Is there a genetic link to being an extremely nice boy?
Flash is not your average puppy. Yellow Labrador, named after one of the first British guide dogs of 1931, she is playful, affectionate and loves to learn new commands. Flash herself is enrolled in an elaborate program, a program that takes two years and nearly $ 50,000 to train her to become a guide dog for the blind and visually impaired. Her temporary caregiver, Mélanie, will make sure she maintains a healthy routine: walking twice a day in different environments, a train ride here, a trip to a mall there to get used to others. But Melanie has already accomplished one of her most important tasks: When Flash was five months old, she dabbed the puppy’s cheek and sent the saliva to a team of researchers trying to decipher the link between genetics, health and dog behavior.
About half of dogs bred for guiding don’t end up doing this job due to health or behavioral issues. Modern dogs suffer from many genetic diseases, a side effect of separating breeds and selecting them for desirable traits. Some of these purebred dogs might have the right look, but not the right temperament, to become a working dog. But what if breeders could predict what makes a good guide dog and select unwanted traits, making sure they don’t get passed on to the next generation?
Over 500 traits analogous to human genetic conditions have been described in dogs – both species can suffer from cancer, eye disease, or hip dysplasia, to name a few. Cheap DNA tests for dogs can detect changes, called mutations, in a single gene. The causes of many other conditions, however, are more complex. They can be linked to multiple genes or to environmental factors like exercise, food, dust, or mold spores. “We really want to master complex traits,” says Tom Lewis, head of dog genetics at Guide Dogs. The association breeds around 1,000 puppies per year, who spend their first year with volunteers before undergoing formal training.
Prior to joining Guide Dogs in January, Lewis worked for the Animal Health Trust and the Kennel Club in the UK, where he studied the genetic risk of hip dysplasia in breeds registered with the club. Dysplasia is one of the inherited conditions that can be difficult to diagnose and treat. It is a malformation of the hip joint that develops during growth, although traumatic injury, being overweight, or lacking muscle strength can make the condition worse. For example, puppies raised in homes with hardwood floors may develop less muscle mass in their legs – they cannot have traction on the floor and glide and slide, which is hard on their small joints. The constant pain can eventually develop into lameness and arthritis in adult dogs, rendering them unfit to guide or help people with disabilities.
Good health is essential for guide dogs, but temperament is just as important. They should guide their owners around obstacles and other people while remaining calm and obedient. They should resist chasing squirrels or getting too excited when they encounter other dogs. Not all races have what it takes. For example, the typical cocker spaniel is smart, affectionate, and a great option for families, but he’s also overly excitable. “Even if you give them the same training, you would never expect a spaniel to be a guide dog. They’re far too temperamental misfit, and that’s probably a genetic thing, ”says Lewis.