EN
The aim of this study was to determine the prevalence of infection with F. magna flukes in roe deer from the conifer forest Bory Zielonogórskie. Parasitological dissection was performed on 20 roe deer hunted in May 2016. Faecal samples from the animals were examined by the decantation method. One roebuck was verified to be infected with F. magna, which yielded a prevalence of 5%. We noted fibrinous deposits on the diaphragmatic surface of the liver with adhesions to the diaphragm, as well as five dark-coloured nodular protrusions on the liver surface. In the cross section view of the infected liver, we saw five pseudocysts corresponding to the nodular protrusions observed on the liver surface. Three of the pseudocysts were filled with dark brown liquid containing a few flukes, their eggs and cell detritus. The other two pseudocysts contained dark fluid and fragments of dead flukes. Although, no liver fluke eggs were detected in the faeces, thousands of eggs were found in the pseudocysts. Previous studies in Poland revealed two foci of this parasitosis: in south-western and south-eastern parts of the country. It is possible that the range of both foci is expanding due to red deer migrations and the spread of infected water snails and larval forms of the parasite in watercourses and rivers. Fascioloides magna infection is a threat for cervids and domestic ruminants. Therefore, it is important to monitor the occurrence of this fluke in Poland. It is essential to determine the range of fascioloidosis, examine the intermediate host species and record cases of F. magna infection in domestic ruminants.