The first hardcover Conant mystery, custom-groomed for dog people, whose devotion to the canine goes beyond that of mere dog lovers--dog people are those ``who can discuss impacted anal sacs [at a party] without gagging on their Brie.'' The sleuth here is Holly Winter, in a mystery plot one shouldn't worry too much about. It concerns the disappearance of Dr. Oscar Patterson, DVM, who had recommended vet Lee Miner to Holly's vet/inamorato Steve Delaney as a partner in his clinic. It was Dr. Miner (a cold dish of Iams) who'd heard a row between Dr. Paterson and an owner whose dog had just died in the small hours. Is Oscar dead? And where is Jackie Miner, Lee's wife? Featured here is a rare breed, the Chinook, related to the malamute, Holly's chosen breed. The mystery itself wobbles here and there, but the Cambridge, Mass., setting is fun (Harvard at Christmas with super-pipes ``with a range of three notes'' and Morris dances), and the dog talk for the hard-core dog crowd is fine. Come. Sit. Stay.