Lots of good ideas!!
My advice would be a combination of the above---
1) reinforce your coop!!
2) the underground fence idea is wonderful, for coop/run-kept birds. It obviously wouldn't work for free rangers
3) If you have an outside dog, get a 10'x10' dog kennel, along with reinforcing your coop. A lot of different dog breeds can climb pretty well, especially hunting-type dogs.
4) a shock collar would only work when you are there to shock the dog, but it should work
5) an old wives' tale says to tie the dead bird to the collar of the dog until it falls off on its own. I haven't tried this, but it is supposed to work.
I have a chicken killer too, and she had to be tied up. No dogs in the house here
She has gotten loose on occasion, but thankfully hasn't killed anyone else. Mostly she ignores the chickens now, whether she is on a leash or a chain, unless they are fighting or running. Too much of a temptation then.