Contagious equine metritis in the USA.

This research article documents the first outbreak of contagious equine metritis, a reproductive disease in horses, in the United States. The disease was traced back to stallions imported from France and spread to multiple farms via handlers and contaminated environments.

Background

• The report outlines an outbreak of contagious equine metritis (CEM) in Kentucky. This was the first time the disease had been identified in the United States.
• CEM is a highly contagious disease that affects the reproductive system of horses. It is transmitted primarily through mating, but can also be spread indirectly through contaminated equipment and people who handle the animals.

Outbreak Timeline and Discovery

• The initial case was reported in February 1978. A mare that had been bred with a stallion imported from France displayed clinical signs of CEM eight days after mating.
• Shortly after, other mares that had been covered by the same stallion also became infected.
• By March, two additional mares that had been bred to two other stallions from France showed signs of the disease. It was discovered that all these stallions were on the same farm, suggesting the disease was being spread in the breeding shed.

Propagation Factors and Response Measures

• The investigators found that stallion handlers and contaminated floors in the washing area of the breeding shed were significantly contributing to the spread of the disease.
• The wet, contaminated floors apparently provided the perfect conditions for the transfer of the CEM organism from one stallion to another.
• As more mares showed signs of CEM, all having been bred at the two stud farms where the original French stallions were, a two-week halt on breeding was established by the State of Kentucky. All sick mares and suspect stallions were cultured for the disease during this period.

Conclusions and Implications

• The study illustrates the speed at which CEM can spread in a horse population and underscores the importance of biosecurity measures in preventing disease transmission.
• This report suggests that improved sanitation procedures in breeding areas as well as the thorough cleaning and disinfecting of tools and equipment can help mitigate the spread of the disease.
• The findings have significant implications for import regulations and the need for better health screening of imported animals to prevent disease outbreaks.