A product such as Flee Plus IGR for Dogs works systemically, so you should not expect it to eradicate all fleas that quickly. We always recommend treating the environment where the fleas are found in addition to treating the pets themselves. Please take a moment to look over our Flea Control Guide for more information on how to implement a successful flea treatment program.
FLEE Plus IGR for Dogs is only labeled for use on dogs. You can find the products we offer for cat fleas here.
We are not aware of any changes with active ingredients or formulations. We recommend contacting the manufacturer of FLEE Plus IGR for Dogs directly for product support, either by calling (315) 736-8231, or by visiting their website's contact page here.