Grit Blogs > Arrows and Minnows

CEM Infects U.S. Horses

By Caleb Regan, Managing Editor

Tags: livestock, farm, ranch, horses,

I was a little disheartened Thursday when I learned that Contagious Equine Metritis (CEM) has made its way into the United States and has infected several horses at one farm out East. This is especially surprising because the United States was declared to be CEM free as late as 1998.

American Quarter Horse stallion

Growing up, my family had six horses – one for each member of the family and an old Shetland pony we rode as young boys. We even traded a colt from our best Missouri Fox Trotter for my older brother’s first truck.

Horses were a big part of our family when and where I grew up. Evenings were often spent riding through an area my dad called “the motherland,” in search of deer and other wildlife and always culminating with watching the sun set from the same ridge we’d been to a hundred times before.

Once it was dark, we turned the horses back, and ran them fairly hard back through the motherland towards home, them knowing they were headed for oats and water. I unsaddled many more horses in the dark than during the day, I know that for sure.

For my three brothers and I, horses played a prominent role in our entertainment on the farm, our bond with each other and our bond with our parents.

We had very good luck with horse health, and it seemed our friends did too. No one really had to be concerned with diseases like CEM. reports that CEM, a highly contagious venereal infection, causes short-term infertility in broodmares. Foals born to infected mares can also become infected while in the uterus. The danger, to me, seems to be the ease with which the infection can spread, either through natural breeding or by artificial insemination. Since there are no visible or behavioral symptoms, the likelihood of a widespread outbreak is even higher.

Stallions, too, can become carriers of the infection, and harbor the organism (Taylorella equigenitalis) externally on genitals and can spread CEM to mares and farm equipment. It can also be spread by farm hands, handlers, breeders or grooms who don’t maintain proper hygiene while handling horses.

The scary thing, for people like myself (though I don’t currently own horses), is that this infection surfaced at a prestigious farm, and mares bred at this farm now may have been sent back to their home farms and further spread the infection. At that point, CEM would seem to me to become very difficult to track. The surfacing of the infection could also affect equine transport.

Again according to, currently, no known vaccination will prevent the infection. Treatment involves strict cleansing and applying chlorhexidine, and then nitrofurazone ointment once the chlorhexidine dries.

Hopefully, these animals can be quarantined and the infection can once again be eradicated from the United States. Get the most current information at

Anybody else out there heard more about this issue?

Photo courtesy

Caleb Regan and his wife, Gwen, live in rural Douglas County, Kansas, where they enjoy hunting, fishing, and raising and growing as much of their own food as they can. Caleb can’t imagine a better scenario than getting to work on a rural lifestyle magazine as a profession, and then living that same lifestyle right in the heartland of America. Connect with him on .