Seasonal Pattern of Prevalence and Excretion of Eggs of Baylisascaris transfuga in the Brown Bear ( Ursus arctos ).

Research paper by Ladislav L Molnár, Alžbeta A Königová, Peter P Major, Zuzana Z Vasilková, Martina M Tomková, Marián M Várady

Indexed on: 29 Dec '20Published on: 24 Dec '20Published in: Animals : an open access journal from MDPI


The seasonal dynamics of the prevalence, abundance, and mean intensity of egg excretion by the nematode parasite in the European brown bear () were monitored relative to environmental factors (mean temperature, humidity, and temperature) over three years. The prevalence, abundance, and mean intensity of egg excretion tended to increase from spring to autumn throughout the monitoring period. The seasonal prevalence (84.2-90.6%), abundance (470.2-545.3 eggs per gramme (EPG) of faeces), mean intensity of excretion (558.3-602.1 EPG), and number of eggs (1150 EPG) were highest in autumn. The prevalence of eggs (up to 48.5%), abundance (37.8-60.6 EPG), and mean intensity of excretion (94.4-125.0 EPG) were high in winter, despite the period of hibernation. The seasonal dynamics of abundance in bears, the mean temperature between spring and autumn, and the seasonal trend of increase in intensity of egg excretion with temperature from winter to summer were interrelated. Abundance differed significantly between winter and autumn, spring and autumn, and summer and autumn ( < 0.0001) in all years and between spring and summer in 2016 ( < 0.005), 2017 ( < 0.05). abundance differed significantly between the seasons over the three years only in spring ( ≤ 0.0001).