Maybe, but I have lines I won't have crossed and killing my family is one of those. Instinct or not that dog is not getting the chance to do that again.
In this scenario you've imagined here though, the rage you feel towards the dog is actually caused by your own negligence. Reflect on that if you like, or don't. Either way I won't return to this post because it's a depressing subject I would rather move on from.
You're really leaving it? Because you sure love judging others for it. This wouldn't happen in my situation because I have had 3 kids and a dog the whole time and they've all lived.
But let's assume I had been negligent. I'd still kill the fuckin dog. Because any dog with that kind of problems doesn't need to go to a pound to do it to someone else.