Contagious Equine Metritis

On the 10 th of December Contagious Equine Metritis (CEM) was diagnosed during routine testing of a stallion in Kentucky. Since then, several other stallions have been diagnosed with the disease in Kentucky and Indiana. We expect more horses will be diagnosed with CEM in other states in the following weeks. Clemson University Livestock and Poultry Health regulatory personnel are performing the initial epidemiological investigation of several mares which were artificially inseminated with semen from the infected stallions. Please visit the USDA APHIS web site for more information on the outbreak:

At least 250 additional horses are actively being traced, with owners of those horses located in at least 27 States.  Only 12 States have not been involved in the CEM investigation process to date. All exposed horses are under quarantine and undergoing testing protocols.

Contagious Equine Metritis is a transmissible 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 breeding but also may be transmitted indirectly through artificial insemination or contact with contaminated hands or objects.

There is no evidence that CEM affects people.

CEM-infected horses must be quarantined and treated with disinfectants and antibiotics over a period of several weeks.  Following a course of successful treatment and re-evaluation, the animals may be certified CEM-negative and released from quarantine.