On May 23, 2024, the National Veterinary Services Laboratories in Ames, Iowa, reported confirmation by bacterial culture a positive case of Taylorella equigenitalis, the causative agent of contagious equine metritis (CEM), in an 11-year-old domestic pony mare in Orange County in Florida.

The mare had been bred by live cover on May 10 to a 3-year-old pony stallion. After breeding, the mare had retained free fluid in her uterus and was treated by uterine lavage on May 13. The uterine fluid was collected and sent for routine bacterial culture, which ultimately yielded the confirmed positive results for T. equigenitalis.

The mare and the stallion are both being held under state quarantine in Florida and the stallion has been sampled for testing at NVSL with results pending. 

Traceback and epidemiological investigation is ongoing. USDA-APHIS posts updates, as they become available, under “Confirmed CEM Cases in the United States,” click here.

According to USDA-APHIS web resources, USDA has eradicated CEM from the U.S. equine population after each previous detection. The USDA last reported a confirmed CEM in the U.S., an imported mare, in May, 2013.

Additional resource USDA CEM Factsheet: click here.

Return to the May 29 issue of Wire to Wire