Ok we have three dogs and the smallest Ollie will NOT keep his collar on. The problem is here in FL apparently they can ticket you if you do not have the collar on the dog even when it is on your property, weighs 7lbs and lives on your heels! He manages to get it off and lose them instantly. I have had him fitted at two different pet shops thinking it must be me. But never the less my little rat still can get them off. And we tried a harness and that some how managed to disappear as well. I just don't get it!