NAHMS Study Ranks EIA Awareness and Testing Rates

Horse owners' familiarity with equine infectious anemia (EIA) varies greatly by where they live, the size of their operation, and how they used their horses, according to the National Animal Health Monitoring System's (NAHMS) Equine 2005 study.

Overall, 46.5% of equine operation managers (such as farm owners or trainers) said they were "knowledgeable" about EIA. Managers in the Southern U.S. regions were the most likely to say they were knowledgeable, (54.3%), followed by Central region managers (46.5%).

Inversely, 14.4% of operation managers in the Northeast said they had never heard of EIA before, followed by managers in the West, at 12.6%.

The size of facility and primary use of the horses also appeared to affect awareness rates. Boarding or training facility managers were the most knowledgeable (69.6%) about EIA, while farms and ranch managers were least likely to have heard of EIA (13.5%).

Those with large operations (more than 20 horses) were the most likely to consider themselves knowledgeable (63.3%), compared to those with small operations (42.9% knowledgeable). 

Across regions, 37.6% of horses were tested for EIA during the previous 12 months. Southern horses were the most tested for EIA (50.1%), followed by Central (37.8%), Northeast (35.3%), and West (14.7%).

EIA is an infectious blood-borne viral disease with no treatment or vaccine. The virus is spread by the exchange of bodily fluids, often via insect vectors. Affected horses remain infectious carriers for life, and must be euthanatized or quarantined for life to prevent transmission to other horses.

The survey findings were published in the Equine 2005, Part I: Baseline Reference of Equine Health and Management, 2005 report. This survey was conducted by the USDA, in conjunction with the National Agricultural Statistics Service and the Animal and Plant Health Inspection Service. This was the group's second industry report. The sample included 3,349 equine operations in 28 states that were selected to generate estimates for the 28 states with equine operations with five or more equids.

NAHMS conducts national studies on the health and management of America's domestic livestock populations. In 1998, the group took its first in-depth look at the U.S. equine population. Multiple reports, information sheets, and scientific articles were generated from that study.

To learn more about NAHMS, and to see the full 2005 report, visit

About the Author

Erin Ryder

Erin Ryder is a former news editor of The Horse: Your Guide To Equine Health Care. She owns a portly gray gelding named Duncan and dabbles in several equestrian disciplines, with an emphasis on dressage.

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