I have this book at home that's called Dog Heaven by Cynthia Rylant. I'll post it now.
When dogs go to Heaven, they don't need wings because God knows that dogs love running best. He gives them fields. Fields and fields and fields. When a dog first arrives in Heaven, he just runs. Dog Heaven has clear, wide lakes filled with geese who honk and flap and tease. The dogs love this. They just run beside the water and bark and bark and God watches them from behind a tree and smiles. There are children, of course. Angel children. God knows that dogs love children more than anything else in the world, so He fills Dog Heaven with plenty of them. There are children on bikes and children on sleds. There are children throwing red rubber balls and children pullin gkites through the clouds. The dogs are there, and the children love them dearly. And, oh, the dog biscuits. Biscuits and biscuits as far as the eye can see. God has a sense of humor, so He makes His biscuits in funny shapes for His dogs. There are kitty-cat biscuits and squirrel biscuits. Ice-cream biscuits and ham-sandwich biscuits. Every angel who passes by has a biscuit for a dog. And, of course all God's dogs sit when the angels say "sit." Every dog becomes a good dog in Dog Heaven. God turns clouds inside out to make fluffy beds for the dogs in Dog Heaven, and when they are tired from running and barking and eating ham-sandwich biscuits, the dogs each find a cloud bed for sleeping. They turn around and around in the cloud... ...until it feels just right, and then they curl up and they sleep. God watches over each one of them and there are no bad dreams. Dogs in Dog Heaven have almost always belonged to somebody on Earth and, of course, the dogs remember this. Heaven is full of memories. So sometimes an angel will walk a dog back to Earth for a little visit and quietly, invisibly, the dog will sniff about his old backyard, will investigate the cat next door, will follow the child to school, will sit on the front porch and wait for the mail. When he is satisfied that all is well, the dog will return to Heaven with the angel. It is where dogs belong, near God who made them. The dogs in Dog Heaven who had no real homes on Earth are given one in Heaven. The homes have yards and porches and there are couches to lie on and tables to sit under while angels eat their dinners. There are special bowls with the dogs' names on them. And each dog is petted and reminded how good he is, all day long. Dogs in Dog Heaven may stay as long as they like and this can mean forever. They will be there when old friends show up. They will be there at the door. Angel dogs.
Run free Charlie and Frankie. Run free.