CEM Update
The Horse.com reports that the ongoing contagious equine metritis (CEM) investigation in the US has now identified more than 820 exposed or positive horses. (Note the important difference between potentially exposed and positive - the vast majority of exposed horses will end up being negative). The expanse of this investigation is impressive, involving horses in 48 states. The investigation is taking a long time because of the prolonged testing required to determine that exposed horses are indeed negative for the causative pathogen, Taylorella equigenitalis. This testing is also quite expensive, which make this disease a significant burden on the system even when only a few horses are infected.
Not a lot of new information has come to light recently. Hopefully that's a sign that the outbreak has finally been contained. Unfortunately, it's now known that some of the infected horses were positive for quite some time (years), and tracking all potentially exposed and infected animals over such a long period of time can be very difficult. The most recently diagnosed case was a stallion that was infected in 2006, if not earlier. The potential for spread of the disease, therefore, is still concerning, although two months have passed since the last new case was reported. The efforts to test exposed horses, costly and time-consuming as they are, are crucial due to the potentially even more costly consequences if CEM becomes established throughout the US (and therefore, almost inevitably, in Canada).
More information about CEM and the US outbreak can be found on the USDA website.
