Canine dirofilariosis endemic in Central Europe-10 years of epidemiological study in Slovakia

The study presents the comprehensive results of a detailed epidemiological study on canine dirofilariosis in Slovakia, Central Europe. More than 4000 dogs were investigated, and several epidemiological factors were considered. The mean prevalence in individual regions ranged from 2.0 % in northern Slovakia to more than 25.0 % in the south-western part of the country, with the nematode Dirofilaria repens confirmed as the dominant causative agent. Canine dirofilariosis occurred more often in animals more than 3 years old and in dogs of large and giant breed sizes. Short-haired animals were infected more often than dogs with a long coat. Also, the infection was significantly more prevalent in animals kept in rural areas in comparison with urban environments. Counts of microfilariae (mf) in peripheral blood reached their highest levels in May and August and corresponded to activity peaks and population maximums of potential vectors, the mosquito species Aedes vexans and Culex pipiens, the two most prevalent species in Slovakia. Moreover, two dogs naturally infested with D. repens were included in the experiment in order to monitor daily microfilarial periodicity. This fluctuation showed the same tendency in both animals, with a peak of circulating mf recorded at 4 a.m. and minimal mf counts at 4 p.m.