New USDA Rule for Horses Imported from CEM-Affected Countries

The USDA's Animal and Plant Health Inspection Service (APHIS) is amending its regulations regarding the importation of horses from countries affected with contagious equine metritis (CEM).

"The additional testing added to our existing import regulations will strengthen protections for horses in the United States," said John R. Clifford, DVM, deputy administrator for APHIS' veterinary services program.

APHIS is taking this action after reviewing probable causes of CEM outbreaks in the United States. This review identified the need to strengthen testing protocol for horses arriving from CEM-affected countries.

CEM 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 can also be transmitted indirectly through artificial insemination or contact with contaminated hands or objects. It can be treated with disinfectants and antibiotics.

To strengthen testing requirements for imported horses, APHIS is requiring additional entry requirements for imported horses of certain ages. For yearlings and weanlings, proof must be given that they have not been bred to other horses either through artificial insemination or through live cover. Imported stallions and test mares (mares bred to the stallion while in quarantine to assure he does not transfer CEM during the breeding process) are now required to undergo an additional CEM test that will help improve the accuracy of final test results. These actions will provide additional safeguards against the introduction of CEM through the importation of affected horses.

This interim rule is published in the March 25 Federal Register and became effective upon publication. Consideration will be given to comments about the interim rule received on or before May 24. If you wish to submit a comment online, go to the Federal eRulemaking portal.

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