The National Animal Health Monitoring System (NAHMS) is sponsored by the USDA:APHIS:Veterinary Services (VS). The NAHMS Equine '98 Study was designed to provide information about the nation's equine population. Twenty-eight states were included in the study. The USDA's National Agricultural Statistics Service (NASS) collaborated with VS to select a statistically-valid sample such that inferences could be made to all equids and operations with equids in the 28 states. For the purposes of the study, equids included domestic horses, miniature horses, ponies, donkeys/burros, and mules. For Part III of the study, data were collected by Federal and State Veterinary Medical Officers and Animal Health Technicians between March 16, 1998, to April 10, 1998, from 1,178 operations that had 3 or more horses present as of January 1, 1998. Over 94 percent of operations routinely used some form of rodent control; cats were the most common means (77 percent of operations ). Seventy-eight percent of operations had stalls available for horses. Thirty-one percent of operations with stalls used lime on stall floors on a routine basis. Twenty-five percent of operations removed all bedding and manure from a stall once a horse was permanently removed from its stall. Operations with horses primarily used for breeding were more likely to disinfect stalls between horses than were operations with resident horses for other specific uses. Evidence of wildlife in the vicinity was often or sometimes seen on 99 percent of operations. Mice were the animals most frequently seen (on 99 percent of operations) , followed by deer or elk (84 percent of operations ). Fifty-one percent of operations trimmed horses hooves five or more times per year. Thirty-one percent of operations reported the majority of resident horses were not shod; thirty percent of operations reported resident horses were shod 5 or more times in the previous 12 months. Twelve percent of operations reported hospitalization of a resident horse in the previous 12 months. Seventy-three percent of operations never tested for parasites; twenty-two percent of operations tested in response to a clinical problem. Over 95 percent of operations had dewormed the majority of horses in the previous 12 months. Sixty-four percent of operations vaccinated horses less than 12 months of age; nearly 75 percent vaccinated broodmares and other horses over 12 months of age. Across age categories, vaccine against tetanus was most frequently given. Sixty-one percent of operations with broodmares had vaccinated them against influenza in the previous 12 months. Contact for this paper: Lindsey Garber