Ticks and associated tick-borne pathogens from dogs and red foxes from Bulgaria

Climate changes in recent years led to a sharp rise in the tick population and an increase in the number of animals and people with tick-borne infections. The domestic and wild carnivores, especially the dogs, have a huge role for the distribution of ticks in certain areas. In this study 60 ixodid ticks collected from domestic dogs and red foxes from Bulgaria have been investigated for infection with Ehrlichia canis, Hepatozoon canis, Babesia spp., and Rickettsia spp. The results showed that the dogs were infected with two tick species - Rhipicephalus sanguineus (72%) and Ixodes ricinus (28%). The red foxes were infected with only one species - I. ricinus. Out of all R. sanguineus ticks, 43.6% were female and 56.4% male. The opposite was observed for I. ricinus - female specimens (86.7%) were significantly more prevalent than males (13.3%). Similar trend was found out for I. ricinus collected from red foxes - 66.7% of the ticks were female and 33.3% male. Infectious agents were found in 31.7% of the investigated ticks. Ehrlichia spp. was established in 79% and Rickettsia spp. in 21% of the infected ticks. Ehrlichia spp. was found only in ticks collected from dogs. The majority of the ticks infected with Ehrlichia spp. were Rh. sanguineus (93.3%) and only one tick was I. ricinus (6.7%). Four ticks were positive for Rickettsia spp., two were Rh. sanguineus and two - I. ricinus, one of the latter was found on a fox. This is the first report about detection of Ehrlichia spp. in Rh. sanguineus ticks from Bulgaria as well as Rickettsia spp. in I. ricinus ticks collected from red foxes from this country.</jats:p