A species (scientific name 'Canis familiaris') that is a specialization of canine (q.v.). Each instance of dog is a canine animal that has either been bred to be a domestic pet (see domesticated animal) or is a wild canine animal that is not an instance of wolf, fox, or any other non-dog specialization of canine. Note that although dog and wolf are considered distinct species, instances of the two can and do interbreed successfully. This species classification is therefore unusual, and in some circles, controversial.