Ever since Lassie graced the television screen, the Collie has been a popular dog breed. Collies  are highly intelligent making them easy to train and loved as a family pet. They were originally bred for their herding ability, but have also been used as rescue dogs and guide dogs. The level of intelligence that makes the Collie a great pet also means it's sometimes difficult for the owners to keep up. If you're keeping up with your collie, you're already showing a level of loyalty.