Killing the Dogs

[Linux.Blue]

I read in a walkthrough that you can't kill the dogs (except for that steam area). But one day I was playing the beginning and thought I'd have "fun" with the dog. I hit it with the hammer, it got knocked down for a very brief second. I hit it again and again. The dog ran off, and within just a couple seconds, off in the distance, I saw it coming right at me again.
I hit it again a few more times with the hammer, and it was dead.