New Genetic Disease found in Quarter HorsesBy Kentucky Equine Research Staff · February 8, 2010

Researchers have identified another in a growing line of genetic diseases affecting Quarter Horses.

According to Dr. Stephanie Valberg and Dr. Jim Mickelson of the Universityof Minnesota, glycogen branching enzyme disease (GBED) is carried on a recessive gene and causes foals to be born dead or extremely weak.

Affected foals rarely survive more than a few weeks due to an inability to build glycogen, the source of energy for many body tissues. It is estimated that 10% of the Quarter Horse population carries the defective gene, and a test has been developed to show which breeding horses are carriers.