Flea Remedies With Brewer's Yeast

Due to concerns about the toxicity of conventional treatments, such as topical insecticides, to eradicate flea infestations in pets, so-called "natural" flea remedies have grown in popularity. One such remedy to control flea problems in dogs and cats is brewer's yeast, also called nutritional yeast. Brewer's yeast flea treatments for pets are typically administered as a powdered additive to pet food, topically or as a supplement in tablet form; however, the effectiveness of brewer's yeast treatments to kill fleas is not supported by scientific research.

  1. As a Food Additive

    • As a natural flea treatment remedy, holistic veterinary care professionals including Diane Stein and Christine Makowski recommend feeding brewer's yeast to cats and dogs by adding a powdered version of this fungus to the pet's food. Stein says in her book, "Natural Healing for Cats and Dogs," that adding brewer's yeast, which contains thiamine (vitamin B), to your pet's diet, makes the animal's blood less palatable to fleas. Makowski, in an article published by "Mother Earth News," says that 1 milligram of thiamine daily for each 5 lbs. of your pet's body weight is ideal; this would translate to 1 tsp. of brewer's yeast for an average-sized cat or 1 tbsp. for a large dog. Scientific research does not support these claims. One study, published in the "Journal of the American Veterinary Association," found that brewer's yeast, when given to dogs as a powdered food additive at the rate of 14 grams per day, failed to repel or kill fleas.

    Topical Application

    • Makowski says brewer's yeast can also be dusted on externally as a flea powder, claiming that if your pet licks some off, there's no harm done. Other veterinarians, including Alfred Plechner and Juliette de Bairacli, warn against topical (as well as oral) brewer's yeast flea treatments, denouncing them as dangerous allergens, particularly for dogs. Veterinarian Narda G. Robinson also says that topical treatments for natural flea control frequently cause allergies or dermatitis. Robinson writes in a 2007 paper examining the effectiveness and safety of popular natural flea treatments, including brewer's yeast, "Unfortunately, certain natural flea control options may pose more dangers than conventional products, and offer less effectiveness."

    Supplemental Tablets

    • Brewer's yeast treatments for flea control are also sold in the form of concentrated oral supplements. Several retailers sell brewer's yeast for flea treatment via supplemental tablets. Many supplemental tablets for flea control that contain brewer's yeast also contain extracts of garlic, another holistic flea remedy. Some vets, including Makowski, recommend brewer's yeast and garlic supplements as a safe and natural alternative to conventional flea treatments. However, other vets, including Robinson, as well as the ASPCA, warn against these concentrated nutritional supplements, claiming that the ingredients may be toxic to both dogs and cats.