David S. Miller and Grey Stafford As with all species, a “good death” is the bar for which veterinarians should strive when euthanasia of zoo and aquarium species is required. However, euthanasia of zoo and aquarium vertebrate animals presents many practical challenges, given the diversity of anatomy, physiology, behavior, size range, and other characteristics associated with over 8500 different species managed in these facilities (Marcy 2021). Many of the euthanasia methods used for domestic animals can be directly used for zoo animals or modified to meet a species’ characteristics. Nevertheless, substantive challenges for appropriately selecting and applying euthanasia methods include: Therefore, the inherent biological complexity of animal species in zoos and aquariums, coupled with the diversity of societal perspectives, must be accounted for before, during, and after euthanasia of these animals (Figure 6.1). The current standard‐bearers among the zoo and aquarium background reflect an evolution from centuries of wildlife being valued solely for exhibition to the inclusion of broader scientific objectives. Therefore, in addition to exhibitions, many zoological institutions have embraced education, conservation, and research as a part of their mission. These scientific missions influence care and management decisions for animals throughout their life, including the institution’s management system (traditional, semi‐free ranging, use of ambassador animals, applied behavioral management, and other management systems). The scientific missions can affect when and how euthanasia is conducted as well as postmortem disposition of the body (AVMA 2020). Figure 6.1 A zoo habitat with polar bear resident. Careful consideration must be given to the time and place for the procedure. Source: Barb Wolfe, DVM, PhD, DACZM. It is also important to recognize that some animals in zoos and aquariums become recognized by the public and become a part of the local, national, or international human community’s focus and interest. This can have an impact on facility’s financial security via paid attendance, donations, and other sources of income and goodwill. There can also be tensions caused by responsible population management objectives and where there is limited space and resources for meeting animal welfare needs. The preceding reflects the perspectives of North American authors, but these perspectives are not necessarily shared globally; cultural, religious, local, or regional conventions, and other concerns may influence when and how animals’ lives are ended. The potential for adverse publicity is highlighted by the international controversy over the decision to end a young giraffe’s life and the subsequent feeding of the giraffe’s carcass to the zoo’s carnivores, even though the postmortem handling of the giraffe, by definition, did not pose animal welfare concerns for a deceased individual (Parker 2017). There is the need to recognize that society’s perspectives on zoos and aquariums, and humans’ relationship with animals and wildlife are evolving over time. North America is a reflection of society’s shift to more urban environments and fewer opportunities to interact with animals. This evolution may also overlay differing values among generations. Each of the above sociological factors has the potential to influence or cloud the decision whether to euthanize an animal and guide which methods are used. Zoos and aquariums differ from client‐owned animals in that multiple personnel with differing roles have a stake in animal husbandry and management. Zoo directors, oversight boards, trustees, curators, animal care staff, and other personnel have varying levels of animal care and high‐level perspectives and may have differing tolerances for the involvement of external interest in high‐profile or routine euthanasia events. While facilities staff, concession workers, and others may not appear to have a stake in animal euthanasia events, there is value in considering their contact with the public as a part of euthanasia‐related communications. Veterinarians conducting euthanasia within zoological institutions must be cognizant of their personal biases and potentially adapt their approach according to the institution’s exhibition and scientific missions, as well as staff needs. Accommodation of the human‐animal bond, aesthetics, and opportunity to grieve, must be addressed for zoo and aquarium personnel while balancing the investment that staff make in caring for their animals with intra‐institutional dynamics, and external audiences. At least half of staff’s waking hours are devoted to their animals. Therefore, a great deal of staff’s pride, as well as their personal and professional identity, are a part of caring for and bonding with their animals. This must shape discussions regarding when and how to euthanize, as well as the adjustment and emotional processing after an animal’s life is ended when daily staff’s participation is required for optimal euthanasia events. There is an inherent tension between the investment that staff must make to provide optimal care for their animals and the need to “let go” when euthanasia is required. This tension can be further complicated by population management, economic, and other considerations external to animal health and staff’s personal value systems. Therefore, end‐of‐life considerations for zoo and aquarium staff are similar to and often of greater magnitude than for companion animals and humans (Figure 6.2). While quality of life concerns for individual animals are a common justification for euthanasia of nondomestic animals, population management euthanasia can be a justification for euthanasia of zoo and aquarium animals (Browning 2018). Population management euthanasia is the euthanasia of otherwise healthy animals due to limited resources such as space, social interruptions affecting the previously mentioned institutional goals, and/or welfare of other animals, and/or the individuals’ limited genetic value to the population. The philosophical perspective supporting population management euthanasia includes: Figure 6.2 Zoo staff gathering to work with a giraffe. Animals of this size require many people to keep the animal and staff safe. Source: David Hamilton. Counterarguments to population management euthanasia include concerns for ethical responsibility to the animals, public perceptions, alternative population management strategies, and staff resistance (Powell and Ardaiolo 2015; Browning 2018). This does not eliminate other options for population management that will vary by species and circumstances. However, this does require effective communications with internal and external audiences about the justification for population management euthanasia and how animal welfare concerns are addressed. Intra‐unit, intra‐institutional, and professional community dynamics and public relationships have the potential to be particularly strained where community, national, or international attention is focused on the fate of high‐profile animals, particularly where institutional norms are not strong and supportive. A notable challenge is where the inevitability of animal death clashes with philosophical perspectives that animals should not be under human care. In these instances, the circumstances surrounding the animal’s death may be perceived and communicated differently according to the agenda of differing interests and thereby complicate decisions such as when to end an animal’s life, selection of euthanasia method, and the caretakers’ grieving process. While end‐of‐life considerations for zoo and aquarium animals that do not have a high profile may be less complicated or emotionally charged, caretakers still face difficult decision‐making challenges and grieving similar to those associated with companion animals within institutional context. External resources such as GRAZE (www.zoomentalhealthsupport.com) may be of value for proactive and crisis responses that can assist with addressing the social concerns associated with euthanasia of zoo and aquarium animals. There is a need to recognize the means by which information is shared external to the institution. Currently, there is a shift from conventional media and journalism to internet and social media technology and this prolongs news cycles that permit revisiting of videos. This increases the potential for perceptions of euthanasia and other zoo and aquarium activities to be skewed according to the interests of the media holder and this can impact legislative and regulatory actions that can limit options for optimizing animal welfare. Addressing this requires institutional and professional community clarity on birth‐to‐death management plans that address animal welfare, population management, research, and other scientific missions. Based on this, there is a need to develop advanced communication plans and a comprehensive euthanasia protocol that clarifies the decision process and methods of euthanasia while not losing sight of the need to address animal welfare as effectively as possible (Figure 6.3). Figure 6.3 Bonded animals make any euthanasia more complicated. Source: Barb Wolfe DVM, PhD, DACZM. Euthanasia complications in non‐domestic species can occur and this topic has been incompletely discussed at this time (Hepps‐Keeney and Harrison 2022). Measures to minimize the occurrence of undesirable euthanasia outcomes should be carefully considered and planned for. The following section will operate under the thesis that planning for prevention of undesirable outcomes is an obligation for veterinary professionals, and that there are three stages where end‐of‐life considerations are relevant (Figure 6.4). These three stages are: There is a need to proactively plan for optimizing animal welfare during all stages of an animal’s life, including a plan for end‐of‐life concerns. Optimal animal welfare must consider basics such as provision of a balanced diet and water, meeting the animal’s environmental, health, behavioral and social needs, and basic management to include monitoring of weight, training for voluntary behaviors (Table 6.1), and other animal management. These measures serve as preparation for euthanasia by providing baselines for future comparisons, delaying the occurrence of euthanasia by improving animal’s quality and duration of life, and by providing a husbandry and training foundation for low‐distress handling that will improve the quality of euthanasia procedures. Regular quality of life and daily assessments throughout an animal’s life as a routine part of work culture will serve to determine how management and animal welfare can be improved and serve as a reference for assessments of geriatric‐aged animals (Campbell‐Ward 2023). Simple tools such as videos and lameness assessments can minimize subjectivity and reinforce an animal welfare‐centric work culture (Hunter‐Ishikawa et al. 2023). Figure 6.4 A dying primate is euthanized after zoo personnel consider all other options. Source: Dakota Zoo. Table 6.1 Routine positive reinforcement training procedures throughout a zoo and aquarium animal’s life that can maximize the odds that euthanasia procedures will be optimal for animal and staff welfare. The decision‐making process for euthanasia including decisions whether, when, and how to conduct euthanasia must be transparent and open to the greatest extent possible. While there are many details to consider, the optimal decision will ideally mesh the ideals of each stage of the process (Table 6.2). There are three euthanasia decision‐making stages: whether, when, and how euthanasia should be conducted (Figure 6.5). Whether euthanasia should be conducted will always be the first stage. When euthanasia should be conducted will generally be driven primarily by animal welfare concerns. However, in some difficult situations, such as very large animals, how euthanasia will be conducted will be the second stage, and this will drive when euthanasia can be conducted. Decisions regarding whether to conduct euthanasia should be made within the framework of collection plans and institutional animal welfare structure, with modifications for the specifics of a situation. A lifetime history of quality‐of‐life assessments can assist with determining what is best for an animal by serving as a record for tracking subtle and overt changes that represent significant health, and other concerns in animals that often hide their illnesses. In instances where urgent decisions are not required, scientific considerations may enter the discussion. For instance, germplasm collection and the fate of in utero or juvenile animals may be important for endangered species population management. Population management and other scientific concerns have the potential to delay or accelerate the timeline for euthanasia. Also of concern are social groups, such as disruptions in hierarchy when dominant animals are removed from a group. Table 6.2 Elements of whether, when, and how to conduct euthanasia of zoo and aquarium animals to maximize the odds of a successful outcome. Figure 6.5 Euthanasia decision‐making stages. Source: David Miller DVM, PhD, DACZM, DACAW. The decision process can present a substantive challenge to staff that have been devoted to optimizing an animal’s welfare throughout its life. In many instances, an animal’s caretaker will be a part of the decision process. However, the transition to “letting go” can be difficult to incorporate into objective decisions to terminate an animal’s life, much as with companion animals and some other settings. Additional concerns for surviving members of the animal’s social group can also complicate the decision to euthanize, such as when there are not “good” options for caring for the surviving member of a pair. Another circumstance that can present challenges for euthanasia decision‐making is when the need for a resolution is immediate (e.g. due to severe traumatic injury) or imminent due to animal welfare concerns or disasters such as where an animal’s basic needs cannot be met. Regardless of the factors involved, it is important to strive for consensus and anticipate sources of objections and potential responses. When to conduct euthanasia is dependent upon animal welfare concerns including how severe a condition might be and the condition’s timeline for progression. There is also a need to consider: conservation/science needs, social conspecifics’ needs, emergency constraints, public health, euthanasia method, and staff involvement and availability, as previously addressed as part of the decision process for whether to euthanize. Above all, an effective communication plan with all internal staff and external audiences is essential. Consider whether advance communications about a euthanasia procedure will be beneficial or result in disruption by excess or external participants. Safety is paramount for considering when to conduct euthanasia. Human safety is the first priority, with an emphasis on the physical safety of the staff (particularly with potentially dangerous species), as well as concern for transmission of zoonotic agents, staff emotional safety, and other considerations. Animal physical safety must also be considered, such as for animals that are situated arboreally, for large animals where falls to hard surfaces during initial immobilization are a risk, animals in aquatic environments at risk of drowning, and other factors that will vary across settings. Decreasing the impact on socially housed conspecifics, minimizing the transmission of zoonotic agents, minimization of sensory impact (such as alarm odors emitted by euthanized animals), and other factors must be identified and managed to the best extent possible. Broad consideration of the various negative impacts on all potentially affected humans and people will maximize the odds of having a successful euthanasia procedure. The most impactful part of euthanizing zoo and aquarium animals is appropriate handling. Appropriate handling can be the difference between a “good” and a “bad” end‐of‐life procedure. This is where lifetime training for voluntary shifting (Heidenreich 2019), manual restraint, and medical procedures, as well as trust in their caretakers and comfort in their environment, are directly relevant to euthanasia. Lifetime training for routine husbandry and veterinary procedures maximizes the odds of a calm animal that will accept administration of medications or physical euthanasia methods with little or no distress. Lifetime training may also increase the ability to adapt handling and euthanasia procedures according to the animal’s quality of life and current condition or limitations. Lifetime training can be modified prior to euthanasia, when needed, to account for the specifics of a pending procedure, such as within enclosure “furniture,” drug volume, and delivery method (e.g. intramuscular [IM] injection, oral [PO] administration). Unlike survival anesthesia or sedation, food rewards are acceptable for euthanasia. There is a need to anticipate from the animal’s perspective responses to potential adverse or novel stimuli such as extraneous personnel, sound, touch, visual and emotional stimuli in environment, including due to other animals. Staff proficiency and efficiency in animal handling are also important during procedures for minimizing distress. Emotions from the humans in attendance and unneeded noise also have the potential to stimulate a sense of arousal in the animal and this arousal may counter immobilizing and sedative drugs, as well as confound physical restraint. A culture of routine open dialogue and documented protocols will help ensure that the best choices are made.
6
Zoo Species Euthanasia Considerations and Techniques
6.1 Sociocultural Considerations
6.2 Institutional and Professional Community Considerations
6.3 End‐of‐Life Considerations
6.3.1 Lifetime Considerations
Handling procedures
Voluntary medical procedures
6.3.2 Euthanasia Decision‐making Considerations
6.3.2.1 Whether to Conduct Euthanasia
Elements of whether to conduct euthanasia
Elements of when to conduct euthanasia
Elements of how to conduct euthanasia
6.3.2.2 When to Conduct Euthanasia
6.3.2.3 How to Conduct Euthanasia
6.3.2.3.1 Animal Handling
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
