West Nile virus (WNV) is a mosquito-borne flavivirus that remains an important public and veterinary health concern across Europe. Periodic outbreaks affecting humans, horses, and wildlife highlight the complex ecological interactions underlying viral circulation. This narrative review aims to synthesize current knowledge regarding WNV epidemiology, transmission dynamics, and surveillance strategies in Europe, with particular attention to the Romanian context. Available surveillance data indicate recurrent seasonal transmission in several European regions; however, reported case numbers may be influenced by differences in diagnostic capacity, reporting practices, and surveillance intensity among countries. Recent studies suggest that environmental variability, vector adaptation, and host community composition play important roles in shaping regional transmission risk, although the relative contribution of these factors remains incompletely quantified. Despite expanding surveillance networks and One Health initiatives, important knowledge gaps persist regarding the integration of environmental risk indicators, vector ecology, and operational preparedness into coherent risk-assessment frameworks. This review therefore examines current epidemiological patterns, evaluates surveillance approaches, and discusses emerging drivers of WNV transmission in Europe. As a narrative synthesis based on published literature and surveillance reports, this review is subject to limitations related to heterogeneity in available data and differences in national reporting systems. Nevertheless, a clearer understanding of these interacting factors may support improved surveillance strategies and more adaptive public health responses to future WNV transmission events. Reported surveillance data should be interpreted cautiously, as differences in national surveillance intensity, diagnostic capacity, and reporting frameworks across Europe may influence notified case numbers. Consequently, reported outbreaks do not necessarily reflect proportional differences in transmission intensity.

West Nile Virus (WNV) is a mosquito-borne zoonosis with recurrent equine and human cases in Romania. Horses, although dead-end hosts, act as sentinels for local viral circulation. Farm-level risk conditions remain under-characterized. This pilot, exploratory cross-sectional study assessed 42 equine facilities in western Romania (2024). A standardized 10-item checklist was applied and a Composite Environmental Risk Score (CERS) (0–10, unweighted) was computed per facility. Spatial analysis in QGIS included distances to nearby water bodies. No serological or entomological data were collected; these are recommended for future validation. Stagnant water occurred at 71.4% (30/42) of facilities, uncovered rain-collecting containers at 64.3% (27/42), and outdoor housing of horses at 81.0% (34/42). Insect screens were present at 21.4% (9/42) and chemical/biological control at 33.3% (14/42). By design, the CERS ranged from 0 to 10; in our sample the observed range was 0–8 because not all assessed risk conditions co-occurred across sites. Overall, 42.9% (18/42) were classified as high risk (≥6). Neurological signs were reported anecdotally by some managers but were not analyzed. Mosquito-favorable conditions are widespread in Romanian equine facilities. CERS shows promise as a low-cost, rapid tool for routine facility-level assessment of environmental conditions favoring mosquito presence and prioritization of preventive actions. Integrating environmental risk scoring with entomological and serological surveillance could strengthen One Health early-warning systems. Such integration would support prevention of WNV and other mosquito-borne zoonotic pathogens in endemic European settings.

West Nile virus (WNV) circulates endemically in Romania, yet prevention of WNV infection in horses largely depends on owner-driven decisions that require accurate risk perception and veterinary guidance. A cross-sectional online survey was carried out between May and November 2025 to evaluate the knowledge, attitudes, and preventive practices (KAP) regarding WNV among 227 horse owners from various Romanian regions. In total, 67.4% of respondents had previously heard of WNV. The main transmission route was correctly identified as mosquito bites by 49.8% of participants, while 32.2% answered “don’t know” or presented misconceptions: horse-to-horse contact (9.3%), tick bites (10.6%) and blood transfusion (0.4%). Recognition of clinical signs was limited, with fever (31.3% of respondents) and gait abnormalities or ataxia (24.7% of respondents) being most frequently mentioned, followed by inappetence (19.4% of respondents), seizures (18.1% of respondents), coughing (8.8% of respondents), and abortions (10.6% of respondents); 47.6% of respondents were unable to identify any specific signs. Awareness of the existence of an equine WNV vaccine was reported by 23.8% of respondents, while only 4.0% indicated that their horses had been vaccinated. The most common preventive measures included the use of insecticides in stables (61.2%) and topical repellents on horses (55.5%), whereas environmental control actions such as removing standing water (14.1%) or avoiding swampy areas (11.9%) were less frequent; 19.4% reported taking no preventive measures. Veterinary communication was limited, with only 17.2% of respondents having received information about WNV from a veterinarian, and 21.6% perceiving a real risk of infection in Romania. Overall, the data show a marked disconnect between awareness and actionable prevention (particularly vaccination and environmental mosquito control), indicating that targeted owner education must be paired with structured veterinary communication to translate knowledge into preventive uptake in endemic settings.

West Nile virus (WNV) is a globally distributed mosquito-borne flavivirus with significant implications for both veterinary and public health. While horses are incidental dead-end hosts, their epidemiological role extends beyond clinical disease, as they can serve as effective sentinel hosts for detecting local viral circulation. Their frequent exposure to mosquito vectors, ability to mount measurable antibody responses, geographic stability, accessibility for monitoring, and the possibility of observation within managed owner–veterinarian systems make them particularly suitable for surveillance within a One Health framework. Evidence from Europe and the Americas demonstrates that equine seroprevalence and field surveillance can identify transmission hotspots, reveal silent circulation, and contribute to the understanding of spatial and temporal risk patterns. The review also addresses key limitations, including vaccination effects, flavivirus cross-reactivity, methodological heterogeneity, and challenges in interpreting serological data across different ecological contexts. Strengthening equine sentinel surveillance through standardized methodologies and integration with predictive and geospatial approaches may improve early warning capacity and support more effective control of WNV and other emerging arboviral diseases.

West Nile virus (WNV) is a mosquito-borne flavivirus of growing importance for both human and equine health in Europe. Horses are highly susceptible to neurological disease and, because they share ecological exposure with humans, they represent valuable sentinels for detecting local viral circulation within a One Health framework. However, diagnosis of WNV infection in equines is complicated by the short and low-level viraemia, which limits the sensitivity of molecular assays, and by serological cross-reactivity with related flaviviruses and the confounding effects of vaccination. In this narrative review, we summarise the current diagnostic tools for WNV in horses, including direct detection methods (RT-qPCR, virus isolation, antigen detection) and indirect serological approaches (IgM and IgG ELISA, virus neutralisation tests), and discuss their practical performance and constraints in clinical and surveillance settings. We further examine equine surveillance systems, passive clinical reporting, active serosurveys and sentinel cohorts, and their integration with vector, avian and environmental monitoring. Key challenges include methodological heterogeneity, limited access to confirmatory testing and variable cross-sector data sharing. Finally, we outline future directions, highlighting the need for harmonised laboratory protocols, innovative field-deployable diagnostics, genomic surveillance and integrated, multi-source monitoring systems to strengthen early warning capacity and improve preparedness for WNV outbreaks in equine populations.

Pasteurellosis is a major bacterial disease of domestic rabbits, commonly associated with respiratory disorders, abscesses, reproductive pathology, and systemic infections. This study investigated the occurrence, clinical manifestations, pathological lesions, and antimicrobial susceptibility of bacterial isolates obtained from rabbits raised in traditional extensive systems in western Romania, with identification of Pasteurella multocida performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). A total of 308 rabbits from 23 holdings were clinically examined, necropsied when applicable, and subjected to bacteriological analysis. Clinical signs compatible with pasteurellosis were observed in 132 rabbits (42.9%), including respiratory diseases, abscess formation, otitis, and reproductive disorders. Samples collected from affected and deceased rabbits were cultured and analyzed using MALDI-TOF MS, confirming 87 isolates as P. multocida. Antimicrobial susceptibility testing using the VITEK 2 system revealed high resistance to tetracyclines (63.22%) and beta-lactams (55.17%), while higher susceptibility was observed for enrofloxacin (91.95%), gentamicin (89.66%), ciprofloxacin (86.21%), and florfenicol (80.46%). The presence of multidrug-resistant isolates highlights the need for laboratory-guided antimicrobial therapy and improved biosecurity measures in traditional rabbit holdings.