Dead Dog/Alive Dog? --Spoilers

[Linux.Blue]

you may have done things out of order. All I am aware of, there should only be two dogs until you blow up that cave-in, then there will be more dogs afterwards, but you'll no longer be in that area up there.
If there are more than two dogs in the area you're talking about, then something may be up. otherwise, it's pretty much just scripted to have those two dogs.

Where did this second dog appear? on the south side of the locked door (where you start) or the north (newer area)?