I have Sadie and Pooh Bear on Frontline Plus for flea control. They have both been very itchy for a few months now. I even took Sadie to the vet for a Prednisone shot a few weeks ago. Pooh Bear has been itching and scratching a lot and I was just now sitting here petting him. He has several red irritated areas that he has been biting at. As I am looking at this red spot on him, I see a flea! I got it off of him and squished it. Now why isn't their Frontline working? I'll call the vet Monday.