A nested polymerase chain reaction assay was used to determine the presence
of Ehrlichia chaffeensis, E. canis, and E. ewingii DNA in blood samples of
free-ranging coyotes from central and northcentral Oklahoma. Of the 21 coy
otes examined, 15 (71%) were positive for E. chaffeensis DNA; none was posi
tive for E. canis or E. ewingii. Results suggest that E. chaffeensis infect
ions are common in free-ranging coyotes in Oklahoma and that these wild can
ids could play a role in the epidemiology of human monocytotropic ehrlichio
sis.