Show and Pet Collies
Certain types of Collie (for example Rough Collies, Smooth Collies, Shetland Sheepdogs and some strains of Border Collie and other breeds) have been bred as pet and show dogs for many generations. These types have proven to be highly trainable, gentle, loyal, and well suited as pets. Their gentleness and devotion also make them quite compatible with children. They are often more suitable as companions than as watch dogs, though the individual personalities of these dogs vary. Famously, the temperament and intelligence of the Rough Collie was exaggerated to mythic proportions in the character Lassie which has been the subject of many films, books, and television shows from 1938 to the present.
Working Collies
Working collies are extremely energetic and agile dogs with great stamina, able to run all day without tiring, even over very rough or steep ground. They are intelligent and are instinctively highly motivated to work. These characteristics generally make the working types unsuitable as pets as few owners are able to give them the mental and physical challenges they need. If not well-fulfilled, they may become unhappy and badly behaved. However, in addition to herding work they are well suited to active sports such as sheepdog trials, flyball, dog disc, and dog agility. Working collies have strong herding instincts and some dogs can be single-minded to the point of obsessiveness. They are often intensely loyal.