Imported and Travelling Dogs As Carriers of Canine Vector-borne Pathogens in Germany

Background: With the import of pets and pets taken abroad, arthropod-borne diseases have increased in frequency in German veterinary practices. This is reflected by 4,681 dogs that have been either travelled to or relocated from endemic areas to Germany. The case history of these dogs and the laboratory findings have been compared with samples collected from 331 dogs living in an endemic area in Portugal. The various pathogens and the seroprevalences were examined to determine the occurrence of, and thus infection risk, for vector-borne pathogens in popular travel destinations.

Results: 4,681 dogs were examined serological for Leishmania infantum, Babesia canis and Ehrlichia canis. Buffy coats were detected for Hepatozoon canis and blood samples were examined for microfilariae via the Knott's test. The samples were sent in from animal welfare organizations or private persons via veterinary clinics. Upon individual requests, dogs were additionally examined serological for Anaplasma phagocytophilum, Borrelia burgdorferi and Rickettsia conorii. Overall B. canis was the most prevalent pathogen detected by antibody titers (23.4%), followed by L. infantum (12.2%) and E. canis (10.1%). Microfilariae were detected in 7.7% and H. canis in 2.7% of the examined dogs. In 332/1862 dogs A. phagocytophilum, in 64/212 B. burgdorferi and in 20/58 R. conorii was detected. Of the 4,681 dogs, in total 4,226 were imported to Germany from endemic areas. Eighty seven dogs joined their owners for a vacation abroad. In comparison to the laboratory data from Germany, we examined 331 dogs from Portugal. The prevalence of antibodies/pathogens we detected was: 62.8% to R. conorii, 58% to B. canis, 30.5% to A. phagocytophilum, 24.8% to E. canis, 21.1% to H. canis (via PCR), 9.1% to L. infantum and 5.3% to microfilariae.

Conclusions: The examination of 4,681 dogs living in Germany showed pathogens like L. infantum that are non-endemic in Germany. Furthermore, the German data are similar in terms of multiple pathogen infection to the data recorded for dogs from Portugal. Based on these findings the importation of dogs from endemic predominantly Mediterranean regions to Germany as well as travelling with dogs to these regions carries a significant risk of acquiring an infection. Thus we would conclude that pet owners seek advice of the veterinarians prior to importing a dog from an endemic area or travel to such areas. In general, it might be advisable to have a European recording system for translocation of dogs.