Current Surveys on the Prevalence and Distribution of Dirofilaria spp. in Dogs in Germany

Abstract
The Central Upper-Rhine (Baden-Württemberg, Germany) is one of the warmest regions in Germany and also harbours abundant numbers of mosquitoes. Case reports on presumably autochthonous occurrence of Dirofilaria spp. were reported previously and were a reason for a further investigation into the occurrence of vector-borne pathogens. For this purpose, 44 hunting dogs from the Central Upper-Rhine region were tested between 4th and 29th June 2007. The blood samples were tested using the Knott’s test and IDEXX SNAP® 4Dx® test. The Knott’s test revealed unsheathed microfilaria identified as Dirofilaria repens by PCR in 3 dogs with no history of travelling (6.8%; 95% CI: 2.4–18.2%). The seroprevalence for Anaplasma phagocytophilum was 43.2% (95% CI: 29.7–57.8%), but only 4.5% (95% CI: 1.3–15.1%) for antibodies to Borrelia C6 peptide. Dirofilaria immitis antigen was not detected in any of the samples. A further 288 blood samples from non-hunting companion dogs of the Central Upper-Rhine region were tested negative for heartworm antigen between February and August 2007.