Final NAHMS Equine '98 Study Information Released

Lameness ranks as the most expensive health issue for horse owners nationwide (as compared to colic and EPM), according to the United States Department of Agriculture's National Animal Health Monitoring System (NAHMS) Equine '98 Study. NAHMS recently released four information sheets pertaining to equine health. These are the final products of the Equine '98 Study, which was designed to provide educational and research information on America's equine population.

Results of the comprehensive Equine '98 study have been released in segments since August of 1998, and they have covered everything from the biosecurity of equine operations to parasites. The reports have been applicable to horse owners, researchers, and manufacturers, giving an accurate glimpse of the issues facing the U.S. equine industry.

The first sheet, "National Economic Cost of Equine Lameness, Colic, and Equine Protozoal Myeloencephalitis (EPM) in the United States," compares the cost of these health issues to the equine industry. Researchers found that lameness was the most expensive of the three issues overall at $678 million, with $448 million (about 66%) of the total attributed to days of lost use and $35 million (5%) attributed to death loss. The total estimated cost of colic ($115 million) was less than lameness, but roughly 66% of the colic costs ($76 million) were attributed to death loss. EPM affected a smaller segment of the equine population compared to lameness and colic, but had a substantial economic impact. Days of lost use because of EPM added up to $16 million (roughly 57%) of the $28 million in total expenses related to the disease in 1998 (more from NAHMS in the chart below).

"Incidence of Colic in U.S. Horses" summarizes the national incidence of colic and the associated fatality rate. The impact of colic on the horse industry at a national level had never been estimated before this project. "The most common cause of owner reported colic was 'unknown,' followed by gas colic and feed-related factors," noted the study.

Finally, the last two sheets described "Infectious Upper Respiratory Disease (IURD)" incidence and lab results. About 11.6% of equine operations reported at least one horse with IURD during one quarter of the year. Summaries regarding lab results of IURD showed that an estimated 69.7% of all horses had a detectable antibody titer to equine influenza virus, meaning that they have a decreased risk of disease during an outbreak. Swabbing of nearly 6,000 horses showed that a small percentage were positive for different species of Streptococcus bacteria.

These information sheets, as well as previous NAHMS reports, are available at


About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

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