Chagrin Falls, Ohio; September 25, 2008-University of Minnesota Veterinary Researchers identified a gene in Labrador retriever dogs linked to exercise-induced collapse. Labradors that start to lose control of their hind legs after intense hunting, and retrieving exercise may be able to enjoy normal lives now that the underlying cause has been detected. A mutated form of a gene called dynamin1 is responsible for these dogs becoming affected with wobbly hind legs that often just give out and in rare cases the dogs die. This syndrome affects an estimated 3-5 percent of Labradors.
The dynamin 1 protein normally functions to maintain proper chemical communication between adjacent nerves, which is also referred to as synaptic transmission. The mutated form of the dynamin protein has diminished function, which interrupts normal nerve signals during intense exercise, and causes the muscle-controlling nerves to not respond correctly. This is the first naturally occurring mutation of this gene identified in any mammal, according to James Mickelson, Ph.D, at the University of Minnesota Veterinary School. This discovery holds future insight into normal and abnormal neurobiology in both animals and people.
Up to 30 percent of Labrador retrievers carry the mutated gene and a genetic test has been developed to determine which dogs are affected. This test is valuable because it not only helps to confirm the diagnosis, but can also be used to help dog breeders prevent litters from inheriting the mutated gene. Owners can have their dogs tested by asking their veterinarian to submit a blood sample to the University of Minnesota Veterinary Diagnostic Laboratory. Dog Breeds such as Chesapeake Bay and Curly-Coated Retrievers, both closely related to Labradors, also carry the dynamin 1 mutated gene.
Research is ongoing to determine what other breeds might be involved.