Mixed Breed

The mixed-breed dog, sometimes called a mutt, is the result of generations of spontaneous crossbreeding between different breeds and represents the vast majority of dogs in shelters and on the streets worldwide. There's no fixed standard of appearance: size, ear shape, coat color, and body proportions vary enormously from one individual to the next.

Because they don't come from heavily selected genetic lines, mixed-breed dogs often display so-called "hybrid vigor," with a lower incidence of the specific hereditary diseases that affect highly inbred purebreds — though that doesn't mean immunity to health problems, which still depend on good nutrition, vaccination, and regular veterinary care.

Temperament is equally variable, since it depends on both individual genetics and each dog's life history — animals rescued from the street tend to be more independent and cautious at first, while those socialized from puppyhood are often just as affectionate and sociable as any purebred. Adopting a mixed-breed dog from a shelter or rescue organization is a responsible way to bring a dog into your life, and it directly helps reduce the number of abandoned animals.