<Table> <Tr> <Td> </Td> <Td> This article possibly contains original research . Please improve it by verifying the claims made and adding inline citations . Statements consisting only of original research should be removed . (June 2015) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article possibly contains original research . Please improve it by verifying the claims made and adding inline citations . Statements consisting only of original research should be removed . (June 2015) (Learn how and when to remove this template message) </Td> </Tr> <P> A mongrel, mixed - breed dog or mutt is a dog that does not belong to one officially recognized breed and is not the result of intentional breeding . Estimates place their numbers at 150 million animals worldwide . Although the term "mixed - breed dog" is preferred by some, many mongrels have no known purebred ancestors . Furthermore, crossbreed dogs, while literally a mix of breeds, differ from mongrels in being intentionally bred . Although mongrels have at times been considered somehow lesser than intentionally bred dogs, they are thought to be less susceptible to genetic health problems associated with dog breeding (based on the theory of heterosis), and have enthusiasts and defenders who prefer them to intentionally bred dogs . </P> <P> Although mongrels exhibit great variation, generations of uncontrolled breeding and environmental pressures may tend to shape them toward certain general average body types and characteristics known as landraces, some of which may be developed by people into new breeds such as the Alaskan husky . </P>

What do you call a dog that is a mixture of many breeds