**3. European bison health threats of the twentieth century**

Despite that the species was just starting to be re-established, European bison were put under epidemic pressure and exposed to many pathogens endemic to domestic ruminants in Poland at the beginning of the twentieth century. After the Second World War, the European bison population in Poland systematically increased, except for several incidents associated with the occurrence of infectious diseases (**Figure 2**). Konrad Wróblewski [14], a vet and researcher, gave the first detailed descriptions of the health problems in European bison in Białowieża at the turn of the nineteenth and twentieth centuries. At that time, the causes of morbidity and pathological changes were not yet fully understood due to the lack of knowledge and research tools. Dr. Wróblewski observed pleuropneumonia caused by *Pasteurella multocida* and connected to the *Strongylidae* invasions of lungs [15]. The problem of purulent pneumonia is still observed in European bison at Białowieża [6]; however the agent, *Pasteurella multocida subsp. multocida* serogroup A was identified just recently [16]. At the time, the highest mortality in European bison was caused by blackleg. The infection with *Clostridium chauvoei* probably caused death of 172 European bison in 1904 [14]. The most common were *Fasciola hepatica* and *Trypanosoma* parasite invasions, which affected health condition causing weakness, weight loss, and secondary infections. Occurrence of Tryp*anosoma wrublewski* protozoans in the blood of European bison was reported still in the 1990s [15]. Another problem was FMD, endemic in cattle from the area; nevertheless Dr. Wróblewski described only 5% mortality in European bison in the 1920s. However, FMD was taking its toll in the 1950s at the south of Poland causing almost complete depopulation of European bison reserves in Pszczyna, Niepołomice, and Gorce [17–19]. Staśkiewicz [13] has observed FMD in American bison and European-American bison hybrids bred in Smardzewice reserve in 1938. He has noticed significantly higher resistance to FMDV infection of those animals in comparison to European species. This also contends against the introduction of this invasive to Europe bison species into the areas where European bison are being reared.

In 1980s, due to the occurrence of Q fever in domestic animals in northeastern Poland, several dozen free-ranging European bison from Borecka Forest were

**Figure 2.**

*Dynamics of the European bison number in Poland (bars) and Białowieża Forest (curve) between 1947 and 2017 (European Bison Pedigree Book). The cases of diseases which caused significant declines in the population size and dates of their detection are marked.*

**151**

**Figure 3.**

*Infectious Disease Monitoring of European Bison (*Bison bonasus*)*

examined for the presence of specific antibodies [20]. The high seroprevalence (76%) to *Coxiella burnetii* found in European bison indicated that they could be a potential reservoir of Q fever for humans and other animals. The European bisonhuman transmission was suspected, since the infection was also confirmed in some employees (some hospitalized) of the Białowieża National Park (BNP) staff. Szarek et al. [21] have linked *C. burnetii* infection with the pathomorphological changes of

The first signs of another important disease in the male European bison, referred to as necrotic posthitis or balanoposthitis (called also pizzle rot), the causes of which still remain unsolved, were observed in Białowieża in 1980 remain unsolved, were observed in Białowieża in 1980 (**Figure 3**) [22]. *Trueperella pyogenes* and some other purulent bacteria have been isolated from the diphtheroid-necrotic changes observed on the prepuce and penis, which may lead to self-mutation of the penis in severe cases causing primarily great pain and immunosuppression, excluding the affected males from breeding [6, 22–24]. Infection with BoHV-1 causing similar symptoms in cattle was excluded from the investigation, since hardly any European bison affected had detectable antibodies to the virus and no isolation from the tissues was possible [1, 22, 25]. Also no association between *Trypanosoma* invasion and balanoposthitis was found [1]. Prior to the prepuce and penis lesions reported in Białowieża, similar symptoms were observed in Pszczyna, in the eastern part of Białowieża Forest (now Belarus), Ukraine, and Russia [1]. The epidemic of balanoposthitis in Białowieża included annually up to 15.2% males in 1993, with the average of 6.1% between 1980 and 2015. Selective culling was found the most effective method to decrease the cases, especially in the recent years [1, 6]. The symptoms are observed in all age groups of males, including calves and 2–3-year-old European bison males, yet not reproductively active [1, 6, 23]; therefore venereal route of transmission may rather be rejected. Since most cases occurred at Białowieża Forest, involvement of some environmental or vectors such as ticks was speculated, however, never verified. Since European bison genetic pool had gone through a dramatic "bottleneck" at the beginning of the twentieth century, high inbred was suspected to play a role; however,

One of the most devastating bacterial diseases, which remains a current problem in Polish European bison populations, is tuberculosis. The disease was diagnosed in the free-living European bison population in the Bieszczady mountains in the 1990s [28–31], European bison are very susceptible to mycobacterial

*Male Bison bonasus with clinical signs of balanoposthitis showing symptoms of impeded urination (stranguria)* 

*and swelling of the whole external genital area (photo: Ł. J. Mazurek).*

the heart and kidneys observed in European bison specific for Q fever.

*DOI: http://dx.doi.org/10.5772/intechopen.84290*

little evidence was reported [26, 27].

#### *Infectious Disease Monitoring of European Bison (*Bison bonasus*) DOI: http://dx.doi.org/10.5772/intechopen.84290*

*Wildlife Population Monitoring*

bison are being reared.

**3. European bison health threats of the twentieth century**

Despite that the species was just starting to be re-established, European bison were put under epidemic pressure and exposed to many pathogens endemic to domestic ruminants in Poland at the beginning of the twentieth century. After the Second World War, the European bison population in Poland systematically increased, except for several incidents associated with the occurrence of infectious diseases (**Figure 2**). Konrad Wróblewski [14], a vet and researcher, gave the first detailed descriptions of the health problems in European bison in Białowieża at the turn of the nineteenth and twentieth centuries. At that time, the causes of morbidity and pathological changes were not yet fully understood due to the lack of knowledge and research tools. Dr. Wróblewski observed pleuropneumonia caused by *Pasteurella multocida* and connected to the *Strongylidae* invasions of lungs [15]. The problem of purulent pneumonia is still observed in European bison at Białowieża [6]; however the agent, *Pasteurella multocida subsp. multocida* serogroup A was identified just recently [16]. At the time, the highest mortality in European bison was caused by blackleg. The infection with *Clostridium chauvoei* probably caused death of 172 European bison in 1904 [14]. The most common were *Fasciola hepatica* and *Trypanosoma* parasite invasions, which affected health condition causing weakness, weight loss, and secondary infections. Occurrence of Tryp*anosoma wrublewski* protozoans in the blood of European bison was reported still in the 1990s [15]. Another problem was FMD, endemic in cattle from the area; nevertheless Dr. Wróblewski described only 5% mortality in European bison in the 1920s. However, FMD was taking its toll in the 1950s at the south of Poland causing almost complete depopulation of European bison reserves in Pszczyna, Niepołomice, and Gorce [17–19]. Staśkiewicz [13] has observed FMD in American bison and European-American bison hybrids bred in Smardzewice reserve in 1938. He has noticed significantly higher resistance to FMDV infection of those animals in comparison to European species. This also contends against the introduction of this invasive to Europe bison species into the areas where European

In 1980s, due to the occurrence of Q fever in domestic animals in northeastern Poland, several dozen free-ranging European bison from Borecka Forest were

*Dynamics of the European bison number in Poland (bars) and Białowieża Forest (curve) between 1947 and 2017 (European Bison Pedigree Book). The cases of diseases which caused significant declines in the population* 

**150**

**Figure 2.**

*size and dates of their detection are marked.*

examined for the presence of specific antibodies [20]. The high seroprevalence (76%) to *Coxiella burnetii* found in European bison indicated that they could be a potential reservoir of Q fever for humans and other animals. The European bisonhuman transmission was suspected, since the infection was also confirmed in some employees (some hospitalized) of the Białowieża National Park (BNP) staff. Szarek et al. [21] have linked *C. burnetii* infection with the pathomorphological changes of the heart and kidneys observed in European bison specific for Q fever.

The first signs of another important disease in the male European bison, referred to as necrotic posthitis or balanoposthitis (called also pizzle rot), the causes of which still remain unsolved, were observed in Białowieża in 1980 remain unsolved, were observed in Białowieża in 1980 (**Figure 3**) [22]. *Trueperella pyogenes* and some other purulent bacteria have been isolated from the diphtheroid-necrotic changes observed on the prepuce and penis, which may lead to self-mutation of the penis in severe cases causing primarily great pain and immunosuppression, excluding the affected males from breeding [6, 22–24]. Infection with BoHV-1 causing similar symptoms in cattle was excluded from the investigation, since hardly any European bison affected had detectable antibodies to the virus and no isolation from the tissues was possible [1, 22, 25]. Also no association between *Trypanosoma* invasion and balanoposthitis was found [1]. Prior to the prepuce and penis lesions reported in Białowieża, similar symptoms were observed in Pszczyna, in the eastern part of Białowieża Forest (now Belarus), Ukraine, and Russia [1]. The epidemic of balanoposthitis in Białowieża included annually up to 15.2% males in 1993, with the average of 6.1% between 1980 and 2015. Selective culling was found the most effective method to decrease the cases, especially in the recent years [1, 6]. The symptoms are observed in all age groups of males, including calves and 2–3-year-old European bison males, yet not reproductively active [1, 6, 23]; therefore venereal route of transmission may rather be rejected. Since most cases occurred at Białowieża Forest, involvement of some environmental or vectors such as ticks was speculated, however, never verified. Since European bison genetic pool had gone through a dramatic "bottleneck" at the beginning of the twentieth century, high inbred was suspected to play a role; however, little evidence was reported [26, 27].

One of the most devastating bacterial diseases, which remains a current problem in Polish European bison populations, is tuberculosis. The disease was diagnosed in the free-living European bison population in the Bieszczady mountains in the 1990s [28–31], European bison are very susceptible to mycobacterial

#### **Figure 3.**

*Male Bison bonasus with clinical signs of balanoposthitis showing symptoms of impeded urination (stranguria) and swelling of the whole external genital area (photo: Ł. J. Mazurek).*

infections, and since no vaccination programs or treatment could have been introduced, the only method of disease control and prevention from spreading was the elimination of infected European bison [28, 29, 31–34]. The eradication resulted in a significant depopulation observed in decrease of the numbers of European bison (**Figure 2**). Tuberculosis affecting European bison in Poland is caused by *Mycobacterium caprae* [35]. The management of the diseases is extremely difficult especially in wildlife, since the mycobacteria transmit readily between different wild species such wild boar, deer, and wolves in Bieszczady mountains [31]. American bison bred in Poland are also considered important reservoir of tuberculosis [36].
