If you don't mind talking animals (the dogs here chat in a sort of Tonto Amish), this recycling of the most reliable canine formula--Man loses Dog, Dog endures an ordeal/journey, Man finds Dog--may be a Disney-ish treat; it's certainly preferable to Winston Groom's cutesy Only (p. 55). Nop is a black-and-white Border Collie, beloved stockdog of taciturn Virginia farmer Lewis Burkholder. But Nop is stolen away by evil, hillbilly-ish Grady Gumm, who's hoping to get $300 from slimy Doug Whitenaur--the Ohio dog-breeder who keeps losing at stockdog ""trials"" (contests) to the wonderful Nop. When Lewis comes hunting for Nop, however, Grady sells him for a few dollars to ex-rodeo-clown T. T. Raines--who uses Nop as part of a rodeo comedy-act, ""The Littlest Buckaroos"" (Nop as horse, a monkey as rider). Nop proves too rebellious, however, for rodeo life; so Raines sells him to villain Whitenauer, who has caught a glimpse of the ""Buckaroos"" on television. And when the indefatigable Lewis trails Nop to Whitenaur's Ohio kennel, the dog is again passed on--first to a cutesy/crazy bag lady, then to a Kentucky chemical lab, where Nop is about to be used in vile experiments. . . when it's Lewis to the rescue, commandeering a local fire truck for the mission. McCaig, author of the impressive miner-novel The Butte Polka (1980), fills out this children's-book scenario with an uneven assortment of subplots and shadings. Among the better digressions: Lewis' gruff, growing affection for his unwanted son-in-law Mark--who accompanies him on some of the Nop-searches. (They stop off and visit Mark's sad mother and his young, autistic brother.) Among the less persuasive ones: the rediscovery of sex between Lewis and his wife; the dog-training endeavors of Lewis' very pregnant daughter Penny; and the intensely anthropomorphic thoughts and speeches of Nop & Co.--including a lecture from the disillusioned Nop on the canine world's ""covenant with man."" Still, those ready to be tolerant of rampant sentimentality and pooch lyricism will find sturdy lost-dog melodrama here--along with authentic details on Border Collies and dog-handling.