Ketogenic Diet for Dogs with Cancer

By Paul Raybould, founder of KetoPet · Last updated October 10, 2026

If your dog has just been diagnosed with cancer, you may be reading this late at night with a great deal on your mind. One of the first questions many people ask is whether they should change what their dog eats. This guide is our honest answer: what a ketogenic or low-carbohydrate diet is, why it is being studied in dogs with cancer, what the research does and doesn't show, and how to begin safely with your veterinarian.

First, keep your dog eating

A dog who is eating well and holding their weight is in a stronger position, whatever the cancer. In a study of 324 dogs with lymphoma or osteosarcoma, dogs with lymphoma who were underweight when diagnosed had shorter survival times, and dogs who gained weight during treatment lived longer.⁴ Most dogs are not underweight when they are diagnosed, and many are carrying a little extra.

So any change in food should help your dog eat, not put them off. If your dog's appetite drops, they lose weight, or they start vomiting or have diarrhea, tell your veterinarian promptly. This is not the time for a strict weight-loss diet. If your dog is carrying extra weight, ask your veterinarian whether, and how gently, to bring it down.

What is a ketogenic diet for dogs?

A ketogenic diet is very low in carbohydrate and high in fat, with a moderate amount of protein. With so little carbohydrate coming in, the body burns more fat and makes ketones, which most healthy tissue can use for fuel. Blood glucose usually drops a little and stays steadier.

A low-carbohydrate diet is a gentler version of the same idea: far less starch, more meat-based protein, and moderate fat. Many dry dog foods get a large share of their calories from starch, so cutting carbohydrate is a real change for most dogs. Our guide How to Find the Carbohydrate in Your Dog's Food shows you how to work it out from the label.

For dogs with cancer, a stricter ketogenic diet may help, planned with your veterinarian. For most other dogs, far less carbohydrate is enough. We explain how our own thinking changed in The Science Behind KetoPet.

Why diet is being studied in canine cancer

Nearly a century ago, the biochemist Otto Warburg noticed that many cancer cells take up and burn glucose far faster than healthy cells, even when oxygen is available.¹ In dogs, veterinary researchers found that dogs with lymphoma handle carbohydrate differently from healthy dogs, with higher blood lactate and insulin, and that these changes did not go away even when chemotherapy put the cancer into remission.²

The idea behind a ketogenic diet follows from this. If many tumors depend heavily on glucose, lowering the carbohydrate in a dog's diet, while giving healthy tissue fat and ketones to run on, might make conditions harder for the cancer. It is a reasonable idea. It is not yet a proven one.

What the research shows, and what it doesn't

So we offer this honestly. A ketogenic or low-carbohydrate diet is a sensible step for many dogs when it is planned with a veterinarian and given alongside the treatment your veterinarian recommends. It is not a replacement for that treatment.

What we saw at the KetoPet Sanctuary (2014–2017)

Many of the dogs who came to the KetoPet Sanctuary were shelter dogs with advanced cancer and few other options. When Modern Dog magazine visited in 2016, the ranch was caring for 26 of them.⁷ Every dog had a PET-CT scan at intake, which confirmed whether the dog had cancer and, if so, what type. Dogs with cancer were scanned again about every 60 days and had blood work every week.

A PET-CT scan combines two pictures in one session. The CT (computed tomography, sometimes called a "CAT scan") part shows the body's structure: the size and shape of organs, and of any tumor. The PET (positron emission tomography) part shows activity. Before the scan, the dog receives a tiny dose of a glucose-like tracer, and the scan shows where in the body that glucose is being taken up. Many cancers take up far more glucose than healthy tissue, so they show up brightly.

We chose PET-CT over MRI (magnetic resonance imaging) or CT alone because those show structure only. For a project studying whether lowering glucose could help dogs with cancer, PET-CT let the team see where each tumor was and how actively it was using glucose, and follow each dog's disease over time alongside their treatment and diet. Those records are kept in KetoPet's archive.

Cali, a Hungarian Vizsla, was KetoPet's first dog. Her hemangiosarcoma was found during an ultrasound meant to show a litter of puppies, and after surgery she was given a six-week prognosis. She lived for years beyond it, and has since passed. Read Cali's story.

Blazer, a Staffordshire mix with a Grade II mast cell tumor, was scanned when he arrived and again sixty days later, during the sanctuary's full program, which included standard veterinary care. The second scan showed no evidence of disease. He has since passed. Read Blazer's story.

These are two dogs, not a study. Some dogs at the ranch did not respond, and some passed away during or after the program.

Families at home

Families have tried this at home too. When Jan's black Labrador, Sierra, was diagnosed with osteosarcoma in 2018, the family chose a ketogenic diet and, later, amputation to relieve her pain. Jan shared Sierra's story with us in 2020. Osteosarcoma is painful, and amputation and pain relief, often with chemotherapy, remain the standard treatments; diet does not replace them. Lisa Olver's Sommer's Story is another family's account. You'll find more on our Case Studies page.

Is this right for my dog?

First steps

1. Talk to your veterinarian or veterinary oncologist. Questions to bring: Is there any reason my dog shouldn't eat less carbohydrate? Could a change of diet affect treatment? How should I watch weight and appetite? Can we check blood glucose before I start?
2. Get a blood glucose reading first. Ask for a baseline before you change anything, then again at about two and four weeks. Your veterinarian takes these readings; you don't need to test at home.
3. Change food gradually. Mix a little of the new food into the old, and increase it over several days, or longer if your dog's stomach is sensitive. Watch appetite and stool as you go.
4. Keep a simple note. Appetite, stool, energy and anything new each day, and weight once a week.
5. Get your dog moving, gently. Walks, fetch and chase games that raise the heart rate, at a level that's safe for your dog. If your dog has bone cancer or is recovering from surgery, ask your veterinarian what's safe first.
6. Track quality of life. Our Quality of Life Score helps you notice how your dog is doing from week to week.

What to feed

Homemade meals

Our free Keto Diet Calculator builds a homemade plan for your dog's weight and activity, with the amounts worked out for you. Homemade meals are built around meat, with fat and a small amount of low-starch vegetables.

• Calcium: meat alone is low in calcium. We recommend Animal Essentials Sea-Cal, 1 teaspoon per pound of prepared food. It provides calcium and trace minerals; it is not a complete multivitamin.
• Raw or cooked: many healthy dogs do well on raw meat, but raw food can carry bacteria that a dog with a weakened immune system may not cope with. During chemotherapy, or whenever your veterinarian says your dog's immune system is low, cook the meat lightly: steam it, or simmer it in water or bone broth, never in fat or oil.
• Bone broth: use homemade broth, or one made without onion or garlic.

Ready-made food

If cooking isn't practical, a ready-made food can work well. Look for:

• Low carbohydrate. Labels don't list it, but you can work it out in a minute.
• A "complete and balanced" statement on the label.
• Named meats as the main ingredients.

Some canned and fresh foods are lower in carbohydrate than most dry foods, but check each one. If your dog needs extra calories or has another condition, your veterinarian may suggest a veterinary diet.

Treats

Swap biscuits and starchy chews for small pieces of cooked meat, or freeze-dried meat or fish.

What to avoid

• Sudden switches. They can upset the stomach and put a dog off food.
• Fasting or skipping meals to lower blood sugar. It isn't safe for a dog with cancer, especially one who has lost weight or appetite. Our article on intermittent fasting explains why.
• Old very-high-fat plans. Some older plans that still circulate online, including early ones from the KetoPet Sanctuary days, are very high in fat and leave out calcium. Please use the current calculator instead.
• Cooking meat in fat or oil.
• Hidden carbohydrate: rice, potato, sweet potato, peas, lentils, corn, wheat and oats, and most biscuits and dental chews.
• Foods that are toxic to dogs: onion, garlic, grapes, raisins, chocolate, xylitol and macadamia nuts.
• Keeping your veterinarian in the dark. Tell your veterinarian about everything your dog takes, including supplements and remedies suggested in online groups. Some can affect cancer treatment.

Quality of life is the point

KetoPet exists to help dogs have more good days. Food is one part of that, alongside comfort, pain relief, time outdoors and time with you. If a change of diet is making your dog unhappy, it isn't helping. Our Quality of Life Score, based on the scale created by veterinary oncologist Dr. Alice Villalobos and used with her permission, can help you see how your dog is really doing.

Frequently asked questions

Can a ketogenic diet cure cancer in dogs?

No. No diet has been shown to cure cancer in dogs. A ketogenic or low-carbohydrate diet may support a dog alongside the treatment their veterinarian recommends, but the evidence is still early.

What should I feed my dog with cancer?

Food your dog will eat that keeps their weight steady. Many families choose a meat-based, low-carbohydrate diet that is complete and balanced, either homemade using our calculator or ready-made. Talk it through with your veterinarian first.

Does sugar feed cancer in dogs?

Partly. Many cancer cells use glucose heavily, which is why PET scans can find them. But the body makes its own glucose too, so food can only lower blood glucose a little. Cutting sugar and starch is sensible, but it won't starve a tumor on its own.

Is low-carbohydrate dog food good for dogs with cancer?

For many dogs it is a reasonable choice, alongside treatment. Check the label to find the real carbohydrate content, make sure the food is complete and balanced, and change over gradually.

Will changing my dog's diet interfere with chemotherapy?

A lower-carbohydrate diet is not known to stop chemotherapy working, but tell your veterinary oncologist before you change anything. Chemotherapy can upset the stomach, so it helps to change food gradually and to add one new thing at a time. Check with your oncologist before giving any new supplement.

Can I feed raw food during chemotherapy?

We suggest cooking meat lightly during chemotherapy, or any time your dog's immune system is low. Raw food can carry bacteria that a weakened immune system may not cope with.

Are there keto recipes for dogs with cancer?

Our free Keto Diet Calculator builds a homemade plan for your dog, based on their weight and activity. We don't publish fixed recipes, because the right amounts differ from dog to dog.

My dog won't eat. What should I do?

Call your veterinarian if your dog skips more than a meal or two, or stops eating. Your veterinarian can help with nausea and appetite. In the meantime, gently warming the food or offering a favorite cooked meat can help. While appetite is poor, any food your dog will eat is better than none.

Is it too late if my dog's cancer is advanced?

It is never too late to focus on comfort and good days. Many of the dogs at the KetoPet Sanctuary had advanced cancer. A diet change won't reverse advanced disease, but food your dog enjoys and digests well can be part of caring for them.

How will I know if it's helping?

Watch appetite, weight, energy and stool, and use the Quality of Life Score. Your veterinarian's glucose checks show how the diet is affecting blood sugar, and their examinations and scans show how the cancer itself is doing.

Where to get help

You don't have to work this out alone. Our Get Help page has the next steps, and the KetoPet community on Facebook is a kind place to talk with other families. Our free guide, What's Really in the Bowl, explains what goes into dog food and how to choose well. Everything here is free, and always will be.

Sources

1. Warburg O. On the origin of cancer cells. Science. 1956;123(3191):309–314. PubMed
2. Ogilvie GK, Vail DM, Wheeler SL, et al. Effects of chemotherapy and remission on carbohydrate metabolism in dogs with lymphoma. Cancer. 1992;69(1):233–238. Abstract
3. Ogilvie GK, Fettman MJ, Mallinckrodt CH, et al. Effect of fish oil, arginine, and doxorubicin chemotherapy on remission and survival time for dogs with lymphoma: a double-blind, randomized placebo-controlled study. Cancer. 2000;88(8):1916–1928. PubMed
4. Romano FR, Heinze CR, Barber LG, Mason JB, Freeman LM. Association between body condition score and cancer prognosis in dogs with lymphoma and osteosarcoma. Journal of Veterinary Internal Medicine. 2016;30(4):1179–1186. Full text
5. Weber DD, Aminzadeh-Gohari S, Tulipan J, et al. Ketogenic diet in the treatment of cancer: where do we stand? Molecular Metabolism. 2020;33:102–121. PubMed
6. Kent C. KetoPet Sanctuary: Ketosis, Cancer and Canines, Part 2. IVC Journal, 2019. A trade journal article, not a peer-reviewed study. Read it (also Part 1 and Part 3)
7. Nosek J. Could a change in diet cure your dog's cancer? Modern Dog, Summer 2016, pp. 66–68. A magazine profile of the sanctuary; it reflects views at the time, some of which KetoPet no longer holds.

This article is general information, not veterinary advice.