Petco Text Logo
Petco Pet Logo
  • Two Easy Ways to Start Earning Rewards!

    rewards header
    Become a member today!
    Members-only pricing and offers, personalized care notifications, Vital Care points back on every purchase and more!
    Petco Pay LogoBecome a credit card member today!

    Earn 2X Pals Rewards points at Petco
    when you use Petco Pay!

    APPLY NOW
    Learn More About Petco Pay Benefits

Is my cat's B12 or Prednisolone treatment feeding his cancer?

Updated on September 23rd, 2025

Pet's info: Cat | Domestic Shorthair | Male | 17 years old

Hello, My cat Bugger has had skin cancer below his eye for 5 years. It is getting bigger. I have heard that the b12 shots he has been receiving feeds the cancer and makes it progress. He takes it for inflammatory bowel disease. His vet does not know. I don't know if I should stop giving it to him. He also receives Prednisolone every other day - one half of a 5 mg pill. I am afraid that could also make the cancer grow. Please advise. Thank you. Linda

1 Answer

Most Helpful Answer

Linda G,  MS, DVM

Answered By Linda G, MS, DVM

Veterinarian

Published on June 10th, 2021

Hello. At this point in time, there is no credible information concerning carcinogenicity and Vitamin B12. Long term studies in animals have just never been done.
In any situation where you have co-morbidities, in this case IBD & skin cancer, you & your veterinarian have to decide if the risk of one possible problem outweighs the benefit it gives for the other problem. Since there is no credible information associating B12 with cancer growth, & it is controlling Bugger's intestinal symptoms, you must decide about continuing the supplement.
Thanks for contacting Petco Pet Education Center, formerly Petcoach.
Vote Icon1Pet Parents found this answer helpful

Smart Picks for Smart Questions

Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Share

Styled arrow button