My Great Pyrenees has been wearing these year round for about 5 years. I only replace the collar once a year, when Spring is around the corner and then leave it on her for 8 months, remove it or leave it on. My Pyr has incredibly sensitive skin and every year before this she got hot spots which i believe were in combination with getting fleas, even if only a few bites. She hasn't had fleas since i got her on this collar. She is a total furball, and the collar sits just under her tagged collar, so its not noticable and she has never acted anything but indifferent to the whole experience.