“You tested, now what?”: Exploring British Columbian dairy producers' perceptions on Salmonella Dublin management and mitigation

Abstract

Salmonella Dublin (S. Dublin) is a bacterial disease that affects dairy cattle, causing calf loss, abortions, and reduced milk yield, and is often difficult to control as some animals become chronic carriers. In British Columbia bulk tank milk serology found that 30 % of dairy farms in the province were positive for Salmonella Dublin, which prompted a need for investigation into S. Dublin disease management and mitigation. The objective of this study was to explore BC dairy producers' perceptions and experiences of S. Dublin and how they relate to their actions in S. Dublin management and mitigation, and to leverage this information to inform provincial S. Dublin management programs. Semi-structured interviews were held with 10 BC dairy producers, which were recorded, transcribed and analyzed using the Health Belief Model. Overall, dairy farmers in this study expressed uncertainty surrounding S. Dublin and its management. This uncertainty stemmed from several key sources: 1. Unclear roles and responsibilities regarding disease management among stakeholders, specifically government; 2. Differing views on the necessity of government regulation; 3. Confusion about how information on S. Dublin and disease management is communicated; and 4. Challenges with self-efficacy in the management of S. Dublin. Together, this points towards a need for improved communication and messaging surrounding S. Dublin in BC. Given the perceived value of peer-to-peer communication and narratives, disease messaging may be more effective when coming from sources like producer-led organizations, herd health veterinarians, and “boots on the ground” government officials, as opposed to faceless, top-down government messaging. Ultimately, a deeper understanding of how producers approach S. Dublin management over time and across Canada would strengthen the development of effective strategies for the management of and mitigation of S. Dublin.

1. Introduction

Although the identification of risk factors and transmission pathways is crucial in the development of any disease management program, one of the most critical component centers on the willingness and ability of producers to implement changes associated with reduced risk and thereby potentially interrupt transmission pathways. A key example showing the importance of farmer buy-in comes from Denmark, where one year after legislation was passed requiring dairy farms to develop and implement a farm-specific biosecurity plan, no farms had complied with the legislation [1,2]. This prompted an investigation into producer perceptions of biosecurity and possible motivations and drivers. The findings were used to develop a program that combined incentives for compliance and enforcement through compliance checks and associated penalties for noncompliance (e.g., no financial support for disease outbreaks on noncompliant farms) [1,2]. Overall, control measures like these aided Denmark in reducing the prevalence of S. Dublin among their dairy herds from 26 % to 6 % over 8 years [3].

Producer perspectives on managing dairy-specific diseases range and are influenced by a variety of factors. For example, in Ontario, one study sought to investigate dairy producer and veterinarian perceptions of barriers and motivators to adopting disease management practices to help prevent and manage Johne's disease, a bacterial infectious disease that often results in chronic wasting in dairy cattle [4,5]. They found that time, money, and infrastructure, along with producers' perceived importance of Johne's disease management, were key barriers to adopting management recommendations [4]. A similar study in Great Britain that explored attitudes of dairy producers regarding implementing cattle disease prevention and control measures found that producers were positively motivated to adopt measures if brought up by their veterinarian, but negatively motivated if guidelines were provided by the government, often citing government guidance as not effective or relevant [6]. Further, following devastating disease outbreaks in the United Kingdom of bovine spongiform encephalopathy and foot and mouth disease, there was surprisingly little support from dairy producers to improve biosecurity [7]. Indeed, one producer stated that they were subjected to “an externally imposed solution to an externally imposed problem”, implying that biosecurity should not be their responsibility ([7], page 369). Together, these studies suggest that producers' perceptions of disease importance, the trustworthiness of the source of information, and the perceived roles and responsibilities of stakeholders like government were important factors in disease management uptake.

Like Johne's disease, Salmonella Dublin (S. Dublin) is a bacterial disease that affects dairy cattle, causing calf loss, abortions, and reduced milk yield, and is often difficult to control as some animals become chronic carriers [8]. Producers' perceived barriers around implementation of biosecurity for S. Dublin have been investigated in Ontario [9] where focus groups revealed that, at least for some of the participants, there was an underlying belief that the risk of S. Dublin was low. However, those who had experienced an outbreak had a shift in perspective towards becoming more proactive with biosecurity [9]. There was some consensus among producers that producer organizations, government, and academia needed to provide more guidance to producers on how to mitigate the spread of S. Dublin [9]. Based on their findings, they concluded that unless the perceived risk of S. Dublin increased, there was unlikely to be significant motivation among producers to proactively adopt biosecurity measures for its prevention [9].

Understanding the risk factors in any given health crisis requires an understanding of the perceptions and motivations of the stakeholders involved. Just such a health crisis arose recently in British Columbia, when bulk tank milk (BTM) serology found that 30 % of the 470 dairy farms in BC were positive for S. Dublin [10]; this was twice as high as other provinces with similar surveillance programs [11,12,13].

In British Columbia, herd health decisions fall upon the individual producer, which makes understanding producer motivations, perceived health beliefs, and possible barriers imperative. The objective of this study was to explore BC dairy producers' perceptions and experiences of S. Dublin and how they relate to their actions in S. Dublin management and mitigation, and to leverage this information to inform provincial S. Dublin management programs.

2. Methods

2.1. Positionality statement

This study was conducted by a multidisciplinary team. EB is a veterinarian and veterinary epidemiologist, and one of the team leads of the BC Ministry of Agriculture's Salmonella Dublin Investigation and Management Program (SDIMP). EC is the provincial dairy inspector, a member of the SDIMP, and has extensive experience with the BC dairy industry. CH is a veterinary epidemiologist and veterinary pathologist, as well as the Deputy Chief Veterinary Officer of British Columbia. She is a team lead of the SDIMP, with the responsibility for overseeing the program's review. KB is an experienced qualitative researcher with expertise in One Health and is an Assistant Professor in the University of British Columbia's School of Population and Public Health.

2.2. Theoretical frameworks

Semi-structured interviews were used to better understand BC dairy producers' perceptions of S. Dublin and any barriers they face when working towards preventing, managing, or mitigating this disease. The interview questions were constructed using an adapted Health Belief Model (Fig. 1) [14]. To analyze the content of the interviews, we used an exploratory descriptive qualitative approach [15]. In brief, this approach first aims to explore and describe experiences of the participants and second to use these statements to create generalizations. The generalizations are then used to identify the main themes and core experiences that help address the research question [15].

Fig. 1.

The Health Belief Model adapted from Champion and Skinner [14] explores how key concepts interact to determine the likelihood of a person undertaking a health behavior. Specifically, the model holds that a person's perceived susceptibility and severity explain their perceived threat of an issue and subsequently the motivation to respond to the threat; perceived benefit and perceived barriers determine how one evaluates a goal (preventing disease), and subsequently their willingness to respond; cue to action and self efficacy evaluate an individuals likeliness of responding to a threat, and finally, self identity can function as a modifying factor that influences all other variables. Sample questions that correspond to each concept demonstrate how this can be used to investigate S. Dublin.

The Health Belief Model was originally developed in the 1950s by the US Public Health Service to explore why people fail to participate in disease prevention programs [14]. The model contains seven primary concepts that are used to help predict and understand why people take action to prevent disease (see Table 1). This model has been used extensively in human public health research to understand behaviours surrounding disease prevention, such as breast cancer screening and smoking cessation programs [16,17]. More recently, it has been applied in veterinary research, including studies on allergy elimination diets in pets and on rabies prevention [18,19]. The model focuses on how individuals perceive health threats and decide to act based on the value individuals place on a particular goal and the likelihood that actions taken towards that goal will be successful. To better fit the goal of this study, concepts were adapted to relate to dairy producers and S. Dublin (Table 1).

Table 1.

Adapted Health Belief Model Concepts used to explore BC dairy producers' perceptions and experiences and their relation to their actions towards management and mitigation of S. Dublin.

Concept	Adapted definition
Self-Identity	The salient and enduring part of one's self-perception as it may relate to their willingness to implement strategies to manage and mitigate S. Dublin.
Self-Efficacy	Personal belief of one's own ability to identify, prevent, and manage S. Dublin.
Perceived Severity	An individual's judgment as to the seriousness of S. Dublin in relation to the health of their herd.
Perceived Susceptibility	Perceived risk of their herd contracting S. Dublin.
Perceived Benefit	An individual's evaluation of the positive outcomes involved in participating in S. Dublin research and mitigation and management programs.
Perceived Barriers	An individual's opinion regarding the difficulty or cost of preventing or managing S. Dublin.
Cue to Action	Internal and external prompts that would trigger an individual to pursue health promoting behaviours pertaining to S. Dublin.

2.3. Study population and recruitment

The population of interest for this study comprised individuals that currently own and/or operate a licensed dairy farm in British Columbia. Producer participants were recruited from a previous survey-based study documenting S. Dublin risk factors that included a section where farmers could convey their interest in participating in future research on this topic. Producers who indicated that they would be willing to participate in future work were contacted via email, inviting them to participate in a semi-structured interview. Producers were compensated $75.00 for their time. All producers received a consent form prior to scheduling the interview. Producers were classified as positive of negative based off their bulk tank milk status from the ongoing sero-surveillance program described in [10]). There was an attempt to recruit a proportional number of producers with S. Dublin positive farms (∼30 %) [10]. Recruitment continued until data saturation was reached in other words, we sought to gather data to the point of diminishing returns (i.e., when no new concepts, themes or ideas were being brought up during the interviews) [20]. This study was approved by The University of British Columbia's (UBC) Behavioral Research Ethics Board (H24–02210).

2.4. Interviews

Interviews began in December 2024 and continued to March 2025. All interviews were conducted over Zoom by team member EB. A semi-structured interview guide (Supplementary 1) containing questions related to each construct in the Health Belief Model (see Table 1) was used. At the beginning of each interview some questions involving the participant's baseline knowledge of S. Dublin were asked to understand how perceptions aligned with knowledge of the disease. If new themes or ideas were raised during the interview, questions were asked to further explore these concepts. Interviews were recorded to facilitate transcription. An initial transcription was produced using Zoom's internal software and then was manually transcribed by EB to correct any errors. Interviews ranged between 20 and 65 min in length.

2.5. Analysis

A preliminary coding framework was constructed from the concepts outlined in the health belief model using a deductive coding approach. This framework went through multiple iterations with input from all study members (EB, CH, KB). Coding of the interviews was done manually by EB. A priori codes were developed from each pillar of this model (e.g., perceived barriers) with other codes identified through emerging themes as interviews were analyzed. Subcategories within the a priori and emerging codes were used to organise answers. Themes were developed based on the concepts within the Health Belief Model and in vivo by identifying recurring ideas that were relevant to the research questions (e.g., recommendations from producers). Codes were grouped into main themes and subthemes (using the subcategories) that were summarized in a concept map for each interview. Interview concept maps were then compared and contrasted to help determine high-level themes that address the research questions, subthemes that emerged over the course of the interviews, and any outlier opinions. Each participant was given a number to ensure anonymity, and this number was used to label the quote. In addition, the quote was identified as coming from a producer whose farm had tested negative or positive for S. Dublin (ex.1 N or 2P). The transcripts were read and coded multiple times as it was an iterative process among study members (EB, CH, KB) to improve confidence and ensure appropriateness of the codes. Supporting quotes are embedded in the results to ensure participants' voices remain centred and to support transparency of the research process [21].

To avoid overinterpretation or misinterpretation of the data, responses were not quantified. As our sample was not random, the results are subject to participation and reporting bias.

3. Results

3.1. Demographics

There were ten participants from ten BC dairy farms with eight individuals identifying as men and two identifying as women. Eight of the farms were negative for S. Dublin on bulk tank milk surveillance and had never had a known case of S. Dublin on their farm. Two farms were positive for S. Dublin on bulk tank surveillance. Eight farms were in the Fraser Valley and two farms were located in Vancouver Island. There were no participants from the Okanagan, Creston, or the Bulkley Valley, the remaining dairy-producing regions in BC.

3.2. Concepts

Within each a priori concept there were emerging themes that had both positive and negative sentiment (Fig. 2). These themes were placed onto of the adapted Health Belief Model, with colours indicating if the sentiments were positive or negative.

Fig. 2.

Themes identified over the course of the interviews and how they relate to the concepts from the health belief model.

3.3. Self identity

All producers self-identified as being proactive in managing herd health; however, when asked for examples of how they had been proactive, the responses varied considerably. Some participants referenced routine preventative care, such as vaccination and hoof trimming; while others highlighted participation in disease management programs like leukosis testing and strategic culling, emphasizing an importance in calf care as “you know we're not going to sacrifice calves for the sake of cost“– 6 N. Many producers did note that being proactive is likely relative when compared to others and something that may be difficult to self-determine.

“A person might think they are [proactive], but I guess sometimes it's relative to what others are doing, right? So, I think I generally am, but I would say there's probably guys that are doing more than I'm doing.” – 3 N.

When asked about specific ways they were proactive in terms of herd health, almost all producers identified as having “essentially a closed herd”. A closed herd generally means that there is no animal movement on and off the farm; specifically, no animals leaving and returning and no purchasing of cattle, which can prevent the introduction of disease [22]. However, many of the producers that identified as having a closed herd also provided examples of when animals were moved on and off their farm, such as when they “ship in bulls like once or twice a year” – 8 P. Some of these producers did detail quarantine protocols they used when animals were brought on the farm.

“We also are pretty much a closed herd. There is the odd animal that does come in but the ones that we do bring in we tend to separate them from the main herd or main groups that they're going to be going in just to make sure that they're not carrying anything. We make sure that they get vaccinated when they do come in, if they aren't already, and then we just continue on with the vaccine program as soon as they kind of are well established or past quarantine.” – 5 N.

3.4. Perceived susceptibility

All producers felt that their herds were, to some degree, susceptible to S. Dublin infection. In these cases, the producers were able to identify potential entry points for infection on their farm, as well as vulnerabilities they observed at a broader industry level. One area of particular concern was equipment fomites, such as trucks used by those who transport cattle. As stated by one participant: “We're having the cattle hauler come too. I really don't like it if he's got cows on the trailer and they come off. It has happened. Sawdust or manure coming off of a cattle hauler's truck, I am a little worried with that. So, yeah, I kind of see those as some weak points yet at our place.” – 1 N Human fomites, specifically workers who work on multiple dairies, were also highlighted as potential areas of concern regarding disease susceptibility. Some producers also identified pests like mice, rats, birds, and barn cats as possible vector of disease.

“Mice, and rats, and other things like that as well, even I have a cat that runs around to 4 different dairy farms.” – 8P.

On an industry level, some producers expressed concern about the importation of US dairy cattle and cattle brokers and their role in introducing S. Dublin into BC. Some detailed how BC's price for replacement cattle has been about $500–1000 cheaper than other provinces', due to American cattle being brought into the province. Because of this, some cite that buying locally is not an option, as you must directly compete with cheaper American cattle.

“Those cattle brokers could always effectively bring animals up into Canada, from Washington, from Oregon, from Utah, …. and if the cow price in Ontario would be $3,000, it would be $2,000 in BC. We have always historically had low cow prices, for the very reason that animals can be brought up from the States easily.” – 4 N.

Furthermore, some participants raised the concern that there were more farms participating in heifer rearing and other co-mingling locations (e.g., pasture sharing). Some producers perceived that the increase in these practices have contributed to S. Dublin spreading throughout all BC dairy regions.

“There's a number of farms here that don't raise their young stock and raise young stock in the interior. And then ship them back here. So that's a possibility where you're gonna see it show up in those areas because they probably don't keep them all. They probably sell some stock out there.” – 7P.

3.5. Perceived severity

There was mixed opinion among producers on the severity of S. Dublin. Most cited their own lived experience and/or second-hand experience of another producer that had previously dealt with an outbreak as the basis of their perception of severity.

“You haven't heard like, oh, this farm's got 200,000 somatic cell, or it's climbing up to 300,000. And the reason it's so high it's because of Salmonella Dublin right?” – 4 N.

Among producers who perceived S. Dublin to be an important herd health issue, many justified this economically. Specifically, the impact of calf losses and reduction of overall farm productivity were both cited as important, with the gross margin losses from S. Dublin being estimated at $480 CAD/stall ([23]).

“What I call a disaster is when you're having to treat 100% of your calves, that's a disaster.” – 7P.

Additionally, some producers emphasized the social importance of maintaining a negative herd status, noting that positive herds are often viewed negatively and that “The perception means a lot to me” – 10 N, which reinforces their motivation to keep their disease-free status.

Some producers were uncertain of the potential significance of S. Dublin for their farm. They felt that more information on real-world clinical cases or farm outbreaks of S. Dublin would help underscore its importance within the dairy farming community. Some recommended highlighting the lack of effective treatment options and the severe impacts this can have on herd health and farm productivity. They suggested including testimonials and case studies would be helpful as it would make it more real.

“How do you quantify the pain of having it? It's sort of not our problem, right? But I'm sure the guy that's dealing with it feels every bit of it, right? So, I think, not that you have to scare producers, but it's like, hey, this is a real potential concern for you. And it's making that real for people, I guess.” – 3 N.

Some producers did not consider S. Dublin an important herd health issue. This was especially evident in the producers who had firsthand experience with S. Dublin. Many producers stated that it was not a topic of concern within their community of dairy producers, “I'm talking with lots of producers all the time. And it's not really something that's come up honestly. Never had anyone say, ‘how's that working out for you?’ Kind of thing. So, it's not been a topic of conversation.” – 10 N, with other issues overshadowing S. Dublin, like leukosis, scours, avian influenza, and lameness. Some compared S. Dublin to other forms of Salmonella which they had successfully managed in the past through treatment and/or vaccination and therefore were not overly concerned, stating “I mean, I had a cow with Salmonella like 15 years ago once, and like, it was whatever, you know what I mean?” – 3 N. Furthermore, there were accounts of positive farms that had not seen any obvious clinical disease from S. Dublin, and thus these producers did not see it being a priority or concern.

“I wasn't even aware of it until I got a call from [the provincial dairy inspector] who told me that we were positive I was like, oh, cool. And then she kind of gave me some discussion points and things to talk about. And then kind of left it with me, and I didn't really do anything with it. And then nothing happened [in terms of disease].” – 8P.

While perceptions of severity and risk varied at the farm level, all interviewed producers agreed that not addressing S. Dublin would have negative consequences for the dairy industry. Many expressed fears of increasing prevalence of S. Dublin due to failure to investigate key gaps, such as important transmission pathways. Some worried that not addressing S. Dublin would result in mandated action and restrictions like a requirement to pre-test cattle before they could be bought and/or sold.

“[If it gets] to the point where you're a positive herd and you need to identify that you're selling cattle or calves. I think it's a huge risk and a huge cost.” – 3 N.

3.6. Perceived benefit

All producers saw some benefit in disease prevention, investigation, and treatment for S. Dublin and other dairy diseases at the farm level. In terms of prevention, most producers emphasized the importance of biosecurity, specifically boot and equipment cleaning. While some producers had quarantine protocols in place for purchased cattle and cattle leaving and returning to the farm, as well as quarantining sick individuals on farm there was a small number of producers that have moved towards pasteurization of colostrum and milk for calves to prevent disease spread. Other preventative actions discussed by our participants included vaccination protocols and frequent herd health appointments with a veterinarian.

“My dad used to do herd health every 3 weeks. I do it every 2 weeks now.” – 4 N.

When discussing their approach to investigating on-farm illness or a positive disease detection, multiple producers indicated that their first point of contact would be the provincial dairy inspector, particularly if S. Dublin was suspected. As one participant stated “if I came up positive the 1st person I'd probably contact is [the provincial dairy inspector]” – 4 N. This step was often taken in conjunction with consultation with their herd health veterinarian. Notably, a few producers emphasized the benefit of consulting other producers to get firsthand information from those who may have dealt with similar herd health issues in the past.

“So, we quite often compare notes and say, ‘Oh, you know who had this and this is what I'm using, or this is what I've tried to do.’ And she'll say, ‘well, this has been really successful for me’. And you think, ‘oh, okay’. You kind of watch and try some of those things.” – 9 N.

Some producers highlighted the benefits of diagnostic testing and indicated that it was a common tool used when managing disease on-farm. However, the triggers for initiating testing varied considerably among producers, with some pursuing testing as soon as a sick individual was identified, “if we have something funny going on, we'll do the tests.” – 1 N, some waiting for a failed response to typical empirical therapies, and others only initiating testing after experiencing multiple losses within a short period of time.

“We did lose a couple of calves to the point where I was thinking, ‘Wow! Should I be taking something over to Vancouver (Animal Health Centre) to have it you know, checked over?’” – 6 N.

3.7. Perceived barriers

3.7.1. Institutional barriers

Producers were able to highlight many perceived barriers to implementing disease management recommendations and engaging more broadly with government-led disease control programs. Some expressed reluctance to engage with government-led disease initiatives due to skepticism about the intent of government involvement with disease control. This latter case may ultimately be a barrier to adopting recommendations. The perceived lack of alignment between government and producer priorities also created additional challenges which were further complicated by the perceived lack of support for disease management historically.

“I'm not entirely sure what we can expect from the Provincial Government. We, I don't know, I guess, are a little bit pessimistic in that department. We haven't had a ton of support, so I don't really see why we would get some for this.” – 5 N.

Some producers stated that public opinion and welfare recommendations (e.g., not separating the calf and the dam) are often in opposition to disease management recommendations (e.g., separating as soon as possible to reduce disease spread), which can generate conflict.

“And it was part of the next step for me, making decisions as far as pasteurizing the colostrum. Trying to ramp up our biosecurity with regards to removing the calves quicker from cow and then having to have the arguments with public who think they should be left with the cow.” – 7P.

3.7.2. Operational barriers

Many producers highlighted logistical barriers to implementing management recommendations from disease control programs, particularly those related to improving biosecurity, citing time constraints, labour shortages, and associated costs as major challenges, “Guys don't have the time, or they don't want to do the extra work, or they don't have the people to do the extra work.” – 8P. Producers frequently used the word “realistic” when considering if they would be willing or able to make the recommended changes on their farm, “it'd be one of those things where it'd have to be realistic” – 4 N. Many cautioned that if recommendations were not “realistic” then they would not be adapted.

“It has to come from a trusted source, and it has to be easily digestible, and it has to be something that they can act on. If you're giving me information about something I can't control, I'm gonna throw it away.” – 8P.

Notably, many producers brought up social pressures as a large barrier for making disease management changes. Some stated that getting staff and professional visitors on board with biosecurity protocols can be challenging, often resulting in confrontation.

“We had it with our hoof trimmer, like, I was trying to do a boot dip by the hoof trimmer, and he just wasn't having it. This is my personality, I'm not like someone that's gonna keep bugging people or whatever, like, If it's an inconvenience. So, we ended up just not doing the hoof trimming stuff. And yeah, it's probably a gap.” – 1 N.

3.8. Self efficacy

Overall, producers that were interviewed in the current study did not feel confident in their ability to identify, prevent, or manage S. Dublin. Some producers noted that they likely would not be able to tell if an individual animal had S. Dublin specifically but were confident that they would if an animal was sick and would likely pursue some degree of investigation.

“Can I pick out a S. Dublin calf? I don't think so. I think we're going to need to have a blood test, or the fecal, whatever it's going to be done to be able to verify it.” – 1 N.

However, others noted that S. Dublin infection may be something that would be missed entirely given the number of other issues they to deal with on their farms. This was conveyed by one producer who said, “[…] we would probably just chalk it up to regular old scours or regular other things. [We] have enough calf issues already that it would just fly under the radar absolutely” – 8P. This was further reaffirmed by producers that had lived experience with S. Dublin.

“[…] all this time we didn't think we had it. And we had it.” – 7P.

In terms of prevention, some producers felt that their existing biosecurity practices (e.g., closed herd) were their strongest line of defence against S. Dublin infection. However, many pointed out the challenges in keeping up biosecurity and expressed some frustration that, despite rigid protocols, there remained gaps where disease could enter the farm.

“[…] whole thing of biosecurity is just like, you know, it's not a poultry farm, right, where you can't even have an industry person poke their head in the door kind of thing right? Like it's so open, I mean my place particularly. There's so many dairy [farms] surrounding us, and there's waterfowl, coyotes, and whatever, right? Like, okay, yeah, we're gonna wash our boots or we're gonna feed. You know, we're gonna work from youngest to oldest, or whatever, like those are things that we're doing or we can do. But it's like, is that really helping the situation, or like, is it really measurably, you know, preventing things?” – 3 N.

Among positive farms, producers did not feel empowered to manage S. Dublin. They expressed frustration surrounding inconsistency with testing results, difficulty identifying positive individuals, and overall uncertainty that their attempts to manage this disease were effective

“.. I'm scratching my head, and I'm going ‘am I barking up a tree that I should keep barking up, or am I wasting my time’, and just stick good protocols in place, and hope for the best.” – 7P.

3.9. Cue to action

The participants in this study expressed varying opinions on what would prompt them to take action against S. Dublin on their farm. Some stated that one positive result would be enough for them to pursue further testing and mitigation strategies. However, others thought that they would likely need to see evidence of disease prior to investigating further, specifically citing animals not responding to treatment, calf death, and/or drops in production within their milking herd.

“I would weigh it with you know, if everything appears healthy at the time, like, I might resist it until there's trouble.” – 10 N.

Further discussion of disease management and mitigation programs, specifically the S. Dublin surveillance program, was met with mixed opinions by the participants. Some producers saw the surveillance program as a great benefit to them, since a negative result provided reassurance that the disease was not being missed. One producer stated that the surveillance program has made them more proactive as a reaction to being tested and wanting to stay negative. This sentiment was shared somewhat by other producers who thought that S. Dublin was only on their radar because of the surveillance program.

“I feel like it's like we're doing proactive things now. But it's because we were reactive.” – 5 N.

However, some producers expressed that they were not engaged with the program and were unaware of their results or of any other information that was sent via email or available on the website, stating “I'm not reading the emails. I skim it at best.” – 9 N. Similarly, another participant called into question the overall importance of the S. Dublin surveillance program, given the lack of direction and actionable next steps once positive. These producers did not feel they were given realistic tools to help address a positive result and therefore questioned the usefulness of this surveillance system.

“You tested, now what? And I'm glad, of course, that we were negative. And I'm like great, but if I was positive, I don't know what I would have done about it, you know? Like, was I prepared to test all animals, or segregate, or cull, or like, I don't know? It's something that I always, when a producer asked to test something, too, I'm like, okay, what are we gonna do with these results?” – 3 N.

3.10. Perceptions and critiques of current disease management strategies

Some producers recognized the benefit of industry-wide disease management and mitigation programs, including government-led initiatives, and expressed concern that some may not be viewing this issue with sufficient seriousness.

“It is just one of those things where pretending it doesn't exist isn't going to be a good idea.” – 4 N.

However, some participants were critical about the accessibility and quality of information pertaining to S. Dublin, specifically clinical signs, prevention steps, laboratory results, and mitigation recommendations, citing a lack of clarity from the communication. “It was anticlimactic. The first of the emails that they sent out were kind of delayed. And they were unclear, hard to read. So, lots of guys got the email. And they were like, ‘what is this?’ And then they didn't really address it.” – 8P.

Many participants referenced educational events and materials as a large benefit of disease management programs. Some cited specific tools that have helped for other diseases, like decision trees, written protocols, and flow charts, “in my vet room right now I have like some protocols that are stapled to the wall” – 2 N. Others emphasize the importance of literature and events to generate awareness of disease issues. However, some noted that producers can become overwhelmed by all the disease information they receive, so they recommended frequent and consistent disease messaging.

“I mean, literature in general is important, I think. Keep pounding the message that this is important, yeah, I think more clarity is important, whatever that means to you. Because, yeah, like I said, I sat down here and I was frazzled. And I'm like, okay, I'm trying to remember everything I know about Dublin. Yeah, I'm being confused with Mycoplasma and getting confused with HPAI. And I'm like, I know more than most farmers.” – 8P.

Some producers emphasized their preference for educational materials like case studies and firsthand accounts of farms that have dealt with S. Dublin. There was a consensus that this type of educational material was more actionable and less academic.

“Use these case studies, use them, we're talking about Dublin because we have Dublin. Go to these farms that have had it. What did they do? Did they ignore the problem? Did they aggressively treat, you know, after 6 months? Did they have it really bad? This is great because this is actionable.” – 8P.

Some producers questioned the role of government in disease management. There was a consensus that the goals of government-led disease initiatives have not been clearly communicated, and some producers felt they were not adequately consulted or that their priorities were not aligned with those of the program. However, the majority were open to improving this relationship going forward and saw it as an overall benefit.

“Don't take this wrong way, but I would say the [government] was kind of a distant entity, you know, just whatever they were doing, I would say we need much more interaction. And I see it more and more and I just think that's great, like any connections that, you know, the work that the Ministry of Ag is doing with industry. I think that's all positive moving forward. So, I'd encourage that.” – 6 N.

Some producers championed the current S. Dublin surveillance program citing that “We can't act on anything if we don't have info on it. If we don't have data” – 10 N. With some calling to make the program mandatory given that this was an industry wide issue.

“[…] like the fact that we're doing voluntary testing right now. And like some guys are doing it, but I'd love to see everybody doing it. Taking the choice away from the farmers is often a good strategy, just sending it out and saying, hey, we're testing all your bulk tanks for this. Is a good way to do it, because we don't have time to just sit around and debate things all the time.” – 8P.

However, producers cautioned against introducing regulations if S. Dublin continued to spread. Particularly, highlighting that increased regulation could unfairly penalize positive farms without providing clear, actionable pathways to achieve disease free status, and that mandated, on-farm changes may not be effective or practical at the individual farm level.

“It can't be a negative action either. Right. Because what do you? What are you gonna do with that, like? It's on the farm. It's likely gonna be on the farm. They want to do huge changes, or whatever that might look like. But I don't know. Sometimes you're better off to let the farmers deal with it themselves than have somebody who doesn't know the farm dynamic try and tell you what to do with it.” – 3 N.

4. Discussion

Overall, dairy farmers in in this study expressed uncertainty surrounding S. Dublin and its management. This uncertainty stemmed from several key sources: 1. Unclear roles and responsibilities among stakeholders, specifically government; 2. Differing views on the necessity of government regulation; 3. Confusion about how information on S. Dublin and disease management is communicated; and 4. Producers struggle with self-efficacy in the management of S. Dublin; Together, this points towards a need for improved capacity building communication and messaging surrounding S. Dublin in BC.

4.1. Roles and responsibilities

Producers expressed uncertainty about the roles and responsibilities of various stakeholders, specifically the provincial government, in S. Dublin management. Many shared frustrations about a perceived lack of historical support for disease management from the provincial government shaping present relationships. Some producers cited a lack of alignment regarding government priorities and producer priorities. Conversely, many producers indicated that, when met with a disease issue on the farm, the provincial dairy inspector would be one of their first calls along with their herd health veterinarian, highlighting a branch of the government which they actively rely on. A similar phenomenon was seen in Great Britian, where producers were more motivated to adopt strategies when brought up by their veterinarian, as opposed to government [6]. However, as the provincial dairy inspector was identified as a valued contact, it may be that a personal relationship plays a more crucial role in the uptake of recommendations, rather than an individual's affiliation.

Interestingly, one study found that the roles and responsibilities of the producer and the government changed in accordance with the type of disease [7]. Endemic diseases were largely perceived as the fault of an individual “bad” producer who did not keep a watchful eye, and thus “good” producers do not suffer from these diseases and do not warrant government support or intervention [7]. Conversely, epidemic threats were perceived to have external origins outside of the producer's control and therefore were the responsibility of the government [7]. Within the context of S. Dublin in BC, it could be argued that S. Dublin is an endemic disease or an epidemic threat, which may account for the differing opinions on roles and responsibilities.

Most producers encouraged the provincial government to continue or increase the production of educational materials and educational events. Notably, there was little mention of other stakeholders, such as producer-led organizations (BC Dairy) or other regulatory bodies (the provincial milk marketing board) when discussing the roles and responsibilities of disease management, particularly in areas like education and research. This contrasts with findings from a similar study on producer perceptions of S. Dublin in Ontario, where participants highlighted the importance of Dairy Farmers of Ontario's initiatives in helping reduce disease spread [9]. This discordance may reflect regional cultural differences with the dairy industry, participant experiences with producer-led and regulatory organization, or variability in organizational capacity to engage in communication and education; however, further research is needed to better understand the underlying causes. The majority of producers cited their herd health veterinarian as a trusted source of education and information, along with fellow farmers, which has been described in previous studies [6,9,1,4].

4.2. Government regulation

While some producers expressed a desire for increased government support, others cautioned against disease management regulation, emphasizing that farm level decisions should remain with the producer. Some also expressed a desire for more direction from the government without the imposition of formal regulations. This discordance has been seen in similar studies. For example, one UK study found that, when surveyed, most producers indicated that biosecurity was the role of the government but perceived the government would not be competent in the policing or regulation of disease. They were reluctant, however, for responsibility to be placed back on the producer [7]. Notably, some of our producer participants disagreed with this viewpoint and advocated for regulation, such as making the voluntary S. Dublin surveillance program mandatory, arguing that disease management efforts that improved the industry should not be undermined by a few individuals unwilling to participate. A similar attitude was observed in a study of Canadian producers' perceptions of Johne's disease control programs, where the majority supported the use of incentives and penalties to motivate participation and ensure compliance [4].

Overall, comments conveyed a feeling of uncertainty about what actions the BC Ministry of Agriculture should take to address S. Dublin. Some participants expressed not wanting government regulation for the disease, while also emphasizing that government was not doing enough to support them in S. Dublin prevention and management. This struggle to reconcile apparently contradictory beliefs surrounding government health actions is a common theme among different populations. For example, during the COVID-19 pandemic, oftentimes people perceived government health actions to be both “insufficient” and “too strict” [24]. However, what might at first appear to be a cognitive dissonance actually has some logical basis when one considers the fact that regulation can be seen as imposing, whereas support is viewed as empowering. With this perspective, it becomes clear that producers don't want to be told what to do; rather, they want to be provided with a comprehensive set of tools and approaches that they can use to formulate a plan that best aligns with their situation, goals, beliefs, etc.

4.3. Self-efficacy

Overall, producers expressed feeling ill-equipped to prevent, identify, or manage S. Dublin. When evaluating the perceived threat of S. Dublin and producers' ability to prevent disease, we found that overall, all producers felt their herd was susceptible to S. Dublin to some degree. The most common area where producers felt their herd was vulnerable to infection was through equipment fomites and cattle movement, specifically citing cattle drivers as an area of risk due to their frequent contact with multiple herds. There were concerns with having workers and professional visitors complying with the recommended biosecurity protocols. Producers were also concerned that the BC dairy industry was highly susceptible to increasing S. Dublin cases through the importation of US replacement cattle.

When evaluating producers' ability to respond to S. Dublin and how producers evaluated the goal (preventing and/or mitigating S. Dublin) we found that the most common barrier producers cited was the concern that the actions needed to prevent, manage, and mitigate S. Dublin may not be “realistic”. Some producers indicated that if actions centered on S Dublin mitigation were not something they could easily act on they would not be receptive. Similar findings were reported by [4] who indicated that practicality was a major barrier for producers to comply with Johne's disease control recommendations [4]. The term “realistic” ultimately encompasses many of the other barriers cited by producers (cost, time, efficiency) and may be an important consideration when developing herd health action recommendations. This has been highlighted in a similar study investigating barriers to implementing management practices for S. Dublin where producers brought up time, cost, but above all practicality as the main drivers of implementation [9].

In human public health some disease management programs have overcome barriers like time, cost and practicality by grouping together recommendations and health actions. For example, one study looking at ways to promote Pap smears, specifically in uninsured individuals, found that adding on a Pap test to any other visit that required a pelvic exam in an urgent care setting was highly effective, as it reduced cost and time and was ultimately more practical for the patient [25]. This principal could be applied to S. Dublin recommendations, where recommendations could be modified to be more like those of other diseases which producers may be more motivated to prevent. For example, pasteurizing colostrum can help prevent S. Dublin, Johne's disease, and leukosis. Similarly, displaying S. Dublin results on the same dashboard that producers use to view their milk quality results may improve awareness and decrease the time spent solely on S. Dublin, which has been demonstrated in human health [26].

4.4. Communication

Almost all producers cited feeling unclear on how to prevent, identify, or manage S. Dublin, notably expressing uncertainty around the communication surrounding clinical signs, treatment options, and management strategies. Some expressed frustration with the messaging from the surveillance program, noting that it was unclear what the results meant, which led to apathy in some instances. Another UK based study found that inaccurate disease testing and lack of proof that practices were viewed to be major barriers in adhering to disease management recommendations [6]. However, another study cited lack of motivation by producers to pursue action against the disease; a situation that was attributed to the farmers either believing that the disease was not severe enough to act or that the proposed preventative measures would be ineffective [27]. Collectively this suggests that communication should be multi-pronged, not only conveying information about the disease but also highlighting the effectiveness of the recommended action in order to encourage producers to act.

Perceptions of biosecurity practices also varied. For example, producers referred to their herd as “essentially” closed, citing this as evidence that they were proactive in herd health. Producers seemed to view closed herd status as being on a continuum, e.g., not buying cattle often, rather than as a binary, e.g., being closed (no animal movement whatsoever) vs. open (animal movement of any kind). Similarly, Ontario producers identified their herds as being “mostly closed” citing this as justification as to why they were not concerned about S. Dublin [9]. This may indicate the messaging around closed herds is flawed and that future recommendations should include precise language to properly convey risk. However, it may also reflect a disconnect between identity (who producers believe themselves to be) and behavior (what they actually do). Previous research has shown that relationships between different aspects of an individual's identity and their health-related research are complex and not always aligned [28,29]. In this scenario, if a producer strongly identifies as being proactive in herd health, they may not recognize or acknowledge behaviours that run counter to this identity (i.e., those that compromise herd health, like buying or moving animals). Additionally, this identity might cause producers to focus S. Dublin risk factors that are outside of their control (e.g., pests and professional visitors), rather than their own production practices. This, in turn, can lead to diminished self efficacy. A similar phenomenon has been described in human medicine and is grounded in attribution theory, which posits that perceived controllability of a success or failure heavily motivates action [30,31]. When a disease is perceived as outside of an individuals' control (e.g., genetic vs lifestyle induced) there tends to be reduced self-efficacy surrounding coping with said disease [30]. These findings support the need to consider producer identity and its potential relationships with behavior and self-efficacy when developing S. Dublin-related recommendations and interventions.

Disease perceptions appeared to be driven by first-hand, second-hand, or other peer-to-peer experiences. Strong social networks exist within the agriculture communities and thus information flowing out of this network is and has previously been shown to be highly valued among producers; a finding that was evident in the producers we interviewed and in [32]. This trusted route of information, along with consultation from trusted sources that are enmeshed within the dairy community (trusted government officials, veterinarians, and other producers), appears to dominate the information network used by our interviewees when accessing information. We encourage future work to leverage this social network to elevate the stories of producers that have dealt with S. Dublin firsthand, which in turn could change producers' perceptions of S. Dublin and help with disease management compliance. Accessing information through social networks, producers' meetings, conferences, and case studies may work in this case rather than presenting recommendations as a fact sheet or FAQ. Using narratives from peers will likely bring to the forefront more actionable and accessible recommendations, which would hopefully improve uptake. In fact, peer-to-peer learning has been found to be a valuable motivator for producers [4] and has been well established as a novel and effective health communication tool within human public health systems [33]. For example, one study that investigated the role of narrative health communication on cervical cancer prevention found that the more relevant the narrative was to the audience, the more they saw an improvement in perceived efficacy of the prevention action and the perceived severity of the health outcome [33]. As producers interviewed in the current study appeared to value second-hand or other peer-to-peer communication as highly relevant in their overall perceptions of S. Dublin, there is merit in determining if this form of communication could be effective in dairy disease management. This may be applicable to other dairy diseases outside of S. Dublin.

5. Strengths and limitations

A major strength of this study was the use of the Health Belief Model. Much of the work completed to date that has focused on dairy producers has placed a strong emphasis on investigating barriers to change or adopt proven best practices. In contrast, our approach allowed us to explore farmer views on the different motivators for disease action and to encourage them to weigh contrasting concepts against one another during the interview, such as perceived benefit and perceived barriers. However, there has been some criticism of the health belief model; a recent meta-analysis indicated that not all concepts equally predicted health action, with perceived severity being a weak predictor, and perceived barriers and benefits being the strongest predictors [34]. Future work should consider weighing the responses from different concepts according to their predictive capacity when using this model to develop disease management program recommendations.

While the results of this study do offer some insights into producers' perceptions of S. Dublin, the small sample size and non-random sample are limitations that impact generalizability. Despite the this, we did achieve saturation with no new themes emerging within the last few interviews. One study on qualitative sample sizes found that, when studying a known population and participants in said population are information rich, there was a high probability of observing codes and thus minimum sample sizes can drop below ten [35]. However, there would be value in seeking perspectives of producers in different areas of BC and across Canada to understand the possible nuances of different regions.

6. Conclusion

Human perceptions and actions can and do shape the course of infectious disease outbreaks. Understanding these nuances are critical not only to specific diseases but overall prevention, mitigation and response which affect human and animal health as well as food security and the economy. This work describes the experiences and perceptions held by BC dairy producers regarding S. Dublin. Overall, an improvement in clarity in the messaging surrounding S. Dublin, specifically messaging that clarifies uncertainty and empowers self efficacy, would be beneficial. This might include needed messaging around clinical signs, disease testing, preventative actions, and mitigation techniques. It is possible that pivoting to more experience and narrative focused messaging may be highly effective at reducing improving disease management compliance (e.g., changing risky practices, improving biosecurity, etc).

Furthermore, the current roles and responsibilities of various stakeholders regarding S. Dublin mitigation and management remain unclear, with sometimes conflicting opinions occurring. Given the perceived value of peer-to-peer communication, disease messaging may be more effective when coming from sources like producer led organizations, herd health veterinarians, and “boots on the ground” government officials, as opposed to faceless government messaging. We recommend S. Dublin disease management programs invest in providing better support to individuals who are equipped to provided personalized recommendations to producers (e.g., veterinarian, dairy inspector). Additionally, given the confusion around the roles and responsibilities of various actors across the dairy industry, these communications should also seek to outline who is responsible for which actions regarding herd health

Ultimately, more research involving a larger and more representative sampling of producers, or longitudinal studies of how perceptions shape action when faced with clinical cases could further improve understanding of effective strategies for the management of and mitigation of S. Dublin.

CRediT authorship contribution statement

E. Boyd: Writing – review & editing, Writing – original draft, Visualization, Project administration, Methodology, Investigation, Funding acquisition, Formal analysis, Data curation, Conceptualization. E. Cuthbert: Writing – review & editing, Methodology, Conceptualization. C. Himsworth: Writing – review & editing, Project administration, Methodology, Funding acquisition, Conceptualization. K. Byers: Writing – review & editing, Supervision, Methodology, Formal analysis, Conceptualization.

Declaration of competing interest

The authors declare that there are no conflicts of interest regarding the publication of this paper. Specifically, the granting agencies used to fund this work (BC Dairy Industry Research and Education Committee (Langley, BC, Canada; 2021–2023) and the WestGen Endowment Fund (Abbotsford, BC, Canada;2022–2024)) had no influence over the study design, analysis, or results.

Appendix A. Supplementary data

Supplementary material

Data availability

The data that has been used is confidential.