“Since its discovery in 1977, contagious equine metritis (CEM) has been a source of considerable concern for many countries because of the ease with which it can be spread internationally through carrier stallions or mares,” said Peter Timoney, FRCVS, PhD, Head of the Gluck Equine Research Center at the University of Kentucky. Timoney spoke at the 2001 World Equine Veterinary Association conference in Italy on CEM and importation.

CEM is a venereal disease caused by the bacterium Taylorella equigenitalis that can cause infertility and abortions in mares and infertility in stallions. CEM is not a recognized native disease in the United States.

There are pre-export tests that must be done on stallions and mares before they are shipped into the United States. Once here, the horses must go through even more rigorous screening, including test breeding of stallions.

“In the period from September 1997 to June 2001 alone, a total of 16 imported horses, all warmbloods, were confirmed carriers of T. equigenitalis on post-importation quarantine and testing,” said Timoney. “They comprised 11 stallions and five mares. The majority of the carrier animals originated in Germany (10), with the remaining ones from the Netherlands (3), the Czech Republic (1), France (1), and the United Kingdom (1)