Our Corgi JP is 11 weeks old. She is doing great with Potty training, waiting paitentley to be feed and fetching. She already sits on command and knows "ouch when she plays to rough with us. But....we introduced the collar about a week ago and she HATES it! She acts like it weighs a ton and will only come to us after much calling her. She will not even walk upright and does this coyote crawl to you. She will not fetch her ball or chase you with this collar on. We started with the small thin nylon type and it weighs nothing. She does the usual scractching her neck thing and that is to be expected. It is not to tight or to loose. As soon as you take it off she is back to her usual self, happy go lucky and chases the cat:) She sleeps in her crate at night so I do take it off at night and it goes right back on in the am. How long does it usually take and should I switch to a harness? Our other dog(a terrier mix) never had a problem with the collar or leash. She walked on the leash perfect from day one. This girl has me stumped! LOL!! I know that when she is older she could be pulling us with the leash and not behave very good on it if not trained properly.( we know a corgi who is horrible on leash). We take our dogs everywhere and on vacation. So it is very important that she is leashed trained properly! If anyone has advise i would love to hear it!!!