From Pugs to Pekes, small dog pictures could melt the hardest heart. But every breed was created for a reason, and pint-sized pooches are no exception. Their job is to keep people company, perhaps the most important work a dog can do.

Some of the dog photos feature miniaturized versions of working dogs, and some were created solely as beautiful lap dogs -- but without exception, they are all dog. The tiniest of them have no idea that they aren't as big or strong as other dogs, and the small dogs in these pictures may have the heart and courage of a Mastiff concealed in their portable bodies.

That's an endearing quality, but it also means they need to be protected from themselves. Often they'll take on bigger dogs or even human intruders and can easily be injured or killed for their trouble.

In size they range from tiny four-pounders to sturdier weights that reach the double digits. As a group, they're housedogs, unsuited to living outdoors. Their main goal in life is to be with their people, and they'll wilt if left to themselves for long hours day after day.