeks ago)

    Hi everyone. First off, thank you to everyone who has been sharing their stories. My kitty – Bailey – was diagnosed with large cell lymphoma. She is 12 years old and started steroid and chemo treatment today. She was barely eating in the few days before, and is now nauseated. Happy to have the option to try to make her feel better, but feeling bad that she is taking day 1 of treatment so hard. Also, vet informed us *after* treating her, that apparently her rbc is low… Fingers crossed she is feeling better soon. Just wanted to share with others who understand what we are going through. Thanks.

    • Dovemck
      May 9, 2019 at 6:30 am (2 weeks ago)

      {{HUGS}} to you and Bailey. It’s a scary thing to face. Please forgiveme if I just give some unsolicited advice. First see your vet to get something for nausea.
      Second ask questions, take notes, research and ask more questions.
      Treatment is a living, breathing experiment, there is no right or wrong. If something isn’t working ask for a change. I know it sounds harsh but you’re still a paying customer and you deserve service. This includes drugs/side effects, schedules, protocols. Nothing should be off the table.
      You CAN change vets.
      Really pay attention to Bailey’s signals. The longer you two fight this together the more sympatico the relationship. I didn’t think I’d be able to tell when it was time, but in the end, yes, I could.
      I urge you to be an active partner in treatment and advocate on Bailey’s behalf.
      Please give chin-scritches to Bailey for me.

      • Kim
        May 9, 2019 at 7:39 am (2 weeks ago)

        Thank you very much Dovemck. Anti-nausea meds will be here today or tomorrow. She is still a bit food adverse, but is drinking water and hanging out by her food, so at least smelling it isn’t bothering her now. Hoping the appetite stimulant will kick in soon. I gave her some chin scratches and she was purring. 🙂


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