Timely and humane euthanasia is a subject of global animal welfare significance that has been extensively studied, particularly in food animal medicine, to improve the lives of farm animals by minimizing pain and suffering experienced at the end of life (1, 2). The term euthanasia originates from the Greek words “eu” and “thanatos,” meaning “good death.” It represents a critical component of on-farm management, primarily implemented to alleviate the suffering of diseased or injured animals with little to no chance of recovery (3). Despite its acceptance as a humane tool, determining the appropriate time to euthanize remains challenging (4).

In Brazil, euthanasia is classified as a necessary clinical procedure authorized solely for veterinarians [Resolution No 1000, (5)], with guidelines and training materials provided by the Federal Veterinary Medical Council (6) and the Ministry of Agriculture, Livestock and Food Supply (7). However, Brazil’s status as a key contributor of swine industry, producing over 40 million pigs annually and ranking 4th in global production (8), presents unique challenges for ensuring humane euthanasia across its expansive swine industry. The vast inventory of pigs, spread across all 26 states (9), make it impractical to rely on veterinarians as the sole source for conducting euthanasia when needed (10). As a result, most on-farm euthanasia specific to swine is performed by caretakers responsible for daily animal care (11).

Caretakers have not historically received formal training related to the euthanasia decision-making process or the implementation of the procedure itself. In fact, recent work published in 2019 conducted surveys on 371 caretakers working on integrated swine farms in the South of Brazil assessing knowledge and training specific to euthanasia. Only 7% of individuals participating in the study had received any training regarding on-farm euthanasia, and over 90% of surveyed swine caretakers were uncomfortable with making euthanasia decisions and performing the procedure (10). The decision-making process for euthanasia is complex and often influenced by several variables that may impact the caretaker’s ability to perform euthanasia. These variables include, but are not limited to, access to formal training opportunities to perform euthanasia, written standards operating procedures outlining the euthanasia process, appropriate and functioning euthanasia equipment, and time during working hours to perform euthanasia in addition to other job tasks (12). In addition, caretaker’s previous experience with euthanasia and emotional attachment towards the animal can also impact their ability to humanely perform euthanasia in a timely manner (13).

Identifying barriers to conducting timely euthanasia is crucial for ensuring on-farm animal welfare, particularly given that those responsible for performing euthanasia have not been trained and are not comfortable performing the task. Therefore, the objective of this study was to assess Brazilian caretakers’ knowledge and attitudes towards on-farm swine euthanasia and its association to individual’s demographic characteristics, with the goal of identifying barriers to implementing euthanasia in a timely manner.

The study was conducted according to the guidelines of the Institutional Research Ethics Committee for Human Subjects (CEPH) of the Faculty of Animal Science and Food Engineering (FZEA) at the University of São Paulo (USP; #5.674.052).

A total of 117 individuals participated in this study. The farms varied in size, housing between 1,000 to 3,500 sows, with an annual finishing inventory target of 29,000 and 102,000 market hogs.

Timely and humane euthanasia is a critical aspect of animal welfare on swine farms (1, 2). It serves as a necessary intervention to alleviate the suffering of pigs with poor recovery prospects. In Brazil, while euthanasia is designated as a veterinarian’s responsibility, its practical execution often falls to swine farm caretakers. This reliance on caretakers may introduce some challenges given the majority of caretakers lack training and confidence in performing euthanasia (10). Understanding how caretaker knowledge, attitudes and perceptions influence euthanasia performance is needed. Therefore, the objective of this study was to assess Brazilian caretakers’ knowledge and attitudes towards on-farm swine euthanasia and identify barriers to implementing euthanasia in a timely manner.

In this study, most surveyed caretakers identified as male (82.9%), between 18 and 65 years old, with an average of 10 years’ pig experience (± 9.7, range: 2 days to 40 years). In contrast, female caretakers represented less than 20% of surveyed participants, were generally younger (Range: 21 to 51 years old, Avg: 30 years ±8.4) and had less experience (Avg: 4.5 ± 5.5 years) than their male counterparts. Results from this study mirror population demographics for on-farm caretakers across food animal sectors on a global scale (15) and are similar to populations of surveyed participants in previous work addressing caretakers’ attitudes toward euthanasia in the swine [58–86% male representation; (10, 13, 16, 17)], and dairy industry [78–80% male representation; (12, 18)].

Sex and age have been shown to influence perceptions of and confidence regarding euthanasia decision-making. Male caretakers often exhibit more apathy toward performing euthanasia compared to female caretakers (13, 18–20), while female caretakers tend to display higher levels of empathy and emotional connection towards pigs, which can increase the discomfort regarding euthanasia decisions (13). Similarly, age can affect both perceptions and willingness to perform euthanasia, with younger individuals generally expressing greater discomfort with on-farm euthanasia (13, 21). In this study, participants under 36 years of age tended to feel more uncomfortable (p = 0.052) about performing euthanasia compared to older participants and aligns with previous swine-specific euthanasia research (13).

Although this study represents only a small sample of the Brazilian swine industry, it highlights the importance of recognizing how caretaker demographics can influence euthanasia standards and expectations on-farm. Euthanasia training and on-farm implementation must adapt to accommodate changes in the demographic dynamics of those working with pigs, particularly considering shifting demographics in agriculture and the impeding retirements of experienced workers (22). One key challenge in swine euthanasia is the resistance and discomfort towards euthanasia from new caretakers in the field (3), further emphasizing the need for tailored training approaches and development of open dialogues on-farm to address such challenges.

In addition to caretaker demographics, farm-size can also influence the effective implementation of euthanasia on-farm. Previous work by Campler et al. (13) in swine and Merenda et al. (12) in cattle demonstrated that caretakers from smaller farms may have better knowledge or competencies on how to handle sick or injured animals compared to those working on larger farms. However, small-farm caretakers are more likely to report negative emotions toward euthanasia (18). In our study, caretakers working on smaller farms tended (p = 0.051) to feel confident about identifying a sick pig, but uncomfortable with the euthanasia procedure itself. These results agree with previous work conducted with dairy cows’ caretakers demonstrating farm size can impact attachment levels towards animals as well as knowledge and competency performing euthanasia. From the dairy perspective, caretakers working on larger farms were less confident, more detached from the animals, and have less knowledge about euthanasia (12). Given the Brazilian swine industry future trajectory will likely result in larger, more consolidated farm systems (23, 24), understanding barriers to timely euthanasia implementation in such larger and consolidate systems is needed.

In addition to demographic factors influencing euthanasia decision-making, personnel characteristics can also influence the decision-making and implementation of euthanasia on-farm. In the present study, two Clusters were identified among participants surveyed. Cluster 1 participants, defined as empathetic, self-sufficient yet apathetic about euthanasia, represented approximately half of the participating group. These individuals displayed strong empathy and understanding towards pigs, believing pigs are sentient beings that can experience different types of emotions. Cluster 1 participants were confident in identifying compromised animals requiring treatment and needed little to no assistance or guidance from others on-farm to make treatment decisions. However, despite the strong emotional connection to healthy pigs and knowledge pertinent to diagnosing and treating sick pigs, Cluster 1 members demonstrated apathy towards making the decision to euthanize and performing the procedure itself.

Cluster 1 characteristics are similar to previous euthanasia attitude work performed in swine, identifying subpopulations of caretakers that were confident with treating sick pigs yet detached emotionally from the euthanasia process (13, 25). Several factors may be attributing to this caretaker profile. First, individuals with extensive experience managing swine health and disease on-farm often use objective animal-based outcome measures as part of the decision-making process (25–27). This expertise enables them to better assess treatment options and predict the likelihood of recovery for an individual animal using minimal diagnostic testing (1, 35). For example, work conducted on piglet birth weight have shown that piglets born weighting less than 0.86 kg, coupled with impaired vitality scores, have a 94% probability of death by day five of age (28). Therefore, individuals with such knowledge may feel more confident in their ability to predict health outcomes and, consequently, can better safeguard the welfare of the animal by making quicker decisions. However, this confidence does not necessarily imply that euthanasia is performed less frequently. Rather, as caretakers gain more experience with common diseases and injuries encountered at different production stages, the euthanasia decision-making process becomes less emotionally taxing, as the evidence supporting whether a pig should be euthanized or treated is more apparent (15, 25).

Another factor that may be influencing the overall apathy towards euthanasia decision-making and performance in Cluster 1 is the frequency in which euthanasia is performed on farm. Over 40% of Cluster 1 participants stated they had not conducted euthanasia in the past 6 months, 15% had never performed euthanasia, and 37% had never received euthanasia training. This lack of experience may contribute to a reduced awareness of the euthanasia process, potentially diminishing emotional engagement and decision-making urgency, especially if euthanasia is not a regular part of their daily responsibilities. However, it is also possible that the lack of experience could contribute to stress and anxiety about performing euthanasia correctly, as some individuals may feel unprepared or uncertain about their ability to execute the procedure properly. Additionally, many participants may not have had the opportunity or authority to perform euthanasia, as most held caretaker roles, with larger systems often designating one or two employees to make euthanasia decisions and carry out the procedure (12). To better understand the apathy observed in Cluster 1, future research should explore caretakers’ perceptions of euthanasia in greater depth, such as through interviews and focus groups. This approach would provide a more nuanced understanding of the role euthanasia plays in their daily tasks and its emotional impact.

Cluster two participants represented the other half of the surveyed population and shared many similarities with Cluster 1, including a high level of empathy towards pigs and the belief that pigs are sentient beings. However, Cluster 2 participants differed in that they relied more on other resources (co-workers and material) to make euthanasia decisions and expressed emotional discomfort with the euthanasia process. As highlighted in previous work in both swine and dairy industries, the characteristics of Cluster 2 participants are similar to those of other profiles, with individuals demonstrating empathy while being uncomfortable with the decision-making and euthanasia performance process (12, 13). Caretakers’ attitudes towards pigs significantly influence their willingness to perform euthanasia (3, 16, 29), and caretakers often experience negative emotions associated with euthanasia, including guilt and stress related to performing the procedure (14, 30). Exposure to such emotional events can trigger individuals to delay or avoid performing or participating in euthanasia as a result of the “caring-killing paradox” [i.e., tension between providing care and making euthanasia decision; (4, 31, 32)].

In contrast to Cluster 1, the majority of Cluster 2 participants (72%) reported never receiving euthanasia training. Additionally, nearly half (48%) of Cluster 2 members had not performed euthanasia recently, and 9% had never conducted euthanasia at all. These findings underscore the need to further investigate how euthanasia is being implemented on-farm given a humane death for any suffering animal is a priority for the Brazilian swine industry. Thus, developing educational materials and resources to support the mental impact of performing euthanasia and ensuring euthanasia is an accepted tool that needs to be implemented on-farm to relieve animal suffering is critically important.

The last component of this study was to determine previous knowledge regarding euthanasia methods and protocols currently being implemented on-farm. When evaluating data by production stage, 8.5% of participants selected unacceptable methods (such as cardiac perforation and concussion) for breeding stock, while 19% chose blunt force trauma not followed by exsanguination (which is a requirement by MAPA) for pre-weaned piglets. Additionally, 23–33% of participants selected unacceptable methods (including non-penetrating captive bolt, blunt force trauma, and cardiac perforation) for nursery and finisher pigs. These findings reflect similar results to previous work looking at euthanasia methods, where two of the most commonly selected methods (electrocution with homemade equipment and cardiac perforation) are prohibited by legislation under any circumstances (10). The preference for cardiac perforation and electrocution with homemade equipment found in the Dalla Costa et al. (10) study is likely related not only to the minimal cost of these procedures compared to the use of recommended methods with appropriate equipment, but also to the visual aspect of the procedure. Caretakers may prefer these methods because the tonic and clonic convulsions are less intense and shorter in duration compared to the more pronounced motor responses seen with methods such as the captive bolt (10, 33). However, tonic and clonic convulsions are normal and indicate that the procedure was performed correctly (34), although caretakers may mistakenly perceive them as signs of consciousness (33).

Additionally, 64% of respondents, believed that exsanguination was unnecessary following insensibilization, indicating a failure in the second step of euthanasia process, according to Brazilian swine euthanasia guidelines (7). This, in conjunction with the emotional barriers associated with euthanasia, highlight the urgent need for significant work to ensure caretakers can not only confidently identify compromised pigs and determine when to implement euthanasia and consistently utilize appropriate and approved tools for euthanasia by production stage. Collaboration with MAPA and state/country organizations will be an important starting point to ensure euthanasia is implemented on-farm in a timely and humane manner.

The findings from this study provide valuable insights into the experiences, knowledge, and attitudes of swine caretakers regarding euthanasia practices. Caretakers generally demonstrate strong empathy for pigs, acknowledging their capacity to experience pain and suffering. However, notable differences emerged across demographics and farm contexts. Younger caretakers and those on smaller farms reported greater discomfort with performing euthanasia, often linked to emotional challenges and limited technical confidence. Additionally, some caretakers stated the use of non-appropriate euthanasia techniques for different categories of pigs, raising significant concerns about both animal welfare and adherence to recommended practices. Furthermore, a substantial number of caretakers did not consider the second step of the euthanasia process, such as exsanguination, to be important. This oversight highlights critical gaps in knowledge and practice, reinforcing the need for targeted training programs to ensure adherence to proper euthanasia procedures.

Key barriers identified include unclear euthanasia protocols, inconsistent knowledge of legislative requirements, and the psychological toll associated with performing euthanasia. These challenges adversely impact caretakers’ confidence and comfort levels, often delaying timely and humane decision-making. Addressing these issues is essential to advancing animal welfare standards and equipping caretakers with the tools and knowledge needed to manage the complexities of the euthanasia process effectively. As part of a broader project, this study provides the foundation for developing a comprehensive training tool tailored to the unique challenges faced by swine caretakers. This tool will emphasize practical skill development for humane euthanasia techniques, including the critical importance of performing all procedural steps, such as exsanguination. Moreover, it will enhance caretakers’ awareness of legislative and welfare requirements while integrating strategies to build emotional resilience to cope with the psychological demands of the process.

Future efforts should prioritize collaboration with industry stakeholders, policymakers, and animal welfare experts to ensure the tool’s relevance and practicality across diverse farming contexts. Field evaluations and ongoing feedback from caretakers will be crucial for refining the tool and ensuring its adaptability to real-world conditions. By addressing the gaps identified in this study, these initiatives have the potential to empower caretakers to make informed, timely, and humane decisions, reducing unnecessary animal suffering and promoting higher welfare standards on swine farms.