Distribution of pseudocysts in Fascioloides magna infected livers of red deer and fallow deer.

Abstract

In Europe, red deer and fallow deer are the defi nitive hosts for the non-native fl uke Fascioloides magna. Upon entering the host, a juvenile fl uke emerges from the metacercariae and travels through the abdominal cavity in search of the liver. The aim of this study was to determine the distribution of F. magna pseudocysts in the livers of red deer and fallow deer, and to investigate whether this distribution varies within the livers according to host species and the severity of infection. In this study, 143 red deer livers and 178 fallow deer livers were collected. Livers were divided into three sections (observed from the diaphragm side): left containing the lobus hepatis sinister, middle containing the lobus caudatus and lobus quadratus, and right one containing the lobus hepatis dexter. Sections were sliced to a 2 cm thickness and analysed. A signifi cantly higher number of pseudocysts was found in the middle section of the liver compared to the left or right sections, while no differences were found between the left and right sections. The odds ratio indicates a 7 times (red deer) and 3.7 times (fallow deer) higher probability of pseudocysts being present in the middle section compared to the left section, or 10 and 3.8 times, respectively, compared to the right section. Red deer livers generally harboured more pseudocysts than fallow deer livers in all sections. Both species exhibited a similar pattern of pseudocyst distribution in the liver, with the middle section appearing to be the most suitable site for pseudocyst localization due to the abundance of blood vessels and bile duct terminations. No relationship was found between the severity of infection and pseudocyst distribution.