While both Border Collie and German Shepherd are highly intelligent, energetic and have excellent work ethics, there are three key differences that make German Shepherd more suitable police dogs than Border Collie. 1. German Shepherds are much larger. German Shepherds weigh between 65 to 85 pounds, while Border Collies weigh 27 to 55 - even a skinny German Shepherd weigh more than the heaviest Border Collie. Law enforcement duties often time require not only intelligence and energy, but often physical strength as well. Border Collie is ranked No. 1 in intelligence while German Shepherd is ranked No. 3, but German Shepherds are more strongly-built than Border Collies. 3. Border Collies are friendlier - and shyer as well - than German Shepherds. Border Collies can be very friendly around their owners, but shy when around strangers, which makes this dog breed not as suitable to be police dogs as German Shepherds. When trained properly, German Shepherds can be friendly too, but they are overall more territorial than Border Collies. 3. Border Collies' high intelligence and high energy means that they can get bored easily. With proper training, both dog breeds can be excellent family dogs, but they are NOT suitable for first-time dog owners or people with less active lifestyles. 😃