Ah, I see where you're coming from. When I read it, I immediately assumed they meant it in a "survival of the fittest" context as in the dog was just faster than the others so he'd get away from danger. I didn't notice the guy's race until you pointed it out.
Don't assume people are being racist just because you see it in that context. That just perpetuates the problem. It's like the boy who cried wolf. If you start accusing everyone as racist who say or do something that could be implied as racist and their intent wasn't actually racist, your accusations start to lose their value when actual racists are being racist.
P.S. I'm not calling you out because many other's seem to share your same viewpoint (hence all the downvotes).