Cloacal swabs were examined using a peroxidase-antiperoxidase (PAP) method that employs a monoclonal antibody to chlamydiae. The specificity and sensitivity of cloacal-swab PAP examination and the prevalence of chlamydiosis were calculated using both culture and tissue PAP evaluation as standards. The prevalence of chlamydial infections was 9.3% as determined by culture and 46.3% as judged by tissue PAP evaluation. Cloacal-swab PAP examination yielded a sensitivity of 71.4% and specificity of 85.5% when compared with culture results and a sensitivity of 81% and specificity of 85.7% compared with tissue PAP results. Culture had a sensitivity of 47.4% and specificity of 100% compared with tissue PAP results. Similarly, the efficiency of cloacal-swab PAP test was about 84% compared with culture results and tissue PAP. The efficiency of culture compared with tissue PAP was 73.1%.