I have a 4 pound 9 month old little girl...I've been training her to go out on the leash with me, but I still provide a pad for her inside which she fairly good about using.my yard is fully fenced and my big dogs go out without supervision, but I will never be comfortable letting her out alone. I don't have a problem letting such a wee dog go on a pad inside especially in bitter weather..my cat outweighs her 5 times and he has his warm spot