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    Biosecurity Part 1: Introduction

    a clear dome structure encloses two large trees
    Just because you can’t enclose your sanctuary in a protective bubble doesn’t mean you can’t work to keep infectious diseases out! Photo by Yusuf Evli on Unsplash

    This resource was fully updated in preparation for the veterinary review process. It was originally published on November 17, 2018.

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    Veterinary Review Initiative
    This resource has been reviewed for accuracy and clarity by a qualified Doctor of Veterinary Medicine with farmed animal sanctuary experience as of May 2023.

    Check out more information on our Veterinary Review Initiative here!

    Promoting resident health and well-being is one of the primary goals of sanctuary care. To achieve this, we provide residents with a healthy diet, assess their well-being daily through thoughtful observation, perform routine health checks, and provide them with compassionate, individualized, veterinary care. These are just some of the ways in which we strive to keep our residents healthy, and they certainly play an important role in preventing illness (or catching and responding to signs of concern before an illness becomes more serious). However, when it comes to infectious diseases (diseases caused by harmful organisms such as bacteria, viruses, fungi, or parasites), we also need to work to reduce our residents’ risk of being exposed to these disease-causing organisms in the first place. This is where biosecurity comes in! 

    What Is Biosecurity?

    Although the term might sound overly dramatic and conjure up images of folks in full hazmat suits, it doesn’t need to be so scary. Merck Veterinary Manual defines biosecurity as ”the implementation of measures that reduce the risk of the introduction and spread of disease agents [pathogens].” Biosecurity is actually a day-to-day practice that plays an important role in keeping both our residents and the humans who interact with them safe. In this series, we are going to focus on biosecurity measures to protect your residents from infectious diseases, though many will also help protect humans as well. Please refer to this resource for information on zoonotic disease and ways to protect folks who come to your sanctuary. 

    If you’re only familiar with biosecurity in the context of industrial animal agriculture, you may be wondering just how biosecurity looks in a sanctuary space. After all, many of the biosecurity measures taken at commercial operations have no place in sanctuary settings, and others simply are not practical. However, if we consider the definition provided above and remember that biosecurity is simply the implementation of measures that protect our residents from infectious diseases, we realize that there are numerous ways to do this within sanctuary spaces. Keep in mind that biosecurity is not one-size-fits all. Just as biosecurity is going to look different at a sanctuary than it does at a commercial facility, it also will vary from sanctuary to sanctuary. 

    A biosecurity plan typically consists of the following:

    1. Measures that prevent or limit the introduction of pathogens to sanctuary grounds (this is referred to as bioexclusion or external biosecurity). Think of this as keeping infectious diseases out of the sanctuary.
    2. Measures that monitor for infectious disease. By being aware of changes to the degree of risk your residents face, you can update your current plan to appropriately reflect this risk.
    3. Measures that prevent the spread of disease at the sanctuary (this is referred to as biocontainment or internal biosecurity). If an individual or group contracts an infectious disease that is also communicable (contagious), these measures help prevent spread to other residents.

    No single measure is going to mitigate all risk of disease exposure. Therefore, a biosecurity plan should consist of numerous measures that work together to offer more complete protection. This is often explained using “The Swiss Cheese Model.” Just as a slice of (let’s say, vegan) swiss cheese has holes in it, so too do biosecurity measures. The size and number of these holes is different from slice to slice, but if you stack slices on top of each other, the holes in one slice may be covered by another slice. The goal in creating an effective biosecurity plan is to layer your measures (represented by each “cheese” slice) so that there are few to no gaps (represented by the holes).

    Understanding How Infectious Diseases Spread

    In order to implement measures that reduce the risk of exposure to disease-causing agents, sanctuaries must start by identifying the ways in which pathogens may be introduced to and spread between residents. In order to do that, you must first understand how infectious diseases spread. If this is not a topic you are well-versed in, we strongly recommend you check out our resource on infectious disease, which can be found here. To recap information from that resource, there are five main ways an individual can be exposed to pathogens. These are as follows:

    • Direct Contact – This type of exposure occurs when an individual comes into direct physical contact with an infected individual, their tissues, or their bodily excretions, secretions, or fluids. Examples of direct contact include individuals in a shared space rubbing up against each other or individuals in separate, but neighboring, areas making nose-to-nose contact through a fence. 
    • Aerosol – This type of exposure occurs when pathogens become suspended in the air, which may occur when an infected individual breathes, coughs, or sneezes. Pathogens can also become airborne if contaminated soil or dust gets stirred up, which may occur when living spaces are being cleaned or simply when individuals are moving around a contaminated space.
    • Oral – This type of exposure occurs when an individual ingests pathogens (which may occur if their food or water becomes contaminated) or when an individual comes into contact with pathogens when chewing, licking, or suckling on someone or something. The fecal-oral route is a very common transmission route and may occur in various situations such as if food or water become contaminated with infective feces or if an individual ingests infective feces while grooming or nursing. 
    • Fomite – This type of exposure occurs when an individual comes into contact with a pathogen via a contaminated inanimate object (called a fomite). Things like cleaning tools, feeding supplies, brushes, coats, bedding, and equipment can be fomites. Vehicles can also act as fomites, carrying pathogens onto sanctuary grounds on their wheels or undercarriage. When humans introduce pathogens carried on their shoes or clothes to an individual, this is also considered fomite exposure. 
    • Vector-borne – Whereas fomite exposure occurs when a pathogen is introduced via an inanimate object, vector-borne exposure occurs when the pathogen is introduced by a living organism. There are two types of vector-borne transmission: biological and mechanical. Biological transmission occurs when a vector, such as a blood-sucking insect, uptakes a pathogen that then replicates and/or develops inside the vector. The biological vector can then transmit the pathogen to a susceptible individual. Common biological vectors include ticks, lice, and mosquitos. Unlike biological transmission in which the pathogen replicates and/or develops inside the vector, during mechanical transmission, the vector simply carries the pathogen on their body. Flies, gnats, and rodents can act as mechanical vectors of certain diseases. Humans can act as both biological and mechanical vectors of various diseases. 

    In order to be effective, a biosecurity plan should consist of measures that address the main routes of disease exposure and mitigate their risk. For example, quarantining new residents is a basic biosecurity measure that all sanctuaries should adhere to. However, simply keeping a new resident separate from other residents really only prevents direct contact with the new resident. If soiled bedding from a quarantined area is disposed of in a way that does not prevent residents from accessing it, they may come into contact with the new resident’s feces, resulting in possible disease exposure. Similarly, if caregivers who work in the quarantine area do not wear any protective gear, such as gloves, coveralls, and shoe covers, they could easily carry pathogens from the quarantine space to other residents.

    Risk Assessment

    While all sanctuaries will face some degree of risk in terms of infectious disease introduction and spread, the actual level of risk will vary between sanctuaries. A sanctuary’s region, climate, physical location, set up, resident population, and general operations all factor into the amount of risk their residents face. Remember how we said biosecurity is not one-size-fits-all? Part of the reason is that the specific risk factors will be unique to each sanctuary. For example, a sanctuary that does frequent rescue and intake will have a different degree of risk than a sanctuary that does not. Does this mean sanctuaries should stop doing rescue altogether? Of course not! But sanctuaries that do take in new residents will need to identify and implement biosecurity measures that can mitigate the risks associated with rescue and intake as much as possible. 

    To further complicate matters, keep in mind that the risk of infectious disease is not static. While there will always be some risk that your residents will be exposed to an infectious disease, there will inevitably be times when that risk increases. Let’s again use the example of bringing in a new resident – there will always be a chance that the new resident is carrying or actively shedding harmful pathogens, even if they appear healthy. This is why quarantine is so important. However, the risk associated with bringing in a new resident increases during a regional disease outbreak or when the individual is confirmed (or suspected) to have been exposed to a serious and highly contagious infectious disease. Additionally, the risk associated with a new resident increases when they are coming from certain situations such as large-scale industrial operations or hoarding situations. Your typical quarantine practices may be deemed insufficient in certain circumstances, and you may instead decide the individual needs to be quarantined off site. 

    A Balancing Act

    In order to be effective, sanctuaries should have a biosecurity plan in place at all times. However, this plan should change as needed in order to appropriately address the current degree of risk. You may be thinking, “Why not always have the most protective measures in place?” In theory, this would make sense. However, it may look different in practice. This is why we recommend creating what we’re calling “everyday biosecurity measures” that address the typical degree of risk your sanctuary faces and also identifying enhanced biosecurity measures that can be implemented during periods of increased risk (more on this below).

    Impact On Resident Well-Being

    Unlike many other settings, where the focus is productivity, profitability, and “food safety,” in sanctuary spaces, the residents’ health and well-being is a top priority. This means that their needs, desires, preferences, and autonomy should weigh heavily in all decision making. That doesn’t mean these are the only considerations, but they should always be part of the discussion. In the context of biosecurity, that means for every measure we consider, we must also consider the impact it will have on our residents and decide if the protection offered is worth any negative impact the measure may have on residents. 

    Going back to the example of taking in a new resident, does keeping the individual separate from all other residents for a minimum of 30 days have a negative impact on them? In many cases, the answer is yes – since most of the species cared for at farmed animal sanctuaries are social species, if given the choice, they would likely choose to be with others rather than to remain alone. However, given the very real risk of a new resident exposing other residents to infectious disease, the benefit of quarantining new residents is worth the short-term negative impact on their life, though we can and should find ways to lessen this impact. 

    Enrichment Can Help!
    An enrichment plan can go a long way in reducing stress, boredom, and loneliness for a quarantined individual, and we’ve got multiple resources that can give you ideas for how to do this. We suggest starting with this resource on social enrichment!

    When considering the benefit of a biosecurity measure and whether or not any negative impact it has on residents is acceptable, be sure to consider if there are other measures that could be implemented that would offer a similar degree of protection. Looking back at our new resident example: when we consider how infectious diseases spread and the fact that an individual can be carrying and/or shedding pathogens without showing any signs of clinical disease, we realize that there just isn’t a substitute for appropriate quarantine measures. However, when thinking of other protective measures, there may be. Let’s look at a couple hypotheticals to further illustrate this idea:

    These Are Hypothetical Situations!
    Though specific infectious diseases are referenced in the examples below, keep in mind that these are purely hypothetical. We always recommend working with your veterinarian to identify biosecurity measures that are most appropriate for your unique situation. Do not take the information below as guidance for what you should do at your sanctuary.

    Hypothetical #1 – Preventing Pinkeye At Zenith Farm Sanctuary

    The team at Zenith Farm Sanctuary in Winnemac has mostly focused on pig care, but welcomed a small herd of four cows 3 months ago. They just heard that another sanctuary recently dealt with a pinkeye outbreak in their cow residents. This is a condition the staff at Zenith Farm Sanctuary don’t know much about, so they are working hard to learn more and to identify ways to protect their residents. Understanding that flies can play a role in the transmission of pinkeye, one caregiver asks if they should consider restricting the cows to the indoors during the seasons when flies are most prevalent. The team discusses this suggestion, with multiple caregivers raising the concern that restricting the cows to their indoor space will have a negative impact on their lives. The herd enjoys spending their days grazing in the lush pastures and napping in the woods. If restricted to the indoors during fly season, the cow residents will miss virtually the entire grazing season and will need to rely on hay year-round. If restricted to the indoors, they will also have much less space, which caregivers worry will lead to boredom and possibly unhealthy group dynamics. The caregivers also wonder if keeping the cows confined to the indoors will actually keep flies out. In order to have healthy airflow, they can’t possibly keep all the structure doors closed, and even if they covered them with screen or some other material that allowed for airflow while keeping flies out, the structure is not impermeable, and most of the caregivers are skeptical that they’d be able to keep the flies out. 

    Not knowing how to proceed, the team at Zenith Farm Sanctuary decides to get their veterinarian involved. After raising their concerns about their new cow residents being exposed to pinkeye, their veterinarian agrees that keeping the cows indoors is probably not the best option and offers a list of measures they can implement to help protect them from pinkeye. She suggests vaccinating them, keeping their living spaces clean, providing cow rubs and implementing other fly mitigation measures to help lower their risk, and considering fly masks if face flies are a major issue despite the other measures. She also asks for more information about their supplemental minerals to ensure they are getting important minerals for eye health. She explains that early detection and treatment can minimize the risk of spread and help alleviate discomfort to an infected individual, so she teaches the team about the early signs of pinkeye they should be on the lookout for.

    Hypothetical #2 – Biosecurity Adjustments At Avian Allies

    Avian Allies is a small sanctuary in rural Winnemac that has specialized in chicken care for 15 years. They always have everyday biosecurity measures in place, but last year they went on full lockdown following the detection of highly pathogenic avian influenza (HPAI) in the US. Having been through (but thankfully not directly impacted by) a previous outbreak of HPAI in the US, Avian Allies already had an enhanced biosecurity plan ready to implement in the event of another HPAI outbreak. Though there was not yet a detection in the state of Winnemac, given the grave consequences of both the disease and governmental eradication efforts, the team decided to implement their HPAI biosecurity plan as soon as the first case was detected in their flyway. Part of this plan involved restricting avian residents to the indoors in order to prevent direct or indirect contact with wild birds. While the team at Avian Allies recognized that being stuck indoors would have a negative impact on residents, they felt this was the only way to properly protect residents from both the disease itself and from the government’s control efforts, which includes the mandatory killing of all domesticated birds on any property that has a positive case in a domesticated bird. The team planned to use various enrichment strategies to help mitigate any negative impact on the residents and were hopeful that within a few months it would be safe to let the residents outside once again.

    Unfortunately, this HPAI outbreak is not following the same timeline as the previous outbreak. It is looking more and more like the risk of HPAI will not be going away any time soon. The staff meets to discuss the current risk of HPAI (and control efforts) as well as the well-being of the residents while locked indoors. The team acknowledges that it is not safe to go back to life as it was before the outbreak, but also are worried about the impact being locked fully indoors for such a prolonged period of time is having on residents. When they implemented this measure, they never thought it would need to be in place for quite so long. After much discussion, the team decides that they will start retrofitting the residents’ outdoor spaces so that they can provide enclosed spaces that allow the residents to scratch in the dirt and get some sunshine while using materials that can keep wild birds, as well as their feathers and feces, out. The team brings their plan to their veterinarian to see if they have thoughts or suggestions and to ensure that Avian Allies is continuing to do all they can to protect their residents while they attempt to balance resident well-being with HPAI prevention during this prolonged period of elevated risk.

    You’ll notice that both of these hypotheticals involve the idea of keeping residents indoors in order to mitigate the risk of a specific infectious disease. In the case of Zenith Farm Sanctuary, it was ultimately decided that keeping the cow residents indoors was not necessary and, in fact, there were other protective measures that made more sense to implement. In contrast, in the case of HPAI prevention at Avian Allies, it was decided that keeping the bird residents indoors was a necessary measure. When what was intended to be a short-term measure proved necessary for a prolonged period of time, the team decided to create enclosed outdoor spaces for residents in order to mitigate the negative impact the biosecurity measure was having on their well-being while still offering an appropriate amount of protection for their residents. While not the only difference, a key factor in the difference in outcome of these two hypothetical scenarios comes down to the degree of risk associated with the infectious disease in question. A positive case of HPAI is going to have severe and typically life-threatening consequences. While pinkeye can be painful and cause lasting issues if left untreated, it does not carry the same degree of risk as HPAI.

    Feasibility And Practicality

    Biosecurity measures are only effective if they are followed correctly and consistently, which is unlikely if the measure is overly complicated or unrealistic. Now, before we discuss this further, we do want to stress that we are absolutely not implying that a sanctuary can forgo biosecurity altogether if they deem it impractical. While there will certainly be variation between sanctuaries in terms of the specific measures in their plan, all sanctuaries should have measures in place that mitigate the risk of disease introduction and spread. Not taking reasonable measures to do so is unacceptable.

    What Does ‘Unacceptable’ Mean?
    At The Open Sanctuary Project, unacceptable means that we cannot condone (or condone through omission) a certain practice, standard, or policy. See a more detailed explanation here.

    To illustrate what we mean by balancing protection with feasibility and practicality, let’s look at another hypothetical example:

    Hypothetical #3 – Biosecurity Woes At Sunlight Sanctuary

    Sunlight Sanctuary is a newer sanctuary in Winnemac that never really thought about biosecurity. They have no written plan, but because they modeled some of their practices on another sanctuary, they are relieved to realize that they actually do have some important biosecurity measures in place, including the quarantining of new residents. Determined to create a thoughtful biosecurity plan, the team sits down to think about the sanctuary’s risks and measures that can mitigate those risks. Currently the sanctuary cares for cows, pigs, and goats, with each species living separate from the other two. Other than the general risk that always exists in terms of infectious disease introduction, there is no specific threat that they are aware of and the specifics of their location and region do not make their residents more at risk of any serious infectious diseases.

    Until recently, the team was not aware of the role humans can play in disease spread. Now that they have this knowledge, they decide to identify ways they can mitigate this risk. They consider having staff and volunteers put on shoe covers, tyvek suits, and gloves before entering a resident living space and then remove this protective gear when leaving in order to mitigate the risk of humans bringing pathogens from one space to another on their shoes, clothing, or hands. They already had these supplies in stock for quarantine and isolation situations, but not in the quantities needed to implement their regular use. They order more of these supplies, set them up outside of each resident house, and then hang up signs communicating the biosecurity measure. At the end of the first day of implementation of the measure, staff and volunteers express frustration that changing in and out of the gear slows things down so much that they can no longer complete their tasks in the allotted time. Thinking it may take time for everyone to get used to the new measure, leadership asks the care team to hang in there and see how the next week or so goes. 

    As the days go by, not only are the caregivers taking longer than usual to complete their daily tasks, but Sunlight Sanctuary also realizes they are going through shoe covers, tyvek suits, and gloves faster than they anticipated, leading to financial costs they had not considered. With folks coming and going from each space multiple times per day, each person is going through 3-4 sets of gear daily. The sanctuary decides to switch to less expensive shoe covers and gloves and switches from tyvek suits to fabric coveralls that can be washed and reused. This has reduced costs, but has not helped address the time spent changing in and out of the protective gear. Actually, because the coveralls need to be laundered, this change has added to the daily workload! There have also been a few instances where there were no clean coveralls available because the team couldn’t keep up with the laundry, and folks have complained that the cheaper shoe covers often rip while they are wearing them. As the care team became more and more frustrated, they started to become more lax with the biosecurity measure. After all, when there are no clean coveralls, they have to go into resident spaces without them, so why bother wearing them at all? On top of this, their tour season is approaching, and the team hadn’t really considered what this measure meant for visitors. They have no plans to stop allowing tours in with non-quarantined residents, but can they really ask guests to put on all this gear?

    The team decides to have a conversation with their veterinarian, who had not been involved in their original discussion about biosecurity or the decision to implement the new measure involving protective gear. He points out that, while shoe covers, gloves, and coveralls can be very useful in preventing disease spread, given their current situation and risk level, they would likely be better served if they focused on using protective gear for quarantine, since one of their biggest risks of infectious disease introduction is the intake of new residents. Switching to the cheaper shoe covers that easily tear could lead to folks spreading pathogens on their shoes, so he suggests that they go back to the higher-quality protective gear they previously used. He also stressed that just because the current measure was deemed impractical, that doesn’t mean they should abandon their plan to implement biosecurity measures. He suggests that they schedule a meeting to discuss biosecurity and their current practices so that he can help them create a plan that works for them.

    In the above example, Sunlight Sanctuary is taking biosecurity seriously and working hard to identify measures that offer protection. They now realize that in addition to considering ways to protect residents from infectious disease, they also have to consider practicality and feasibility. Wearing protective gear in all resident spaces seemed like a good idea initially, but in practice, it just wasn’t working. In fact, while trying to be more careful, they actually made choices that made their quarantine measures less protective (by using cheap shoe covers that didn’t hold up). By having a conversation with their veterinarian, they were able to identify other measures that made more sense to focus on.

    Keep in Close Communication With Your Veterinarian!
    When considering biosecurity measures, whether as a day-to-day practice or in response to a heightened risk of infectious disease, it is always a good idea to run your plans past your veterinarian! They can help you develop the most efficient and effective ways to protect your residents and can save you significant time and expense!

    Getting Started

    Now that you have a basic understanding of biosecurity and the important considerations that go into the process of identifying the most appropriate measures for your sanctuary, you’re ready to get started creating a biosecurity plan for your sanctuary! For step-by-steps instructions on this process, be sure to read Biosecurity Part 2: Creating And Implementing A Biosecurity Plan.


    Principle Of Biosecurity Of Animals | Merck Veterinary Manual (Non-Compassionate Source)

    Biosecurity: Routes Of Disease Transmission | Center For Food Security And Public Health (Non-Compassionate Source)

    Biosecurity in Livestock and Poultry Production: Basic Course | Center For Food Security And Public Health (Non-Compassionate Source)

    Non-Compassionate Source?
    If a source includes the (Non-Compassionate Source) tag, it means that we do not endorse that particular source’s views about animals, even if some of their insights are valuable from a care perspective. See a more detailed explanation here.

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