Contagious Equine Metritis (CEM) is a venereal disease of horses caused by a bacterium called Taylorella equigenitalis. CEM may be spread through natural breeding, artificial insemination, and contaminated equipment. Mares infected with CEM may show mild or more severe degrees of uterine inflammation and vulvar discharge. Abortion and permanent infertility can occur. Stallions and mares infected with CEM may not show symptoms, but can carry and spread the disease for years. Infected horses can be successfully treated with antibiotics and disinfectants.
CEM is considered a foreign animal disease, not endemic in the United States. If a horse in Minnesota is infected or exposed to the disease, the Board will place the horse under quarantine. Testing and treatment protocols must then be completed before quarantines can be released.