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

Vitamin C and Dog Cancer Update

Updated: April 13th, 2021

There is much talk on the use of vitamin C (ascorbic acid), in it’s various forms, for cancer treatment in the “alternative” medical community. It’s use in conventional cancer care is routinely ignored.

In the spirit of full-spectrum care and rational analysis, let’s take a closer look.

Due to some interesting observations, focus on vitamin C for cancer is still alive and well in the research community.  I’d like to separate the wheat from the chaff and give you some main points.

  • Vitamin C, given by mouth, does not have direct anticancer effects on cancer cells.  The concentration in the blood is too low following oral administration.
  • Vitamin C is known as an anti-oxidant.  While it is at lower doses, the anti-cancer effects at the needed super-doses are actually pro-oxidant. (For more  on these concepts, click here)
  • The way to create the doses needed (vaguely 1000 micromol/L in the blood) is by giving IV injections of the vitamin.  There are published protocols of this having success in a few severe human cancer cases, put out by the Canadian Medical Association.  These can be used with your veterinarian’s cooperation to formulate a plan.
  • In 39 people with terminal cancer, a study found that quality of life improved combining IV and oral vitamin C (less pain, fatigue, nausea, and improved appetite).
  • In a test tube, another study found that high doses of vitamin C killed cancer cells including lymphoma, mammary cancer, pheochromocytoma, kidney cancer, bladder cancer, lung cancer and glioblastoma cells.
  • There is a concern that low (antioxidant) levels (like those achieved from vitamin C taken by mouth) may, at least theoretically, reduce the effectiveness of chemotherapy and radiation.
  • Vitamin C may increase the odds of certain kinds of urinary stones (calcium oxalates) and should not be used in patients with this problem.

What to make of all of this?  When you are dealing with a life-threatening canine cancer, and your dog does not have calcium oxalate urinary stones, you should consider adding IV vitamin C to your dog’s treatment plan.  This is especially true if your dog is not receiving chemo and radiation.  Many more outside the box treatments can be found in The Dog Cancer Survival Guide.

Get your vet involved.  Be your dog’s number one health advocate! Even if your canine companion does not experience a dramatic remission, there is at least evidence that quality of life may improve.

Best to all,

Dr D

Leave a Comment

  1. Vic on December 29, 2022 at 12:02 am

    My 10 yr old German Shepard has a 2.5cm tumour in the wall of his heart most likely a hemangiosarcoma, do you have any recommendations?

  2. Cindy Pelletier on September 15, 2021 at 1:34 am

    My dog has mct tumor and they found a spot on her lung. She is being treated holistically, because she is a 11 1/2 yr old boxer. She acts like a puppy. She gets vitamin c 1000. Turkey tail, Chinese herbs, cbd oil, krill oil, low dose steroids, synthroid ( hypothyroid) homemade grain free food, honest kitchen or dr Harvey’s. Is there anything else I can do to make tumors smaller? Also, I use topical oil with frankincense. I have your dog cancer survival book but might have missed something
    Thank you

  3. mark on November 13, 2019 at 9:42 am


    Thanks for your work. Our dog has hemangiosarcoma and had a ruptured spleen removed. We are considering high dose IV vitamin C. Human oncologists I’ve spoken with have indicated there is no clinical evidence that there is any benefit to Vitamin C.

    Are there clinical trials showing the efficacy of Vitamin C?


  4. Bonnie on March 6, 2019 at 7:54 am

    Hello Dr
    I sent a e mail back I hope you got. Just because I have consult tomorrow and deciding to do Surgery on Friday I would so so appreciate

    a consult today any time later if need be!

    Or before afternoon appt tomorrow can in AM.
    I have all the important report to e mail you on phone or before.
    Im trying to find oit who does the Vit C treatment though should I still have a laser surgery removal and Vit C before and after? Plus the herbals. So far hes still in the ok stage early
    Thank You God Blessings Bonnie

    • Dog Cancer Vet Team on March 7, 2019 at 6:08 am

      Hello Bonnie,

      Thanks for writing. If you are looking to book a consult with Dr. Dressler, you can always contact his veterinary hospital. Here’s the link: 🙂

  5. Michael Santorelli on April 17, 2018 at 1:17 pm

    How do I locate a vet in the LA area can give these treatments? Google and my vet have not been useful.

    • DogCancerBlog on April 18, 2018 at 10:47 am

      Hi Michael, thanks for writing. This isn’t something a veterinarian would necessarily “advertise,” but any vet could technically do a vitamin C iv therapy. We suggest simply calling vets in your area and asking if they ever do this, and if not, who among their colleagues might. You could use the holistic veterinary trade association website to get started in your search, although, again, even conventional vets may offer this therapy:

  6. Dawne on September 11, 2013 at 2:04 am

    Vitamin C is one of the best known cures for MANY conditions. Look up liposomal vitamin C…you can buy it on Amazon or make your own. This is thought to even have better absorption rate than IV vitamin C. A man cured his Leukemia with it..the story was on 60 minutes (the kind you buy on Amazon).

    I have read stories that this works on dogs also. You don’t have to worry about diarrhea as with the oral mega doses of Vitamin C because it is encapsulated and bypasses the stomach. The fact of the matter is that the pharmaceutical companies donate HUGE money to the FDA. They will never fund a clinical trial on a natural substance because they cannot patent it and mark it up over 5000%! They rather create harmful chemicals for you to put in your body to create side effects that you will need even more of their drugs to treat. There really is not one drug (besides the antibiotic) that can CURE anything. They only treat and manage symptoms. Sad…isn’t it? Watch “Run from the Cure” on You Tube and tell me what you think. We have been running and donating to the American Cancer Society and Susan G. Komen for how many years now. What a fraud! Seek other options for you and your pets!

  7. Alberta White on March 20, 2013 at 2:42 pm

    Requesting Dog Cancer News

Scroll To Top