NORTHAMPTON, MA—Three days after burying his beloved labrador retriever, Daniel MacNeil, 9, was told about doggy heaven and hell by his fourth-grade teacher, Sister Doris Behnke. "Don't cry, Daniel. I'm sure Shiner was a very good doggy," Behnke told the mourning child Tuesday. "He's probably in Doggy Heaven right now, running through its big green fields and chasing squirrels. Only disobedient doggies who chew on the furniture or lift their legs on the carpet will burn in the eternal, white-hot kennel fires of Doggy Hell."