Frontline Plus For Dogs Does Anyone Know How Long After Treating Dogs With Frontline Plus I Can Re-treat?

Does anyone know how long after treating dogs with Frontline Plus I can re-treat? - frontline plus for dogs

I treated my dogs with Frontline Plus 15th September. Not be applied correctly (he lost the directions). Instead of a Front-Line, where they went a little bit. You still jumping with fleas. I wonder whether it is safe to return, or if you just try to use the flea shampoo on the correct date. I know this is obviously what I call the vet back tomorrow again, but curosity what others think too. Thank you.