Detection of Dirofilaria immitis and Ehrlichia Species in Coyotes (Canis latrans), from Rural Oklahoma and Texas

There is a lack of knowledge regarding the prevalence of Dirofilaria immitis and Ehrlichia spp. in coyotes in Oklahoma and Texas. Documenting the prevalence of these vector-borne disease agents in coyotes from Oklahoma and Texas underscores the importance of wild canids as reservoir hosts that infect companion animals and humans. To learn more about the sylvatic cycle of D. immitis and Ehrlichia spp. in coyotes from Oklahoma and Texas, we tested for infection with and exposure to, respectively, these disease agents. Coyote carcasses were collected opportunistically from animal control experts and hunters in seven counties in Oklahoma and Texas from January to March, 2010. Serum samples from 77 coyotes were tested with a commercial ELISA test. Five (6.5%) coyotes had D. immitis antigens, and four (5.2%) had antibodies to Ehrlichia spp. The overall prevalence of D. immitis was low relative to studies from the eastern United States. Little is known about the prevalence of Ehrlichia spp. throughout the United States, but coyotes from rural Oklahoma in the current study had a higher exposure rate than those reported from California, and a lower rate than data from an earlier study from Oklahoma.