I started out wearing collars on both Abby and Buddy. That is until on day Abby almost hung herself on my kitchen cabinet handle. She was begging by standing up on her hind legs for her treat, and when she went to get back down to all fours, her collar got stuck on the handle,and she could have choked to death. Thank goodness I was standing right there ,as I was getting out the treats , so I saved her . So since that day, I choose not to wear collars on them, for fear it may happen again, and I may not be so close by. I do have very nice brand new collars for them to wear when they go out,but that is only when they wear them. I thinking of micro-chipping both during their upcoming vet check-ups in december.