Glossary

Mixed breed

A dog whose parents are of different breeds or whose ancestry is unknown, often called a mutt.

Also called: mutt, mongrel, crossbreed, cross-breed, mixed-breed dog, random-bred dog

A mixed-breed dog, also called a mutt or mongrel, has ancestors from more than one breed, or its parentage is simply not known. Most shelter dogs and many family dogs fall in this group. Because the genes come from several sources, size, coat and temperament can be hard to predict, especially in a puppy.

Looks are an unreliable guide to ancestry. Studies of shelter staff guessing breeds by eye show frequent disagreement with the results of a Dog DNA test, so a breed label on a kennel card is only a guess. A DNA panel can estimate the breeds involved, though the estimate depends on the company's reference database.

Mixed breeds are not automatically healthier than purebreds. They can carry inherited conditions found in their ancestry, and the broader gene pool only helps in some cases. Many sports and registries, including the American Kennel Club through its Canine Partners program, welcome mixed-breed dogs in events.

Last reviewed November 8, 2026

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Related terms

Purebred A dog whose parents and ancestors belong to one recognised breed and are recorded in a registry, so its ancestry can be traced on paper. Designer breed A dog deliberately bred from two chosen breeds, often with a catchy name such as Labradoodle or Cockapoo, that is not a recognised breed itself. Dog DNA test A cheek-swab or blood test that analyses a dog's genes to estimate its breed mix, check for inherited disease variants or identify certain traits. Genetic diversity The variety of genes within a breed or population; closed stud books and heavy use of a few popular sires reduce it and make inherited conditions more common.