An attentive audience gathered to learn more about foot and mouth disease (FMD), West Nile virus (WNV), and equine protozoal myeloencephalitis (EPM) from experts on Friday, April 27, at the Kentucky Horse Park in Lexington, Ky. Peter Timoney, FRCVS, PhD, Head of the Gluck Equine Research Center in Lexington, Ky., and William Saville, DVM, PhD, Dipl. ACVIM, of The Ohio State University, were the featured speakers at the seminar held at the Kentucky Horse Park. The seminar was sponsored by The Horse: Your Guide To Equine Health Care.

FMD--Timoney stressed that FMD, although it does not affect horses, is a highly contagious disease of cloven-hooved animals and has a 100% morbidity rate (rate of sickness in a group). There is a vaccine, but it does not eliminate the carrier state and cannot destroy all seven main types and 60 subtypes of the virus. Therefore, FMD-affected countries are trying to eradicate the disease by slaughtering and disposing of all sick and exposed animals. Timoney asserted that introduction of FMD into the United States would devastate the beef and pork industry, and that the United States should be taking every precaution to prevent introduction. Concern was expressed from the audience and Timoney that a person (not an animal) would be the one to introduce FMD to this country, and that little information is provided about the disease at entry points into the United States. Timoney urged people to write to the United States Department of Agriculture to request that more information and education procedures be implemented at entry points.

WNV--Saville and Timoney stressed that measures should be taken to cut down on the mosquito population, and thus the spread of WNV, by removing discarded tires and all standing water, introducing special mosquito larvae-eating fish into ponds, using insect repellants, housing horses during peak mosquito feeding times, and avoiding stable lights during the evening. Saville mentioned that a vaccine for horses might be available this fall or by early 2002, and work on DNA vaccines has shown potential. Saville suggested that people buy mosquito dunks to place in water tanks to reduce the mosquito population. These organic, natural, non-toxic, donut-shaped devices kill mosquito larvae and can be found at hardware stores.

EPM--Saville said that although EPM is a complicated disease to understand and that research is ongoing, there is not a high rate of clinical expression (presence of symptoms). Exposure in Ohio was measured at 54%, while only about 0.5% of exposed horses will actually show signs of the disease. Transport stress appears to be an important risk factor; therefore, horse owners should monitor horses for neurological signs after transport and other stressful events, such as lameness or illness episodes, accidents, foaling, and surgery. He said researchers have found that there are differences in levels of nitric oxide in cerebrospinal fluid (CSF) of EPM horses versus non-EPM horses. This might lead to an auxiliary test to the Western blot when trying to diagnose EPM.

Saville recommends only testing horses which show signs of the disease. Many veterinarians will treat horses showing signs, and if there is improvement, they use the improvement as a confirmation of diagnosis. Saville stressed that treatments are moderately effective. Also, he believes that horses vaccinated for EPM will be positive when tested, rendering the blood or CSF tests for EPM useless as far as a negative (non-exposure) test is concerned. Keeping opossums away from horse feed, water, and pet food and using special fencing designed to keep opossums off of the property might lower the chances of horses becoming infected.

About the Author

Sarah Evers Conrad

Sarah Evers Conrad has a bachelor’s of arts in journalism and equine science from Western Kentucky University. As a lifelong horse lover and equestrian, Conrad started her career at The Horse: Your Guide to Equine Health Care magazine. She has also worked for the United States Equestrian Federation as the managing editor of Equestrian magazine and director of e-communications and served as content manager/travel writer for a Caribbean travel agency. When she isn’t freelancing, Conrad spends her free time enjoying her family, reading, practicing photography, traveling, crocheting, and being around animals in her Lexington, Kentucky, home.

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