Related Experiment Video
Updated: Jul 12, 2025
Author Spotlight: Coproparasitoscopic Examination of Dog Stools for Control and Prevention of Zoonotic Parasite Diseases
Published on: December 15, 2023
Hepatozoon spp. infection in wild canids in the eastern United States
Eliza Baker1, Alex Jensen2, Debra Miller1,3,4
1Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, USA.
Background:
Hepatozoon spp. are apicomplexan parasites known to cause musculoskeletal disease in a variety of animals. Two species are known to infect wild and domestic canids in the US: Hepatozoon canis and H. americanum.
Methods:
In this study, blood, heart, and/or spleen samples were collected from 278 wild canids (180 coyotes, 93 red foxes, and 5 gray foxes) in the eastern US and tested via PCR for Hepatozoon. Histology slides of heart and skeletal muscle were assessed for Hepatozoon cysts and associated inflammation when fresh tissue was available (n = 96).
Results:
Hepatozoon spp. were found in 24.2% (59/278) of individuals, with Hepatozoon canis in 14.0% (34/278) and H. americanum in 10.7% (26/278). One coyote was positive for both H. canis and H. americanum. Foxes were more likely to be positive for H. canis than coyotes (23% and 7% respectively, P = 0.0008), while only coyotes were positive for H. americanum. Of the eight sampled states, H. canis was present in six (Louisiana, North Carolina, Pennsylvania, South Carolina, Tennessee, and Virginia) while H. americanum was found in two southern states (South Carolina and Louisiana). Infection status was positively correlated with myositis and myocarditis, and heart or muscle cysts were found in 83% (5/6) of H. americanum-positive coyotes.
Conclusion:
This survey showed a moderate prevalence of H. canis and H. americanum in states where the parasite was previously unrecorded including South Carolina and Pennsylvania.
