Verified Supplement Data

Dog Supplements (2026): Which Ones Help, and What to Buy

Most healthy dogs eating a complete and balanced dog food do not need a vitamin. Three products have evidence for a specific problem. Find your dog's problem below.

By Erin Rose Updated October 21, 2026 Sources

What to buy for your dog's problem (3)

  1. Bad breath, plaque or tartar

    Greenies Original

    Of the chews on the VOHC list for both plaque and tartar, it costs the least a day for a 30 lb dog. Buy the size for your dog’s weight.

    Compare every dental chew on the VOHC list

  2. Stiff or sore joints

    Grizzly Salmon Plus

    Fish oil has the best evidence for dog joints. This one costs the least for the dose used in a trial.

    Compare fish oil and glucosamine by dog weight

  3. Sudden diarrhea

    Pro-Kolin Advanced paste

    In a trial in dogs with sudden diarrhea, dogs on it got better in a median of 32 hours, against 47 hours on a placebo.

    Compare dog probiotics

Should I give my dog a multivitamin?

Not if your dog eats a complete and balanced food. If the bag or can says those words, it already has the vitamins and minerals your dog needs. The World Small Animal Veterinary Association says adding more is not needed and can be risky, because some nutrients are toxic in high amounts (WSAVA).

It names one exception: dogs with long coats may need a little more fatty acid for their skin and coat. A fish oil, or a different food, can help. Ask your vet before you add anything. Cooking at home is different: see the question below.

When should your dog see a vet first?

Questions

What if I cook my dog’s food at home?

Get the recipe from a board-certified veterinary nutritionist. Studies found most home recipes from books and websites, even some written by vets, are not complete and balanced (AAHA 2021).

Sources

  1. World Small Animal Veterinary Association. Frequently Asked Questions and Myths (Global Nutrition Committee). Updated January 2018. PDF
  2. Cline MG, et al. 2021 AAHA Nutrition and Weight Management Guidelines for Dogs and Cats. J Am Anim Hosp Assoc. 2021. PDF
  3. The sources for each pick are listed on its guide: dental chews, joint supplements, probiotics.