Infections with Dicrocoelium dendriticum, Cysticercus pisiformis, Micipsella numidica and seroprevalence of Toxoplasma gondii in European brown hares (Lepus europeus L.) from Bulgaria

During the period 2009–2016, brown hares (Lepus europeus L.) from different regions of Bulgaria were investigated for infections with liver parasites as well as for seroprevalence of protozoan Toxoplasma gondii. Three helminth species were found in the liver: one trematode – Dicrocoelium dendriticum, one cestode – larval form of Taenia pisiformis – Cysticercus pisiformis and one nema­tode – Micipsella numidica. Dicrocoeliasis was found in all parts of the country with infected hares originating mainly from the western regions. The total prevalence of infection with D. dendriticum was 10.59%. The intensity of infection ranged from 1 to 184, 26.67 on the average. The total prevalence of infection with C. pisiformis was 16.8%. The prevalence of infection was highest among hares from the southern parts of the country, and no cysticercosis was registered in the western parts. The extent of infestation with cysticerci was different – from single cysticerci on the omentum or serosa of some organs in the abdominal cavity to innumerable ones that affected also the organs in the thoracic cavity. However, cases in which the animals were slightly affected, predominated. The total prevalence of infection with M. numidica was 5.31%, and the intensity of infection varied between 1 and 6 parasites in one animal. The nematodiasis was established mainly in hares from southern Bulgaria. The total seroprevalence of T. gondii was 6.15% and the protozoan-positive animals originated from three districts: Stara Zagora, Plovdiv, and Burgas. The current studies also showed that the prevalence of D. dendriticum infection among animals increased with age. No correlation was observed between prevalence of infection with C. pisiformis and M. numidica and host age. No correlation was found between the prevalence of the helminth infections and sex of the animals.