Twilight Zone Third Season

"An old man and a hound dog named Rip, off for an evening's pleasure in quest of raccoon. Usually, these evenings end with one tired old man, one battle-scarred hound dog and one or more extremely dead raccoons, but as you may suspect that will not be the case tonight. These hunters won't be coming home from the hill. They're headed for the backwoods of the Twilight Zone."

Hyder Simpson and his dog Rip dive into a lake after a raccoon. Only the raccoon emerges. He and Rip awaken the next morning next to the lake. When he gets home he finds that no one can see or hear him, not even his wife - they all think he's dead. He finds a fence beside the graveyard and follows it to a gate. The man at the gate tells him it is the gate to Heaven, but dogs aren't allowed. Hyder takes Rip and leaves. Further down the road he meets an angel. The angel explains that the gate was actually the gate to Hell, and Rip wasn't allowed in because he could have smelled the brimstone.

"Travellers to unknown regions would be well-advised to take along the family dog. He could just save you from entering the wrong gate. At least, it happened that way once - in a mountainous area of the Twilight Zone."