Perils in Push to Perfect Canine Gene Pool

Free of the ethical concerns — and practical difficulties — that impede the practice of eugenics in humans, dog breeders are seizing on new genetic research to exert dominion over the canine gene pool. Companies with names like Vetgen and Healthgene have begun offering dozens of DNA tests to tailor the way dogs look, improve their health, and, perhaps soon, enhance their athletic performance.

But as dog breeders apply scientific precision to their age-old art, they find that the quest for genetic perfection comes with unforeseen consequences. And with DNA tests on their way for humans, the lessons of intervening in the nature of dogs may ultimately bear as much on us as on our best friends.