Brewer’s Yeast for Dogs: Understanding the Benefits and Risks

Hanie Elfenbein, DVM
By Hanie Elfenbein, DVM on May 17, 2017

Brewer’s yeast is derived from a single-celled organism responsible for fermentation in beer. It’s also a safe dietary supplement that offers many potential benefits for dogs. As always, consult your veterinarian before administering new supplements to your pet.

What are the benefits of brewer’s yeast for dogs?

Rich in B vitamins (B1, B2, B3, B5, B6, B7, and B9) and antioxidants, brewer’s yeast promotes healthy skin, hair, eyes, and liver function in humans and pets. In addition to these benefits, the high levels of B vitamins may reduce anxiety in dogs.

Brewer’s yeast is also high in selenium, potassium, chromium, iron, zinc, and magnesium. These minerals are essential for a variety of cell and organ functions as well as overall good health. It’s important to note that brewer’s yeast does not contain B12, a necessary vitamin found in animal products and sometimes added to nutritional yeast.

In humans, brewer’s yeast may assist with diabetes control, but this has never been studied in dogs. The high levels of chromium found naturally in brewer’s yeast help regulate blood sugar, but this has not been tested in dogs. Chromium is removed when brewer’s yeast is de-bittered, so read the label carefully. Brewer’s yeast can also be used as a probiotic and digestive aid.

What are the risks of brewer’s yeast for dogs?

In large dogs, the amount of brewer’s yeast needed to have an effect may cause stomach and intestinal upset. Gas is the most commonly reported side effect in all dogs. Brewer’s yeast can interact with some types of anti-anxiety and anti-depressant medications. It should not be given if your dog is immunocompromised, prone to yeast infections, or has yeast allergies. It is also inadvisable for dogs with colitis and other types of bowel disease. Beyond these specific factors, there is little controversy about brewer’s yeast in small doses for healthy adult dogs.

Brewer’s yeast is also high in calories, at about 80 kilocalories per ounce (or more if mixed with omega-3 oils), so it’s important to factor the calorie count in your dog’s daily intake. Be sure to read the label carefully for added ingredients that your dog may be sensitive to.

Does brewer’s yeast repel fleas and ticks?

The short answer is yes. The longer answer is that there is not much scientific information available more recent than USDA pamphlets from the 1950s. Recent studies have combined brewer’s yeast with garlic or oils with mixed results. The amount of garlic in commercially available formulas is safe for pets. It seems as though brewer’s yeast is the important ingredient, but the formulation is vital to its success at repelling fleas and ticks. Scientists have tried to determine which part of brewer’s yeast gives it this repellent property. None of the vitamins or minerals in brewer’s yeast repel ticks and fleas on their own, so it may be multiple components working together.

Recently, dog treats containing brewer’s yeast with and without garlic were tested, and there was no difference in the effectiveness of the treat. The treat hit a snag coming to market because of side effects in the large dogs in the study. Brewer’s yeast mixed with omega-3 oils may have a stronger repellent effect.

It will likely take a few days before you see any flea repellent effect from brewer’s yeast, and not all dogs will have this benefit. Therefore, it is best given in addition to a topical or chewable product that kills fleas so your dog is protected in two ways.

How do I give my dog brewer’s yeast?

Brewer’s yeast is available in powder or tablet form. There are specific formulations of tablets for dogs so that it is an appropriate amount for the size dog you have. The powder is often made of de-bittered brewer’s yeast, which lacks chromium. Some contain added garlic or garlic flavoring while others contain omega-3 oils. You can choose which is best for your dog based on the effects you hope to achieve. After discussing this supplement with your vet, brewer’s yeast may be appropriate for daily administration. 

Hanie Elfenbein, DVM


Hanie Elfenbein, DVM


Dr. Elfenbein graduated from the University of California, Davis School of Veterinary Medicine in 2016. She currently practices in...

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