Veterinary Sciences

Hepatitis E virus (HEV) is a significant public health concern and a leading cause of acute viral hepatitis worldwide. In recent years, HEV has been increasingly recognized as a wildlife-associated zoonotic pathogen, with numerous free-ranging species contributing to its maintenance and transmission. While domestic pigs remain the primary reservoir for human infection globally, growing evidence indicates that wild animals, particularly wild boars, cervids, lagomorphs, rodents, and carnivores, play a critical role in the ecology of HEV. Wild boars are the principal wildlife reservoir, with HEV seroprevalence in Europe ranging from less than 5% to more than 50%, including some of the highest levels reported in the Balkans. In addition to the frequent detection of HEV RNA in wild boar liver and muscle, viral RNA has also been identified in several other game species, most consistently in red deer, roe deer, and, in some regions, hares and wild rabbits, highlighting food safety risks associated with the consumption of raw or undercooked game meat. In regions such as the Balkans, where hunting activities and handling of wild game are widespread, these practices may further increase occupational and dietary exposure to HEV. Rodents may further complicate the epidemiological landscape through environmental contamination of water, soil, and farm surroundings, thereby facilitating indirect transmission pathways. As wildlife populations expand and human–animal interfaces intensify, understanding HEV dynamics in free-ranging species is essential for assessing zoonotic risks and implementing a strengthened One Health approach. This narrative review synthesizes and critically examines current evidence on HEV prevalence, molecular characteristics, and transmission pathways in wildlife, with particular emphasis on Europe and focused consideration of the Balkans as an epidemiologically heterogeneous and underrepresented subregion; examines associated public health implications; and highlights the importance of integrating wildlife into food safety and One Health surveillance frameworks. Existing knowledge gaps and limitations in wildlife surveillance are also discussed.

Pheochromocytomas (PHEO) are rare adrenal medullary tumours characterised by catecholamine secretion. Accurate diagnosis relies on the sensitive measurement of metanephrine (MN) and normetanephrine (NMN); however, the application of liquid chromatography–mass spectrometry (LC–MS/MS) in veterinary medicine remains limited. This study aimed to develop and analytically validate an LC–MS/MS method for the simultaneous quantification of urinary MN and NMN in dogs, establish reference intervals (RIs) for MN- and NMN-to-creatinine ratios (uMN:CR and uNMN:CR), and preliminarily assess the diagnostic utility of uNMN:CR for PHEO detection. The RIs were 2.2–78.9 nmol/mmol for uMN:CR and 4.4–77.4 nmol/mmol for uNMN:CR. Dogs with PHEO showed significantly higher uNMN:CR values compared with dogs with other adrenal masses, non-adrenal disease, or healthy controls. Using the upper RI limit as a threshold, sensitivity and specificity were 91.7% and 35.7%, respectively. Receiver operating characteristic analysis identified an optimal uNMN:CR cut-off of 203.7 nmol/mmol, yielding 78.6% sensitivity, 83.3% specificity, and an overall diagnostic accuracy of 85% (95% CI: 0.68–1.00). These findings support LC–MS/MS as a reliable approach for urinary metanephrine analysis and uNMN:CR as a valuable biochemical tool for PHEO identification in dogs.

Osteopontin (OPN) is a phosphorylated acidic glycoprotein that serves various purposes across various systems. Principally, it aids in adhesion and signaling. It is an important protein related to reproduction, which has been discovered in several species, among which is the dromedary camel, where it has been detected in the endometrium and conceptuses at the time of implantation. The objective of this research is to investigate and examine the expression patterns of OPN mRNA and protein in both endometrial uterine horns with their associated fetal membranes during the first trimester of camel pregnancy. Endometrial and fetal membranes were collected from eight pregnant female camels during the first trimester of pregnancy (Days 70–110 of pregnancy). The temporospatial expression of OPN was studied in endometrial tissues and their conceptuses from the left uterine horn (LUH) and right uterine horn (RUH) using quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC) techniques. The results showed a gradual increase in OPN mRNA expression with advancing pregnancy in both LUH and RUH of endometrial and fetal membranes tissue. OPN protein was predominantly found in the uterine luminal epithelium (LE) and fetal trophectoderm (Tr), stroma, and uterine glands. In conclusion, our findings demonstrate that OPN is consistently present in both the endometrium and fetal membranes throughout the first trimester of pregnancy. This observation advances previous knowledge by confirming OPN expression even during the early first trimester, suggesting its crucial role in supporting embryo attachment, implantation, and placentation processes in the dromedary camel.