You can adopt Shetland Sheepdogs of any age, colloquially known as Shelties, through a rescue organization or shelter. Sheltie Nation lists rescue groups throughout North America and parts of the United Kingdom, while AdoptAPet.com allows people to search for available dogs online.
Shelties are bred to herd sheep; in the absence of sheep, some Shelties may herd humans, while others find their instincts satisfied by seeing everyone together at the same time. They are athletic and intelligent dogs that require medium levels of exercise and mental stimulation to stave off boredom.
A litter of Shelties often produces puppies of varying size. Because of this, people interested in a smaller dog should consult an ethical breeder on selecting a dog that is the right size and weight for their homes. The description "miniature Sheltie" is used more often out of ignorance from backyard breeders who are uninformed about Shetland Sheepdogs, but some breeders also mix Shelties with toy breeds to produce non-purebred dogs or breed runts together to create smaller and more desirable designer puppies. These miniature Shelties often have shorter life spans and more health problems than their healthier full-sized counterparts. Puppy mills are known for breeding dogs without regard to the health of the mothers or litters, and usually supply pet stores.