MEMORANDUM

To:       AHC Member Organizations

From:   American Horse Council

Date:    February 25, 2009

Re:       Contagious Equine Metritis Outbreak – Overview and Update

In December 2008, the Kentucky Department of Agriculture announced that a Quarter Horse stallion tested positive for Contagious Equine Metritis (CEM) during routine testing for international semen shipment. 

Since this discovery a full epidemiological investigation has been underway to locate, test and quarantine any potentially exposed horses.  Currently a total of 11 stallions have been confirmed positive for CEM, four located in Kentucky, three in Indiana, three in Wisconsin and one in Texas.  The Indiana and Texas stallions spent time on the central Kentucky premises during the 2008 breeding season. The Wisconsin stallions were not in Kentucky, but all were co-located during at least one breeding season in Wisconsin with one of the CEM-positive stallions that was on the Kentucky premises in 2008.

Additionally three mares have been confirmed positive, one in California, one in Illinois and one in Wisconsin.  The positive Wisconsin mare was bred by live cover to one of the CEM-positive stallions in Wisconsin, just prior to it becoming known that the stallion had been exposed to CEM.  The positive mares in Illinois and California were each bred by artificial insemination with semen from a positive stallion, but not from the same stallion.

In addition to the 11 positive stallions and 3 positive mares, the locations of 600 CEM-exposed horses have also been confirmed. The total of 614 horses includes 84 stallions and 530 mares located in 45 States. The 84 positive or exposed stallions are located in 16 States, and the 530 positive or exposed mares are in 44 States. There are nine CEM-exposed horse still actively being traced, eight mares and one stallion.

All of the horses that have tested positive for CEM and all exposed horses that have been located are currently under quarantine or are on a hold order.  Testing of all associated horses is underway, as well as treatment of those found to be CEM positive.  None of the positive horses have yet been identified as the source of the CEM outbreak; the epidemiologic investigation continues to pursue all available information relative to determining the origin of this outbreak, but no conclusions can yet be drawn.

The United States Department of Agriculture continues to fund the testing directly associated with this disease investigation.  USDA is funding the diagnostic tests and sample shipping costs for the testing of any exposed horses directly linked to the investigation.  An exposed horse is one that was bred to a CEM-positive horse, either naturally or via artificial insemination, or one that is otherwise epidemiologically linked to a CEM-positive horse, as determined by State and Federal animal health officials.

What is CEM?

Contagious Equine Metritis is a transmissible, exotic venereal disease in horses caused by a bacteria Taylorella equigenitalis. A CEM infection usually results in infertility in mares and, on rare occasions, can cause mares to spontaneously abort.  Infected stallions exhibit no clinical signs.   Stallions and mares can become chronic carriers of CEM and be sources of infection for future outbreaks. The transmission rate is high and naturally occurs by mating, but contaminated instruments and equipment may be an indirect source of infecting horses. The bacteria can also be spread via semen collected for artificial insemination.

 CEM can be treated with disinfectants and antibiotics.  CEM-positive mares, and mares from CEM-positive countries, are required to go through a treatment protocol and remain in quarantine for no less than 21 days.  Stallions that have CEM or come from a CEM-positive country are required to remain quarantined until a treatment protocol is completed and they test negative for the disease.

Canadian Restrictions

Because of this CEM outbreak, Canada has imposed additional restrictions on horse imports from the U.S. into Canada.  Additional certification for horses (including Canadian horses returning to Canada but excluding horses for immediate slaughter) will be required on all U.S. export health certificates issued after January 19, 2009 and for Canadian horses exported to the U.S. after January 19, 2009 and returning on a Canadian health certificate.  The new certification statements are reflected in point 4 and 5 of the protocol. At the present moment, the import permit for the U.S. origin horses is not required, except for the horses from Florida where it is still required because of the recent Equine Piroplasmosis situation.

Points 4 and 5 of the protocol read as follows:

4. The horse(s) have not been on premises where T. equigenitalis has been isolated during the 60 days immediately preceding exportation to Canada or a premises currently under quarantine or investigation for CEM. Any female(s) in the shipment have not been bred naturally to, or inseminated with, semen from a stallion positive for CEM, or a stallion resident upon a positive premises or under quarantine or investigation for CEM  

5.  Showed no clinical signs of CEM on the day of inspection.

Additionally, for Canadian horses returning to Canada on a Canadian health certificate, a supplemental certification document with the above mentioned requirements will be provided by the CFIA endorsing office when advised of intended return. The supplemental certification will need to be attached to the Canadian health certificate after completion and endorsed by USDA before return of the horse(s) to Canada.

The health certificate for equine semen that is exported from the U.S. to Canada now includes the required certification that:

1.      The donor horse(s) have not been on a premises where T. equigenitalis has been isolated during the 60 days immediately preceding collection of the semen for export to Canada or a premises currently under quarantine or investigation for CEM.

2.      The semen was processed using an extender that contains antibiotics effective against T. equigenitalis.

The health certificate for equine embryos that are exported from the U.S. to Canada now contains the following statement certifying that:

1.      The donor mare(s) have not been on a premises where T. equigenitalis has been isolated during the 60 days immediately preceding the collection of the embryo(s) for export to Canada or a premises currently under quarantine or investigation for CEM and have not been bred naturally or inseminated with semen from a stallion positive for CEM, or a stallion resident upon a positive premises or under quarantine or investigation for CEM. 

2.      The flushing medium used to collect the embryo(s) contains antibiotics effective against T. equigenitalis.

The Canadian requirements can be found on the following website:

http://www.aphis.usda.gov/regulations/vs/iregs/animals/animal_canada2.shtml

The American Horse Council will continue to monitor this outbreak closely as the investigation continues.  We will continue to remain in close contact with USDA regarding the implementation of the investigation, the procedures supplied to the states involved, the funding of the outbreak investigation and control, and any additional foreign export restrictions or requirements.  

Please contact us with any questions.

1616 H Street NW 7th Floor   .  Washington DC 20006  .  202-296-4031  .  Fax 202-296-1970

Email: AHC@horsecouncil.org  .  Web Address: www.horsecouncil.org

Equine Piroplasmosis Eradicated From Florida, Canadian Restrictions Lifted

The Florida Agriculture and Consumer Services Commissioner Charles H. Bronson announced that the last premises that was determined to have horses infected with Equine Piroplasmosis (EP) has now been released from quarantine, concluding the disease outbreak investigation.    

The disease investigation began in August 2008 when a horse was diagnosed with EP, a blood-borne parasitic disease of horses that is primarily transmitted by ticks or contaminated needles.  EP is a foreign animal disease that the U.S. has been free of since the 1980s, until this outbreak.

During the disease investigation, 25 premises were quarantined and 201 horses were tested for the disease.  Out of the 201 tested horses, a total of 20 horses on 7 premises tested positive for EP, although the majority of the horses did not show any symptoms.  Currently no horses testing positive for the disease remain in Florida. 

All premises have now been released from quarantine, having met the requirements that all horses must test negative for EP, no exotic ticks are found on the premises, and no domestic ticks determined to be infected with the EP organism are found.  Despite extensive tick surveillance, no ticks that carried the disease were found, concluding that the disease was spread due to management practices through contaminated needles or blood transfusion rather than natural transmission via ticks.

Now that the last quarantine has been released, Florida and the U.S. are considered free of the EP disease. 

Since being notified of the conclusion of this disease investigation, Canada has released all additional export requirements related to EP for horses from Florida, which were the only increased export requirements in place because of this EP outbreak.