Please try to keep recent events in historical perspective and add more content related to non-recent events. You can help by adding to it. Several unofficially recognized crossbreed types date from the 14th century or earlier, such as the lurcher or the longdog. The Encyclopædia Britannica traces the term “designer dog” to the late 20th century, when breeders began to cross purebred poodles with other purebred breeds in order to obtain a dog with the poodles’ hypoallergenic coat, along with various desirable characteristics from other breeds. Like children in a family, a percentage of designer dogs with the same breed ancestry will look similar to each other, even though crossbreeding does not result in as uniform a phenotype as the breeding of purebreds. Often even pups in the same litter will look quite different. Another defining characteristic of designer dogs is that they are usually bred as companions and pets.
Although designer dogs are often selected by owners for their novelty, reputable breeders sometimes use crossbreeding in an attempt to reduce the incidence of certain hereditary problems found in the purebred breeds, while retaining their more appealing traits. Designer dog breeders are often criticised for being more interested in profitable puppy production than in dog health and welfare. Wally Conron comments on the popularity of crosses after his introduction of the Labradoodle: “Were breeders bothering to check their sires and bitches for heredity faults, or were they simply caught up in delivering to hungry customers the next status symbol? The fanciers of designer dogs respond that all modern dog breeds were created from earlier breeds and types of dogs through the same kind of selective breeding that is used to create designer dogs. Health of crossbred dog depends on their being descended from healthy parents. Breeders who select their breeding stock for cost-effectiveness and who skip health testing for the same reason will not produce puppies that are as reliably healthy as those bred by more conscientious breeders. However, studies of longevity in dogs have found some advantage for crossbreeds compared to purebred dogs.