[quote1318427159=Igmuska] Then treat the cat. Buy a topical flea medication and dose the cat. Or, get rid of the cat. Or, deal with the constant battle. DE and Boric acid are great, but be careful, they are a strong respiratory irritants and can cause secondary respiratory diseases and other complications. BA is also poisonous if ingested. [/quote1318427159] Just to clarify, DE comes in a variety of different grades and it is the quantity of silica in it that dictates whether or not it is an irritant. Yes , DE used in soup kitchens and swimming pool filters will certainly give any air breather a problem, but this isn't the one you'd want to use around your house or on your dog, but food grade DE does not contain enough silica to bother anything, it's safe, it can be taken internally for parasites, used directly on the skin, and is very safe to spread around the grounds. - and that's why I mentioned to pick it up at a animal co-op rather than at an industrial supply house. Boric Acid also when used properly, the likelyhood of your dog getting ill from it are almost nil.