CAN A CAT BECOME IMMUNE TO ADVANTAGE? MY CAT IS SCRATCHING HIS EAR SEVERAL TIMES A DAY,BUT THERES NOTHING THERE AND I CAN'T FIND ANY FLEAS. I HAVE TAKEN HIM TO THE VET AND HAD A TEST DONE FOR RINGWORMS WHICH CAME BACK NEGATIVE.
If your pet has no fleas then it sounds like the advantage is working. There must be another cause for the itch. vetcare