**Abstract**

In 2019, the 90th anniversary of the restitution of European bison (wisent) will be celebrated. Therefore, the chapter discusses the past, present, and future health threats of the *Bison bonasus* species that was on the edge of world extinction at the beginning of the twentieth century and was restituted with great efforts from many researchers, breeders, forestry workers, and caretakers. Due to the dramatic genetic "bottleneck" that depleted the gene pool, increasing the inbred of today's European bison, the breeding may face problems of decreased fertility, deficiency in growth, and increased susceptibility to diseases. While the increasing numbers of European bison may be enjoyed by breeders, the suitable habitat for the largest herbivore in Europe shrinks with increasing human population density, forestry, and agricultural activity. Additional threats include inappropriate management based on animal farming rather than sylvatic ecosystems, need for supplementary winter feeding, and establishment of breeding of related species such as American bison (*Bison bison*) in Europe. The control of European bison exposure to pathogens through passive and active surveillance is a key component of the species conservation. Hereby, the current knowledge on the epidemiology of the most significant infectious diseases in European bison is presented.

**Keywords:** wisent, surveillance, health, infection, pathogen
