Diagnostic and clinical aspects of canine anaplasmosis and ehrlichiosis

Objective: Prospective study on the occurrence of Ehrlichia canis and Anaplasma phagocytophilum infections in dogs in Germany and Northern Switzerland. Material and methods: The study covered cases of dogs in Germany and Switzerland (north of the Alps) that were either serologically positive (detection of E. canis or A. phagocytophilum antibodies) or PCR positive for Ehrlichia species DNA. Anamnestic and clinical data were compiled by the treating veterinarians on uniform documentation sheets. Results: The study covered 101 cases (anamnestic and clinical data being available for 82 cases). 56 of these dogs were serologically and PCR positive. In contrast 19 dogs were solely PCR positive and 26 were solely serologically positive. In the second part of the study a 19% pevalence of A. phagocytophilum antibodies was found within 245 randomly chosen dog sera. In contrast the prevalence was 32% within 271 dogs originally requested for Borrelia Western Blot analysis. Conclusion and clinical relevance: The risk of autochthone canine E. canis infections seems to be low in Germany and Northern Switzerland, and mainly travelling or imported dogs are affected. In contrast canine anaplasmosis must be classified as endemic and considered as differential diagnosis in case of tick exposure and clinical pathology (e. g. arthritic problems, lameness or neurological abnormalities). For diagnostic investigation PCR analysis is very helpful to detect fresh or reactivated infections and for therapy control.