Brucellosis is one of the most important bacterial zoonotic diseases worldwide, characterized in domestic animals by long-term reproductive disorders. As known, wild boars (Sus scrofa) are natural hosts for Brucella suis biovar 2, in which the infection passes in inapparent form, increasing the pathogen transmission risk to domestic pigs, other domestic animals and humans. So far, no studies regarding brucellosis in wild boars in Serbia have been published. During the hunting season 2020/2021, 480 sera of wild boars living in Serbia were collected and tested for the presence of anti-Brucella antibodies. For the serological survey, the Rose Bengal Test (RBT) and competitive enzyme-linked immunosorbent assay (c-ELISA) were used. Of the 480 sera, 45 sera tested positive, indicating the acquired Brucella seroprevalence in wild boars of 9.4%. The greatest numbers of Brucella seropositive animals were detected in the eastern parts of the country and in one of the central districts, i.e., Pomoravski, Branicevski, Borski and Juznobanatski. This study provides the first data regarding brucellosis in the wild boar population in Serbia, revealing the seroprevalence of Brucella, thus indicating that wild boars as natural hosts and/or vectors of Brucella likely present a risk for the infection of other animals.

Background: Canine skin and ear infections are common in small-animal practice and increasingly complicated by multidrug resistance (MDR), yet data from Serbia are limited. This study aimed to describe the bacterial etiology and antimicrobial resistance patterns in canine otitis externa and pyoderma. Methods: We retrospectively reviewed laboratory records from the Clinical Bacteriology and Mycology Laboratory, Faculty of Veterinary Medicine, University of Belgrade (January 2017–August 2024). A total of 422 non-invasive swabs from clinically ill dogs were included (ears: n = 210; skin: n = 212). Bacterial identification used conventional methods and commercial systems, and disk-diffusion susceptibility testing followed CLSI/EUCAST guidance. Methicillin resistance in staphylococci was assessed by cefoxitin/oxacillin screening; MRSA was confirmed by PCR and PBP2a detection. Resistance trends were compared between 2017–2020 and 2021–2024. Results: The leading pathogens were Staphylococcus pseudintermedius (ears 48.1%; skin 79.7%) and Pseudomonas aeruginosa (ears 29.1%; skin 7.6%). Staphylococci showed high resistance to macrolides, clindamycin, tetracycline, and first-line β-lactams (amoxicillin–clavulanate, cephalexin), with the highest susceptibilities to amikacin, florfenicol, and rifampicin. P. aeruginosa remained most susceptible to amikacin, polymyxin B, and imipenem. Between the two periods, S. pseudintermedius resistance increased to amikacin, fusidic acid, and cephalexin, while resistance to florfenicol decreased. P. aeruginosa resistance to imipenem increased. The prevalence of methicillin-resistant S. pseudintermedius (MRSP) was 27.4% (74/270). MDR S. pseudintermedius and MDR P. aeruginosa were identified in 38.5% and 53.3% of isolates, respectively. One isolate of each species was resistant to all tested drugs. Conclusions: These findings confirm high levels of antimicrobial resistance in major canine skin and ear pathogens and emphasize the need for susceptibility-based therapy, rational antimicrobial use, and ongoing surveillance in small-animal practice.

Today, pets are the source of numerous infectious diseases that can be transmitted to humans, as a result of their increasingly frequent contact. The most important viruses with zoonotic potential include rabies and influenza viruses as well as rotaviruses and noroviruses. However, the importance of individual viruses varies depending on the climate and infectious disease control systems in certain countries. Dogs, cats, and other increasingly popular types of pets can transmit bacterial zoonotic agents to humans in various ways. In addition to known pathogens such as the bacteria causing leptospirosis, salmonellosis, campylobacteriosis, or brucellosis, the bacteria Pasteurella multocida and Bartonella henselae transmitted by bites or scratches are also significant in human pathology. There has been a significant increase in the prevalence of methicillin-resistant strains of Staphylococcus aureus in isolates originating from pets and the transmission of these strains between humans and animals requires special attention. Furthermore, fungi causing diseases such as sporotrichosis or dermatophytosis are linked to long-term and persistent infections in humans. The epidemiological situation caused by SARS-CoV-2, and the assumption of an interspecies jump of this virus from animals to humans, including its documented presence in domestic cats, dogs, tigers, and martens, have raised the question of the possibility of virus transmission from pets to humans. However, the current pandemic is caused exclusively by SARS-CoV-2 transmission in the human population, and these animals are not a source of infection for humans. A significant number of zoonoses originating from pets is a threat to public health, thus requiring the "One Health" approach through close cooperation between human and veterinary medicine to develop and implement effective health measures for both humans and animals. As part of responsible ownership, pet owners must be informed by veterinarians about measures to prevent infectious diseases and certain risks that are related to keeping certain species of animals.