Designing the perfect dog in the DNA age

Designing the perfect dog: Whippets are racing dogs – bred to be sleek and lithe. But every now and then, amidst a litter of perfect whippet puppies, championship breeders get what’s called a “bully whippet.” It looks more like a long-nosed pit bull.

Some of us might find whippets to be good looking, but breeders of championship whippets want to purge the trait from the breed.

Since the dog genome has recently been mapped, scientists are beginning to discover which genes are responsible for many specific traits. In the case of the bully whippets, scientists found that the “double muscling” is caused by a mutation in a gene that enhances muscle development.

Some Labrador breeders are using DNA tests for coat color to guarantee exotic silver-coated retrievers. Mastiff breeders are testing for shaggy fur to keep out the “fluffies,” long-haired puppies that occasionally are born to short-haired parents.

This is a far cry from creating cockapoos or labradoodles – breeding poodles with cocker spaniels or labradors. This is not about mixing, but purifying. On the horizon, says the Times report, could be tests for “big dogs, small dogs, curly-tailed dogs, dogs with the keenest senses of smell and dogs that cock their heads endearingly when they look at you.”

But (surprise, surprise) there are some consequences in dog breeders’ zeal for genetic perfection. Genes are often tied to multiple traits. Deliberate selection of certain ones can result in imperfection elsewhere. The gene responsible for those silver-coated Labradors is tied to skin problems.

And take the whippets. It turns out that the same mutation that pumps up some whippets makes others among the fastest dogs on the track.

New York Times reports: Free of most of the ethical concerns — and practical difficulties — associated with 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.

Hold on for a second. What exactly does this imply? “Free of most of the ethical concerns — and practical difficulties associated with the practice of eugenics in humans…?”

I’d say it means we can guess what’s likely to happen to the puppy that’s been genetically screened and found to have, say, the bully gene.

It ends up in the dog pound, and I adopt it.

Because my dogs will always be mutts. I have nothing against silver-coated labradors or super fast whippets, or brilliant border collies (though I do like to be a little smarter than my dog.) And it isn’t even that I’m especially kind and want to save a dog from death. I like the surprise. I don’t want to design my dog. I like to watch my own dog emerge, watch what sort of animal develops from that particular puppy. The beauty or the oddball, the mellow or the curious. How big? How hairy?