NAHMS Equine Studies

The National Animal Health Monitoring Systems (NAHMS), a program within the USDA's Animal and Plant Health Inspection Service, conducts various animal health studies. NAHMS conducted specific studies of equine health and management during 1998 and again in 2005. These studies provide information that offers equine owners and managers the opportunity to compare the occurrence of selected diseases in horses or health management practices employed on their operations to the national estimates reported by NAHMS.

Horse owners and their veterinarians know how they manage the horses in their region, and they often assume that others with horses do the same thing, but this might not be the case. For example, based on the NAHMS Equine Study, fewer operations in the Western region (18.4% of operations) vaccinated some or all of their equids against rabies, while a larger percent of operations in other regions reported vaccination of equids against rabies (48.6% of operations in Northeast region, 38% of operations in the South, and 28.8% in the Central region). This information provides an awareness of a region's preventive health measures when horses are being moved between regions. It is important for owners and their veterinarians to ask about vaccination history and not assume that the management practices they use are what other owners practice in different regions.

These studies also point out areas of strength as well as opportunities for improvement in equine health management practices. For example, while a Coggins test or other test for equine infectious anemia (EIA) was required by more than 60% of operations that introduced new animals to their herds, it was less common that these operations required a health certificate and past medical history. Knowing the past and current health status of newly introduced horses would allow the operation personnel to implement specific measures and manage the risk these new arrivals might pose.

In addition, these studies allow the industry and scientific community to determine priorities for future equine research initiatives. There is information contained in the report from these studies that regulatory veterinary medicine professionals can glean. One example is the estimates of testing frequency for selected equine diseases such as EIA.

The Part II NAHMS Equine 2005 report contains comparisons of various equine health occurrences and management practices based on results of the NAHMS Equine 98 and 2005 studies. In addition, this report contains equine health and population estimate summaries of information from various sources for selected diseases, such as EIA, vesicular stomatitis virus, and West Nile virus.

Although NAHMS traditionally has collected animal health data from livestock producers at the farm level, there was a new feature of the Equine 2005 study. This component of the study involved collection of the health management practices employed at various types of equine events (shows, racetracks, polo meets, Western performance events, and other types of equine events) in six states (California, Colorado, Florida, Kentucky, New York, and Texas). This information provides the equine industry with insights into the frequency of various types of infection control strategies employed at equine events. Strategies evaluated included requirement of health certificates, testing for selected infectious diseases, vaccination for selected diseases, and monitoring for illness.

NAHMS studies give the equine industry a baseline for comparison over time, affording individual owners and their veterinarians the opportunity to compare their practices to those of the estimates from this national study of the industry.

The hard copies of the reports, information sheets, and CDs with electronic versions of all the Equine 2005 results are available free upon request from USDA:APHIS:VS:CEAH NAHMS NRRC Building B, 2E7, 2150 Centre Avenue Fort Collins, CO, 80526-8117, or by calling 970/494-7000. The reports and information sheets are also accessible at

About the Author

Josie Traub-Dargatz, DVM, MS, Dipl. ACVIM

Josie Traub-Dargatz, DVM, MS, Dipl. ACVIM, is a professor in the population health section of the Department of Clinical Sciences at Colorado State University’s College of Veterinary Medicine and Biomedical Sciences in Fort Collins. Her current research focuses on diagnosis and control of equine infectious diseases. Traub-Dargatz also serves the equine community as a specialist for the USDA’s Animal and Plant Health Inspection Service (APHIS) Veterinary Service Centers for Epidemiology and Animal Health and is an American Association of Equine Practitioners board member.

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