Smaller yet speedier than greyhounds, whippets can sprint up to 35 mph. That, unfortunately, is one of the reasons Vivi, a 3-year-old champion whippet formally known as Ch. Bohem C'est La Vie, has been missing since Feb. 15, the day after winning an Award of Merit at the Westminster Kennel Club Dog Show in New York City. Due to fly home to California in the cargo hold of a Delta flight, she somehow got loose from her crate on the tarmac of New York's 5,000-acre JFK airport. Workers who later spotted her gave chase in their car, and a police officer came within four feet of Vivi before she squirmed through a hole in the airport fence and dashed toward surrounding marshland.

That weekend, with temperatures dropping below freezing, hopes for the 30-lb. whippet's survival also plunged. Undeterred, teams of volunteers have spent the past week searching for Vivi at JFK and in nearby neighborhoods, handing out flyers and baiting humane traps for her. "After two days, I didn't have very much hope at all," confesses Vivi's co-owner Jil Walton, a Barcelona Olympics equestrian who'd bred the dog (worth approximately $25,000) before and planned to again this summer. "But then I thought about my dog outdoors [at home], doing everything, chasing squirrels, running through barbed wire fences. Of all the whippets, she is probably the most equipped to deal with this."

As days went by, the search party grew to include tracking dogs using the scent of Vivi's doggie bed, and several animal psychics "who pretty much agree that she is okay and is hiding in the [heated] cargo terminals," says Vivi's breeder, Bo Bengtson. "There was [also] a radar sighting of a body [Vivi's size] getting across the runway, and [searchers] did find dog stool in an outlying cargo area that was less than 24 hours old. It's not conclusive, but it certainly is a very positive sign."

Walton, 39, who's taken care of Vivi since she was a pup, and describes her as "just my dog—she sleeps in my bed and goes to work with me every day," has offered a $5,000 reward to the person who brings her home safely.

"A lot of people think this is a bunch of silliness about a dog," says Iva Kimmelman, a friend of Vivi's co-owner and handler Paul Lepiane. "But it wasn't her fault that she got out of her crate, and what do we do, leave her there to die?" Kimmelman's real concern, she says, is that "the more days that pass, the more wild she turns. When dogs are in fear, they seem not to recognize human beings as something they need for survival. I guarantee that dog has heard people calling her."