Lori Brannigan of Loudonville, N.Y., has owned a hybrid for 16 years, since she first spotted Tuffy, a shih-poo, in a pet store. (Shih-poo is a cross between a shih tzu and a poodle, not to be confused with a poo-shi, the hybrid of a poodle and a Japanese breed called the shiba inu.)

The club now registers 500 new hybrid litters every month, [Garry Garner] says; to date, it has registered 8,500 labradoodles, 7,000 puggles (pug plus beagle) and about as many goldendoodles (golden retriever plus poodle). The hybrid club tracks more than 200 crossbreeds, with more added weekly. It sets no standards, and allows breeders to choose what to call new hybrid mixes.

Wallace Havens, who owns Puppy Haven Kennels in Kingston, Wis., now produces 30 kinds of hybrids, including the kimola (American Eskimo plus Lhasa apso), poo-tzo (miniature poodle plus shih tzu) and yorkie-poo (miniature poodle plus Yorkshire terrier), as well as labradoodles, bashar/sharp asset and puggle.