Very VERY lucky...

Glad they are ok.

Just a thought... is there nowhere you can hang their collars by the door on the way out to the kennel ? Or.... can they not be hung up IN the kennel out of reach ?

Either way you have to pick the collars up before the dogs go out.

Not a critism.. just a suggestion. You said this isnt the first time.... there simply may not be a good outcome to a "next time".