Login Sign in
Login Sign in

Join thousands of pet parents and get vet-approved guidance, product reviews, exclusive deals, and more!

Benefits of Brewer’s Yeast for Dogs and Cats

dog and cat eating
Skip To

As more people turn to vitamins and supplements to boost their immune system and improve their overall health, it comes as no surprise that pet parents are also shelling out for supplements for their pets.

One nutritional supplement that has been making a comeback in recent years is brewer’s yeast. It has long been used by humans, but is brewer’s yeast good for dogs and cats too? If so, what are the benefits for our furry companions? Let’s take a closer look at this nutrient-rich source of protein.

What Is Brewer’s Yeast?

Saccharomyces cerevisiae, commonly known as brewer’s yeast or baker’s yeast, is a species of budding yeast that has been used to make fermented beverages and foods, like beer, wine and bread, for thousands of years (1). Brewer’s yeast is essentially the spent yeast that’s leftover from the beer brewing process. Rich in B vitamins and protein, the dried, inactive form of brewer’s yeast can be used as a nutritional supplement (2). But humans aren’t the only ones who can benefit from brewer’s yeast—it is a common ingredient found in pet food formulas and treats. Brewer’s yeast supplements can also be added to your dog’s or cat’s diet. 

Although brewer’s yeast and nutritional yeast come from the same species of yeast (S. cerevisiae), they are not one and the same.

Benefits of Brewer’s Yeast for Dogs and Cats

Brewer’s yeast is a good source of natural protein, dietary fiber, B-complex vitamins, selenium, and potassium (3). Though scientific research is limited, there are some purported benefits of brewer’s yeast for cats and dogs. These may include:

  • Increasing palatability of food
  • Improving nutritional deficiencies
  • Enhancing immune function
  • Supporting healthy digestion
  • Maintaining skin and coat health

If you look closely at the nutrition label on your pet’s food or treats, you may notice dried brewer’s yeast listed as an ingredient. Pet food companies often add dried brewer’s yeast (or other yeast products) to dog and cat food formulas to enhance the flavor. A moderate amount of brewer’s yeast in pet food appears safe for dogs and cats (4). While studies have demonstrated dogs’ preference for diets containing yeast compared to control diets (4), cats may be less likely than dogs to find them more palatable. 

Supplementing with brewer’s yeast isn’t guaranteed to make your pet like his or her food more, but it may be worth considering if you have a finicky eater. If you’re looking to reap benefits beyond a flavor boost, your best course of action is to speak with your veterinarian first, advises Dr. Michelle Burch, a veterinarian at Safe Hounds Pet Insurance.

“If you supplement for more than palatability, I recommend discussing with your veterinarian about more definitive diagnosis and treatment recommendations,” Burch says. “Supplementing with brewer’s yeast for underlying problems has a high chance of not treating the disease, and prolonging treatment of a disease can make it worse.”

A good quality pet food should provide complete and balanced nutrition and meet standards set by the Association of American Feed Control Officials (AAFCO). If your pet has a nutritional deficiency, your veterinarian may recommend a change in your dog’s diet or using dietary supplements. Brewer’s yeast is rich in B-complex vitamins, including thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, biotin and folic acid. B vitamins support healthy digestion and play an important role in maintaining skin and coat health (5). 

“Brewer’s yeast is used for folic acid deficiency, typically seen in chronic upper small intestinal disease or inflammation,” Burch says. She adds that vitamin B supplementation may also help improve intestinal disease and iron deficiencies in dogs and cats. However, keep in mind that brewer’s yeast does not contain B-12—which aids in digestion and helps prevent a certain type of anemia—unless the product is fortified with it.

Brewer’s yeast is approximately 50 percent protein by weight (6), and that protein is highly digestible (4). One study found that supplementation with an S. cerevisiae fermentation product may have a beneficial effect on gut health, enhance immune function, and decrease inflammation in dogs (7). The immune-boosting properties of brewer’s yeast may be due in part to selenium, an essential mineral with antioxidant properties (8). 

Some human studies have found that brewer’s yeast may help regulate blood sugar in diabetic patients (9), thanks to its high chromium content, but there is limited evidence to support its effectiveness.

You may notice some companies selling a blend of brewer’s yeast and garlic for dogs and cats and promoting it as a natural flea repellent. However, there is not enough scientific evidence to support this claim. “Brewer’s yeast supplements have been used for flea control but it is questionably effective,” says Dr. Stacy Choczynski Johnson, vet expert at Pumpkin Pet Insurance. “It is not uncommon for dogs who are treated with brewer’s yeast to present at the veterinary hospital with flea infestations.”

How to Use Brewer’s Yeast for Dogs and Cats

As with any dietary supplement for dogs and cats, it’s important to read the label carefully and follow proper dosing instructions. Brewer’s yeast is given orally to dogs and cats and comes in powder and tablet forms. The powder is typically sprinkled on or mixed with food, Burch says. Brewer’s yeast may also already be featured as a supplemental ingredient in your pet’s food or treats. 

If you’re wondering how many milligrams of brewer’s yeast for dogs and cats is considered safe, it will vary based on the product and your pet’s weight. Talk to your veterinarian about the ideal amount for your individual pet. 

Brewer’s Yeast for Dogs and Cats: Side Effects 

In general, brewer’s yeast for dogs and cats is considered safe if you purchase it from a reputable company and use it according to the label. It is intended for intermittent or supplemental feeding only. 

According to Burch, brewer’s yeast has a wide safety margin. Pets that ingest too much brewer’s yeast may experience mild gastrointestinal side effects. “The most common sign seen with an overdose of brewer’s yeast is an upset stomach with vomiting and transient diarrhea,” she says.

That being said, many brewer’s yeast formulas contain garlic, which can be toxic to dogs and cats in high doses. While only a small amount of garlic is typically used in pet foods and supplements, caution should still be used, especially when purchasing supplements from an unknown manufacturer. Products may also be fortified with other nutrients, so pay close attention to the ingredient list. 

If your dog or cat has a current health condition, check with your veterinarian before feeding your pet brewer’s yeast. Because brewer’s yeast is high in specific B vitamins and purines, it may not be ideal for breeds that are prone to urinary problems, for instance. “Dalmatians tend to develop a type of urinary stone that is exacerbated by a high purine diet, so I recommend avoiding brewer’s yeast in this breed,” Johnson says.

Where Can I Buy Brewer’s Yeast for Dogs and Cats?

Brewer’s yeast for dogs and cats can be purchased from reputable online retailers, pet specialty stores and pharmacies, health and wellness retailers, and big-box stores.

When shopping for brewer’s yeast for dogs and cats, look for products that are third-party tested for safety, strength, purity, and quality. Find out whether the company adheres to Current Good Manufacturing Practice (CGMP) regulations enforced by the FDA. You can also check the label to see if the product carries a quality seal from the National Animal Supplement Council (NASC). This is similar to the USP (United States Pharmacopeia) dietary supplement verification seal for human products. Companies that display the NASC quality seal on their products must pass an independent facility audit every two years and demonstrate an ongoing commitment to quality, consistency, vigilance, and continuous improvement. They must comply with strict labeling guidelines and include any warnings or caution statements for certain ingredients as recommended by the FDA’s Center for Veterinary Medicine and the NASC Scientific Advisory Committee.