Veterinary Epidemiology Research Articles

The functions of veterinary epidemiology in public health

This paper aims to describe the core functions of veterinary epidemiology in public health to understand the ultimate objective of preventing, mitigating, or eliminating zoonotic diseases in susceptible populations. However, the ideas came from a variety of sources. The field of veterinary medicine has significantly contributed to many aspects of public health, including human and environmental wellness, animal welfare, comparative and basic medical study, and the mitigation of zoonotic illness. Veterinary epidemiology, one of the disciplines that make up veterinary public health, is particularly concerned with disease surveillance, response, and prevention. In the veterinary study, epidemiological methods examine diseases' dynamics, prevalence, and causes in populations of interest. The ability to better comprehend hazards and how to prevent widespread sickness is now possible for veterinary epidemiologists. Veterinarians can help advance public health studies and policies by employing various methodological approaches and collaborating with networks of expert epidemiologists in the field.

Vesicular stomatitis Indiana virus near-full-length genome sequences reveal low genetic diversity during the 2019 outbreak in Colorado, USA.

DATA REPORT article Front. Vet. Sci., 14 February 2023Sec. Veterinary Epidemiology and Economics Volume 10 - 2023 | https://doi.org/10.3389/fvets.2023.1110483

Less Typical Courses of Rhodococcus equi Infections in Foals

This article aims to present several interesting and less typical courses of Rhodococcus equi infections in foals, collected during the 2019-2021 foaling seasons in some Polish studs. The study was conducted by the Division of Veterinary Epidemiology and Economics, Warsaw University of Life Sciences-SGGW, and concentrated on ultrasonographic contribution to diagnostics and treatment of the disease. Among many standard cases of rhodococcal pneumonia, some rare ones occurred. The aforementioned issues include the potential contribution of rhodococcal infection to a grave outcome in a prematurely born filly, lost as a yearling, so-called "extrapulmonary disorders" (EPD), a hypothesis of inherited immunodeficiency with grave outcome in a breeding dam line from one stud, and macrolide-induced anhidrosis. The main benefit of this report would be to supplement the general picture of clinical rhodococcosis.

Design and Evaluation of the Veterinary Epidemiology Teaching Skills (VETS) Workshop: Building Capacity in the Asia-Pacific Region.

Building workforce capacity in epidemiology skills for veterinarians in the Asia-Pacific region is crucial to health security. However, successful implementation of these programs requires a supply of trained veterinary epidemiology teachers and mentors. We sought to design and evaluate delivery of a 4-day Veterinary Epidemiology Teaching Skills (VETS) workshop as part of a larger project to strengthen field veterinary epidemiology capacity. Thirty-five veterinarians were selected to participate in the 4-day VETS workshop, consisting of nine modules delivered synchronously online. Participants were formatively assessed and given feedback from peers and facilitators on all activities. Data were collected with pre- and post-course questionnaires. Numeric values were categorized to convert into an ordinal scale with four categories. Qualitative data were analyzed using thematic analysis. Thirty-four veterinary epidemiologists from eight countries of the Asia-Pacific completed the workshop. Participants felt able to achieve most key learning outcomes through provision of succinct literature, teaching frameworks, and active participation in small groups, with multiple opportunities to give and receive feedback. Although the online workshop provided flexibility, participants felt the addition of face-to-face sessions would enrich their experience. Additionally, protected time from work duties would have improved their ability to fully engage in the workshop. The VETS workshop granted an effective online framework for veterinary epidemiologists to develop and practice skills in teaching, facilitation, assessment, feedback, case-based learning, program evaluation, and mentorship. A challenge will be ensuring provision of local teaching and mentoring opportunities to reinforce learning outcomes and build workforce capacity.

How size and genetic diversity shape lifespan across breeds of purebred dogs.

While the lifespan advantage of small body size and mixed breed status has been documented repeatedly, evidence for an effect of genetic diversity across dog breeds is equivocal. We hypothesized that this might be due to a strong right-censoring bias in available breed-specific lifespan estimates where early-dying dogs from birth cohorts that have not died off completely at the time of data collection are sampled disproportionately, especially in breeds with rapidly growing populations. We took advantage of data on owner reported lifespan and cause of death from a large public database to quantify the effect of size and genetic diversity (heterozygosity) on mortality patterns across 118 breeds based on more than 40,000 dogs. After documenting and removing the right-censoring bias from the breed-specific lifespan estimates by including only completed birth cohorts in our analyses, we show that small size and genetic diversity are both linked to a significant increase in mean lifespan across breeds. To better understand the proximate mechanisms underlying these patterns, we then investigated two major mortality causes in dogs - the cumulative pathophysiologies of old age and cancer. Old age lifespan, as well as the percentage of old age mortality, decreased with increasing body size and increased with increasing genetic diversity. The lifespan of dogs dying of cancer followed the same patterns, but while large size significantly increased proportional cancer mortality, we could not detect a significant signal for lowered cancer mortality with increasing diversity. Our findings suggest that outcross programs will be beneficial for breed health and longevity. They also emphasize the need for high-quality mortality data for veterinary epidemiology as well as for developing the dog as a translational model for human geroscience.

Application of Bayesian Regression for the Identification of a Catchment Area for Cancer Cases in Dogs and Cats.

Research on cancer in dogs and cats, among other diseases, finds an important source of information in registry data collected from hospitals. These sources have proved to be decisive in establishing incidences and identifying temporal patterns and risk factors. However, the attendance of patients is not random, so the correct delimitation of the hospital catchment area (CA) as well as the identification of the factors influencing its shape is relevant to prevent possible biases in posterior inferences. Despite this, there is a lack of data-driven approaches in veterinary epidemiology to establish CA. Therefore, our aim here was to apply a Bayesian method to estimate the CA of a hospital. We obtained cancer (n = 27,390) and visit (n = 232,014) registries of dogs and cats attending the Veterinary Medical Teaching Hospital of the University of California, Davis from 2000 to 2019 with 2,707 census tracts (CTs) of 40 neighboring counties. We ran hierarchical Bayesian models with different likelihood distributions to define CA for cancer cases and visits based on the exceedance probabilities for CT random effects, adjusting for species and period (2000–2004, 2005–2009, 2010–2014, and 2015–2019). The identified CAs of cancer cases and visits represented 75.4 and 83.1% of the records, respectively, including only 34.6 and 39.3% of the CT in the study area. The models detected variation by species (higher number of records in dogs) and period. We also found that distance to hospital and average household income were important predictors of the inclusion of a CT in the CA. Our results show that the application of this methodology is useful for obtaining data-driven CA and evaluating the factors that influence and predict data collection. Therefore, this could be useful to improve the accuracy of analysis and inferences based on registry data.

Risk Communication for Poultry Farms by Detection of HPAI (H5N1) Virus in Wild Birds during the Winter Season of 2021/2022 in the Republic of Korea

Approaches in Poultry, Dairy & Veterinary Sciences Risk Communication for Poultry Farms by Detection of HPAI (H5N1) Virus in Wild Birds during the Winter Season of 2021/2022 in the Republic of Korea Youngmin Son, Hachung Yoon*, Ilseob Lee and Eunesub Lee Veterinary Epidemiology Division, Animal and Plant Quarantine Agency, Republic of Korea *Corresponding author: Hachung Yoon, Veterinary Epidemiology Division, Animal and Plant Quarantine Agency, Gimcheon, Gyeongsanhbuk-do, 39660, Republic of Korea Submission: April 26, 2022;Published: May 12, 2022 DOI: 10.31031/APDV.2022.09.000703 ISSN: 2576-9162 Volume9 Issue1

The reporting of p values, confidence intervals and statistical significance in Preventive Veterinary Medicine (1997-2017).

BackgroundDespite much discussion in the epidemiologic literature surrounding the use of null hypothesis significance testing (NHST) for inferences, the reporting practices of veterinary researchers have not been examined. We conducted a survey of articles published in Preventive Veterinary Medicine, a leading veterinary epidemiology journal, aimed at (a) estimating the frequency of reporting p values, confidence intervals and statistical significance between 1997 and 2017, (b) determining whether this varies by article section and (c) determining whether this varies over time.MethodsWe used systematic cluster sampling to select 985 original research articles from issues published in March, June, September and December of each year of the study period. Using the survey data analysis menu in Stata, we estimated overall and yearly proportions of article sections (abstracts, results-texts, results-tables and discussions) reporting p values, confidence intervals and statistical significance. Additionally, we estimated the proportion of p values less than 0.05 reported in each section, the proportion of article sections in which p values were reported as inequalities, and the proportion of article sections in which confidence intervals were interpreted as if they were significance tests. Finally, we used Generalised Estimating Equations to estimate prevalence odds ratios and 95% confidence intervals, comparing the occurrence of each of the above-mentioned reporting elements in one article section relative to another.ResultsOver the 20-year period, for every 100 published manuscripts, 31 abstracts (95% CI [28–35]), 65 results-texts (95% CI [61–68]), 23 sets of results-tables (95% CI [20–27]) and 59 discussion sections (95% CI [56–63]) reported statistical significance at least once. Only in the case of results-tables, were the numbers reporting p values (48; 95% CI [44–51]), and confidence intervals (44; 95% CI [41–48]) higher than those reporting statistical significance. We also found that a substantial proportion of p values were reported as inequalities and most were less than 0.05. The odds of a p value being less than 0.05 (OR = 4.5; 95% CI [2.3–9.0]) or being reported as an inequality (OR = 3.2; 95% CI [1.3–7.6]) was higher in the abstracts than in the results-texts. Additionally, when confidence intervals were interpreted, on most occasions they were used as surrogates for significance tests. Overall, no time trends in reporting were observed for any of the three reporting elements over the study period.ConclusionsDespite the availability of superior approaches to statistical inference and abundant criticism of its use in the epidemiologic literature, NHST is substantially the most common means of inference in articles published in Preventive Veterinary Medicine. This pattern has not changed substantially between 1997 and 2017.

Surveillance of Highly Pathogenic Avian Influenza on Poultry Farms in Tracking Livestock Vehicles in the Republic of Korea

Approaches in Poultry, Dairy & Veterinary Sciences Surveillance of Highly Pathogenic Avian Influenza on Poultry Farms in Tracking Livestock Vehicles in the Republic of Korea Hachung Yoon1*, Ilseob Lee1, Giphil Cho2, Hyunmin Kim2 and Eunesub Lee1 1Veterinary Epidemiology Division, Animal and Plant Quarantine Agency, Republic of Korea 2Finance Fishery Manufacture Industrial Mathematics Center on Big Data, Pusan National University, Republic of Korea *Corresponding author: Hachung Yoon, Veterinary Epidemiology Division, Animal and Plant Quarantine Agency, Gimcheon, Gyeongsangbuk-do, 39660 Republic of Korea Submission: November 02, 2021;Published: November 19, 2021 DOI: 10.31031/APDV.2021.08.000694 ISSN: 2576-9162 Volume8 Issue4

Towards a Framework for High-Performance Simulation of Livestock Disease Outbreak: A Case Study of Spread of African Swine Fever in Vietnam

The spread of disease in livestock is an important research topic of veterinary epidemiology because it provides warnings or advice to organizations responsible for the protection of animal health in particular and public health in general. Disease transmission simulation programs are often deployed with different species, disease types, or epidemiological models, and each research team manages its own set of parameters relevant to their target diseases and concerns, resulting in limited cooperation and reuse of research results. Furthermore, these simulation and decision support tools often require a large amount of computational power, especially for models involving tens of thousands of herds with millions of individuals spread over a large geographical area such as a region or a country. It is a matter of fact that epidemic simulation programs are often heterogeneous, but they often share some common workflows including processing of input data and execution of simulation, as well as storage, analysis, and visualization of results. In this article, we propose a novel architectural framework for simultaneously deploying any epidemic simulation program both on premises and on the cloud to improve performance and scalability. We also conduct some experiments to evaluate the proposed architectural framework on some aspects when applying it to simulate the spread of African swine fever in Vietnam.

At the Crossroads of One Health: Lessons Learned from Foot and Mouth Disease in COVID-19 Pandemic

Foot-and-mouth disease (FMD) and Coronavirus Disease 2019 (COVID-19) are transboundary diseases caused by single-stranded positive-sense RNA viruses with similarities in genome replication and viral protein synthesis. In FMD, asymptomatic infection leads to carrier status and persistently infected animals that threaten the animals vaccinated with a trivalent inactivated whole virus vaccine. Similar information on COVID-19 is not yet available. As COVID-19 vaccination is introduced in January 2021 (since 16 January 2021 in India), its outcome can be assessed by the year-end; and while doing so, the experiences gained in the control of FMD in livestock worldwide can be applied, including monitoring of vaccination response, duration of immunity, level of herd immunity developed, and antigenic matching of the vaccine virus. Antigenic divergence of the virus is a major issue in FMD, and different geographical regions in the world use different virus strains in vaccine preparations to antigenically match circulating virus strains in respective regions for control of the disease. Non-synonymous mutations in the critical antigenic determinants of SARS-CoV-2 have been observed, and there is likely the existence/ development of antigenic variants. Therefore, during the post-COVID-19 vaccination regime, it will be essential to monitor the suitability of the in-use vaccine strain region-wise from time to time, as there could be an eruption of isolated outbreaks in a country arising due to antigenic variation and variants. In the context of the present scenario of COVID-19 around the Globe and multiple ongoing efforts to develop suitable vaccine(s) to control the disease, it is a must to develop NSP-antibody (that differentiate infected from vaccinated) assays to differentiate infected from vaccinated individuals(DIVI; DIVA in veterinary epidemiology). The techniques used and experiences gained in ongoing FMD control programs in the endemic countries can be applied to COVID-19 control in a country; and finally, the Globe. After achieving the control of COVID-19, the aim would be to eradicate the virus, which will be tough even with vaccination, as the disease/ infection may become endemic during the time to come. To achieve this, applying the principles of Progressive Control Pathway for Foot-and-Mouth Disease (PCP-FMD; FAO/OIE) to COVID-19 control will be beneficial in its control. The present review discusses the issue of control of COVID-19.

Systematic review of the status of veterinary epidemiological research in two species regarding the FAIR guiding principles

BackgroundThe FAIR (Findable, Accessible, Interoperable, Reusable) principles were proposed in 2016 to set a path towards reusability of research datasets. In this systematic review, we assessed the FAIRness of datasets associated with peer-reviewed articles in veterinary epidemiology research published since 2017, specifically looking at salmonids and dairy cattle. We considered the differences in practices between molecular epidemiology, the branch of epidemiology using genetic sequences of pathogens and hosts to describe disease patterns, and non-molecular epidemiology.ResultsA total of 152 articles were included in the assessment. Consistent with previous assessments conducted in other disciplines, our results showed that most datasets used in non-molecular epidemiological studies were not available (i.e., neither findable nor accessible). Data availability was much higher for molecular epidemiology papers, in line with a strong repository base available to scientists in this discipline. The available data objects generally scored favourably for Findable, Accessible and Reusable indicators, but Interoperability was more problematic.ConclusionsNone of the datasets assessed in this study met all the requirements set by the FAIR principles. Interoperability, in particular, requires specific skills in data management which may not yet be broadly available in the epidemiology community. In the discussion, we present recommendations on how veterinary research could move towards greater reusability according to FAIR principles. Overall, although many initiatives to improve data access have been started in the research community, their impact on the availability of datasets underlying published articles remains unclear to date.

Infrastructure of animal farms: key constructional elements in terms of biosecurity based on experience from Germany

The infrastructural design of an animal farm can significantly motivate or discourage adopting biosecurity measures in the daily routines. Proper planning and collaboration between architects, farmers and veterinarians is critical in the prevention of serious biosecurity issues, possible financial and animal losses. The consistent use of a uniform nomenclature that encompasses both, construction-functional and veterinary-epidemiological terms is therefore essential. We developed a conceptual framework for key constructional elements in terms of biosecurity and characterize key concepts from both disciplines, architecture and veterinary epidemiology. From an epidemiological point of view, we focus on pathogens and vectors, and from a constructional perspective on biosecurity areas, barriers and locks. The central aspect of the framework is the capability of barriers and locks to prevent (uncontrolled) movement of vectors between different biosecurity areas, thus interrupting pathways of pathogen transmission. Concepts are abstracted and aggregated in such a way that they can be applied to any animal husbandry system, regardless of species or size, and independently of a particular disease. The aim is providing a common basis of terminology that facilitates cross-sectoral cooperation.

Sample Size Estimation in Veterinary Epidemiologic Research.

In the design of intervention and observational epidemiological studies sample size calculations are used to provide estimates of the minimum number of observations that need to be made to ensure that the stated objectives of a study are met. Justification of the number of subjects enrolled into a study and details of the assumptions and methodologies used to derive sample size estimates are now a mandatory component of grant application processes by funding agencies. Studies with insufficient numbers of study subjects run the risk of failing to identify differences among treatment or exposure groups when differences do, in fact, exist. Selection of a number of study subjects greater than that actually required results in a wastage of time and resources. In contrast to human epidemiological research, individual study subjects in a veterinary setting are almost always aggregated into hierarchical groups and, for this reason, sample size estimates calculated using formulae that assume data independence are not appropriate. This paper provides an overview of the reasons researchers might need to calculate an appropriate sample size in veterinary epidemiology and a summary of sample size calculation methods. Two approaches are presented for dealing with lack of data independence when calculating sample sizes: (1) inflation of crude sample size estimates using a design effect; and (2) simulation-based methods. The advantage of simulation methods is that appropriate sample sizes can be estimated for complex study designs for which formula-based methods are not available. A description of the methodological approach for simulation is described and a worked example provided.

Multi-level impact of continuing professional development on Sri Lanka’s veterinary sector

ABSTRACT A capacity-building programme between a veterinary school in the UK and the veterinary school in Sri Lanka was developed. Scholarships for two distance learning MSc programmes were offered to Sri Lankan veterinarians: ‘Veterinary Epidemiology and Public Health’ and ‘Livestock Health and Production’. In addition, scholarships were offered to academic staff members at the veterinary school to undertake the Postgraduate Certificate in Veterinary Education. A blended learning approach was taken, though the majority of learning was by distance. This study used a case-study approach to assess the programmes’ impact at different levels: individual, institutional, institution’s students, the profession, the public and animals. Previous students were interviewed and current students participated in a focus group. Staff of the Sri Lankan university were interviewed. Data were transcribed and qualitative content analysis conducted. Participants had achieved personal satisfaction, gained new knowledge and skills and progressed professionally. These impacts translated to societal impacts including disseminating understanding of One Health, improving animal welfare laws and assisting the development of the undergraduate veterinary curriculum. The graduates from theblended learning programmes are experts at the centre of a new community of practice and have the ability to inspire future generations of Sri Lankan veterinary surgeons.

Potential paths for the introduction of risk analysis to improve the veterinary epidemiology curriculum in Ukraine.

The main purpose of veterinary education institutions is to prepare qualified, well-trained and knowledgeable professionals ready to serve local and global communities. Veterinary programmes vary within and among countries, creating a disparity in competencies. In less-developed economies, adhering to the World Organisation for Animal Health (OIE) ‘Day 1 competencies' and following its ‘Guidelines for a Model Core Veterinary Curriculum' may decrease this discrepancy. The authors offer a comparison of Ukraine's veterinary epidemiology curriculum with the OIE suggested ‘Core Veterinary Curriculum', particularly for infectious disease pathology in which epidemiology is taught, and propose different paths to structure advanced educational programmes in epidemiology. This course is relevant for the development of international animal trade and expansion of markets for animal products in Ukraine.

Participatory Epidemiology: Principles, Practice, Utility, and Lessons Learnt.

Participatory epidemiology (PE) evolved as a branch of veterinary epidemiology and has been largely employed for the control and early warning of infectious diseases within resource-limited settings. It was originally based on combining practitioner communication skills with participatory methods to facilitate the involvement of animal caretakers and owners (embracing their knowledge, experience, and motivations) in the identification and assessment of animal disease problems, including in the design, implementation, monitoring and evaluation of disease control programs, policies, and strategies. With the importance of understanding social perceptions and drivers receiving increasing recognition by epidemiologists, PE tools are being adapted for an increasingly wide range of settings and endeavors. More recently, PE tools have been adapted for use in food and nutrition security programs, One Health activities, wildlife disease surveillance and as part of mixed-methods research across a range of socio-economic settings. This review describes the evolution of PE (in relation to veterinary epidemiology and briefly in relation to public health epidemiology), the underpinning philosophy and principles essential to its effective application and the importance of gender-sensitive approaches and data triangulation, including conventional confirmatory testing. The article also provides illustrative examples highlighting the diversity of approaches and applications of PE, hallmarks of successful PE initiatives and the lessons we can learn when these are missing. Finally, we look forward, describing the particular utility of PE for dealing with emerging infectious diseases, gaining attention of field-level cross-sector officials who can escalate concerns to a higher level and for continuing to raise the voices of those less-heard (such as women, minority groups, and remote communities with limited exposure to formal education) in defining the problems and planning activities that will likely impact directly on their well-being and livelihoods.

Ecological Niche Modeling: An Introduction for Veterinarians and Epidemiologists

Most infectious diseases in animals are not distributed randomly. Instead, diseases in livestock and wildlife are predictable in terms of the geography, time, and species affected. Ecological niche modeling approaches have been crucial to the advancement of our understanding of diversity and diseases distributions. This contribution is an introductory overview to the field of distributional ecology, with emphasis on its application for spatial epidemiology. A new, revised modeling framework is proposed for more detailed and replicable models that account for both the biology of the disease to be modeled and the uncertainty of the data available. Considering that most disease systems need at least two organisms interacting (i.e., host and pathogen), biotic interactions lie at the core of the pathogen's ecological niche. As a result, neglecting interacting organisms in pathogen dynamics (e.g., maintenance, reproduction, and transmission) may limit efforts to forecast disease distributions in veterinary epidemiology. Although limitations of ecological niche modeling are noted, it is clear that the application and value of ecological niche modeling to epidemiology will increase in the future. Potential research lines include the examination of the effects of biotic variables on model performance, assessments of protocols for model calibration in disease systems, and new tools and metrics for robust model evaluation. Epidemiologists aiming to employ ecological niche modeling theory and methods to reconstruct and forecast epidemics should familiarize themselves with ecological literature and must consider multidisciplinary collaborations including veterinarians to develop biologically sound, statistically robust analyses. This review attempts to increase the use of tools from ecology in disease mapping.

Autoregressive Models Applied to Time-Series Data in Veterinary Science.

A time-series is any set of N time-ordered observations of a process. In veterinary epidemiology, our focus is generally on disease occurrence (the “process”) over time, but animal production, welfare or other traits might also be of interest. A common source of time-series datasets are animal disease monitoring and surveillance systems. Here, we scan the application of methods to analyse time-series data in the peer-reviewed, published literature. Based on this literature scan we focus on autocorrelation and illustrate the recommended steps using ARIMA (Autoregressive Integrated Moving Average Models) methods via analysis of a time-series of canine parvovirus (CPV) events in a pet dog population in Australia, 2009 to 2015. We conclude by identifying the barriers to the application of ARIMA methods in veterinary epidemiology and suggest some possible solutions. In the literature scan the selected 37 studies focused mostly on infectious and parasitic diseases, predominantly for analytical, rather than descriptive or predictive, purposes. Trends and seasonality were investigated, and autocorrelation analyzed, in most studies, most commonly using R software. An approach to analyzing autocorrelation using ARIMA methods was then illustrated using a time-series (week and month units) of CPV events in a pet dog population in Australia, reported to a national companion animal disease surveillance system. This time-series was derived by summing veterinarian reports of confirmed CPV diagnoses. We present data analysis output generated via the R statistical environment, and make this code available for the reader to apply to this or other time-series datasets. We also illustrate prediction of CPV events by rainfall as a covariate. Time-series analysis using ARIMA methods to understand and explore autocorrelation appears to be relatively uncommon in veterinary epidemiology. Some of the reasons might include limited availability of data of sufficient time unit length, lack of familiarity with analytical methods and available software, and how to best use the information generated. We recommend that wherever feasible, such time-series data be made available both for analysis and for methods development.

"They've got to be testing and doing something about it": Farmer and veterinarian views on drivers for Johne’s disease control in dairy herds in England

There needs to be an understanding of the reasons why key stakeholders engage in disease control efforts if disease is to be successfully and sustainably controlled. It is increasingly recognised within veterinary epidemiology and policy making in animal health that these ‘people factors’ are important influences on the success or otherwise of animal disease control programmes. Research methodologies adopted from the social sciences offer ways to understand this important dimension through investigating the attitudes and opinions of the key actors involved. The study reported in this paper, based on qualitative interview research, investigates the views of dairy farmers and cattle veterinarians on the drivers and incentives for controlling Johne’s disease in English dairy herds. Twenty semi-structured interviews involving 17 dairy farmers and seven veterinarians were conducted in two dairy-intensive regions of England. The findings demonstrate the varied influences of veterinary advice and encouragement; appreciation of the economic cost of the disease at herd level; a voluntary national control plan; and fear of a future consumer food scare as the main reasons to engage in Johne’s disease control on dairy farms. The study demonstrates how a combination of a voluntary industry-led control scheme, compulsory participation through retailer and processor contractual requirements, and threats of reputational harm and market loss have strongly influenced farmer and veterinary behaviour in relation to Johne’s control without statutory involvement. The findings illustrate the importance of considering the political economy and societal impact of animal disease.