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

Vitamin C for Canine Cancer Patients? Part 2

Updated: December 17th, 2018

Well, it’s been 2 days since the lead-in entry on Vitamin C….which may (or may not) be a long time to wait 🙂  Anyway, here you go:

As I had indicated, it turns out that if one were to take vitamin C, at huge doses by mouth, the blood levels you get are puny. When you, or your dog, takes a pill, some gets absorbed into the body, but some passes out in the waste.

People who took 18 grams of the stuff (which equals gagging down 9-18 of those “horse pill” tablets) per day, only ended up with 220 micromol/L in their blood. That means a huge amount Vitamin C ends up literally going down the toilet.

Those studies showing that cancer cells die when exposed to vitamin C  needed more than 1,000 micromol/L.  Since 220 is much less than 1000, the cancer cells were not dying.

This is probably why the two clinical trials where people had to down 10 grams of vitamin C daily showed no benefit in surviving their cancers.

So the message seems clear…don’t bother with strait oral vitamin C (ascorbic acid) when you are trying to help your dog kill cancer cells.  In my opinion, bases on the evidence, you can’t get the levels you want for cancer cell death.

But there are other ways to get the stuff in the body.  What about injections?? Does that help?

Well, I could not find solid reports on the effects of intravenous vitamin C given to canine cancer patients.  Recall I want good, solid, science-based information…however, I did find some in the human literature.

A paper came out in 2006 that showed 3 human patients with tumors that would have been expected to have led to their demise opted for IV vitamin C at whopping doses.  Read the abstract here.

Get a copy of the Dog Cancer Survival Guide for more helpful information and tools

One had a form of lymphoma (lymphosarcoma), one a kidney tumor, and other was transitional cell cancer of the bladder.  All had signs of either local spread (into the surrounding areas) or distant spread (metastasis). Bad, bad stuff.

The amazing thing is that in each of these three, the tumors went away.  Gone.  Nada. Zippo.  And that, my friends, is pretty astounding.  Granted, the lady with the kidney tumor (a chronic smoker) developed lung cancer 4 years later…but the information is pretty impressive regardless.

Does this mean everyone with a dog should go out and schedule IV vitamin C injections for their dogs? No. Especially not dogs with urinary stones like calcium oxalates, which likely can be worsened or theoretically even caused by the injections.

But, it does mean that in certain circumstances, it should be considered.  Vitamin C IV injections appear fairly safe overall, and people are starting to pay attention to Vitamin C IV injections in cancer therapy…check it out.  For the vets out there, the protocols are here too.

Note that it is, at this point, probably unwise to give these doses of IV vitamin C in conjunction with chemotherapy until the issue of whether it helps or hinders chemo is clarified.  I would also avoid IV vit C at these doses if your dog is receiving radiation therapy.

Best to all,

Dr Dressler


Leave a Comment

  1. Cherie Guidry on October 1, 2012 at 4:53 am

    Dr. Dressler,
    Wyla is already on Apocaps! Is it still safe to do IV Vit. C therapy? I am assuming it is! Wyla has inoperable brain tumors and now spine tumors diagnosed over a year and a half ago. She had radiation therapy in June of 2011. I do have a few human protocols that I have found. How many times a week should I do it? I am ordering the Vit. C today so we can get started as soon as possible. Also, in the studies that I have researched, there are different amounts being giving. Some are giving 15 g twice weekly and some are giving as high as 75 g twice weekly. Is it safe to give in fluids like LRS or should I just do it in 0.9% sodium chloride? All of the studies say to give it slowly. Any more suggestions would be great! Thanks for all of your help!!


  2. Richard Gruberg on August 3, 2012 at 6:05 am

    Hello Dr. Dressler
    Concerning your comment,
    “Note that it is, at this point, probably unwise to give these doses of IV vitamin C in conjunction with chemotherapy until the issue of whether it helps or hinders chemo is clarified,”

    the notion that vitamin C interferes with chemotherapy is based on flawed research performed by Mark Heaney at Sloan Kettering. It has been thoroughly refuted. Please see the following well written article on the subject by Steve Hickey of the University of Manchester:

    At the University of Kansas Medical, where they perform intraveneous vitamin C therapy on human cancer patients, they have also been successful with combining traditional chemo (eg., carboplatin) with intraveneous C.

    My dog is receiving intravenous vitamin C for his osteosarcoma and, at least so far, it seems to be helpful.

    Richard Gruberg
    Baltimore, MD

    • Dr. Demian Dressler on August 8, 2012 at 1:28 pm

      Dear Richard,
      I have read this and many other articles including basic science. we need more info concerning dosing and specific cancer drugs and larger groups of patients studied.
      But believe me, I am open to Vit C having used it plently with my patients.
      So the conclusion to hold off is based on much research and hands on use, as opposed to a lack of information. If you read the book I wrote and check out the index concerning vitamin C you will find many references….
      In medicine, especially in my position where i am forced to deal with not only many thousands of readers but also vets, oncologists, professors, etc, one has to err on the side of caution before making general recommendations.
      I hope this clarifies things a bit …
      Dr D

  3. Geoff on April 23, 2012 at 9:22 pm

    sorry i posted twice…by mistake only



  4. Geoff on April 23, 2012 at 9:21 pm

    HI DR Dressler

    Hopefully you can suggest a dosage as i can’t find the estimate of how much my vet should be injecting .I have seen the estimate yu wrote for a rotty ,and the estimate for a terrier,but all dogs vary..My golden is 35 kg and chemo is now a failure,she is using apocaps,and i also try DCA,digestive enzymes and K9 plus…But please can you give me an estimate to try for lymphoma..i also see it may not help but we’ll try..

    Thanks for being here ..and helping


    • Dr. Demian Dressler on April 25, 2012 at 6:30 pm

      Dear Geoff,
      the doses are all across the board on the Vitamin C. Your veterinarian will be administering this so please check with your vet as oral vitamin C does little to help. The severity of the issue (how advanced the cancer is) also may dictate the dose. Dogs of your Golden’s size could go easily up to 20 g per dose, although many vets will use half that amount, twice weekly in a slow IV drip. Btw, it seems DCA is getting rather popular and I do not advise it at this time. Have you read the Guide? No Apocaps or Neoplasene??
      I hope this helps
      Dr D

  5. Geoff on April 23, 2012 at 9:21 pm

    HI DR Dressler

    Hopefully you can suggest a dosage as i can’t find the estimate of how much my vet should be injecting .I have seen the estimate yu wrote for a rotty ,and the estimate for a terrier,but all dogs vary..My golden is 35 kg and chemo is now a failure,she is using apocaps,and i also try DCA,digestive enzymes and K9 plus…But please can you give me an estimate to try for lymphoma..i also see it may not help but we’ll try..

    Thanks for being here ..and helping


  6. Coral Berry on April 1, 2012 at 7:03 pm

    My 10 year old Rhodesian Ridgeback was diagnosed with osteosarcoma last year and had her back leg amputated and has had chemo but she developed a large tumour in her lungs and she has now been given 3-4 weeks to live.
    Would it be helpful for her to have IV Vitamin C? I am also planning to try artemisinin as well. Please let me know if these will help her. Also any other suggestions would be very much appreciated. Hope you can help. Regards,

    • Dr. Demian Dressler on April 12, 2012 at 3:01 pm

      Dear Carol,
      I am sorry to hear about this, it sounds very rough.
      I would be reading the Guide ASAP as opposed to trying to analyze the different alternatives on your own.
      IV vitamin C is a possibility but I would definitely talk to your vet about apocaps, neoplasene, and artemisinin. If this were my dog I would be considering these three with medical supervision. Vit C would be a secondary choice,
      I hope this helps
      Dr D

  7. Queenie on February 17, 2012 at 8:06 pm

    Dear Dr Dressler,

    My 12yr, 25lbs, female schnauzer has diagnosed with osteosarcoma on the left upper jaw a month ago, and she had her partial upper jaw removed 3 weeks ago. Since I knew she got this problem, I’ve been searching and reading about osteosarcoma. I found and bought your book, and I’m following the homemade food diet but with everything organic except the organs. However, I’m wondering if I can cut out carbs completely?
    We avoid radiation therapy because the tumor was too close to the nose, and we think that maybe too much for her age. So, we put her on metronomic chemo (piroxicam and cyclophosphamide) last week and stopped because she started to have hives after the second dose. Unfortunately, we could not reach our oncologist since he is only here every 3-4 weeks. We feel helpless because of that, plus he told us there is no more he can say about our case because oral osteosarcoma is not very common so has very limited information about what works better. Instead of waiting, would you suggest switching treatment to regular chemo via IV injection?
    She is also taking bunch of supplements: krill oil, flax seed, a herbal supplement called ES-Clear. It would be great to know what else can help her, and what else can I do for her.
    Please bring us a hope.

  8. Cherie Guidry on February 17, 2012 at 4:21 pm

    Hi Dr. Dressler,
    I have been just recently trying IV vitamin therapy in dogs. (I am a vet in Washington State). Right now I have 4 protocols developed for humans by a naturpatic doctor whom I am friends with. I have scaled the doses down for dogs with all 4 protocols. This week, I have just tried my first case on a dog with chronic renal failure and I got amazing results. I have a few questions. Where are you getting the protocols from? Do you have other protocols besides IV Vit. C? I am certainly willing to try this. In fact, I am very excited! I just feel like I need more guidance from other vets that have tried this. Any help would be greatly appreciated!! Thanks for the info.

    • Dr. Demian Dressler on February 28, 2012 at 4:36 pm

      Dear Dr. Guidry
      the protocols for IV vit C are all extrapolated from human studies. It is no big deal. Just titrate in saline over several hours, watch for oxalate stones as contraindication or complication (rare).
      Yes, there is one that some use combining Vit C with vit K3 that has some reported successes. You might also be interested in apoptogen therapy.

  9. Dawn Allington on February 8, 2012 at 8:27 am

    Our Dog, 8 yr old Rottweiller called Faye, had been unwell for a few weeks, a finally
    diagnosed with a spleenic mass, which was removed. Today we have the results
    of the biopsy as an agressive tumour that the vet says will almost certainly have
    seeded somewhere else. She seems well at the moment one week after op.
    We would very much like to try the IV Vit C therapy that I have been reading about here. We live in the UK, Essex. Does anyone know of any of this treatment done in
    England. Also Laura (last post) how is Smudge now. Do hope he is doing well.
    Kind Regards, Dawn and Lyle

  10. Laura on December 2, 2011 at 5:42 am

    I have a wonderful dog named Smudge, 13 years young. He was diagnosed with hemangiosarcoma…he spleen was removed with a bleeding mass and there were a few small dark patches on his liver that also were cancerous. I was told Smudge would be dead within a month with no further treatment and he would possibly live 4 to 6 months with chemo. The vet was willing to do intravenous chemo every 3 weeks (for six sessions) along with two different oral chemo medications. I was told that none of this would increase his life span past the 4 to 6 months. I was told I needed to decide quickly because this is a very aggressive cancer. I am lucky to live in the north east and have access to a very well know alternative veterinary clinic (Smith Ridge Veterinary Center, in
    South Salem, NY). My own traditional vet was very open to looking into alternative help for my dog. I went to Smith Ridge and they explained iv Vitamin C therapy for cancer and how they had been doing this therapy for the past 25 years with great success. I liked that the therapy wouldn’t hurt Smudge, and it was not toxic to him but to his cancer. The level of vit. C in the bloodstream was critical and involved three days in a row, six hours each day of being on the iv drip. Smudge suffered no side effects….I stayed with him the whole time because he is very nervous at any vets office. It has now been a week since his therapy and he is bouncing around like a pup. He is eating, sleeping, playing going for walks….I pray I have done the right thing for my dog. From all the cancer and vitamin C research I’ve done in both human and dog cancers I feel good about what we have done for our sweet dog. His diagnosis was 5 weeks ago and he is showing no signs of illness. The cost was 1400.00 for three days of treatment…including some supplements. I’m hoping for the best for my dog.

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