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Featuring Demian Dressler, DVM and Sue Ettinger, DVM, Dip. ACVIM (Oncology), authors of The Dog Cancer Survival Guide

Dog Cancer and Food…what’s the Carbo Problem?

Updated: December 18th, 2018

Everybody loves sugar.

Late night snacks, movies, late afternoon….kids and grown-ups alike….and dogs like their carbs in dog food and in dog treats, which of course are changed in the body to sugars…

Cancer in dogs loves sugar too.  Especially sugar.  Cancers tend to gobble sugar way more than fat or protein.  Cancer definitely has a sweet tooth.

It is an odd thing in some ways.  Fat has more calories than sugar on the basis of weight (a gram of sugar has fewer calories than a gram of fat, roughly 4 cal versus 9 cal).   It seems strange at first that cancer would like to use a lower calorie food for fuel.

Turns out that one of the  most reliable changes that happens in the dog body, usually before any signs of actual cancer, is that the metabolism of sugar starts to change.  The blood sugar starts to go up.  This favors the growth of the developing cancer.  The cancer sends messages to the body to kick up sugar release into the bloodstream.  Once in the blood, the circulation delivers the cancer cells their favorite meal.  Read more.

As a matter of fact, sugar use is a reliable indicator of the progression of cancer.  New technologies are being developed (positron emission tomography) that can see how the chemo is working by looking at the sugar levels in the blood. Here’s the abstract.

Cancers start more easily in the presence of sugar in the bloodstream. That means high blood sugar is present first, then cancer develops. Some examples in human literature include cancers of the pancreas, liver, colon, rectum, cerix, esophagus, and the bile duct. Check it out.

So here we have links both between sugar before cancer starts, and sugar after it starts.

Take home message: limit carbohydrate intake in your dogs, whether cancer free or cancer patients. Some of the newer pet foods producers are aware of this concept and have integrated it into their pet food design.

Best to all,

Dr D


Leave a Comment

  1. Benny England on June 20, 2021 at 6:28 am

    My American bulldog has a tumor on his lung surgery. Is a month away so I’m trying to find a diet that he can’t resist in order to keep his body weight up

  2. Susan Kazara Harper on September 21, 2014 at 10:20 pm

    Hello Mare,
    Sweet potatoes are so frustrating, because generally they have so many health benefits. However, the benefits really no not outweigh the risks, as this wonderful vegetable metabolizes into sugar much too quickly in the body. An occasional treat would not really harm, but please don’t make it a regular part of your dog’s diet. Have you read the Dog Cancer Diet? which is also in the Dog Cancer Survival Guide book The full diet provides so many food sources that strengthen the immune system and have been proved to work against cancer in our dogs.
    Regarding Omega 3s, your vet is correct. Dogs with cancer require very high levels of quality Omega 3s in their diet. Dr. Dressler recommends Krill oil. Many fish sources of omegas are cod liver, and larger fish however, Krill is much lower on the food chain and less likely to have absorbed metal and other toxins. Literature on EPA, DHA and omega 3 fatty acids supports the need for high doses.
    As the sudden introduction of fatty acids can cause stomach upset and diarrhea, work up to
    a full dosage over about fourteen days.
    Dogs up to 10 pounds: 1,000-2,000 mg daily
    Dogs 10.1 – 35 pounds: 3,000-4,000 mg daily
    Dogs 35.1-60 pounds: 6,000-9,000 mg daily
    Over 60.1 pounds: 10,000-12,000 mg daily
    You can switch between Krill and another fish oil every few days. I hope this helps. Give your girl a good hug for doing so well, and both of you keep going. All the best!

  3. Mare on September 20, 2014 at 4:19 am

    Dr Dressler, I hope you can help me? Are sweet potatoes ok to give to a 13 yr old Airedale rescue dxd last fall with both abdominal cancer (spleen/pancreas/intestines) AND kidney disease (PLN)? I know that sweet potatoes are a carb and that sugar feeds cancer, even natural-sourced sugar. I keep hearing though that sweet potatoes are anti-cancer despite their sugar content…how can this be true? She already been getting a lot of Omega-3s per Vet. Oncologist Dr Greg Ogilvie (he says in cases of cancer to give as much animal-sourced Omega-3s incl fish ‘body’ oil, as the dog can tolerate)

  4. tina on November 18, 2013 at 1:03 am

    Hi Dr Dressler
    My 10 year old Boxer dog has been given a few days to live after been diagnosed with MST grade III that has spread to the lymph nodes. She had an infection last week which has been treated with antibotics – the swelling and infection has reduced significantly. She is eating well, going for walks, wagging her tail, barking and generally seems fine. I am going to start your diet recommendations and immune boosting supplements, but wanted to know if at this late stage you had any experience of recovery? Many thanks Tina from UK.

  5. Virginia on October 11, 2009 at 3:57 am

    Hello Dr. Dressler,

    I hope you’re still out there are well. I just found out that my 9 year old healthy & energetic mutt has a mast cell tumor. It will be removed this week then we’ll get the low down.

    Because of former intestinal issues in her youth (sibo) I feed her Royal Canin rabbit & sweet potato kibble. On this her stool has been beautiful for years. She also loves all fruit so I add apples and sometimes mangoes to her kibble. I’m reading these comments and info here and see that fruit, among other foods, should be stopped. I am going to change her diet once the surgery is over – looks like the sweet potato in her kibble is a bad idea. Are there any fruits, aside from berries, that are ok to feed her or should I just be safe and end all fruit?

    Thank you for this blog.


  6. christina on September 29, 2009 at 2:00 am

    how do you feel about the Dr harvey dog food diet? I am now very concerned about what to safely feed my two cancer dogs!

  7. Anonymous on September 28, 2009 at 2:04 pm

    my dog has cancer in his back leg, i was told to do grain free dog food is that true? i have given him chicken, broccoli and some carrots is that ok? i also bought natural treats now. please let me know if i am doing more harm then good. he is also on remadyl twice a day.he seems to be doin ok so far, happier looking too. he is a shephard mix and a funny guy. he is a family member we love very much. Dina

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