A serological survey of pathogens associated with the respiratory and digestive system in the Polish European bison (Bison bonasus) population in 2017-2022.

BACKGROUND: The European bison (Bison bonasus) is a near threatened species and requires health monitoring. The aim of the present study was to determine the prevalence of antibodies to pathogens known to cause respiratory and digestive illness in ruminants. RESULTS: In the studied 328 European bison, the highest seroprevalence was observed for Bovine herpesvirus-1 (BoHV-1) (50.27%), Bovine Coronavirus (BCoV) (26.36%), and Bluetongue Virus (BTV) (12.83%). For Mycoplasma bovis strains and Bovine Viral Diarrhea Virus (BVDV), positive results were rare. Interestingly, a higher prevalence of BTV antibodies was noted in the northeastern populations and older animals. CONCLUSIONS: Our findings indicate that the Polish European bison population appears to have considerable contact with BoHV-1; however, this does not appear to be of great significance, as clinical symptoms and post-mortem lesions are rarely noted in Polish European bison population. The high seroprevalence of BTV in the north-east of Poland is an ongoing trend, also noted in previous studies. It is possible that European bison may perpetuate the virus in this region. This is the first report of antibodies for BCoV in European bison.

Comorbidities and concentration of trace elements in livers of European bison from Bieszczady Mountains (Poland).

European bison is a species for which health monitoring is essential in conservation activities. So far, little research has been carried out on the concentration of elements in this species. Most previous studies did not associate the concentration of elements with susceptibility to diseases. In this study we investigate the relationship between comorbidities in European bison and concentrations of a wide spectrum of elements in the liver. Samples were collected during the monitoring of the European bison population in Bieszczady (southeast Poland) over the 2020-2022 period. Each individual was also visually inspected by a veterinarian in the field for the presence of lesions as a part of a post-mortem examination. The animals were divided into 3 groups: group A-one type of clinical sign; group B-two types of clinical signs; group C-three or more types of clinical signs. The ICP-OES method was applied to assess the concentration of 40 elements in livers. Discriminant analysis showed clear differences between the mineral status of individuals in the groups with one, two, and at least three types of clinical signs. Detailed analysis of selected elements showed that, in the case of eight elements, there was a relationship with age, sex, or comorbidities. Cu, Se, and Zn showed significant differences in relation to comorbidities, but only Cu concentration was lower when the frequency of lesions was higher. We concluded that in research on the mineral status of the population, apart from the availability of trace elements in the environment, the health condition of the studied individuals should also be considered. However, inferring the mineral status of the population on the basis of randomly obtained samples from dead individuals may give an incomplete view of the population, especially in the case of species susceptible to diseases, such as European bison.

A Serological Survey of Paratuberculosis in the Polish European Bison (Bison bonasus) Population in 2018-2021.

The European bison (Bison bonasus) is an endangered species which faces a range of health threats. As little is known of exposure of European bison to paratuberculosis caused by Mycobacterium avium spp. paratuberculosis, known to cause losses in cattle, the aim of the present study was to conduct serological survey in Polish bison herds. Between September 2018 and February 2021, blood samples were collected from 165 European bison from different regions of Poland. Samples were taken whenever the animals were immobilized (e.g., putting on telemetry collars) as well as from any dead animal. The serum samples were tested with ELISA. Three individuals, originating from different captive herds, were found to be seropositive. In conclusion, it was found that Mycobacterium avium subsp. paratuberculosis infections are not currently a problem in European bison, especially in free-range herds.

Pesticides and conservation of large ungulates: Health risk to European bison from plant protection products as a result of crop depredation.

The coexistence of large mammals and humans in the contemporary landscape is a big challenge for conservationists. Wild ungulates that forage on arable fields are exposed to the negative effects of pesticides, and this problem also applies to protected species for which intoxication by pesticides may pose a health risk and directly affect the effectiveness of conservation efforts. In this paper we assessed the threat posed by pesticides to the European bison Bison bonasus, a species successfully restituted after being extinct in the wild. We studied samples of B. bonasus liver from three free-living populations in Poland (Bialowieska, Knyszynska, and Borecka forests) and captive individuals from breeding centres. LC-QTOF-MS/MS two-step analysis for the detection, identification and confirmation of pesticide residues in liver samples, which included MS and targeted MS/MS scans, was conducted. It was found that European bison are exposed to pesticides as a result of crop depredation: the presence of tetraconazole, fluopyram and diazinon residues in 12 liver samples was confirmed. The concentration levels of the detected substances were quite low, but in the liver samples more than one substance was usually found, and the potential health risk to European bison may result from the synergistic interaction of these substances. The place of occurrence of the population, abundance, and the management regime affect the exposure of European bison to pesticides. Due to the high conservation status of the European bison, the monitoring of intoxication by pesticides should be included in the conservation plans of this species. This issue should also be more widely included in the study of other wild ungulates because knowledge about the impact of pesticides on wildlife is still insufficient.