I wouldn't let the perfect 20/20 hindsight bother you too much,Phish.There are a lot of other folks that own different breeds that find themselves in your position.You obviously didn't see this coming.

You make a good point about the dog not understanding its limits with the kid.It still presents a danger though.

For what it's worth,I would follow the same course of action that you have chosen.I would use a different method,if I had to put the dog down,but otherwise I agree with your decision.

Good luck in finding the dog a proper home!