Kentucky Breeding Regulations Amended

As was stated Feb. 4 in a news story on this web site, the Kentucky Department of Agriculture filed emergency regulations regarding testing procedures for contagious equine metritis (CEM) to be followed when breeding an imported mare in the state. These regulations require an extra pre-breeding swab of the endometrium, and will allow a stallion covering an imported mare to be treated and returned to service rather than waiting the previous 12-hour mandatory rest period. Other news sources have confused this issue slightly, so farm managers and veterinarians are encouraged to check the state’s official web site at for complete regulations and day-by-day requirements for breeding imported mares and treating stallions. This web site is being updated to reflect the new emergency regulation changes.

The regulations are to protect Kentucky’s Thoroughbred industry from CEM, a venereal disease that struck the state in 1978 and caused tremendous financial losses to some farms. Stallions can harbor the causative gram-negative coccobacillus Taylorella equigenitalis without showing clinical signs of disease. A mare can harbor the bacterium in her reproductive tract. It can cause endometritis characterized by a profuse, mucopurulent vulvar discharge. However, some mares show little or no sign of disease, but can still experience a period of temporary infertility due to infection with Taylorella equigenitalis. Mares rarely abort, but foals can be infected at birth and remain so until of breeding age.

The Kentucky Department of Agriculture’s web site also contains a list of 200 mares imported to Kentucky from CEM-affected countries since June 1, 2001. This list is continuously updated, including mares released from quarantine as of Feb. 4, 2002.

Questions about CEM and the new regulations can be directed to your veterinarian or to the Kentucky State Veterinarian’s office in Frankfort, Ky., at 502/564-3956. For more on CEM, see Article Quick Find #460 and #3191 at

About the Author

Kimberly S. Brown

Kimberly S. Brown was the Publisher/Editor of The Horse: Your Guide To Equine Health Care from June 2008 to March 2010, and she served in various positions at Blood-Horse Publications since 1980.

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