Details Revealed on KY CEM Case

A Kentucky-based stallion has tested positive for the contagious venereal infection.

By Erin Ryder

State and federal agriculture officials announced Dec. 16 that a Quarter Horse stallion standing at stud in Kentucky has tested positive for contagious equine metritis.

As the United States is considered free of the highly contagious venereal infection (which can cause infertility and abortions, or can exist and spread subclinically), this raises two major issues: where did it come from, and will it affect equine transport, either interstate or internationally?

According to Rusty Ford, equine programs manager in the office of Kentucky State Veterinarian Robert Stout, the affected stallion is a 16-year-old Quarter Horse who came to a farm in Kentucky in February, after being collected for breeding via artificial insemination in Texas.

Twenty-one other stallions, all Quarter Horses, stood at the Kentucky facility. The CEM causative organism, Taylorella equigenitalis, was discovered when the affected horse was examined prior to his semen being shipped to the European Union. All but eight of the stallions had shipped to other farms this summer, following the conclusion of the 2008 breeding season. One stallion had moved to another farm within Kentucky and the rest moved out of state.

USDA officials and state veterinarians are working to locate these horses, as well as 44 mares that were inseminated with semen from these stallions, for testing. Preliminary information puts the horses' owners in 18 states, but whether the horses are currently located in those states is one of the questions officials are working to answer.

The affected horse is currently in treatment to eliminate T. equigenitalis from his system. Since the bacterium can hide in every nook and cranny of a stallion's genitalia, this involves both external and systemic treatment.

An outbreak of CEM in 1978 among Kentucky's Thoroughbred population shut down the breeding season. The cost to the industry was estimated at $1 million a day.

The potential effects go well beyond the breeding shed and the pocketbook. As a reportable disease, the CEM case could encumber, or even potentially halt, interstate and international transport of horses.

"We don't know what the reaction will be--I'm sure there will be some," said Stout. "It will be reported to OIE (Office International des Epizooties, or World Organization for Animal Health), and each country will probably react in its own way. We do know now that some shipments have been contained and others have been allowed to move."

According to Ford, a shipment of horses destined for Brazil had to remain grounded on Sunday--Brazil and Argentina both have regulations specifying that horses coming into the country had to originate from a country "free of contagious equine metritis."

Ford said USDA officials were in talks to change these requirements to specify horses from CEM-free premises so that exportation could resume. While not yet official, it is thought that Argentina is going to allow the premises rule.

The Kentucky Department of Agriculture has been in communication with other state veterinarians. At this time, no states have placed restrictions on Kentucky horses.

Ford said since the primary route of transmission of the organism is venereal, and there's been limited opportunity for transmission as these stallions did not perform live covers, he does not expect to see major restrictions as a result of the case.

Kentucky's commissioner of agriculture, Richie Farmer, and Gov. Steve Beshear have discussed the issue and its potential ramifications for the state's signature industry. According to Ford, "Both have expressed confidence in our abilities and have committed that we'll make every effort needed to minimize the impact this will have on Kentucky's and the state's industries."

As testing begins and authorities work to iron out regulation wrinkles, one major question remains: where did this come from? Other than two isolated Lipizzaner stallions in Wisconsin in October 2006, the United States hasn't reported CEM since 1997.

To investigators' knowledge thus far, the affected horse was not imported, nor were any of the other horses on the farm.

"The nation's industries as a whole have expressed concern over this, because this is an organism that is not known to exist in this country, and our objective is to find, or determine as best we can, how this animal became infected," Ford said.