Dog in the Sky: The Authentic and Unexpurgated Odyssey of Runyon Jones by Norman Corwin (1952)
Norman Corwin (1910-2011, -- that's right, another long life well lived) was one of the most recognized writers of radio scripts in the world. Dog in the Sky was his first novel.
Runyon Jones, age nine years and four months, is looking for his dog Pootzy, who had been run over and killed by a car he was chasing. Pootzy was "an auto chaser and tire nipper class 4; a resister of leashes; he assaulted a dogcatcher with intent to bite; and he was known to have stayed out all night on at least one and possibly several occasions." All of which made Pootzy a perfect dog for a nine-year-old boy. Alas, it also made Pootzy ineligible for Heaven and thus he was sent to Curgatory.
Runyon starts his quest on the 131st floor of The Building, at the Department of Lost Dogs. From there he is sent to the 197th floor, the Department of Deceased Dogs. An argument with the director of that department, Mr. Bubb, led to both being brought before the Supervisor. (On the way, they pass the Hall of Fame for dogs; there's a staue of Rin Tin Tin and one for Hunding, who once bit Adolph Hitler and caught rabies from him, and one of Highandry, a rescue Saint Bernard who carried kegs of brandy under his nose for ten years and never touched a drop.) The supervisor, touched by Runyon's pleas, broke/bent the rules by giving Runyon passports and documents to someone who might know the location of Curgatory.
So Runyon begins his journey to find Curgatory. It's not an easy task, but nothing is as determined as a boy separated from his dog. Unknown to Runyon, he is chased across the universe by a contingent of demons who would be able to use him to expand their powers beyond Earth. On his epic journey Runyon also encounters Father Time, Mother Nature, old man Winter, heat-loving Summer, the Harpy, and the Giant. He also meets strange people and creatures from all parts of the galaxy, including a cosmetics salesman whose most powerful perfume is called STATUTORY RAPE, which is "violent and irresitible; a flaming sword; yet it is perfectly safe when worn with a chaperone," and the prosletizing Mr. 62Kru, who is a Hunkerlite "resolute in [his] virute, confident in the supremacy and inviability of love, and [we] have alreadyy killed several million disbelievers to prove this."
Dog in the Sky is charming and whimsical, a juvenile that really is not a juvenile. The novel is an expansion of one of Corwin's radio plays, The Odyssey of Runyon Jones. The radio play can be found in Corwin's collection Thirteen by Corwin (1942).