This flea busting dog biscuit recipe is simple and healthy. As you can see, no wheat flour or corn meal (which are common ingredients that cause allergies in dogs) is used in the recipe.
Like Brewer's yeast, nutritional yeast can be used to repel fleas. Both types of yeast are deactivated, then dried and made into a powder or flakes. They are therefore non leavening and are safe for consumption by dogs. (Dry active yeast used for baking bread should not be given to dogs as it will cause gastrointestinal problems.)
So what are the differences between nutritional yeast and Brewer's yeast?
Brewer's yeast is a by-product of beer making, whereas nutritional yeast is not obtained during beer making but is instead grown on molasses or some other medium.
The nutritional profiles between the two types of yeast are a bit different. While both types are rich in protein and B-vitamins, nutritional yeast is often fortified with additional vitamin B12 because, like Brewer’s yeast, B-12 does not naturally occur in nutritional yeast.
On the other hand, Brewer's yeast is rich in the minerals chromium and selenium; however, nutritional yeast is not (unless it is fortified with these minerals).
Another difference between the two types of yeast is the flavors. While Brewer's yeast tastes a little bitter (which some dogs may not like), nutritional yeast tastes nutty and cheesy (which most dogs like).
I prefer nutritional yeast mainly because of the taste factor!
A word of caution: While Brewer's yeast and nutritional yeast have flea repelling properties, some dogs are allergic to these yeasts. If you are giving either of these yeasts to your dog for the first time, try sprinking a small amount of yeast on your dog's food to see if your dog has any allergic reactions.