||Texas Among 27 States Testing Horses
for Contagious Equine Metritis (CEM)
Texas is among 27 states
tracing and testing horses that may have been exposed to contagious equine
metritis (CEM), a highly contagious disease that can be transmitted during
breeding or artificial insemination. CEM can cause temporary infertility
of horses. The disease, not known to affect humans, was first detected
in the U.S. in 1978, then again in l979. In both instances, the infection
In mid-December 2008, a CEM-infected quarter horse stallion was detected
in Kentucky during routine testing for international semen shipment. The
USDA and Kentucky animal health authorities quickly initiated an epidemiological
investigation, leading to the testing of more horses. To date, seven infected
stallions have been detected: four in Kentucky, and three in Indiana.
The Indiana stallions had spent part of the 2008 breeding season on the
Kentucky premises where the initial CEM case was detected.
As of January 2, 2009, 78 potentially exposed horses (nine stallions and
69 mares) in 27 states have been identified and located, and placed under
hold order or quarantine by state animal health authorities, pending test
In Texas, veterinarians from the Texas Animal Health Commission (TAHC),
the state regulatory agency for livestock health, have contacted the owners
of 14 mares and a stallion with epidemiological links to the infected
horses. Testing of the 15 horses in Texas will begin the week of January
5. Currently, Texas has no known CEM infection.
As the epidemiological investigation widens, at least 250 additional horses
are being traced in more than 25 states.
Dr. Ellis, Texas’ assistant state veterinarian, stressed that CEM
is spread by infected equine animals during breeding, not by casual contact
or shared boarding facilities. CEM is a venereal disease transmitted by
infected stallions either during natural service or through artificial
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.