Paper Prevalence of Bartonella species infections in cats in Southern Germany M. Bergmann, T. Englert, B. Stuetzer, J. R. Hawley, M. R. Lappin, K. Hartmann Bartonella species are zoonotic pathogens, and infections in cats are common. However, prevalence in cats in Southern Germany is still unknown. Therefore, prevalence of Bartonella species DNA in blood of 479 Southern German cats was determined using a previously published conventional PCR targeting a fragment of the 16S-23S rRNA intergenic spacer region. Associations between Bartonella bacteraemia, housing conditions, feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) status, including progressive, regressive and abortive FeLV infection, were evaluated using Fisher’s exact test. Prevalence of Bartonella species bacteraemia was 2.5 per cent (12/479; CI 0.01–0.04 per cent). Bartonella henselae DNA was amplified in 11 of the 12 cats. One cat was positive for Bartonella clarridgeiae DNA. Of the infected cats, 2/12 cats were ill; 6/12 cats had thrombocytopenia. There was a significantly higher risk of Bartonella species infection in young and shelter cats, but not in FIV-infected or FeLV-infected cats. Prevalence of Bartonella species bacteraemia is low in Southern German cats, but there is still a risk of zoonotic transmission associated with ownership of young cats. Most of the infected cats did not show clinical signs. Thrombocytopenia was common in Bartonella species-infected cats and further studies are required to define its clinical relevance. Bartonella species are zoonotic Gram-negative intracellular bac- teria with increasing importance in veterinary and human medi- cine (Brunt and others 2006, Chomel and others 2006, Breitschwerdt and others 2010). The family Bartonellaceae includes the single genus Bartonella with over 22 species. Bartonella species replicate intracellularly in red blood cells or endothelial cells and are usually transmitted by arthropods (Boulouis and others 2005, Chomel and others 2006, Bradbury and Lappin 2010, Lappin and others 2013). Cats are the main reservoir hosts for Bartonella henselae, Bartonella clarridgeiae and likely for Bartonella koehlerae. B henselae and B clarridgeiae are the most common Bartonella species in cats (Lappin and others 2006, Lappin and Hawley 2009). They are transmitted among cats or from cats to people by Ctenocephalides felis or through its faeces (Chomel and others 2006, Bradbury and Lappin 2010). Ixodes species can also act as vectors (Cotté and others 2008). Bartonella-infected cats can develop persistent or recurrent bacteraemia lasting for several months (Kabeya and others 2002). Typical for reservoir hosts, B henselae and B clarridgeiae rarely cause clinical signs in infected cats, and infections often remain undetected (Stuetzer and Hartmann 2012, Pennisi and others 2013). Bartonella species infections are associated with cat scratch disease in human beings, a number of chronic disease syndromes in immunocompetent veterinary healthcare providers or Bartonella researchers (Breitschwerdt and others 2007), bacil- lary angiomatosis and peliosis hepatis in immunocompromised people (Lange and others 2009) as well as endocarditis and other severe syndromes in human beings and dogs (Chomel and others 2006, Breitschwerdt and others 2010). To date, it is unclear whether immunosuppression in cats predisposes to Bartonella species infection or whether it influences the course of Bartonella species infection and the development of clinical signs (Buchmann and others 2010, De Bortoli and others 2012). Worldwide, cats are commonly infected by Bartonella species. Prevalence of infection differs among cat populations and geo- graphical region (Brunt and others 2006, Lappin and Hawley 2009, Breitschwerdt and others 2010, Barrs and others 2010). In Germany, three studies investigated the prevalence of Bartonella species bacteraemia so far (Buchmann and others 2010, Mietze and others 2011, Morgenthal and others 2012), but in all studies, cats originated from Northern Germany. Prevalence in cats in Southern Germany is unknown. Thus, the aim of this study was to determine the prevalence of Bartonella species infections in cats in Southern Germany. Associations between Bartonella species infections and housing conditions as well as feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) infection status were also evaluated. Materials and methods Animals The 479 cats evaluated in this study were either presented to the Clinic of Small Animal Medicine of the LMU Munich, Germany, or to private veterinary clinics in Southern Germany for various Veterinary Record (2017) doi: 10.1136/vr.103843 M. Bergmann, DVM, T. Englert, DVM, B. Stuetzer, DVM, K. Hartmann, DVM, PhD, Clinic of Small Animal Medicine, Centre for Clinical Veterinary Medicine, LMU Munich, Veterinaerstrasse 13, Munich 80539, Germany J. R. Hawley, Research Associate, M. R. Lappin, DVM, PhD, Center for Companion Animal Studies, Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA E-mail for correspondence: n.bergmann@medizinische- kleintierklinik.de Provenance: Not commissioned; externally peer reviewed Accepted January 2, 2017 10.1136/vr.103843 | Veterinary Record | 1 of 5 Paper