A wolfdog is a canid hybrid

Canid hybrid

Canid hybrids are the result of interbreeding between different species of the canine family -Genetic considerations:Members of the dog genus Canis: wolves, dogs , coyotes, and golden jackals cannot interbreed with members of the wider dog family: the Canidae, such as South American canids, foxes,...

 resulting from the mating

Mating

In biology, mating is the pairing of opposite-sex or hermaphroditic organisms for copulation. In social animals, it also includes the raising of their offspring. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization...

 of a wolf

Gray Wolf

The gray wolf , also known as the wolf, is the largest extant wild member of the Canidae family...

 (various Canis lupus subspecies) and a dog

Dog

The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...

 (Canis lupus familiaris). The term "wolfdog" is preferred by most of the animals' proponents and breeders because the domestic dog recently was taxonomically recategorized as a subspecies

Subspecies

Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 of wolf. The American Veterinary Medical Association

American Veterinary Medical Association

The American Veterinary Medical Association , founded in 1863, is a not-for-profit association representing more than 81,500 U.S. veterinarians working in private and corporate practice, government, industry, academia, and uniformed services....

 and the United States Department of Agriculture

United States Department of Agriculture

The United States Department of Agriculture is the United States federal executive department responsible for developing and executing U.S. federal government policy on farming, agriculture, and food...

 refer to the animals as wolf–dog hybrids. Rescue organizations consider any dog with wolf heritage within the last five generations to be a wolfdog, including some established wolfdog breeds.

In 1998, the USDA estimated an approximate population of 300,000 wolfdogs in the United States (the highest of any country world-wide), with some other sources giving a population possibly as high as 500,000.
In first generation hybrids, gray wolves

Gray Wolf

The gray wolf , also known as the wolf, is the largest extant wild member of the Canidae family...

 are most often crossed with wolf-like dogs (such as German Shepherds, Siberian Huskies

Siberian Husky

The Siberian Husky is a medium-size, dense-coat working dog breed that originated in north-eastern Siberia. The breed belongs to the Spitz genetic family...

, and Alaskan Malamute

Alaskan Malamute

The Alaskan Malamute is a generally large breed of domestic dog originally bred for use as a utilitarian dog and later an Alaskan sled dog. They are sometimes mistaken for a Siberian Husky, but in fact are quite different in many ways...

s) for an appearance most appealing to owners desiring to own an exotic pet

Exotic pet

An exotic pet is a rare or unusual animal pet, or an animal kept as a pet which is not commonly thought of as a pet.The definition is an evolving one; some rodents, reptiles, and amphibians have become firmly enough established in the world of animal fancy to no longer be considered exotic...

.