We've had a lot of trouble this year with fleas among our rescue kittens. They obviously come in with fleas. Our protocol is to treat with Capstar and then work to keep the flea population down, sometimes retreating with Capstar to kill the adult fleas at regular intervals. When the kittens are old enough they are treated with Frontline. However, most of the kittens still have fleas and Frontline doesn't seem to be doing the job anymore. Is this due to resistance to the active ingredient in Frontline? What are you using in your practice? A vet that did a big S/N clinic for us recommended using Prometrix. Do you have any experience with it and does it work better than Frontline? This vet commented that it is a lot cheaper than Frontline and she found it seemed to work better. I was not familiar with the active ingredient in this product and it seems to have been approved recently (I used to work as a consultant helping companies register products).