Cytauxzoon felis infections are present in bobcats (Lynx rufus) in a region where cytauxzoonosis is not recognized in domestic cats Adam J. Birkenheuer a, * , Henry S. Marr a , Camille Warren a , Anne E. Acton a , Eric M. Mucker b , Jan G. Humphreys c , Melissa D. Tucker a a Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, 4700 Hillsborough Street, Raleigh, NC 27606, United States b United States Army Medical Research Institute of Infectious Diseases, 1425 Porter Street, Frederick, MD 21702-5011, United States c Indiana University of Pennsylvania, 325 Weyandt Hall, Department of Biology, Indiana, PA 15705, United States Received 3 August 2007; received in revised form 10 January 2008; accepted 11 January 2008 Abstract This study was performed to determine the prevalence of Cytauxzoon felis (C. felis) infections in bobcats (Lynx rufus) from a region where C. felis is recognized in domestic cats, North Carolina (NC), and a region where C. felis is not recognized in domestic cats, Pennsylvania (PA). Samples from NC (n = 32) were obtained post-mortem via cardiac puncture from legally trapped bobcats. Samples from PA (n = 70) were collected post-mortem onto Nobuto blood collecting strips by the PA Game Commission. Each sample was tested using a C. felis specific PCR assay as well as a PCR assay targeting host DNA to rule out the presence of PCR inhibitors. Three samples were excluded due to the presence of PCR inhibitors. Thirty-three percent (10/30) of the samples from NC and 7% (5/69) of the samples from PA tested positive for the presence of C. felis. The proportion of C. felis positive bobcats from NC was significantly different than that from PA (P < 0.005). Despite the lower prevalence of C. felis infections in bobcats from PA this finding is unique and indicates the potential for C. felis infections in domestic cats in the northeastern USA if the appropriate tick vectors are present. Veterinary practitioners in PA should be on alert for cytauxzoonosis in domestic cats. Further studies about the epidemiology and transmission of C. felis infections among both domestic cats and bobcats are needed. # 2008 Elsevier B.V. All rights reserved. Keywords: Cytauxzoonosis; Piroplasmosis; Cytauxzoon felis; Bobcats; PCR; Tick 1. Introduction Cytauxzoonosis is an emerging infectious disease of domestic cats in North America caused by the protozoan parasite Cytauxzoon felis (C. felis)(Birkenheuer et al., 2006a). Domestic cats that become infected with C. felis develop a rapidly progressive febrile illness and succumb to multi-organ failure secondary to schizont-laden macrophages occluding small blood vessels. Death occurred in the majority of infected cats reported in the literature (Birkenheuer et al., 2006a; Ferris, 1979; Hoover et al., 1994; Wagner, 1976). Because of this, domestic cats are typically considered to be an accidental host for C. felis. They are presumed to become naturally infected with C. felis via tick vectors and bobcats (Lynx rufus) are considered to be the reservoir host. The American dog tick (Dermacentor variabilis) has been www.elsevier.com/locate/vetpar Available online at www.sciencedirect.com Veterinary Parasitology 153 (2008) 126–130 * Corresponding author. Tel.: +1 919 513 8288; fax: +1 919 513 6336. E-mail address: ajbirken@ncsu.edu (A.J. Birkenheuer). 0304-4017/$ – see front matter # 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.vetpar.2008.01.020