What happens: My dogs will stand in lava until dead. They stand on cactus. They drown in water covered by dirt when there's air over the water block right next to them.
What I want to happen: Dogs will avoid injury and retreat from it when encountered.
Arguably, undead are too dumb for this behavior, but most other things in the game should have the sense to get out of harm's way when safety is a block away.
this is not a bug, see the minecraft forum for requests.