Parafasciolopsis fasciolaemorpha is a liver fluke typically parasitising moose in Central and Eastern Europe. The aim of our studies was to describe a case of fatal moose parafasciolopsosis, with special emphasis on the histopathological changes caused in the liver tissue by around 10,000 flukes. A male moose, found dead in Polesie National Park, eastern Poland, was subjected to parasitological necropsy. Macroscopic and histopathological examination of the liver was performed. Over 10,000 flukes identified as P. fasciolaemorpha were isolated from the liver parenchyma. Histopathological examination of the liver revealed the presence of multiple cavities, which were filled with flukes and cellular detritus and encysted with a layered capsule of connective tissue. Extensive liver fibrosis with signs of incomplete septal cirrhosis was also observed. Parafasciolopsosis with accompanying diarrhoea was the most probable reason for the moose’s death. However, it is possible that most moose are able to survive extremely intensive P. fasciolaemorpha infection by formation of extensive fibrosis, which isolates flukes from the liver parenchyma and therefore retards the failure of the organ. To the best of our knowledge, this is the first histopathological description of changes in the liver of a moose infected with P. fasciolaemorpha.

Nineteen species of gastro-intestinal nematodes were recovered from 10 Burchell's zebra. These include: Cyathostomum alveatum, C. montgomeryi and C. tetracanthum; Cylicocyclus auriculatus, C. gyalocephaloides, C. insigne and C. triramosus; Cylicodontophorus schürmanni and Cylicodontophorus n.sp., Cylicostephanus bidentatus, C. calicatus and C. minutus; Poteriostomum ratzii, Craterostomum acuticaudatum, Triodontophorus minor, Habronema majus, H. muscae, H. zebrae, and Draschia megastoma, as well as Cylindropharynx spp. The highest burdens encountered were those of Cylicocyclus triramosus (159 491), Cylindropharynx (19 875), Cylicocyclus auriculatus (15 792), Cylicostephanus calicatus (16 658) and Cyathostomum tetracanthum (13 723). The nematodes consistently present in all zebras were: Cylicostephanus calicatus, Cylindropharynx spp. and Draschia megastoma.

Postmortem examinations were done on 51 wood bison (Bison bison athabascae) killed as part of a multidisciplinary research project in the Mackenzie Bison Sanctuary, Northwest Territories, Canada, between 1986 and 1988. There was no gross, histological or bacteriological evidence of brucellosis or tuberculosis in these bison. Traumatic lesions were seen in one calf that had been attacked by wolves and a second calf that had been gored. Antibody titers to Brucella abortus were not found in sera from these 51 animals or an additional 112 wood bison that were chemically-immobilized or killed in the Sanctuary between 1986 and 1990. The combined prevalence of the diseases in the population could not have exceeded 5.95% for the necropsy survey to have missed finding at least one infected animal, and the prevalence of brucellosis in the population would have had to be less than 1.95% for the broader serological survey to have failed to find at least one reactor animal on the battery of tests. These results, and the cumulative epidemiological information on brucellosis and tuberculosis in bison, indicate that bovine brucellosis and tuberculosis are not enzootic in the wood bison population in and around the Mackenzie Bison Sanctuary, and suggest that the population is free of these diseases. However, this expanding population is at risk of contracting both diseases from the infected bison population in and around nearby Wood Buffalo National Park.

In the conditions of the Republic of Belarus there was analyzed fauna of parasites of gastro-intestinal tract and natural resistance of horses in the conditions of Polesye State Radiation Ecological Reserve. There were worked the most efficient antihelminthic compounds. Analysis of helminthological state showed that extensiveness helminthic and gastrophilosis invasion of horses was at a high level. In this regard the nematodosis and gastrophilosis (Gastrophilus intestinalis) invasions prevailed. In mature and growing horses there was marked the dominance of nematode worms of Strongylidae / Trichonematidae families (78,9-83,8%) and Gasterophilidae (95,8%). Next, at growing horses there were stated nematodes Strongyloides westeri and cestoid worms of Anoplocephalidae family, at mature horses – of Gasterophilidae, Parascaris equorum and Oxyuris equi families. The following antihelminthic compounds ans preparations showed the best efficiency: Univerm; Avermektin paste 1%; Fenbendazoli, Rivertin 1%.