Animal Cruelty?

Check out this article at slate that discusses what we have done to dogs by breeding them as we do.

The reason [dogs are] useful for genetic research is that dogs are neatly divided into breeds, each of which is plagued by specific diseases. And the reason dogs are divided into diseased breeds is that we made them that way. Dogs are the world's longest self-serving, ecologically reckless genetic experiment, perpetrated by the world's first genetically engineering species: us.
...[this led to] epilepsy for springer spaniels, diabetes for Samoyeds, bone cancer for Rottweilers.

Here is the link.