The pig is susceptible to numerous zoonoses and represents the main reservoir for some zoonoses. These include Paslahepevirus balayani (formerly called HEV), Mycobacterium avium paratuberculosis (MAP), and Brucella suis. These infections cause mild symptoms in pigs (the only one to cause truly evident symptoms is Brucella suis, which causes reproductive disorders) but have serious consequences in humans. The purpose of this study was to assess the swine population's exposure to three zoonotic infections (Brucella suis, Mycobacterium avium, and HEV) in the Campania region (Southern Italy). A total of 370 blood samples were collected and tested with commercial indirect ELISAs to evaluate the circulation of these pathogens. Prevalences of 41.4%, 3.5%, and 0% were found for HEV, MAP, and Brucella suis, respectively. The data obtained are in line with what has been found in other European countries or in other industrialized countries undergoing eradication plans for Brucella. The data relating to HEV have also been confirmed in other epidemiological studies in the literature (pigs and deer are the main reservoirs of the infection, and therefore, the presence of anti-HEV antibodies in these species is very frequent). The evaluation of risk factors highlighted how higher seroprevalences were obtained in animals at the end of their production careers. This study highlights the spread of some zoonoses in the pig population and the need for continuous surveillance in reservoir species.