posted by Demigodess: one thing I would worry about (and I am curious what other people think) is them getting their collars stuck on something and strangling themselves?>>>

Excellent question, and one that has bothered me since
I got multiple large dogs.

(In my case the dangers were not from the back yard such
as hanging, but when the dogs would grab each-others necks.
I was afraid one of the dogs would get their jaws caught
etc. on the collar.)
I am a stickler for collars/id's.
So with Rocky and Sheba I bought
those quick release collars awhile back.
Pretty much daily I would have to hunt for their collars
around the back yard because the collars came
off when the dogs would horse play.
(I am sure they made the collars a bit less quick released
since I bought mine)
So neither dog wears a collar
unless they are away from the house.
Rocky is chipped and Sheba is tatooed,
but it still bother's me about them not wearing a collars.
My yard is escape proof/gates are always locked.
I do not think anybody would or could steal my Akita's.

I recently ordered a leather rolled buckle collar just for Rocky.
He will wear a collar/ID and Sheba will not, unless she is away from the house.
Sheba is in the house most of the day, and
Rocky is in the house with her when I am at work.
(In the house both dogs sleep) so I think I am safe
with Rocky wearing his collar all the time.