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Featuring Demian Dressler, DVM and Susan 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


Discover the Full Spectrum Approach to Dog Cancer

Leave a Comment

  1. finallywakingup on December 4, 2017 at 4:05 pm

    Where is part 1 of

    Vitamin C for Canine Cancer Patients?

  2. Whit on October 19, 2017 at 10:56 am

    What about liposomal vitamin C

  3. Susan Kazara Harper on June 1, 2015 at 3:53 pm

    Hi Terry,
    That answer really needs to come from your vet. Any IV treatment would be vet-advised and both weight and overall condition can be taken into consideration. If it’s cancer of the spleen, are you talking about hemangisarcoma? If so, you may want to ask your vet about metronomic chemotherapy. It has been shown to have positive effects on that type of cancer, and is very gentle on the dog. Good luck!

  4. Terry Huser on May 13, 2015 at 8:54 pm

    My Keeshond has cancer on her spleen would like to know how much vitamin C IV for a 45 lb dog would be?

  5. Maria on November 27, 2012 at 11:31 am

    Dr. D.,
    I have an 85# yellow lab, Solomon, just dx in Oct.2012 with stage IV Hemangiosarcoma: the tumor on his spleen ruptured, resulting in an emergency spleenectomy. It was 50/50 but he made it home that very day. About a week later, we placed him on Neoplasene (plant alkaloids) and his PCV is 42%; TP 7.3 a/o 10.29.12 – still in the norm. I am concerned because his fatty tumors are growing – not aspirated because I did not want the possibility of this spreading as well. He is on a white rice/cooked organic meats/vegetable diet while on the Neoplasene. I would like to place him on IV Vitamin C as soon as possible. Is this ok to do IV Vitamin C while on Neoplasene at the same time? Or would you do the IV Vitamin C for a few weeks, stopping or reducing the Neoplasene? Or do you know if there is a “protocol” that is successful in the use of both of these cancer fighters? Either way, will you please let me know the dose recommendations for IV Vitamin C? (I plan to add the Turkey Tail Mushroom to his diet as well because of its success against Hemangiosarcoma.) Thank-you for your help!

  6. Tony on November 16, 2012 at 9:00 pm

    I once had a vet that cured my shepherd of Heartworms using homeopathic remedies.
    The key was high dose IV injection of vitamin C in combination with Black walnut hull / wormwood / mugwart combination as best I recall. Using this method it wasn’t long and Max tested negative.

    I need to know what is a safe high dosage injection for a 135 pound dog?


  7. Patty on October 2, 2012 at 4:34 pm

    Dear Doctor my Golden is currently on an oral chemo drug Satraplatin and the tumor started to increase in size our Oncologist suggested IV Vit. C he is currently doing acupuncture, cold laser and ozone therapy. He has a Pheochromocytoma have you heard any good news using this therapy for his type of cancer? Thanks!

  8. 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!!


  9. 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

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

    sorry i posted twice…by mistake only



  11. 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

  12. 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


  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. peter dykstra on November 13, 2011 at 3:21 pm

    Dear Dr Dressler,
    I am in Australia,and have a lifetime of involvement with animals commercially-breeding /growing/nutrition etc.Now -in retirement I spend my time with my favourite animal and breed Malamutes.I have always had a dogged determination to get to the bottom line-the cause-of any puzzling problem,and with the numbers and will at my disposal,and with some veterinary help-knowledge has been acquired,There is no substitute for ‘on the ground’ experience as you will know.
    I am always amazed and disappointed why there is not more research or study of cancer in dogs.Not so much the cures ,but more the why is it so?
    After all ,dogs do not smoke-they are always covered when exposed to sunlight-not exposed to excessive pollution or vehicle emmisions etc.
    Leaves only food-and what ingredients are in the food.
    I am searching for statistics on cancer deaths in dogs -comparing say Australia and Europe-perhaps you may be able to help?
    I stronly suspect that the growth hormones used in the Aussie cattle industry are the culprit-I don’t know the situation in the US,but this practice is banned in the EU.
    Certainly in the case of cancer in humans-I believe there has been a huge increase over the last 30 years-coinciding with the practice of lot feeding or finishing nearly all cattle.When cattle arrive at feedlots they are treated for parasites etc. and also get a HGP implant.It’s all about money and profit like so many things today!
    Re the Vit C discussion-It is available anywhere in OZ-very cheap as previous writers have said.I use it in cases of snake bites and paralysis ticks.It is amazing how effective it can be-but the quicker it can be started -the better,before the toxins do significant damage.

  19. Connie Fish on November 10, 2011 at 9:12 am

    Dear Dr. Dressler,

    I have a boston terrier with chronic leukemia. The oncologist vetinary doctor said it is rare and that it is a people form of cancer. She is only 2 years old. Yesterday, he told me she only has 2 weeks to live. She still has energy and we take 40 minute walks every day. I would like to try the vitamin C therapy. I just need to know where I can get it and how much I need to give. I live in Ocala, Florida. Please respond!!


    • Dr. Demian Dressler on November 12, 2011 at 1:31 pm

      Dear Connie,
      oral vitamin C is not very effective at all as you cannot get the proper doses. The doses are all taken from human literature and depend on the weight of the dog. I would guess for a Boston about 3 grams IV twice weekly, but you will find variability. There are many more steps that should be done beyond IV vitamin C as this treatment is not always reliable in helping dogs with cancer. If things are that bad, you should consider also chemo, as well as the Dog Cancer Diet, apoptogens, immune support, and the rest of Full Spectrum Treatment discussed in the Guide.
      I hope this helps, and have your veterinarian supervise the treatment,
      Dr D

  20. Caroline Young on November 5, 2011 at 6:05 am

    I personally know three individuals, for whom high dose vitamin C, both through IV method and lypo C drinks, have worked wonders. Two were cancer patients, and the third was plagued with chronic pulmonary fibrosis (which the doctors had been unable to treat in the 10+ years he was afflicted) , type II diabetes, high cholesterol, and high blood pressure. The cancer patients went into remission, and the third case no longer has pulmonary fibrosis, and all his numbers are normal. Their doctors are blown away by this. I also have two friends whose dogs have cancer, so I am advocating vitamin C treatments as an alternative to high cost chemotherapy (with its own host of debilitating side effects) that destroys good cells as well as bad, and that compromises the natural immune system that’s supposed to fight off diseases in the first place.

  21. Cory on November 4, 2011 at 1:31 am

    Dr. D
    My dog was diagnosed with ectopic thyroid carcinoma 9/2010 he under went surgery, radiation and chemo (doxorubican) and has been cancer free well over a year now. I was reading your article concerning Vitamin C injection via IV. I know that my dog is “cured” but I was wondering if giving him Vit C injections could be beneficial regardless ?? Can the dosage be given via an injection rather then IV and have the same effect and what what the correct dosage would be for a 12 lbs Papillion and how often. Any assistance you could give would be greatly appreciated. Thank you Cory

    • Dr. Demian Dressler on November 12, 2011 at 2:11 pm

      Dear Cory,
      I need a bit of clarification. An IV injection is an injection, just in the vein. Can you help?

  22. Sasha on July 28, 2011 at 7:38 pm

    Dear All,
    I have been using injectable vit c(sodium ascorbate) for my dog. Not for cancer but to help her prepare for a big surgery to remove a lipoma. Now I have a cancer scare. The vit c I use is from Troy Laboratories in Australia. I’m from Australia so I can get it easily.I’m sure you can find somewhere that will ship it to where you live. It’s reasonably, cheap 100mls for 11-15 dollars. The bottle says 500mg/ml. I’m surprised some of you can’t get this easily. It’s used widely in the horse racing and greyhound racing community. Please follow your vets advice . I had my vets ok to use it subcutaneously of course. It does cause discomfort sometimes and after one painful injection my dog gets scared of the next one. It’s not a nice thing to put a already sick animal through. Please just talk to your vet and get the ok. Even if he or she dosn’t think it will work. You just want to have their word that it wont do harm 🙂 We have enough stress worrying about the cancer spreading.
    I hope this is some help to someone.

  23. Galina on May 23, 2009 at 4:56 pm

    Dear Dr. Dressler!
    Almost 3 month ago my dog Toto, a 12-year-old toy poodle, was diagnosed with an aggressive oral melanoma with an extremely poor prognosis. His lymph nodes in the neck on the side of a tumor were noticeable and x-rays of the lungs did not give a clear answer. Toto went through immediate surgery and vaccination with a new “break through” DNA based vaccine against cancer-associated protein tyrosinase that claimed to extend dogs life from 6 month to a year. Browsing the web for unconventional cancer treatments I came across your website with a report of high dose vitamin C IV injections curing three patients. Thinking that it might be difficult to perform I concentrated on the pills, lots of pills, day and night. Three weeks later just overnight his lymph nodes in the neck enlarged to the size of my fist! I understood that nothing was working. There was no time to loose and to my luck the veterinarian had vit C injectable. We started with 1g/4ml injections (Toto is 17 lb) just under the skin because I tried to avoid IV. After the first injection the tumor loosened up and after the third (every day) it shrunk back to the size it was three weeks ago (1.5cm). WOW! Since then Toto was getting under skin injections, 1g, every day. My pharmacy gave me twice more concentrated vit C so the volume was reduced to 2ml. The injections were painful but other than that no side effects!!! Unfortunately after a month of injections his lymph nodes started to enlarge again and I did not have any choice but to accept IV injections, the dose was doubled (2g, 4ml plus veterinarian added 10ml of 0.45 saline solution) and IV was given every other day or so. To my surprise Toto takes IV injections extremely well: he is not shivering any more at the vets office, very joyful, playful, has good appetite. No side effects!!! Just yesterday I found out that one doctor at Thomas Jefferson Hospital (Philadelphia) was organizing clinical trials to cure lymphoma with high dose of vit C injections!!! That gave me more hope!

  24. J Motts on May 2, 2009 at 7:08 am

    I have spoken to my local vet, she had never heard of it. I went to the only specialists in town, they aren’t interested in trying and said it might damage my dog’s liver? Recommendations?

    • Julie Kolaj on June 5, 2009 at 5:18 am

      Dear Dr. Dressler,
      Further to my comment on depression/cancer in dogs, i am curious if ester c or c ester, as i believe it is known in your country, may be of help to dogs with cancer. As vitamin c is water soluble and ester c is non acidic and fat soluble i believe ester c can penetrate the thin membrane encasing a cell thus concentrating in the cell plasma Whether this would be of value to dogs with cancer i don’t know. However on a slightly different subject i know large dose have been proven to affect a disappearance of symptoms of hip dysplasia. I have also read that alpha lipoic acid is 400 times sronger as an anti-oxidant than vits c and e, and raises the levels of these vits in the body, in humans. I don’t know if you can give alpha lipoic acid to dogs and if so would it offer any help to dogs with cancer.Would value any info you may have on this.Julie (England)

  25. Candace on April 14, 2009 at 4:38 pm

    I was looking for info for my mother’s dog but thought I would post a great sight for getting high doses of vitamin c in a new oral method. I am a cancer patient and I use this stuff daily and I feel like a new person.

    • Bill on July 13, 2009 at 10:39 pm

      Hi Dr. Dressler

      Interesting read. We as humans know the benefits of vitamin C. So what does one do? Should the regular vet already know the benefits of vitamin C, and have the education on the dosage and frequency or is this something that we can/need to get from you? Is the dosage in regards to pounds of weight of the dog? For example, our Taz is pretty close to 100 pounds and 11 years of age.


  26. Dr. Dressler on December 5, 2008 at 1:52 pm

    Talk to your vet. It is easy to get, cheap, and simple to do! Print out the blog page and print out the papers linked to so you can educate if needed. Also please read as much of this blog as you can (previous entries)

  27. richard grain on December 4, 2008 at 6:44 pm

    where can I get IV vit C shots for my dog in Los Angeles? This sounds so wonderful; it gives me hope. My dog has a cancerous bone tumor in one of her femurs. It has just been diagnosed after she developed a limp. Thank you for any advice you can give. Richard Grain.

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