New liver fluke species detected in foxes and elk in South-Eastern Finland
“Two new liver fluke species detected in foxes, Metorchis bilis and Pseudamphistomum truncatum, are parasites whose hosts are mammals and birds feeding on fish. As far as biologists know, infestation is only possibly through consumption of raw or inadequately cooked fish of the Cyprinidae family, such as roach. On their trips along shorelines or at drill holes left by ice fishermen, foxes may find dead fish for food. By eating raw fish, dogs and cats may also become infested by liver flukes. Humans should avoid consuming poorly cooked cyprinids – such as roach – in those areas where these parasites occur. According to the research literature, infestation may cause pain in the abdominal cavity and lead to jaundice, fever and nausea”, says Professor Antti Oksanen, Evira.
Pseudamphistomum truncatum was previously known to occur in seals in the Baltic Sea, and in sea eagles.
Following observations made by an elk hunter, small-size liver flukes, representing the species Parafasciolopsis fasciolaemorpha, were found in Ruokolahti in the spring of 2015. There is no evidence of humans becoming infested by this species of liver flukes. Previously, this parasite was only found in Russia and Eastern Europe.
“This parasite in not considered to poise a particularly grave danger to the elk. In addition to the deer family, Cervidae, it has been found to occur in the wisent, the European bison, as well as in domestic ruminants. The interesting fact is that it is only now that this parasite has been found in Finland. This can be regarded as an indication of the fact that the postglacial remigration of species to Finland is occurring at a slow pace”, remarks Oksanen.
Hunters contribute valuable information to disease monitoring of animals
Disease monitoring of wild animal is important, as diseases they carry may also be transmitted to domestic animals and to humans. Hunters provide Evira with valuable material by supplying foxes, raccoon dogs and other animals, which can be used in the monitoring of rabies vaccination and the occurrence of the Echinococcus multilocularis, a tapeworm species. Under Evira’s monitoring programme for contagious diseases, the health status of animals is always checked.
With regard to disease monitoring of wild animals, Evira collaborates with citizens and particularly with hunters. Disease monitoring of game used for food is largely based on specimens of game animals, sent by hunters and suspected of being disease carriers.
“Hunters with hygiene training in particular are qualified to make observations on the health of game. For example, an individual hunter took note of the bile ducts of the liver of an elk which were infected and swollen, alerting us to the occurrence of a new parasite”, Oksanen comments.
For additional information, contact:
Antti Oksanen, Head of Research Unit, tel.
+358 44 561 6491
Production Animal and Wildlife Health Research Unit