Little Dog Syndrome & Other DNA Stories


Our best friend’s DNA is probably the second most studied on the planet (next to human DNA, of course.)  Nearly every month, another doggie DNA breakthrough is announced somewhere in the world.  Recently, the cause of Little Dog Syndrome was determined by the National Human Genome Research Institute.  

    Yes, human DNA researchers are also studying canine DNA.  Why are these scientists trying on a dog’s genes for size?  According to Chief Scientist Dr. Elaine Ostrander, the selective breeding of dogs allows “us to more readily analyze the genetic causes of particular traits than is possible in humans.”

    The initial study of Little Dog Syndrome was conducted on Portuguese Water Dogs because this breed has a lot of variation in their height.  In this study, the scientists were trying to pinpoint what makes some dogs tall and others short.   After locating the ‘little dog’ gene, a follow-up analysis was conducted on over 3000 dogs representing 143 breeds. Discovery of the canine height gene (called IGF-1) may have implications for humans and animals since a similar gene is found in many species. However, identification of the height gene doesn’t mean that you’ll be looking eye-to-eye with a giant Chihuahua any time soon—little dogs are bound to stay little for some time.

    Another DNA tale involves a company that has announced a ‘major breakthrough with great potential.’ The company, XY, Inc. boasts the ability to select for male or female puppies.  Unfortunately, this breakthrough isn’t ready for mainstream use—partially because it is costly and difficult.

    The sex-selecting technology used by XY, Inc. was tested on a black Labrador who had a litter of 5 puppies—3 female and 2 male.  The company sees this as a 60% success rate for gender selection (they were selecting for female puppies).  Now, I’m no statistician, but it seems to me that the odds of a female puppy without this new fangled technology is right at 50%.  Is a 60% female:male ratio a major breakthrough that is worth the cost?  I suppose that’s up to you to decide.

    Finally, genetic testing is now available to determine the breeds that make up your mutt. That’s right, by swabbing the cheek of your beloved mixed breed dog and sending off to the laboratory, you can learn if your dog is a Husky/Beagle cross or just looks like one.

    This testing costs $65 + s/h and takes about 6 weeks to get results.  The company will ship a test kit to you and mail you a “frame quality” Certificate of DNA Breed Analysis that displays the breeds in your dog.  Genetic markers for thirty-eight dog breeds are compared to your dog’s DNA to determine your mutt’s background.  Your dog’s ancestry probably doesn’t make a difference to him, but the certificate sure sounds cool. Every dog deserves its own diploma.

    Though this may seem like a ‘Brave New World,’ genetic research in dogs is not new--for thousands of years, humankind has been ‘customizing’ dogs for temperament and physical traits through selective breeding programs.  DNA research simply promises to speed up a process that is already centuries old.


Editor's Note: Have you tried the breed analysis test? Did it confirm your suspicions about your dog's breed/mix or did it further confound you? We'd be interested to hear your experience.