Can I get some opinions on this subject. I have both a collar and a harness for my little Tess (11 weeks). Needless to say she doesn't like either one, but she seems to tolerate the collar better. I need to have one or the other on her when I take her out for potty breaks, because she seems to like to take off. Sometimes she doesn't come when I call her and I end up chasing her all over the neighborhood. I'm concerned about pulling on her neck with the collar - but which one is really best for this little gal?