Preventive Veterinary Medicine

IntroductionAntimicrobial Resistance (AMR) presents a critical public health challenge, particularly in smallholder broiler farming, where antibiotics are often used preventively in the absence of effective biosecurity measures. ObjectiveThis study investigates the adoption of biosecurity practices as a sustainable alternative to antibiotics through Participatory Systems Mapping and Experimental Games. MethodsA participatory mixed-methods study was conducted in southern Bangladesh (September 2024-June 2025). Causal Loop Diagrams (CLDs) were co-created with farmers, dealers, and veterinary officers. Ten broiler farmers from single village were selected via purposive and snowball sampling. Experimental games simulated four production cycles where farmers chose Option A (biosecurity, adopters) or Option B (antibiotics, non-adopters) after several interactive trainings. Key metrics including biosecurity compliance (0-12 scale), mortality, FCR, antibiotic use, outbreak history, and economic outcomes were recorded. ResultsCLD analysis revealed a reinforcing loop of increased antibiotic reliance driven by fear of mortality, and balancing loops involving training, biosecurity practices, and consumer incentives to reduce use. Five farmers chose Option A, and both groups remained stable until Round 4. Adopters had flock sizes of 800-2000 birds (non-adopters, 600-1000; mean for both = 1000), were younger, and more educated compared to non-adopters. At baseline, both groups had similar biosecurity scores (0). Adopters had higher mean outbreaks (2 vs. 1.4), mortality (5.6 vs. 4.2), antibiotic use (3.6 vs. 3), and FCR (1.8 vs. 1.6) compared to non-adopters. By Round 4, adopters improved biosecurity scores by 125%, eliminated outbreaks, reduced mortality by 52.6%, stopped antibiotic use, improved FCR by 13.3%, and gained 71.72% profit per bird compared to non-adopters. Non-adopters, influenced by adopters, increased biosecurity scores by 25%, reducing outbreaks, mortality, antibiotic use, and FCR. Adopters also increased direct sales to consumers, yielding a 10%-16% profit gain per bird each round. ConclusionThis study highlights the successful adoption of biosecurity practices by farmers, replacing antibiotics and improving production outcomes. Farmer-driven adoption of these practices fosters long-term sustainability and supports a healthier planet within the One Health framework.

ObjectiveThis study aimed to compare a novel surveillance methodology to detect Porcine Reproductive and Respiratory Syndrome virus against oral fluid methodology in swine herds. Materials and methodsTwo pilot studies were conducted using two separate, high-risk commercial nurseries in central Nebraska, comparing two different surveillance sampling approaches (DARO Systems vs. oral fluid (OF)) in the detection of Porcine Reproductive and Respiratory Virus (PRRSV). Each nursery contained eight rooms with an average site inventory of 12,500 pigs. Weekly testing conducted in three of the eight rooms using DARO Systems and OF methodology to identify PRRSV until there was a positive sample, then daily testing of all rooms was conducted. Reverse Transcription-Quantitative Polymerase Chain Reaction was used for identification of positive PRRSV. ResultsSurveillance testing using novel methodology DARO Systems identified PRRSV in nurseries on average 3.91 days earlier than OF. ImplicationsDARO Systems allows for a more robust whole-herd sampling technique to rapidly and accurately detect PRRSV 3.91 days earlier than gold standard approaches. Additionally, DARO Systems allows for an unbiased, whole-herd sampling approach. This method enables producers to implement earlier disease mitigation strategies.

Compassion fatigue is a well-documented hazard among healthcare and veterinary professionals, yet the psychological toll on informal caregivers of feral cat colonies, likely numbering several tens of thousands in Portugal, remains largely unexplored. This cross-sectional study examines internal and external factors associated with the secondary traumatic stress component of compassion fatigue among 172 informal caregivers in Portugal. Secondary traumatic stress refers to work-related secondary exposure to individuals who have experienced extremely stressful or traumatic events. Structured telephone interviews assessed sociodemographics, colony management, compassion satisfaction, resilience, spiritual well-being, and perceived social support. Univariate and multivariable linear regression identified predictors of secondary traumatic stress. Results indicate that 47% of participants experienced moderate secondary traumatic stress, and 10% reported high levels. Multivariable analysis revealed that caring for large colonies (more than 25 cats) and being unemployed were significantly associated with higher fatigue. Conversely, older age, higher perceived family support, and the resilience dimension of serenity served as protective factors. Interestingly, finding meaning in life was positively correlated with fatigue, suggesting that caregivers who perceive their role as central to their life purpose may become more emotionally invested, increasing vulnerability to distress when unable to help animals. Official colony registration and formal institutional support did not significantly alleviate fatigue. These findings highlight that institutional support alone is insufficient to mitigate fatigue among informal caregivers, who experience significant distress driven by both practical burdens and profound emotional involvement. The most frequently reported concern among caregivers was the inability to cover the costs of feeding and veterinary care for the cats. Interventions must address both external needs (e.g., support to cover veterinary and feeding expenses for the cats) and internal coping mechanisms. Implementing psychosocial support alongside trap-neuter-return programs may also improve caregiver well-being and foster sustainable urban feral cat management. This underscores a One Health perspective, demonstrating that animal health is closely interconnected with human well-being and environmental health.

Ethiopia experiences devastating economic losses from an ongoing endemic burden of trans-boundary animal diseases (TADs). TADs are highly transmissible infectious diseases of animals, often able to spread rapidly with significant economic and public health consequences. Contagious bovine pleuropneumonia (CBPP), foot-and-mouth disease (FMD), and lumpy skin disease (LSD) are among the global priority TADs for cattle. In this study, we used responses from a survey about cattle disease delivered to livestock keepers across Ethiopia. We used generalized additive mixed models applying neighborhood cross-validation method which accounts for spatial dependence in the data to investigate the spatially variable relationships between bioclimatic variables and distribution of CBPP, FMD, and LSD in Ethiopia. We also developed model-based risk maps of these diseases using a geostatistical kriging method to guide knowledge-based decision making. The results show the risks of CBPP vary with altitude and relative humidity, risks of FMD with temperature and relative humidity, and of LSD with temperature and precipitation. The gaussian spatial smooth terms are all significant. The maps are produced using rigorous statistical analysis with very low prediction errors and can thus be considered reliable. Our results have implications for the impacts of climate change, and the vulnerability of communities in high-risk areas. The risk maps illustrate how such maps contribute to climate-informed disease early warning systems.

Purpose: Alpha-gal syndrome (AGS) is an emerging health issue. This syndrome, caused by the bites of ticks, induces allergic reactions to the sugar molecule galactose-alpha-1,3-galactose after exposure to non-primate mammalian meat and other byproducts. Agricultural workers spend significant time outdoors placing them at an increased risk for tick bites and tick-borne diseases, like AGS. This study aimed to characterize farmers and ranchers' prior knowledge, symptomology, and diagnostic experiences with AGS. Methods: We conducted a cross-sectional survey of more than 200 farmers and ranchers with a self-reported AGS diagnosis. The survey captured farmers and ranchers' experiences related to prior knowledge and experience with tick bites and AGS, reported symptoms, and obtaining a diagnosis. Findings: A total of 201 respondents across 26 states participated in the survey, with the majority from Missouri and Oklahoma. We identified four distinct symptom clusters, with the most reported symptoms being abdominal cramping, diarrhea, itchy skin, and nausea. Women more often reported gastrointestinal discomfort, and men were more likely to be in the mild symptom category. On average, participants reported 2.98 medical provider visits before receiving a diagnosis, most being diagnosed by general practitioners and allergists. Conclusions: No previous studies have focused on the symptom and diagnostic experiences of farmers and ranchers with AGS. Capturing such data is essential as these workers may experience unique occupational challenges following AGS diagnosis. The diagnostic experience data support a continuing need to educate and empower AGS patients and providers, especially agricultural workers and providers serving rural communities.

Introduction Nontyphoidal Salmonella enterica (NTS) is a major zoonotic enteric pathogen. Animal contact-related NTS outbreaks have increased in the United States of America (U.S.) over the last decade. Geospatial analysis can identify locations with elevated risk of NTS outbreaks where public health authorities can focus their NTS prevention and intervention efforts. Methods We analyzed NTS outbreak data reported from individual states to the Centers for Disease Control via the National Outbreak Reporting System between 2009 and 2022 across the continental contiguous U.S. A geospatial analytical framework that included disease mapping, spatial interpolation, and global and local clustering methods was applied to identify regions with high NTS outbreak rates. Results A total of 104 NTS single-state outbreaks were reported to the National Outbreak Reporting System (NORS) during the study period. The mean annual incidence rate was 0.02 NTS outbreaks per million person-years. The primary animal contact categories associated with these outbreaks were mammals (cattle, pigs, sheep, and horses), birds (backyard chickens, ducklings, and turkeys), and reptiles (turtles and lizards). Exposure settings included farms, fairgrounds, agricultural feed stores, veterinary clinics, dairy/agricultural settings, and residential settings. The local cluster detection methods consistently identified areas with significantly high NTS animal contact-related outbreak rates in the Mountain West, Midwest, and Northeast of the US. Conclusion NTS animal contact-related single-state outbreaks revealed distinct spatial clustering across the United States, with potentially higher risks in the Mountain West, Midwest, and Northeast. Diversity of animal-contact sources and exposure settings depicted complex transmission dynamics of NTS. Focused prevention and control programs in these areas are needed to mitigate the burden of NTS outbreaks.

Effective management of Bovine Respiratory Disease Complex (BRDC) requires timely, non-invasive diagnostic tools to protect calf health and welfare. Among early clinical signs, coughing stands out as both frequent and informative. To explore its potential for early BRDC detection, we deployed an artificial intelligence (AI)-driven acoustic monitoring system that recorded over 2,730 hours of audio during a 30-day period. Four experimental pens, each housing seven calves and stratified by infection status and antibiotic treatment, were equipped with a dedicated microphone to enable targeted acoustic surveillance. This configuration enabled pen-specific detection of cough events, which were subsequently classified using an AI HuBERT-based model trained on 1,045 labelled clips. The classifier achieved 92% accuracy. Temporal patterns in cough frequency aligned with infection dynamics, treatment responses, and circadian patterns. Notably, AI-detected coughs consistently preceded clinical scores by 1-2 days, confirming the systems sensitivity to early respiratory disorders. These findings support the use of acoustic surveillance as a valid, scalable, and autonomous tool for continuous monitoring and early warning of respiratory diseases in calves. ImplicationsThis study demonstrates that AI-powered acoustic monitoring enables real-time, non-invasive detection of coughs in calves for early warning of respiratory diseases, outperforming traditional veterinarian clinical scoring by 1-2 days. Its high accuracy and sensitivity to respiratory infection dynamics and treatment effects position it as a scalable tool for precision livestock farming.

BackgroundNontyphoidal Salmonella enterica (NTS) is a major public-health threat in the United States of America (U.S.). Evaluating associations between serovars, exposure sources, and settings in multistate outbreaks can reveal the drivers of NTS transmission and guide prioritization of targeted prevention and control strategies. MethodsWe analyzed multistate animal-contact NTS outbreaks reported to the CDC National Outbreak Reporting System during 2009-2022. We calculated incidence rates per 10 million population-years (MPY) and assessed temporal trends using Joinpoint regression. We constructed interstate co-occurrence networks linking serovars, exposure sources, settings, and states, and applied a random forest classifier to identify variables most useful for distinguishing outbreak profiles. ResultsWe identified 177 multistate outbreaks (0.06 per 10 MPY) involving 40 serovars. Incidence significantly declined from 2009 to 2013 and remained stable thereafter. Random forest rankings identified birds and reptiles as the most influential exposure sources and agricultural feed stores and residential homes as the most influential exposure settings in distinguishing outbreak profiles. Co-occurrence network analysis revealed two major communities. The first included outbreaks involving serovars Enteritidis and Infantis, bird exposure source, and agricultural feed stores or farms as exposure settings, with hubs across the Midwest, Northeast, and Southern regions. The second community involved outbreaks linked with reptiles and mammals as exposure sources, residential homes and farms as exposure settings, and serovars Hadar, Typhimurium, and Braenderup, which were concentrated in the Western and Southern regions. ConclusionsMultistate animal-contact NTS outbreaks clustered into distinct serovar-exposure, source, setting, and region patterns, suggesting different NTS outbreak transmission pathways. The persistence of NTS serovars across states, diverse animal-contact sources, and exposure settings underscores the ongoing zoonotic transmission risk at the human-animal and environmental interfaces. A region-specific One Health approach to prevent and control NTS outbreaks is suggested to reduce the health burden.

BackgroundAntimicrobial resistance (AMR) is a global public health threat driven significantly by antimicrobial misuse in agriculture, particularly in poultry farming. This study assessed the awareness, knowledge, practices, and associated factors related to antimicrobial resistance among poultry farmers in Osun State, Nigeria. MethodsA cross-sectional study was conducted among 289 poultry farmers selected through stratified random sampling across Osun State. The study included actively practicing poultry farmers aged 18 years and above who used antimicrobials in their operations. Farmers not using antimicrobials were excluded. Data were collected using a pre-tested, structured, interviewer-administered questionnaire and analyzed with SPSS version 27. Descriptive statistics, chi-square tests, and inferential analyses were used to examine relationships between variables. ResultsThe majority of respondents (89.6%) had heard of AMR, the majority 239 (92.3%) of the respondents heard it from veterinary doctors. The majority (77.2%) also demonstrated good knowledge. Most farmers (89.6%) used antibiotics, with 52.9% using them occasionally. Personal experience (57.8%) was the primary basis for antibiotic selection. About 71.6% implemented biosecurity measures, and 57.8% had received training on AMR. Significant associations were found between knowledge and practice (p<0.001) and between attitude and practice (p<0.001). ConclusionDespite high awareness, antibiotic misuse persists, driven by factors such as reliance on personal experience and limited veterinary consultation. There is a need for enhanced farmer education, stricter regulatory enforcement, and the implementation of targeted antimicrobial stewardship programs to mitigate AMR risks in poultry farming.

The spread of any pathogen depends on the dynamics of its hosts, with transmission rates typically assumed to either scale linearly with host population density (density-dependent transmission) or to be independent of it (frequency-dependent transmission). For vector-transmitted pathogens, a key determinant of transmission scaling is whether vector abundance is constant or sensitive to host abundance, with the latter being consistent with density-dependent transmission. Here, we assess whether Culicoides vector abundance increases in a manner that indicates density-dependent transmission of Culicoides-transmitted pathogens. To test this, we conducted trapping of Culicoides midges on eight livestock operations across a wide range of cattle abundances, placing traps at varying distances from the host aggregation. We used hierarchical Bayesian models to estimate the effect of host abundance on the vector-to-host ratio while accounting for differences in trapping efficacy between locations. Our results indicate a positive linear effect of host abundance on the ratio of vectors to hosts, with a posterior probability of 0.83. Median posterior values of the effect of host abundance on vector density predict a 2.3% increase (95% credible interval: -0.8, 23.2%) in the vector-to-host ratio with every 1,000 additional hosts. The weight of evidence from our study suggests that Culicoides-transmitted pathogens are likely subject to density-dependent transmission, and that transmission may be amplified in high-concentration livestock environments.

BackgroundIn 2021, the Los Angeles County (LAC) Department of Public Health suspected a leptospirosis outbreak in LAC affecting over 200 client-owned dogs. ObjectiveTo characterize the outbreak and describe microbiologic findings, risk factors, diagnostic test performance, and outcomes in dogs diagnosed with leptospirosis at two specialty practices. MethodsLeptospira culture isolates from four cases were subjected to serotyping and whole genome sequencing (WGS); WGS was also performed on one enriched genome isolate. After the outbreak, data were gathered on 59 cases through record review and compared to the background hospital population (controls, n=15,536). ResultsAll isolates were Leptospira interrogans serovar Canicola, but each was distinct based on WGS. Cases clustered in space and in time. Cases evaluated during the outbreak peak had increased odds of exposure to indoor congregate facilities (ICFs). None of 47 dogs with known leptospirosis vaccination history were completely vaccinated. Leptospira real-time PCR on blood and urine and initial serologic testing using the microscopic agglutination test and point-of-care tests were positive in 15/56 (27%), 49/54 (91%) dogs, 22/29 (76%), and 27/35 (77%) dogs respectively. Fifty-four (92%) of 59 dogs survived to discharge; some remained azotemic. No associated human cases were identified. Conclusions and Clinical ImportanceL. interrogans serovar Canicola was associated with a leptospirosis outbreak in unvaccinated dogs from LAC, which had public health implications given widespread dog ownership rates. Data analysis suggested multiple infection sources, including ICFs. Urine PCR was the most sensitive diagnostic test. Such outbreaks might be prevented through more widespread vaccination.

BackgroundThe emergence of the highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b in North America, beginning in February 2022, has highlighted the dynamic, unpredictable, and regionally variable risk of infections. Studies are needed to assess the spatiotemporal clustering of HPAI H5 at the interface between wild waterfowl and commercial poultry to better understand and mitigate this risk. MethodsPublicly available data on HPAI H5 detections in wild birds and commercial poultry from January 2022 to January 2026 were analyzed at the county level. Retrospective space-time permutation models were used to identify and scan for clusters with higher than expected detection rates. ResultsA total of 17,091 HPAI H5 detections were reported in wild birds across 1,467 county-level locations. Four species, Mallard (Anas platyrhynchos) (2,848 detections, 16.66%), Canada goose (Branta canadensis) (1,496, 8.75%), Green-winged teal (Anas carolinensis) (1,364, 7.98%), and Snow goose (Anser caerulescens) (1,084, 6.34%), accounted for 39.73% of detections. In commercial poultry, 532 outbreaks in turkey operations, 148 outbreaks in table-egg layer operations, 99 outbreaks in broiler chicken operations, and 89 outbreaks in commercial duck operations were reported, respectively. Several spillover events followed an east-to-west expansion. In early 2022, mallard detections preceded outbreaks in Northeast egg-layer and duck farms, while snow goose detections in the Upper Midwest coincided with turkey farm outbreaks. In the Pacific and Mountain West during summer 2022, detections in Canada geese overlapped with turkey farm outbreaks. A resurgence occurred in the Midwest (2025), with snow and Canada goose detections overlapping severe outbreaks in turkey and layer flocks. Additionally, in the Upper Midwest, Canada goose and mallard detections overlapped with outbreaks in commercial duck farms during fall-winter 2025. ConclusionsThe study findings demonstrate distinct vector-based transmission dynamics of HPAI H5 at the wild waterfowl-poultry interface. Farm biosecurity strategies must adapt to these recurrent, vector-specific risks.

BackgroundLivestock production systems in peri-urban areas are associated with high levels of interaction between humans, animals, and the environment, which may contribute to the dissemination of antimicrobial resistant bacteria. However, genomic characterization of resistant bacteria in the interconnected systems of humans, animals, and the environment in low- and middle-income countries like Cameroon is very limited. MethodsThis study was undertaken to investigate the ESBL-producing E. coli and K. pneumoniae in the peri-urban pig production systems in Yaounde, Cameroon, through the application of the One Health genomic approach. A total of 338 samples were collected from humans, pigs, and the environment. Enterobacterales were isolated using standard microbiological procedures, followed by antimicrobial susceptibility testing of the isolated bacteria using the Kirby-Bauer disk diffusion method based on the EUCAST breakpoints. Ten multidrug-resistant Enterobacterales with similar resistance profiles were sequenced to identify their sequence types, resistance determinants, plasmid replicons, and virulence determinants. ResultsEnterobacterales were found in 187 samples, comprising 38 human, 98 pig, and 51 environmental samples. E. coli (166 isolates) was the most prevalent species, followed by K. pneumoniae (100 isolates). Whole-genome sequencing revealed eight E. coli and two K. quasipneumoniae isolates from human, pig, wastewater, and farm environmental samples. The E. coli isolates represented seven sequence types, including the globally successful ST410 lineage. Notably, E. coli ST3580 was found in human and environmental samples from the Afanoyoa farm in different sampling months, while K. quasipneumoniae ST1535 was found in human and pig samples from the Etoudi farm in different months. All genomes encoded ESBL genes, with blaCTX-M-15 being the most prevalent, accompanied by other resistance genes to various antibiotic classes and several plasmid incompatibility groups. ConclusionsThese results show the circulation of genetically diverse ESBL-producing E. coli and K. pneumoniae in human, animal, and environmental reservoirs in peri-urban pig farming systems and the potential for cross-reservoir persistence of particular lineages. Improved One Health antimicrobial resistance surveillance and stewardship are critical to address antimicrobial resistance in rapidly urbanizing environments.

Mycoplasma bovis was first detected in cattle in New Zealand in 2017, prompting an eradication programme that incorporated extensive surveillance and a test-and-cull policy. Genome sequence data and phylodynamic models were used to inform decision making throughout the eradication programme. Isolates from 697 cattle on 126 farms were collected and sequenced between July 2017 and December 2023. Phylodynamic models were used to estimate the time of most recent common ancestor, the effective reproduction number (Reff) and effective population size, and long-range and local between-farm transmission dynamics. The analysis revealed the dramatic impact of movement restrictions and culling up to early 2020, with a sharp reduction in the Reff to less than 1 in 2018/9 and the extinction of two of three major lineages in 2020. This was followed by three-years of residual infection in farms in the South Island, associated with persistent infection of a large feedlot farm and nearby farms. The comprehensive dataset of genomic and epidemiological data provided a unique opportunity to study the dynamics of a country-wide outbreak of a single-host pathogen from first detection to potential eradication, underlining the utility of integrated genomic surveillance during an outbreak response. Author summaryThe economically important cattle pathogen, Mycoplasma bovis, was first detected in New Zealand in 2017. This led to a large-scale, successful control programme aimed at eradication of the pathogen. The decision to undertake an eradication programme was informed by initial analyses of whole genome sequences from isolates collected as part of the surveillance programme. The analysis showed that the bacteria had entered New Zealand relatively recently and was unlikely to be widespread. Over the subsequent years, genome sequencing and modelling of transmission dynamics informed important policy decisions made by the New Zealand Government and the cattle industry, and helped to monitor progress of the eradication programme. The impact of the detection, movement control and culling programme was profound, with sharp reductions in transmission between 2018 and 2020. This was followed by a long tail of localised infection in the South Island, involving transmission from a large feedlot farm. Provisional eradication was achieved after depopulation of this feedlot. This analysis highlights the role of genomic surveillance and modelling to inform decision making during an infectious disease outbreak.

Porcine Reproductive and Respiratory Syndrome Virus 2 (PRRSV-2) represents a major threat to the global swine industry. The epidemiological dynamics of PRRSV-2 are characterized by the recurrent annual emergence of dozens of variants. Long-distance spread of PRRSV-2 is largely driven by animal shipments. Spatiotemporal dynamics of PRRSV-2 in the USA have been explored; however, how fast variants spread to new regions after their emergence remains unclear, and this information could improve preparedness. To address this, we analyzed 14,835 sequences, retrieved from the Morrison Swine Health Monitoring Project (MSHMP), representing 156 variants sampled from 2015 to 2024, covering the five major swine-producing regions in the USA: the Upper Midwest (UM), Lower Midwest (LM), Atlantic Seaboard (AS), Northeast (NE), and Great Plains (GP). Time to spread was assessed using the time-to-dispersal event analysis and waiting time analyses. Genetic diversity was measured using Hill numbers. The UM had the highest variant richness (n=123), followed by the LM (n=47), AS (n=35), NE (n=45), and GP (n=38). Of the 62 variants that initially emerged in the UM, 17 later spread to other regions. The UM also received the highest number of variant introductions (n=24), followed by LM (n=14), NE (n=14), AS (n=4), and GP (n=7), highlighting regional differences in connectivity and risk. Our results suggest faster dispersal corridors among interior regions (e.g., GP to UM and LM to UM, [~]1.2-2.0 years) and slower for coast to interior pathways (AS to interior, [~]2-3 years). These findings may help anticipate the risk of PRRSV-2 variant introduction and provide more accurate dispersal time estimates, which are useful for improving epidemiological models and disease preparedness.

Mycoplasmopsis [Mycoplasma] agassizii is one of the principal pathogens associated with upper respiratory tract disease (URTD) in tortoises, yet its epidemiology in European wild chelonian populations remains poorly understood. The pathogen has been linked to population declines in some wild tortoise populations and is frequently detected in captive tortoises, where infections may persist subclinically and prolonged contact can facilitate transmission. In this context, the pet trade and the release or escape of captive individuals represent potential pathways for pathogen exchange between captive and wild populations. We assessed the presence and prevalence of M. agassizii in wild Mediterranean tortoises in Spain and compared infection patterns with captive populations. A total of 259 tortoises were sampled between 2020 and 2025, including spur thighed tortoises (Testudo graeca; 127 wild; 63 captive) and Hermanns tortoises (Testudo hermanni; 46 wild; 23 captive). Detection of M. agassizii was performed using PCR. The pathogen was detected in both species, but prevalence patterns differed markedly between captivity status and species. High prevalence was consistently observed in captive individuals of both species. In contrast, wild populations showed species-specific patterns: T. graeca exhibited very low or absent prevalence across wild populations, whereas T. hermanni showed comparatively higher prevalence in the wild. These results provide the first baseline assessment of M. agassizii occurrence in Mediterranean tortoises in Spain and highlight the importance of incorporating pathogen surveillance into conservation and management strategies for European chelonian populations.

BackgroundGastrointestinal helminths of companion animals are neglected sources of zoonotic infection in low and middle-income countries. In Bangladesh, close humananimal contact and large free-roaming dog and cat populations may facilitate parasite transmission, yet region-specific data remain limited. This study assessed the prevalence, species diversity, and zoonotic potential of gastrointestinal helminths in companion animals in northeastern Bangladesh. MethodsA cross-sectional study was conducted between January and December 2025 across urban and rural areas of the Sylhet Division. Fecal samples from 900 animals (600 dogs and 300 cats; owned and stray) were examined using standard coproscopic techniques. Molecular confirmation of selected positive samples was performed using PCR targeting ITS-2, 18S rRNA, and mitochondrial cox1 genes, followed by sequencing. Risk factors associated with infection were evaluated using multivariable logistic regression. ResultsOverall, 45.9% (95% CI: 42.6-49.2) of animals were infected with at least one gastrointestinal helminth, with mixed infections detected in 18.4%. Prevalence was similar in dogs (45.7%) and cats (46.3%) but significantly higher in stray animals (65.7%) than in owned animals (36.6%). Predominant zoonotic helminths included Ancylostoma spp., Toxocara canis, Toxocara cati, Dipylidium caninum, and Taenia/Echinococcus spp. Molecular analysis confirmed 93% of morphologically identified infections and revealed high genetic similarity to zoonotic reference strains. Stray status, lack of deworming, young age, and outdoor roaming were significant risk factors for infection (p < 0.05). ConclusionsCompanion dogs and cats in northeastern Bangladesh harbor a high burden of zoonotic gastrointestinal helminths and represent important reservoirs for human exposure. Strengthening One Health-based surveillance, routine deworming, and stray animal management is essential to reduce zoonotic transmission.

Dairy cattle have emerged as a prolific amplifying host for highly pathogenic avian influenza virus (HPAIV) H5N1 clade 2.3.4.4b and a new source for cross-species and zoonotic transmission. Independent introductions of H5N1 with unclear exposure routes have been reported in several dairy herds across the U.S. These events escalate the pandemic potential of HPAIV H5N1 as transmission within and between mammalian species present opportunities for mammalian adapted H5N1 viruses to emerge. Although more than 1000 herds have been infected, bovine H5N1 influenza virus pathogenesis, transmission, and evolution in dairy cattle remains not well characterized. Working with H5N1-infected lactating cattle in high containment has been a major challenge due to the required infrastructure and logistics associated with housing, husbandry, and waste management for this model. Thus, developing alternative bovine models that maintain biological relevance while reducing operational complexity is warranted. Here we evaluate the susceptibility of lactating Jersey cattle in the dry-off period and characterize the effect of inoculation dose on the mammary pathogenicity of HPAIV H5N1 genotype B3.13. The results of this study demonstrate that dairy cows 21 days into the dry-off period are highly susceptible to HPAIV H5N1, recapitulating the severe clinical and pathological outcomes observed in infected lactating cows under experimental conditions and in field cases. We also observed an association between virus dose and the onset and severity of mastitis in individual udder-quarters and compartmentalized clonal expansion of variant populations. Overall, this study demonstrates that dry cows can provide a feasible model to study H5N1 virology, pathology, and humoral immunology in dairy cows.

Calves are one of the most common carriers of antibiotic-resistant bacteria among farm animals. However, the impact of antibiotic usage on resistance mechanisms, transmission routes between farms, and the transmission of resistant bacteria to humans remain largely unknown. Here we analyzed the population of {beta}-lactam resistant E. coli isolated over five calving seasons on 444 farms scattered throughout Wallonia, Belgium. Restrictions on critical antibiotics usage led to a reduction of resistance to 3rd generation cephalosporins but has no impact on population structure and {beta}-lactamase genes indicating a resilient population. The correlation between short genetic distances and geographic proximity suggests indirect transmission between farms by fomites with differences between regions east and west of the river Meuse. Phylogenetic analysis of calf isolates with isolates from public databases indicates transitions from bovine to human adaptation. These findings provide new means to further model the spread of E. coli in livestock farming.

Emerging respiratory disease outbreaks pose a major threat to food production systems. Agricultural workers live in larger, more crowded households than the general population, amplifying their potential exposure to respiratory pathogens, yet the consequences for worker health and food production remain poorly understood. We developed a household-structured susceptible-infectious-recovered (SIR) transmission model to compare disease dynamics between agricultural workers and the general U.S. population across six regions. We simulated outbreaks across a range of epidemiological scenarios and assessed productivity losses in California for three labor-intensive crops (oranges, iceberg lettuce, strawberries) with different harvest seasonalities. For a baseline reproduction number of R0 = 1.5, peak disease prevalence among agricultural workers was 1.23-1.45 times higher than that of the general population across regions, and final outbreak sizes were 1.15-1.28 times higher. Peak productivity losses ranged from 0.50%-0.62% across crops, translating to millions in lost revenue. At higher transmissibility and severity (R0 = 3 and assuming all infections are symptomatic), losses were over 2.5 times higher. Household crowding may lead to disproportionate respiratory disease burden among agricultural workers, highlighting the need for targeted outbreak preparedness and mitigation strategies in the agricultural sector to maintain food system resilience and support public health in these communities.