I give "Brewers Yeast with Garlic". It also repells fleas. I do not treat for fleas in any other way (no Frontline, etc.) and we are FLEA FREE. The Brewers Yeast is from Walmart (only Walmart product I buy for my Yorkies) and is an 8-in-one vitamin. Stinky little pills that the dogs love and are convinced it is a treat

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