Because of current discussion on the forum that 'Lil Abby started about her dogs collar getting caught in the carpet and a recent near disaster that one of my son's dogs had I thought to put this site on the reviews.
The company that makes the gentle leader also makes a nylon collar with a breakaway feature. The clever design makes it possible to attach a leash and bypass the break-away feature. The collars come in several colors sizes small to extra large. Fortunately, i have had no personal experience with it actually working, but it is well made and looks like it would come apart if the dog were caught and struggling. Certainly it would be much more likely to come apart than an ordinary collar. They are available at bestfriendsgeneralstore.com. I would hyperlink it for you, but my computer has so many "guards" on it that sometimes I can't get through them and this is one of those times.