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. Depending on the type of cancer, treatment options may include surgery, radiation, and chemotherapy.

Cancer changes the body’s metabolism

Cancer changes how the body metabolizes nutrients. Cancer cells metabolize glucose (from carbohydrates) and make lactate that the body then tries to convert back into glucose. This process diverts energy from the cat, feeding the cancer instead. Cancers also convert amino acids, the building blocks of protein, into energy, which causes muscle wasting, poor immune function, and slow healing. Additionally, tumor cells have difficulty utilizing fat as a source of energy. All of this results in what’s known as “cancer cachexia,” a progressive weight loss and depletion of muscle and connective tissues.

Good nutrition is critically important in cats with cancer

For all of these reasons, adequate species-appropriate nutrition is critically important in feline cancer patients. Unfortunately, cats will often lose their appetite when they’re not feeling well. It’s important to stay on top of how much your cat is eating. Refusal to eat can ultimately be a quality of life indicator in cats with cancer.

The optimal diet for a cat with cancer

The optimal diet for a cat with cancer is not all that different from the optimal diet for a healthy cat: a diet high in quality protein and low in carbohydrates, and that means meat. There is not much research available on diets for cats with cancer. Many veterinarians recommend feeding a high protein, high fat and low carb diet based on studies that were conducted with dogs. Omega-3 fatty acids are also recommended since they are a good source of fat and also have anti-inflammatory properties.

Many premium quality grain-free diets will meet these parameters.

Alternately, you may want to consider a home prepared diet for cats with cancer. A holistic veterinarian or veterinary nutritionist can help you design appropriate recipes.

Raw feeding is controversial for cats with cancer, and some veterinarians caution against it. “I recommend avoiding raw meat based diets for cats that are on immunosuppressive medications like chemotherapy drugs, or higher doses of cortisone-type drugs like prednisolone,” says Andrea Tasi, VMD, a holistic feline veterinarian and owner of Just Cats Naturally.

It’s more important that cats with cancer eat, than what they eat

Even though feeding an optimal ratio of protein, fat and carbs is ideal, this is not the time to force a diet change. While dry food may be the worst possible nutritional choice for a cat with cancer, it is an option if it’s the only thing your cat will eat.

Cats with cancer may become finicky about eating, and encouragement may be needed. Adding incentives such as freeze dried meat treats, tuna juice, small pieces of cooked meat, or nutritional yeast can all help encourage cats who have lost their appetite. For more information, read How to Get Finicky Cats to Eat.

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35 Comments on The Right Diet for Cats with Cancer

  1. My boy Sachi is 12.5 years old. White Maine Coon. I found two lumps on him and they were removed, tested and it’s cancer. The oncologist has him on lomustine every three weeks and prednisolone 5mg twice a day. We are only two weeks into this routine, but I’ve found his legs seem to be rather weak, especially on smooth surfaces like granite. This started right after he was recovering from the surgery to remove the lumps and it doesn’t seem to be getting any better in time. He was always 14 pounds and is now down to around 12.5. So I’m trying to bulk him up a bit and have been reading your articles and comments on that (thank you). I tried a transdermal ointment yesterday in his ear and he acted like a drunken sailor and this morning seemed agitated. Mirataz is the ointment that is supposed to increase his appetite but I’m hesitant to use it again. My bottom line question is this: is anyone seeing a weakening of legs in their cancer babies?

    • My kitty has done really good with the mirataz. She eats like a fiend now. Unfortunately she didn’t get a good report today. Cancer on her kidney and a spot on her lung. I don’t think there is anything we can do.

  2. Hello. My kitty was taken to the vet twice for vomiting and vet gave me prilosec. I finally told her this week I wanted an xray of her stomach. She did and found swelling n inflammation of her intestines and a mass. She said she could operate n put her on chemo. Had to go in next day since they did not have ultrasound equipment n a technician was called in. After sonogram she just said mass in lymph node and may have spread and gave me prednisone to give her 2x day. Five mg each time. And switched her food from Prescription digestive ID to prescription ZD.
    I am going to consult with a holistic vet after she can read ultrasound report in which she said was not read by radiologist yet. And that is supposedly tomorrow. And want to see oncologist. I want all options.
    This could have been prevented and I’m so sad. She has lost 2 lbs since April. She is eating good. Just constipated.

    I wanted to ask what do you think of high alkaline water? And can I give her bone broth?

    • I’m sorry about your kitty. It’s always a good idea to know all the options before making treatment decisions. I’m not familiar with high alkaline water. I don’t see any reason why you couldn’t give her bone broth. You may also want to consider a better quality diet.

      • Please check in to medicinal mushrooms. Turkey Tail. There are also a few more that could benefit her. I’m not a vet but also have a cat I am dealing with. I just started giving her the turkey tail along with a tri mushroom supplement. I am hoping for the best. Please research like I did and make your choice as to which would benefit your cats ailments.

        • Reaching out to see if the mushroom supplement helped. My female cat is about 9-10 years old and has a external mass that looks like an open wound. Vet said likely cancer but looking for a holistic option. I hope your kitty is ok.

          • Check out Neoplasene Cancer Treatment. Topical that will eliminate the bad (cancer) cells. Talk to your vet.

  3. Hi there, can someone please advise me on what I can give my cat to eat? My cat Chicken is 12yrs, I was told on Monday he has a cancerous lump on his intestines. The PDSA, which is a charity run vets, has told me surgery is not an option cos of where it is. They’ve put him on steroids for a week to see if they will start to shrink it. As soon as he went off his food last week, before I took him to the vets, I started to feed him chicken and rice. The vet’s never advised me about what to feed him. After reading your blog,I now feel terrible for giving him rice! Yesterday he was sick and brought up all the rice. I’m due to go back to the vet’s on Monday and I will be expressing my disappointment that they didn’t advise me on what to feed him. I’m boiling chicken thighs for him right now and making bone broth. He is a strong boy, he used to weigh 4.6k but is now 2.8k, Please help,!

      • Thank you for your response Ingrid. I gathered that boiled chicken is not enough but as I said, I’m making bone broth and I was thinking of also cooking up red meat for him too. Other then the list of foods you’ve posted, us there anything else you can suggest that I can give him? He does like biscuits, so grain free biscuits are ok?

        • I don’t usually recommend dry food, but for a cat with cancer, the most important thing is that they eat, so if he likes dry food, then grain free is better than other dry food.

  4. Hi,
    Can you provide citations for the research you mention showing that dogs with cancer benefit from a lower-carb diet?

  5. Hello, My cat was just diagnosed with large cell lymphoma. His vet switched him to Hills a/d urgent care from Instinct Limited Ingredient because he’s loosing a half a pound a week and is down to 6 pounds now (from 12lbs). Before canned food, he was eating raw whole ground rabbit. I’m considering switching him back to raw food because I’m concerned that the quality just isn’t there with the canned food and he’s still dropping a half a pound a week. Why is it recommended for cats with cancer to not eat raw?

    • If your cat is going through chemo therapy and/or taking steroids, his immune system is suppressed. While the risk is probably relatively small, a healthy cat can handle any possible pathogens in raw food, a cat with a compromised immune system may not be able to. You could gently cook the raw food to eliminate that risk.

      • Okay. Thanks Ingrid! We have an appointment with the oncologist on Monday to see if he will be able to start chemo. I will definitely cook it a bit first to be safe. If he’s not able to do the chemo, should I still cook it?

  6. Hi, My cat is currently losing weight and has been in chemo since August. I used to feed my cat Innova but it was discontinued in the summer so I switched to Fancy Feast. It’s not the best brand and my cat has been losing weight. I want to switch to a higher quality, higher fat and less fake cat food. Do you have any brand suggestions? I was thinking of Evo. It’s funny because my cat is eating, but I’ve switched him to more wet food but the weight isn’t staying on. He was chunky to begin with, but the doctor is concerned. Another option is kitten food. Any suggestion would be appreciated.

    I love your blog by the way. i found it a few months ago when I had a breakdown over not being able to put my cat in a carrier. He has a eye tumor but I will do what I can to help him.

  7. Bone broth is one of the best things you can make for any pet with or without illness but it has worked wonders with my cat who was diagnosed with cancer. I give it to her in a 1 ml syringe most times to ensure she is getting enough – she doesn’t pull her head away at all and seems to relax with the warmth. Sometimes I will add a pinch or 2 of nutritional yeast which she likes – not necessary though as bone broth is a complete “food”.

    • How do you make bone broth. My 13 year old cat was just diagnosed with cancer and had to have his left rear leg tee removed. It’s been a struggle to get him to eat. And he’s on steroids twice a day now too.

      • Hi! I have a 13 year old with all kinds of growths and inflammation in her stomach and small intestines, liver and gall bladder. Don’t know if it’s cancer without a biopsy BUT I started her on this. Bone broth is easy especially if you have a crock pot. Go to your local butcher(I’m a vegan so this was a ton of fun) and tell them you want to make bone marrow broth and they will cut you a few bones. Whole Foods and Wegmans or any higher end grocery should have this option)My last batch I did 2 lbs bones and enough water to cover bones. Add 2 tbls of apple cider vinegar(I use raw unfiltered)this pulls out the good stuff. Put slow cooker on high for 2 hours then about 18 hours on low. My girl loves the taste and I am happy she is getting something that is helping fight cancer.

        Google- Nate the Cat story, I also started her in CBD 1x a day(I give in a Syringe with 3 ml fresh wheat grass juice) in addition to what I found in this article. After about 10 days so far of this regimen she seems to be doing a little better

  8. Can someone please give me a sample meal for a cat with cancer?
    I just learned my 13yr old cat has cancer yesterday(she has a fairly large lump on her right rib). The vet wants to put her to sleep, but I’m trying to desperately help prolong her life. I just changed her food. I used some canned salmon cat food and then I added some egg and a few bits of sweet potato. She ate some of it but she’s only eating if I bring her food.

    Please help!

    • I’m sorry about your cat’s diagnosis, Tiffany. The most important thing for a cat with cancer is that she eats, even if it may not be the kind of food we want her to eat. You may need to break out the “junk food” to tempt her appetite. If you want to have someone formulate a homemade diet for her, there are a couple of different resources that can help: and Both have vets on staff.

    • Hi Tiffany,

      I’m so sorry for your cat’s diagnosis. My 15 1/2 year old cat has a probable case of bone cancer (the chickpea sized VERY hard lump on his back rib is now a 3 inch mass with multiple larger lumps–took about 8 months to grow that large; the vet thinks it’s osteosarcoma & I decided against further tests since the vet said surgery would probably not prolong his life.) That said, although my cat’s mass hasn’t grown much in the past 2 months and he otherwise seems ok.

      I have no medical proof to back this up but I feed my cat these things:
      1) solely wet food that very very low in carbs and fairly high in fat. I’m currently mixing Wellness Complete Chicken with Fancy Feast Classic Salmon with Cats in the Kitchen Chicken Frick a Zee.
      2)in the morning squeeze an omega 3 cat tab on the food

      I feed put his food out four times a day. I try to get him to eat it when I put it out, but if he doesn’t I cajole him during the the hours between servings. My cat weighs about 11 pounds, I give him about 250 calories a day and on a good day he eats about 3/4 of it. On a bad day about 100-125 calories.

      While my cat sleeps a lot and a lot of the time and I have to hand-feed him sometimes (he’ll gobble up the food if I hand-feed him; yes, he’s gotten spoiled), he does eat and drink.

      I have no idea if this is prolonging his life or not. I hope it is. I do think it is crucial to give your cat a low carb diet (only because I read somewhere that cancer will not grow quickly on a high fat diet but will grow quicker with sugar carbs.) Again, I have no idea if this is true. I just know my cat, while he has a large mass is still ok and it’s now nearly 5 months since the vet noticed it and nearly 14 months since I first noticed his lump. I with you the best.

      PS There’s a great site, , that has charts with every single type of cat (wet) and lists the protein/carb/fat calories.

  9. Great article!

    My cat is 15 years old and has a probable malignancy. I say “probable” because he had a small very very very hard lump on his rib (first noticed it 1 year ago), 1st vet said it was nothing, 2nd vet, last Dec. thought it was something–bone cancer. On the rib (axial osteoarcoma.)

    I decided against a biopsy because vet told me surgery probably wouldn’t extend his life and because my cat is in diabetic remission (long story, but he went into remission 4 days after his diagnosis just by switching to high quality wet low carb food)he cannot take chemo (which I doubt I’d want to do in the first place.

    So I’m letting him live out the rest of his life being loved. His tumor has grown tremendously –it’s currently weird shaped (bumpy, about 3″ long) but aside from not being as active as he used to me, he seems fine. Eating well, drinking, going to the bathroom. He doesn’t seem to be in any distress. I’ve decided to switch his food so it’s still low carb but higher in fat (I also give him 1 omega 3 a day and he gets freeze-dried chicken crumbled on top of his food which he loves.)

    Any other suggestions to (hopefully) prolong his life? Thanks in advance!

  10. Such a wonderful article, Ingrid, and really underlines the importance of not stressing out a cat with cancer further by making new diet rules. As always, kindness is key with our furry ones.

  11. Hi Ingrid-

    I’ve mentioned here before that my Maddie has been dealing with small cell lymphoma for over a year now and I totally agree that while it would be good for her to be on a certain diet, I am just happy when I can get her to eat her fancy feast.


  12. Hi Ingrid. I lost a beloved kitty to cancer, and while I chose to take the vet’s advice in her case, and put her on chemo, it was the worst experience and made her last few weeks wretched. I regret putting her through that, because clearly it made her miserable. Back in those days, little of us had heard about a Species Appropriate Diet…diet is everything!! Now, my Wilford has cancer tumors throughout his body, along with CHF and HyperT. Wilford is a very picky man- you don’t get to dictate what Wilford eats, he is a man with his own agenda. To that end, he has scoffed at 99.9% of everything “healthy” I’ve tried to nudge him in to. That being said, after months and months of prodding, he is taking his CannaPet daily and it has done wonders at stimulating his appetite. Along with increased appetite from the CannaPet (now voracious, plus increased due to the HyperT stimulation) he amazes the vets with how well he is doing- overall. The CannaPet has been a God-send in getting my Wilford to eat. I encourage any kitty owner to get this hemp product, especially if they’re struggling with cancer, arthritis, IBD- especially cancer- it has made all the difference in whether my Will’s eats, or not.

    • I’m so sorry about your kitty, Elizabeth. Some cats do really well with chemo, others have a hard time with it, like yours. I’m glad CannaPet is working so well for Wilford!

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