I learned a lesson the hard way this morning. While shaving and getting ready for work I heard my 4 month old GSD pup screaming like someone was torturing her. I ran to the bedroom an my wife had awoken and had to free her from the side of the crate. Her dog tags had gotten caught and luckily she wasn't high enough where she was hanging. This was her night time crate which is the wire type. She has a plastic travel kennel that we leave her in if we leave the house. I had just read about this on a GSD forum about a week ago and didn't heed the warning. From now on the collar goes off in the crate. I felt like such a dumbass and horrible pet parent.