I rescued a 9 month old Boxer 2 evenings ago. He has fleas. Not a horrible case of them but I know how quickly they can multiply. I bathed and treated him with Frontline but I noticed this morning that he still has them. Did I do something wrong? Did I not do enough or have I just not waited long enough? I have a 6 month old Boxer and a cat also and don't want this to get out of control. Both of my other animals are already on Frontline and have been. Any suggestions?