Obi-Wan Kenobi wrote:
If animals go to heaven, it cannot be in the same way that humans do, for precisely the reason that Doom gives.
There's this hunter out with his dog, and they are attacked and killed by a bear, the both of them. They were out hunting together year in and year out. The epitomy of friendship. As they were walking down the trail toward the great big heavenly gate, the gatekeeper says to the hunter, "By golly, you made it to heaven! Welcome! Come on in, your life is about to really start!" As the hunter starts walking, he whistles to his dog to come along, and the gatekeeper stops him, "Whoa! Whoa! Wait a minute! We don't allow dogs in here, you need to leave him outside!" The hunter looks at his dog, then looks beyond the gait, hesitates, and says, "Ah, never mind, I am going to go down the other trail. I am going to the other gate. I won't go to heaven if I have to leave my dog behind!" And so, off the hunter walks with his dog. When he comes up toward the other, darker gate, he sees a man waiting for him. The man asks, "Well, why didn't you pass through the other gate? They invited you through!" The hunter replies, "I ain't gonna go to heaven if I can't take my dog!" And all of a sudden the man looks brilliant, and the gait begins to glow, and the gate keeper says, "Well, my name is Peter, welcome to heaven!" The hunter remarks, "Well, I don't understand..? What's this all about?" And St. Peter says to him, "Heck, you think we want anyone in heaven that would leave his dog behind?!?"
I've seen this in an expanded version. It was also an episode on the original Twilight Zone.