Prevalence and geographic distribution of and detection of in free-ranging California coyotes (.

species are intraerythrocytic piroplasms that can result in disease characterized by hemolytic anemia and thrombocytopenia. Of the 5 species that are known to infect canids in the United States, is most frequently diagnosed in California, and is prevalent in the US. Despite the recent re-emergence of , the mechanism of transmission is not known. Coyotes () have been a proposed reservoir of disease, and previous work has shown that dogs with known aggressive interactions with coyotes are at greater risk for infection. This study aimed to determine the prevalence of in wild coyote populations in California to assess the viability of coyotes as a potential source of infection for domestic dogs. Four hundred and sixty-one splenic samples were obtained during post-mortem examination of coyote carcasses from Southern California, Fresno, and Hopland. Demographic data including age, sex, cause of death, and urbanity were collected for each coyote. DNA was extracted from samples and amplified using real-time PCR with primers specific for the gene. The gene was amplified and sequenced using conventional PCR primers specific to the genus from any coyotes positive for In total, 22 coyotes tested positive for in Fresno (n = 15), Orange (n = 4), San Bernardino (n = 1), and Los Angeles counties (n = 1) with an overall prevalence of 4.8%. Coyotes from Fresno (.01) and rural coyotes (.01) were significantly more likely to be infected with . Ten of 14 samples sequenced were 99-100% homologous to and 4 samples were 100% homologous with DNA indicating co-infection with both pathogens. This study demonstrates that coyotes can become infected and harbor and and should be investigated as a possible source of infection in domestic dogs.