Retrospective evaluation of vector-borne pathogens in cats living in Germany (2012-2020)

Background:Blood-feeding arthropods can transmit parasitic, bacterial, or viral pathogens to domestic animals and wildlife. Vector-borne infections are gaining significance because of increasing travel and import of pets from abroad as well as the changing climate in Europe. The main objective of this study was to assess the percentage of cats with positive test results for selected vector-borne pathogens in Germany and explore any possible association of such results with time spent abroad. Methods: This retrospective study included test results from cats included in the "Feline Travel Profile" established by the LABOKLIN laboratory at the request of veterinarians in Germany between April 2012 and March 2020. This diagnostic panel includes the direct detection of Hepatozoon spp. and Dirofilaria spp. via PCR as well as indirect detection assays (IFAT) for Ehrlichia spp. and Leishmania spp. The panel was expanded to include an IFAT for Rickettsia spp. from July 2015 onwards. Results: A total of 624 cats were tested using the "Feline Travel Profile." Serum for indirect detection assays was available for all 624 cats; EDTA samples for direct detection methods were available from 618 cats. Positive test results were as follows: Ehrlichia spp. IFAT 73 out of 624 (12%), Leishmania spp. IFAT 22 out of 624 (4%), Hepatozoon spp. PCR 53 out of 618 (9%), Dirofilaria spp. PCR 1 out of 618 cats (0.2%), and Rickettsia spp. IFAT 52 out of 467 cats (11%) tested from July 2015 onwards. Three cats had positive test results for more than one pathogen before 2015. After testing for Rickettsia spp. was included in 2015, 19 cats had positive test results for more than one pathogen (Rickettsia spp. were involved in 14 out of these 19 cats). Conclusions: At least one pathogen could be detected in 175 out of 624 cats (28%) via indirect and/or direct detection methods. Four percent had positive test results for more than one pathogen. These data emphasize the importance of considering the above-mentioned vector-borne infections as potential differential diagnoses in clinically symptomatic cats.