Wisconsin animal health officials have reported two cases of contagious equine metritis (CEM) in Mount Horeb to the Office International des Epizooties (OIE, or World Organization for Animal Health). A ProMED-mail post announced the disease occurrence this week.

Taylorella equigenitalis is a Gram-negative bacterium that’s responsible for CEM, which causes infertility and abortions in mares and infertility in stallions. Contagious equine metritis is considered a foreign animal disease in the United States, but it has afflicted horses here via imported stallions and semen.

“The affected animals are two Lipizzaner stallions imported into the United States of American from Eastern Europe,” the Oct. 16 OIE report said. “The 2 stallions have been continuously maintained at an equine breeding and research facility in Dane County where they recently tested positive for Taylorella equigenitalis during a breeding soundness test” on Oct. 4.

The diagnosis was confirmed using pathogen isolation on cell culture at the USDA’s National Veterinary Services Laboratory