Horse Health Alert: Mare in California Tests Positive for Contagious Equine Metritis


The State of California has issued a press release after the discovery that a mare has tested positive for Contagious Equine Metritis (CEM) in that state. CEM is a highly contagious venereal disease that affects horses but is not transmissable to humans. Owners of mares, whether they are bred or not, should be aware of this disease, particularly if they don’t know much about the mare’s history.

SACRAMENTO, February 12, 2013 – A 17-year-old Lusitano mare from California has been confirmed positive by the National Veterinary Services Laboratory (NVSL) for Taylorella equigenitalis, the bacterium that causes Contagious Equine Metritis (CEM).

CEM is a contagious bacterial infection spread between mares and stallions during live breeding or artificial insemination with infected semen. It can also be transmitted on contaminated breeding equipment.

CEM is not known to infect other livestock or humans. Stallions infected with CEM do not exhibit any clinical symptoms, but infection in the mare can cause fertility problems.

“Our goal is to isolate this disease and limit its spread as much as possible by quarantining and treating the infected mare and any other affected animals,” said California State Veterinarian Dr. Annette Jones. “We have had success in the past in tracking and eradicating this disease and we are confident in the measures we are taking to protect our horse population. Peak breeding season is getting underway, so we encourage horse owners to work with their veterinarians if they have any questions or concerns.”

The positive mare was presented to a private practitioner for infertility concerns and samples were submitted for culture. The mare remains under quarantine while being treated for the disease with antibiotics. The epidemiologic investigation of the positive mare is currently in progress. Information collected to date indicates that her breeding activities were limited, and no horses located outside of California are currently known to have been exposed.

CEM is considered a foreign animal disease in the United States. The disease was previously detected in California in 2009 and 2010 and quickly eradicated. There is no known relationship between the positive mare and any horses associated with previous U.S. cases of CEM. Further, testing at the NVSL confirms that this isolate does not match those of any other isolates from previous CEM detections in the United States and do not match any isolates ever found on post-entry CEM quarantine testing of horses entering the United States from CEM-affected countries.

More about CEM:

Arabian Stallion in Arizona Tests Positive for Contagious Equine Metritis; State to Trace Mares He Bred
USDA Announces Interim Rule Regarding the Importation of Horses from Contagious Equine Metritis – Affected Countries
Second Wisconsin Stallion Tests Positive for Contagious Equine Metritis; 42 States Now Affected
Nine Horses in New York Potentially Exposed to Contagious Equine Metritis
Friesian Stallion in Wisconsin Tests Positive for CEM
Contagious Equine Metritis: The List of Exposed Horses Grows and Grows
Horse Health Emergency in Kentucky: “Bring in the Feds!” State Officials Say, As Labs ID Two More CEM-Infected Stallions
USDA Ease on Quarantine is Music to the Ears of Dancing Stallions (Spanish Riding School)
Health Concerns Force Force Cancellation of 2008 USA Tour of the Spanish Riding School of Vienna
Good News from Vienna: Spanish Riding School Stables Are Open Again
When Bad Things Happen to Nice Horses: Equine Venereal Disease at Austria’s Spanish Riding School




Related Posts

Gray horse head in profile on EQ Extra 89 cover
What we’ve learned about PPID
Do right by your retired horse
Tame your horse’s anxiety
COVER EQ_EXTRA-VOL86 Winter Care_fnl_Page_1
Get ready for winter!


"*" indicates required fields


Additional Offers

Additional Offers
This field is for validation purposes and should be left unchanged.