Kentucky veterinary officials are now requiring that stallions coming from Wisconsin be tested for contagious equine metritis (CEM) prior to entering the state. The order, issued today by State Veterinarian Robert C. Stout, DVM, stems from Kentucky’s investigation into cases of CEM, which were first discovered in the state in December. This is the first official interstate movement restriction to result from the nationwide investigation, which includes 614 horses in 45 states.

Investigators in Kentucky have concluded that a Paint stallion was infected with the causative organism when he came to the state from Wisconsin in 2008. Today’s order was issued to minimize the opportunity for the organism to be reintroduced into Kentucky while the investigation in Wisconsin continues. Currently, there are three CEM-positive stallions in Wisconsin and four in Kentucky.

With testing and treatment of Kentucky horses well under way, the state veterinarian’s office expects Kentucky to again be free of CEM in the coming weeks.

Rusty Ford, equine programs manager in the Kentucky State Veterinarian’s office, classified the move as precautionary. “As the epidemiology in Wisconsin matures, and we’re better able to identify associated risks, we will be happy to review our entry requirements for stallions coming into the state from Wisconsin,” Ford said. “We certainly commend (Wisconsin State Veterinarian) Dr. Ehlendfeldt and his staff for the enormous amount of work put forth to this point in their investigation. We are continuing to work closely with them, as well as other states involved in the investigation, as it relates to Kentucky.”

Under the order, swabs taken from a Wisconsin stallion must be tested by culture in an approved CEM laboratory and reported negative for the organism during the 28 days preceding entry into Kentucky. The attending veterinarian must make a certification statement verifying that the stallion was not bred, nor was semen collected from the stallion, after the sample was collected.

The current CEM outbreak investigation began in December 2008, when a Quarter Horse stallion in Kentucky tested positive for the causative bacterium, Taylorella equigenitalis, during routine testing prior to shipping semen to the European Union.

As of Feb. 17, a total of 11 stallions and three mares were confirmed infected in the United States. Three of the stallions are located in Indiana, four are in Kentucky, one is in Texas, and three are in Wisconsin. One mare is in Wisconsin, one is in Illinois, and one is in California.

As of Feb. 25, the USDA’s Animal and Plant Health Inspection Service reported it had located 614 horses in 45 states affected by outbreak either by positive testing or exposure to a positive horse. There were 84 exposed or positive stallions in 16 states and 530 exposed or positive mares in 44 states. Another nine exposed horses–eight mares and one stallion–were still actively being traced. All positive horses, and all exposed horses that have been located, are currently under quarantine or hold order.

CEM can be treated effectively with a wide range of disinfectants and antibiotics. Strict hygiene should be observed after contact with horses that test positive for Taylorella equigenitalis. CEM is not known to be transmissible to humans. Read more about contagious equine metritis.

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Kentucky requirements for entry of breeding stallions from Wisconsin:

1) Any stallion entering Kentucky from Wisconsin for breeding and/or semen collection shall obtain an entry permit from the Office of the Kentucky State Veterinarian. The accredited veterinarian issuing the Certificate of Veterinary Inspection shall obtain the required permit by calling 502/564-3956 during normal working hours of 8:00 a.m. and 4:30 p.m., Monday through Friday.

2) A valid Certificate of Veterinary Inspection shall include a complete description and identification of the horse.

3) The stallion shall have a set of individual swabs collected from the prepuce, urethral sinus, fossa glandis, and distal urethra, with each swab submitted to an approved CEM laboratory for testing.

4) The swabs shall be collected and reported negative for CEM bacterium during the 28 days preceding entry into Kentucky

5) The Certificate of Veterinary Inspection shall include a statement that the stallion has not been bred, nor semen collected, following the swabs being collected