Unfortunately I've see this many times too. I actually have a relative that had a dog for over 12 years, her and her husband treated this dog like a child, they were trying to have children and couldn't, then at the age of 35 she became pregnant, had the baby and the dog made a little snap at the newborn..they put the dog down immediately! I was so upset by this, I thought it was so unnecessary
They stated later they regretted it, a little to late fro the poor dog though!!