Brewer's yeast for fleas is thought to be effective, because the yeast contains thiamine. The smell and taste of thiamine is believed to be repulsive to fleas, so when dogs and cats eat brewer's yeast, the fleas are repelled by the presence of thiamine on the skin or in the blood of dogs and cats. Thiamine is a part of the B vitamin group.
Getting rid of fleas with brewer's yeast is easy to do, since the yeast is readily available from grocery stores, health food stores and online sources. It can be bought as a powder, a liquid or flakes. The most practical choice when it comes to using brewer's yeast is its powder form. For natural flea control, the powder can be mixed with pet food, dusted onto a pet's coat or dissolved in water.
Brewer's yeast for fleas should be dosed at 1 teaspoon (4.9 ml) for small dogs or for cats. Medium-sized dogs should be given 2 teaspoons (10 ml), and larger dogs should be given 1 tablespoon (14.8 ml). The yeast can be sprinkled on dog or cat food, or it can be used directly on pets' coats as flea-control powder. If Brewer's yeast is utilized as a dietary supplement, it can take up to a month before it reaches maximum flea control power. Pet owners might want to start dusting their pet's coat or supplementing their pet's diet with brewer's yeast early in the spring, before a major flea problem occurs.
A mix of brewer's yeast with garlic should be avoided. Garlic is toxic to both dogs and cats, with cats being more sensitive to garlic than dogs are. It is possible for either cats or dogs to be allergic to brewer's yeast. If a dog or cat shows signs of an allergic reaction on its skin after it eats brewer's yeast for fleas, then use of the yeast should be stopped. Dog and cat owners need to be careful about how much yeast they give their pets, since overdosing with Brewer's yeast can cause skin allergy.
Another way to use brewer's yeast for fleas is to allow 0.25 cup (59 ml) of the yeast to dissolve in 1 quart (946 ml) water. This solution can be put into a spray bottle and sprayed onto a pet's coat. For maximum effectiveness, the mixture should be combed or rubbed into the fur.