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Even though the numbers of legally protected European beavers in Slovakia are increasing, there is very little knowledge about pathogens that cause infectious diseases of these animals. Scientists from the Institute of Parasitology SAS in Košice have undertaken to fill a gap in this area and monitored the presence of intestinal parasites in beavers in several regions of Slovakia.

The European beaver (Castor fiber) is an animal that inhabits mainly the aquatic environment. "Beavers, which are strictly herbivorous, excrete faeces directly into the water. It represents a potential source of contamination of freshwater by parasites, especially in localities inhabited by humans,” says Ingrid Papajová, Head of the Department of Environmental and Plant Parasitology of the Institute of Parasitology SAS, and explains the intention to do research on this rodent.

For several weeks, parasitologist, together with conservationists, collected samples in the vicinity of beaver burrows by the Danube, Topľa and Laborec rivers, which they subsequently analysed and described in the institutional laboratory. "We did not detect developmental stages of parasites in samples from localities on the Laborec and Danube rivers.  In beavers living by the river Topľa, we recorded up to four species of intestinal parasites. In the faeces, we found oocysts of Cryptosporidium spp., cysts of Giardia spp., eggs of Stichorchis subtriquetrus trematodes, as well as eggs and larvae of nematodes Travassosius rufus,“ says doctoral student Júlia Šmigová Bystrianska from the PÚ SAV (Institute of Parasitology SAS).

The presented results are the first data on the presence of Stichorchis subtriquetrus and Travassosius rufus in the Slovak territory. These are parasites specific to beavers.

"An important finding was that beaver can be a significant source of contamination of surface waters by parasitic protozoa - Giardia spp. and Cryptosporidium spp., which can be dangerous even for humans as they cause diarrhoea. There are known data from Poland that the water around the beaver dams in the Masurian lakes area was significantly contaminated with G. duodenalis cysts and Cryptosporidium spp. oocysts, where the beavers served as reservoirs for these parasites,” explains the young scientist.

The parasitologist and her colleagues processed the findings into a study that was published in the journal Parasitology Research.

The research is carried out within the project VEGA 2/0125/17 called Influence of anthropogenic load on the occurrence of microbial and parasitic organisms in the environment in urban and rural ecosystems. The research team will continue in the project mainly by species specification of the found protozoa using molecular methods. Investigation of beaver faeces from various locations, especially in eastern Slovakia, will continue after the release of pandemic measures.

Edited by: Katarína Gáliková

Foto: unsplash.com/Tim Umphreys, Katarína Čižmáriková, Júlia Šmigová Bystrianska