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

Dog food and cancer: help fight this problem!

Updated: December 12th, 2018

In the last post I wrote about one of the issues in most commercial dog foods contributing to dog cancer: omega 6 fatty acid excess. This is a group of fats that are found in large quantities in corn products, vegetable oils, and meat products like tallow and lard, to name a few sources. Dogs in the wild eat lean meats (imagine an antelope’s body) and digested plant matter from the prey’s intestines. The diets we are feeding them currently are inappropriate, and in some ways harmful.

This omega 6 fat excess sets the stage for cancer development, stimulates cancer cell growth, and decreases the body’s natural cancer-fighting abilities.

Our dog’s bodies can better handle the omega 6 excess by providing them with another type of fatty acid that will decrease the harmful effects of too much omega 6. These are oils containing omega 3 fatty acids, which are found in high concentrations in fish oils. I outline this topic in detail in the upcoming book, but for the purposes of this discussion let’s focus on oil from sardines, menhaden, mackeral, salmon and so on. Cod liver oil is NOT a good source for omega 3 supplementation.

If your loved dog has a cancer at this time, you want to get as much omega 3 in him or her as possible. Start slowly and work your way up to large amounts over about 2 weeks to avoid an upset stomach. Give with food. For a dog about 60 lbs, you want about 18 grams of good quality fish oil containing omega 3’s. This usually means about 15-20 of the typical capsules daily, which is a large amount! For double strength caps, halve the dose. Adjust up or down for the size of your dog. The capsules can be popped and the oil mixed in food if your dog resists eating the capsules by themselves. Watch for digestive upset (vomiting, diarrhea, loss of appetite), and if so, stop and then later start with lower doses increased more slowly.

Krill oil is, in my opinion, the best option for supplementing fatty acids for a variety of reasons…

If your loved dog is not diagnosed with cancer and is on typical commercial food, I would have you begin an omega 3 fatty acid supplement at lower doses than those dogs with cancer. For a 60 lb dog, my opinion is a standard supplemental dose of roughly 4-6 grams of omega 3-containing capsules daily. Remember to start with low doses than work up over 2 weeks.

There is limited, theoretical evidence that you should stop these supplements 10 days before surgery as they may have mild blood-thinning effect. Do this as a precaution, to be on the safe side.

I will be giving many more practical tips to increase your dog’s health in upcoming posts!


Best to all,

Dr Dressler


Leave a Comment

  1. Dr. Demian Dressler on September 30, 2008 at 9:31 am

    Hi Anu,
    could you please expand your question a little to help me answer properly? I am not sure which of the topics you were asking about. Could you clarify for me?

  2. Dr. Dressler on August 24, 2008 at 2:13 pm

    You are welcome!
    Dr D

  3. Lori Michaelson on August 23, 2008 at 2:29 pm

    Well, since she just had a Grade 3 mast cell tumor removed supposedly successfully (taking into consideration there was no Benadryl injection prior to surgery) would you put her in the early stages or the later stages of cancer?

    You now say that you lean more towards the beta glucans in the early stages but in your post on 8/02/08 you say:
    ” If your loved dog has a cancer at this time, you want to get as much omega 3 in him or her as possible. Start slowly and work your way up to large amounts over about 2 weeks to avoid an upset stomach. Give with food. For a dog about 60 lbs, you want about 18 grams of good quality fish oil containing omega 3’s. This usually means about 15-20 of the typical capsules daily, which is a large amount!”

    So I think you can see my confusion.

    I don’t even know if you can answer my question of whether she may be in the earlier or later stages of this terrible diagnosis.

    Thank you for answering the semi-disagreement between my husband and I and perhaps the omega-3’s will slowly be given by him over time. Although you suggest so much more if the dog is already diagnosed.

    Hopefully you can clear up what seems to be contradictory comments as well as suggest what stage she might be in.

    Thank you so much once again for your time and patience!

    Lori Michaelson

  4. Dr. Dressler on August 22, 2008 at 5:51 pm

    First, the post I wrote on the 21st actually posted on the 22nd, so that is the one. Second, Golden Retrievers are the number one breed for canine cancer (in the DNA). Up to 75% of them pass away due to this epidemic disease. Third, I have access to no study comparing omega 3 and beta glucan supplements, and I usually do not pick a single one, even a single combo product seems inadequate to me. We attack the cancers at different levels simultaneously for best results. So I cannot say what the best single supplement really is…kind of like saying what is the most healthy food..good in different ways. Having said that, I lean more towards beta glucans than omega 3’s in the early stages, if I were forced to make a choice. Why not add a little melatonin? It’s cheap and hey, at least it promotes a good night’s rest. Check out EGCG, curcumen, modified citrus pectin, all not too expensive. I’ve got a powerful supplement coming up too so stay trials right now. Fourth,regarding husband: resistance to new information is common. Whenever anyone needs to integrate anything that is truly new or even groundbreaking, a consciousness expansion has to occur. This involves the loss of an old identity to make room for a new identity, which is frightening, since we all really like our identities! Hence the resistance. Don’t get mad at your husband, this resistance is really common. Compassion is best for everyone during these times.
    Dr D

  5. Lori Michaelson on August 22, 2008 at 1:43 pm


    This is the thread that I was ‘referring to’ in my post on August 21 regarding our Golden Retriever’s diagnosis of mast cell cancer stage 3 and pain. I also read your post saying that Krill oil is probably even better even though more expensive. I also read the post from a subscriber saying that he/she used K-9 Immunity (Beta Glucan) with seemingly success for extra months of life for a diagnosed dog. And your response Dr. Dressler.

    Firstly, one has to decide to use one of the three methods above. MEGADOSES of Omega-3 fatty acids for dogs already diagnosed with cancer or Krill oil or K-9 Immunity. IF ANY. Or, let nature take its course.

    Secondly, here is the dilemma in our household:

    After our furry daughter’s diagnosis earlier this month I wrote to Rochelle and she was the one who guided me to this site/blog! After reading the first post about getting as much Omega-3s into the dog as possible (15-22 capsules daily) for bigger dogs like our 80 pound dog Golden angel – I told my husband about this. We already had/have a large jar of 500 mg capsules because our veterinarian suggested using these in February for her worsening dysplasia. It did nothing for her dysplasia is so we still have plenty left over. COSEQUIN worked for her though!!!

    Anyway, after telling my husband about the Omega-3 MEGADOSE suggestion by you he was okay with starting her out with one a day and now we are up to two a day (after two weeks). He is way too leery to try anything close to those megadoses. A few days ago I said that, if it were up to me, *I* would be giving her five capsules a day by now but my husband’s response was that we “would have a sick dog on our hands”.

    Since I am a quadriplegic it is my husband that has to feed her, give her all her medications and supplements, clean up after her, etc. and being my primary caregiver taboot. And HE recently had surgery (that is not healing) so things are harder for him. <— Huge understatement! And there is no one else.

    Even though she is just like a child of his own to him (and he has three adult children) and would do anything in the world for her — I can’t see him budging on this. Megadoses I mean. And the more I nag him about ‘anything’ the less he wants to do it. He knows about it, like I said, and he read my post and your response regarding pain and cancer in dogs. So he knows about this blog as well as Rochelle’s dedication to the cause. I cam across her wonderful website about five years ago!

    From one of his comments I think he also feels that it is all experimental and there is no REAL proof of trying this, or that or that then this, etc, etc, etc, etc. Only a testimonial here or there. and probably feels very much the same way about all of this in exactly the same way Rochelle expressed her opinion on Krill oil.

    We both are “medical people” so to speak but when it comes to many things (including the big “C”and there are many personal experiences in the medical field) I can understand his reservations. BUT, at the same time, *I* would say it couldn’t hurt to keep increasing the dose. But I am not the one in control of that. I’m sure there are many out there who find themselves in such a conundrum. So that is a topic in itself!

    I am just so thankful that our beautiful Golden (Brandy) did not have any terrible symptoms (or any symptoms for that matter) prior to her diagnosis or now. She is still acting the same, eating the same, going to the bathroom the same, etc. etc. Unfortunately, Goldens seem to be much more prone to cancers and bigger dogs do not usually live longer than smaller dogs. I chalk it up to ONLY THE GOOD DIE YOUNG when it happens no matter what we try in the human world or the other animal world.

    Now I am off to try to find the Aug 21 post you referred me to yesterday (21st also) as I could not find it earlier. It is sometimes difficult to find things on blogs even using the search box.

    Any suggestions on household dilemmas as described above are welcome!

    Thank you,
    Lori Michaelson

  6. Dr. Dressler on August 11, 2008 at 3:37 pm

    Hi Carolyn!
    Maintenance doses are less than cancer doses. For maintenance, I advise, using 500 mg capsules, 3-4 daily for the 45 lb dog and 5-6 for the larger doggy. Start slow and work your way up to the full dose over 10-14 days. Give with food. Don’t forget to stop 10 days before any elective surgery to be on the safe side. Give 1 month to see changes in the coat, mobility, etc.
    Dr D

    • Laurie on November 20, 2009 at 4:41 am

      I came across your website and could use some guidance on supplements. My 5 1/2 year old Bassett was diagnosed with mast cell tumor four weeks ago. It originated in his abdomen (no organ involvement can be determined on ultrasound) measure 4.5 X 5 cm. We have lymph node involvement. We decided against surgery given dogs with this usually have a poor prognosis and we wanted him to have the best quality of life possible and couldn’t see doing such an risky surgery. We began him on benedryl, predisone, pepcid A/C, Tramadol, Suclofate. Two weeks ago we started him on the new drug Palladia. He is doing well, very few side effects, is eating a high protein low carb diet (Blue Wildnerness) and is remaining active (as active as a Basset gets anyway). His fourth Ultrasound yesterday showed no change in the tumor, but a new second tumor in the abdomen has been identified (it has only been a week since his last ultrasound). The internal medicine vet is seeking consultation from North Carolina State University. Until then, what else can we do to help “Monk”? He is 82 pounds.

  7. Carolyn Kinsler on August 11, 2008 at 5:40 am

    Great blog. How much krill oil would you recommend for dogs who eat a diet with no corn products (1/2 home cooked with lean meats and 1/2 Wellness Core). My dogs are 45 and 70 lbs.

    Thank you

  8. Dr. Demian Dressler on August 8, 2008 at 11:40 pm

    Rochelle, great point. Krill Oil has some really interesting effects that have real relevance to cancer in our loved dogs. How about I fill in the gaps in a blog post!?

    • Brian Roney on October 26, 2009 at 6:47 pm

      Hi Dr…..maybe you can help me? My dog has a tumor behind his eye….it is cancer….what can I do to help him? Mass omega 3? High protein diet? Exercise? Thanks, Brian

  9. Rochelle Lesser on August 7, 2008 at 5:38 am

    I am interested in your reference to Krill Oil. Is there a particular brand that you recommend? I see that it can be more expensive than salmon oil.

    For example, Mercola has a 100% pure Antarctic Krill Oil, but it sells for over $60 for a bottle of 180 500mg capsules. To give a 60lb dog, 6000mg Krill Oil daily would cost $120 monthly.

  10. Rochelle Lesser on August 7, 2008 at 5:00 am

    Dr. Dressler, it is wonderful to see this new blog and to have you share valuable information with folks that have had a dog diagnosed with cancer. I have been giving my 60-lb Golden 6000 units daily of Sockeye Salmon Oil for years now, and have been stressing at my site how this is critical to good health, mobility, and even coat. I will be referencing this entry, however, at my site where I discuss food as well as cancer diet recommendations.

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