Well my hope is to never have an infestation hahaha. It was more a question in terms of a monthly "preventative." Probably more so for Halpert since he is the one who comes to the park/dog run etc etc. The chis are too good for other dogs
But I dunno. I just don't want to be pumping more chemicals in them than necessary, but at the same time the last thing I need is to bring home any fleas or things. So if it was effective why not use it every so often. But if its not I don't want to waste my money.