Phasianus chaphamaparvovirus 1 is a newly recognized pathogen associated with high mortality in young pheasant chicks with significant losses for pheasant breeders. Here we present an outbreak of necrotizing hepatitis with high mortality in a flock of young pheasant chicks in Bosnia and Herzegovina associated with Phasianus chaphamaparvovirus 1 and coccidiosis coinfection. Severe necrotizing hepatitis with characteristic intranuclear inclusion bodies in affected hepatocytes was observed on microscopic examination. In addition, multifocal areas of intestinal mucosal necrosis with numerous developing stages (meronts) of coccidia were present. Phasianus chaphamaparvovirus 1 was detected with qPCR from the livers of diseased birds. Our report represents the first data on the presence of this new virus in pheasant flocks in the Balkan region and suggests that the virus is widespread across Europe. It further supports the inclusion of Chaphamaparvovirus as a differential diagnosis of pheasant mortality outbreaks both in breeding facilities and in the wild.

Simple Summary The virus responsible for COVID-19 can affect multiple animal species, including wildlife. In this study, we tested, by commercial ELISA, blood samples from red foxes and golden jackals in Serbia for IgG anti-SARS-CoV-2 antibodies. Antibodies were detected in both species, with a seroprevalence of 13.3% in red foxes and 7.3% in golden jackals (overall seroprevalence: 10.3%). All the samples were tested in parallel by an in-house adapted ELISA. These results provide the first evidence of SARS-CoV-2 exposure in wild canids in Serbia. Monitoring pathogens in wildlife improves our understanding of disease ecology and supports early recognition of potential zoonotic risks.

The burden of nephrotoxicity and ototoxicity consequences caused by gentamicin warrants preventive therapeutic measures. Our aim was to evaluate combined and potentially synergistic effects of rosuvastatin and curcumin, both possessing anti-inflammatory and antioxidant properties, compared to their monotherapies in a gentamicin-induced model of nephrotoxicity and ototoxicity. In a randomized, controlled study, 36 male Wistar rats were allocated to six groups and treated for 5 days: negative control group received solvent, model group gentamicin (100 mg/kg, intraperitoneally), treatment groups gentamicin and via orogastric tube either standard-dose rosuvastatin (5 mg/day), reduced-dose rosuvastatin (1.25 mg/day), curcumin (100 mg/kg), or combination of reduced-dose rosuvastatin and curcumin. Human rosuvastatin doses were converted to rat doses using the conversion factor of 6.2. Functional outcomes evaluated by Preyer pinna reflex for hearing and a vestibular battery test were complemented by renal and cochlear histology, biochemical biomarkers of injury, inflammation, and oxidative stress. Gentamicin induced proximal tubular necrosis and cochlear and vestibular damage. Compared to monotherapies, combination therapy significantly preserved renal architecture, improved renal biomarkers, reduced early inflammatory biomarkers, preserved cochlear architecture and drove vestibular protection. It also alleviated gentamicin-induced cardiotoxicity. Rosuvastatin provided stronger auditory protection, with reduced-dose rosuvastatin superior to standard-dose in preserving vestibular function. Bliss independence modelling showed that combined therapy synergistically inhibited kidney injury and inflammation. In conclusion, the combination of reduced-dose rosuvastatin and curcumin outperforms both monotherapies in alleviating gentamicin-induced nephrotoxicity, audiotoxicity and vestibulotoxicity, whilst synergistically attenuating nephrotoxicity and early-phase inflammation in rats. These findings highlight promising preventive strategies against aminoglycoside nephrotoxicity and ototoxicity.

Mosquitoes are important vectors of human and animal pathogens, yet data on their diversity and vector potential remain scarce for the central Balkan country Bosnia and Herzegovina. This study aimed to assess mosquito species composition, associated pathogens, and the potential public health risks in BIH. Adult mosquitoes were collected with light traps, identified morphologically and by barcoding, and screened molecularly for various pathogens, including West Nile virus (WNV), Dirofilaria spp., Trypanosoma spp., and Plasmodium spp. A total of 2691 mosquitoes of 17 species were identified, with Culex pipiens/torrentium being most abundant and new records of Aedes albopictus and Ae. japonicus japonicus. The first detection of WNV (lineage 2) RNA in mosquitoes in BIH highlights the potential risk of circulation in the region, aligning with findings from neighboring countries. In addition, DNA of filarioid nematodes (Dirofilaria immitis, D. repens, and Setaria tundra) were detected, underscoring their role as potential vectors of zoonotic dirofilariasis. Also, Trypanosoma and Plasmodium DNA was detected, warranting further investigation into the possible involvement of mosquitoes in their transmission. The detection of invasive Aedes species and mosquito-borne pathogens emphasize the need for strengthened vector surveillance in southeastern Europe, particularly in BIH. This study provides the first barcode inventory of 17 mosquito species and novel molecular evidence of mosquito-borne pathogens in BIH, offering valuable baseline data for future epidemiological assessments and sustained entomological surveillance.

Hepatozoon spp. are common pathogens in dogs and other Carnivora in many parts of the world, especially in the tropics. There is considerable taxonomic debate concerning the Hepatozoon species infecting Carnivora. Morphological descriptions of several Hepatozoon species are inadequate and their validity is questionable. Additionally, different terminology has been used for the description of life cycle stages. Here, we provide a comprehensive review of the Hepatozoon species in the Carnivora, using a uniform terminology. Worldwide prevalence of clinical and subclinical Hepatozoon infections for the past century is tabulated and critically evaluated. We also review the epizootiology, clinical signs, diagnosis, and treatment of hepatozoonosis in the Carnivora. The morphology and life cycles of seven valid species with known merogonic stages (Hepatozoon americanum, H. canis, H. felis, H. martis, H. rufi, H. silvestris, H. ursi) are summarized in a table using standard terminology. Additional information on H. apri, H. martis, and H. silvestris life cycle stages is provided. Information lacking for H. procyonis, H. luiperdjie and H. ingwe is discussed. The relevance of H. mustelis, H. banethi and H. ewingi is discussed and they are considered as invalid species. For the benefit of future researchers, worldwide reports of prevalence, clinical disease, diagnosis, and treatment of Hepatozoon infections in domestic and wild Carnivora for the past century are summarized in tables alphabetically and chronologically for each country. Co-infections of H. canis, H. americanum, H. felis, and H. silvestris are summarized and discussed. The role of Hepatozoon infections causing clinical illness in wild Carnivora is discussed, particularly for red foxes, coyotes, and mustelids.

Background: Hepatobiliary tumors are uncommon in dogs, and metastatic liver tumors are diagnosed more frequently than primary liver tumors. Hepatocellular carcinoma is the most prevalent primary liver malignant tumor. Case Description: An 11-year-old spayed female Tibetan Terrier was referred to the University of Sarajevo Veterinary Teaching Hospital due to recurrent painful urination attempts, straining urination, hematuria, and decreased appetite. Abdominal ultrasonography revealed a moderately distended bladder containing urolith, bladder wall thickening, and sediment. Incidentally, a hyperechoic hepatic mass on the left medial liver lobe and hepatomegaly were detected along with gallbladder sludge. Surgical cystolithotomy and partial liver lobectomy were performed. Histopathological examination confirmed the hepatic mass as clear cell hepatocellular carcinoma (CCHCC). Conclusion: Although this rare histological subtype has been documented, its biological behavior and clinical features remain poorly understood due to the scarcity of cases. A recent publication by Jung et al. (2021). described the first cytological, histological, and clinical case presentation of CCHCC in dogs, suggesting that obesity and hyperlipidemia may be potential risk factors. However, these proposed risk factors were not detected in the present case, implying that CCHCC in dogs is a rare and poorly understood condition that warrants further attention in veterinary research.

The etiology of transmissible viral proventriculitis (TVP) of broiler chickens has been discussed since its initial recognition 40 years ago. Regardless of its low direct impact on mortality rate, it leads to high economic losses in the broiler industry through reduction of food conversion, weakening of birds, and their increased susceptibility to pathogens. The aim of the present study was to examine the potential presence of TVP on the broiler chicken farms in Bosnia and Herzegovina, to characterize microscopic lesions, and to investigate the viruses implicated in etiology of TVP by PCR-based methods. In total, 143 diseased broiler chickens from 16 farms in Bosnia and Herzegovina were euthanized and subjected to necropsy and subsequent histopathology of proventriculi. A representative number of proventriculi samples (n = 50) that exhibited histopathologic changes were processed for molecular detection of chicken proventricular necrosis virus (CPNV), girovirus (GyV3), chicken anemia virus (CAV), and infectious bursal disease virus (IBDV) by PCR-based methods. In addition, samples of bursa of Fabricius (n = 39) and spleen (n = 50) were tested for IBDV. Histopathology revealed changes consistent with TVP in 39.8% (57/143) and LP (lymphocytic proventriculitis) in 2.1% (3/143) of samples. All 50 proventricular samples showed positivity to CPNV with Ct values ranging between 18 and 26. GyV3 was detected in eight samples (16%), with Ct values ranging from 11.1 to 27.5. The presence of CAV was more prominent (38%), with 19 positive broiler chickens (Ct ranging from 9.6 to 35.6). Pooled samples of spleen, bursa, and proventriculi from three farms were positive for IBDV. The obtained results represent the first documented data on TVP and the first record of CPNV and GyV3 presence in broiler farms from Bosnia and Herzegovina.

Ticks are key vectors of zoonotic pathogens, and their expanding distribution in Europe heightens public health concerns. In Bosnia and Herzegovina, while tick distribution is well documented, molecular data on tick-borne pathogens remain limited. This study aimed to illustrate the presence and diversity of these pathogens, focusing on areas with high human activity. Ticks (n = 556) were collected in April 2022 from eight diverse locations, including urban parks, private properties, and rural sites. PCR-based screening was employed to detect Anaplasmataceae, Borrelia, Francisella, Piroplasmida, Rickettsia, and tick-borne encephalitis virus (TBEV), with subsequent sequencing to confirm results. Further characterization of Borrelia burgdorferi sensu lato was achieved via reverse line blotting (RLB) hybridization and sequencing. Ixodes ricinus was the most prevalent species, followed by Dermacentor marginatus and D. reticulatus. Our analysis revealed an overall infection rate of 22.1% in questing ticks, with Rickettsia spp. and Borrelia spp. predominating. Notably, seven Borrelia species were identified in I. ricinus, alongside Anaplasma phagocytophilum, Rickettsia helvetica, and R. monacensis, with co-infections mainly observed in peri-urban areas. This study provides the first molecular evidence of multiple tick-borne pathogens in the region, underscoring the need for further surveillance and risk assessment of tick-borne diseases in the region.

The peritrophic matrix (PM) is a non-cellular, glycan-rich structure that lines the gut epithelium of most invertebrates, including arthropod vectors that transmit diseases of public health and veterinary concern. This semipermeable barrier, functionally analogous to the vertebrate mucosal layer, separates the gut lumen from epithelial cells and provides protection against invading pathogens and their toxins. Beyond its mechanical protective role in the gut, the PM plays a crucial part in arthropod innate immunity. Here, we summarize the most recent advances in understanding the molecular mechanisms of vector-pathogen interactions in blood-feeding arthropods and discuss the significance of the PM in modulating vector competence. This knowledge could contribute to the development of novel strategies to control vector-borne infections.

Although the importance of the microbiome in the context of tick biology and vector competence has recently come into a broader research focus, the field is still in its infancy and the complex ecological interactions between the tick residential bacteria and pathogens are obscure. Here, we show that an environmentally acquired gut bacterium has the potential to impair Borrelia afzelii colonization within the tick vector through a secreted metalloprotease. Oral introduction of either Bacillus cereus LTG-1 isolate or its purified enhancin (BcEnhancin) protein significantly reduces B. afzelii burden in the guts of Ixodes ricinus ticks. This effect is attributed to the ability of BcEnhancin to degrade a glycan-rich peritrophic matrix (PM), which is a gut protective barrier essential for Borrelia survival. Our study highlights the importance of the gut microbiome in determining tick vector competence and provides a deeper mechanistic insight into the complex network of interactions between Borrelia, the tick, and the tick microbiome.