Testing results announced today confirmed that three Northern Indiana stallions are positive for contagious equine metritis (CEM). The stallions were tested as a result of being exposed to a positive Quarter horse stallion while they were kept at a breeding facility in Kentucky.
Alerts have spread to 20 states and Canada as a result of semen from the infected Kentucky stallions being shipped to mare owners for artificial insemination. The Indiana announcement is the first to confirm positive test results for CEM outside of Kentucky and will undoubtedly lead to the investigation of horses they have been with and mares who have been either bred to them or received their semen by AI.
Contagious equine metritis is a transmissible, exotic venereal disease in horses. It usually results in infertility in mares and, on rare occasions, can cause mares to spontaneously abort. Infected stallions exhibit no clinical signs but can carry the CEM bacteria for years. CEM is commonly transmitted during sexual intercourse, but also may be transmitted indirectly through artificial insemination or contact with contaminated hands or objects.
Testing on the remaining horses that were housed at the Kentucky facility continues as an ongoing investigation. Concerned Indiana horse owners should monitor the state animal health website: www.in.gov/boah.
The first cases of CEM in the United States were diagnosed in central Kentucky in 1978. Another outbreak occurred in Missouri in 1979.