Does pet supply stores sell diatomaceous earth(silicon dioxide) the food grade type, dog has fleas?.?
As far as I have seen none of those places sell it near me. You would have to garden centers or pool supplies stores or on-line. Be sure to say food grade only not pool or garden types. As a warning it does work slowly & you won’t see results quickly & you still must use precautions in handling it so do NOT breathe it in.