A massive invasion of Parafasciolopsis fasciolaemorpha in elk (Alces alces) in Lublin Province, Poland

Liver fluke Parafasciolopsis fasciolaemorpha is a parasite typical of elk (Alces alces). The present study describes the identification of a massive invasion of the liver fluke P. fasciolaemorpha in an elk in the Sobibór Landscape Park, Eastern Poland. In February 2016, samples of liver and faeces were collected from the elk during postmortem examination. A section of liver tissue and three grams of faeces were examined for the presence of flukes or fluke eggs by decantation. In total, 11,150 juvenile and mature flukes of P. fasciolaemorpha were found in the examined liver. Multiple cavities with distinct walls, filled with dark liquid, trematodes, fluke eggs and cellular detritus were seen in the cross section of the parenchyma. Additionally, some of the bile ducts were plugged with calcerous deposits. The three grams of examined faeces were found to contain 322 grey and golden-coloured eggs of P. fasciolaemorpha. The presence of such a massive infection of P. fasciolaemorpha in the examined elk has a significant impact on the health of the individual. We can assume P. fasciolaemorpha has a significant influence on the health and abundance of the entire elk population in Poland.