University of Minnesota College of Veterinary Medicine research published in the journal Nature Genetics this week identifies the direct association of a gene in Labrador retrievers with the sometimes-fatal, exercise-induced collapse (EIC) syndrome.

After intense hunting or retrieving exercise, Labs carrying the identified mutated gene may lose control of their hind limbs, and in some cases may die.

Labradors are the most-common purebred dog in the U.S. and are especially popular among hunters and sportsmen. An estimated 3 to 5 percent of Labradors are afflicted with EIC, say the researchers.


Information on the syndrome appearing on the University of Minnesota Veterinary Diagnostic Laboratory Web page notes: “EIC is being observed with increasing frequency in young adult Labrador retrievers. Most, but not all affected dogs have been from field-trial breedings. Black, yellow and chocolate Labradors of both sexes are affected, with the distribution of colors and sexes closely reflecting the typical distribution in field trials (black males most common).”

The research team identified a mutant form of the dynamin 1 gene as highly associated with EIC. The dynamin 1 protein normally functions to maintain proper chemical communication between adjacent nerves, also known as synaptic transmission. However, the mutated form of the protein can interrupt synaptic transmission during intense exercise, causing the muscle-controlling nerves to malfunction.

“This is very exciting because it is the first naturally occurring mutation of this gene identified in any mammal,” said James Mickelson, PhD, professor of veterinary sciences at the University of Minnesota and co-principal investigator on the study. “Its discovery could offer insight into normal as well as abnormal neurobiology in both animals and humans.”

Researchers also determined that up to 30 percent of Labrador retrievers are carriers of the mutation, and they developed a genetic test to indicate whether dogs have the normal or mutated forms of the gene.

“The test can not only help confirm the diagnosis, but it can also help dog breeders ensure that no dogs inherit two copies of the mutated gene,” said Edward “Ned” Patterson, D.V.M, Ph.D., assistant professor of veterinary medicine at the University of Minnesota and co-principal investigator of the study.

Lab owners can have their dogs tested through their personal veterinarian by submitting a blood sample to the University of Minnesota Veterinary Diagnostic Laboratory.