Contagious Equine Metritis

Contagious Equine Metritis (CEM) is a non-systemic, venereal disease of equines that causes short-term infertility in mares and rare abortion.

The etiological agent is Taylorella equigenitalis, a fastidious, microaerophilic, Gram-negative coccobacillus. CEM was first recognized in the U.S. when it was found in Thoroughbred stallions and mares in Kentucky in 1978.

Venereal transmission of T. equigenitalis by live cover and by AI with fresh cool-transported semen in extender containing antibiotics or frozen semen has been documented. Stallion-to-stallion transmission can occur through contaminated fomites at semen collection facilities or veterinary clinics. Uncommonly, transmission can occur from mare to foal either in utero or post-parturition.