Retrospective analysis of clinical and laboratory findings in hunting dogs with serologic reactions to tick-borne pathogens (Anaplasma phagocytophilum, Borrelia burgdorferi, Babesia canis, Ehrlichia canis, Ricketsia conorii)

Abstract

Seroprevalence of tick-borne infections in endemic areas could be high. In this study, we investigated the seroprevalence of tick-borne pathogens (Anaplasma phagocytophilum, Borrelia burgdorferi, Babesia canis, Ehrlichia canis, Rickettsia conorii) in hunting dogs, naturally infected with one or more pathogens. Serological test results of the investigated animals were compared to those from clinical examination, as well as from haematological and biochemical analyses. A total of 74.14% dogs were seropositive (R.conorii 44.83%, B. canis 32.76%, B. burgdorferi 25.86%, E. canis 13.79%, A. phagocytophilum 8.47%), with 25.86% of dogs seropositive to two pathogens, 15.52% seropositive to three pathogens, and 1.72% of dogs seropositive to four pathogens. Among all registered clinical signs, only pyrexia (p<0.05) and arrhythmia (p<0.05) were significant in seropositive dogs. There was no significant difference between seropositive and seronegative dogs regarding the majority of haematological and biochemical parameters. Statistically significant difference was registered for particular haematological (number of red blood cells and seroreactivity to B. burgdorferi) and biochemical parameters (albumin concentration and seroreactivity to E. canis, and AST and seroreactivity to R. conorii) but these values were not clinically significant. The high exposure to tick-borne pathogens suggests that ectoparasitic profilactic treatment is not adequate in examined population of hunting dogs. Clinical finding of pyrexia need to be further investigated and explained etiologically, which means that molecular diagnosis should be used in order to identify larger number of pathogens because of the possibility of coinfection.