| monthly prevalence (in 1986) of antibody titers against equine monocytic ehrlichiosis in apparently healthy horses in illinois. | the seroprevalence and seasonal trend of antibody titers against equine monocytic ehrlichiosis (potomac horse fever) were determined in apparently healthy horses in selected areas of illinois in 1986. sera from 1,367 horses (6 months to 29 years old) were evaluated for the presence of antibodies against ehrlichia risticii with indirect immunofluorescence. the majority (88%) of the horses were thoroughbred or standardbred racehorses. the number of horses with antibodies against e risticii was 229 ... | 1989 | 2694868 |