Not always that simple. I have a giant doberman. I no-shit threw a frisbee for this doberman 72 times yesterday (and ran with her three miles). She gets more exercise than the sheltie I had as a kid that ran leash-free in the country. And if you dare leave her in the backyard her whine could emit high-pitch frequencies that shake glass. She's a city dog that would be lost in the country without a human to hang with.