Brewers Dried Yeast

Brewers dried yeast is the dried, inactive yeast left over from brewing beer, used in small amounts in many dry cat foods. Tufts veterinary nutritionists describe cats as carnivores with nutrient needs of their own, so yeast sits in a recipe as a minor ingredient next to animal protein. Pettings has not found an FDA restriction on it for cat food. If your cat has a food allergy or another medical condition, ask your veterinarian about it.

Source: sites.tufts.edu

Brewers yeast is added mostly for flavor and nutrients. It brings B vitamins and a fiber called beta-glucan, along with some protein, and it gives kibble a savory taste close to broth, which many cats seem to like. It usually appears near the middle or end of the ingredient list, so the amount in each bowl is small.

No study has shown that brewers yeast in food keeps fleas off cats. The idea is old and widely repeated, and it probably comes from the yeast's B vitamins and smell. The flea claim has not been shown scientifically, so a cat eating a food with brewers yeast still needs a flea control plan. Your veterinarian can suggest a product that fits your cat's age and weight.

A cat can react to almost any protein it eats, and yeast does contain protein. The Cornell Feline Health Center explains that food allergies are diagnosed with an elimination diet, feeding only a novel diet and water for at least eight to 10 weeks and then adding old ingredients back one at a time. If signs return after yeast goes back in, that points to yeast. A veterinarian should guide that trial.

Source: vet.cornell.edu

Pettings gives brewers dried yeast 3 out of 5 and lists it as one of its yeast-based cat food ingredients. It appears on 37 of the 149 dry cat foods we list. That makes it one of the more common supplement ingredients in dry food. Each food's page shows how it scores overall.