Thinking about dogs. Considering people would likely become more dependent on their canine's ability to detect and bark at strangers/protection/hunting etc, if you did happen to shoot someone's dog you probably just made yourself a target. Having said that, I think its highly unlikely (in north america anyway) a scenario would develop where dogs, cats, horses, etc, become possible food sources. Not that it couldn't happen, but by the time things get that desperate you're talking serious world wide collapse and at that point you'd better already have long term food resources in place (growing wheat, potatoes, chickens) or you ain't gonna make it. I say that because resorting to dog meat for sustenance means things aren't going well and what little nourishment you get from that type lean/starving-dog meat isn't going to sustain you for long. Definitely not long enough to get your food crops up and running. Just some mind rambling.