One health considerations in veterinary palliative medicine

Highlights

• •One Health reframes end-of-life veterinary care beyond the patient Palliative care affects animal welfare and caregiver mental health.
• •Euthanasia drugs persist environmentally and pose wildlife risks.
• •Home burial may contaminate soil and groundwater without safeguards.
• •Sustainable Veterinary Palliative Medicine integrates welfare, grief, and ecological stewardship.

Abstract

Veterinary palliative medicine (VPM) is an emerging discipline within clinical veterinary science that addresses the comfort and quality of life of animals affected by chronic or terminal illness. The implications of VPM extend beyond the individual patient. From a One Health perspective, end-of-life veterinary practice encompasses animal welfare, caregiver well-being, and environmental sustainability. This paper aims to present a multidisciplinary synthesis that connects these dimensions. It highlights the health benefits and the emotional costs of the human–animal bond; the psychological risks of caregiver burden/grief; and the ecological impacts of pharmaceuticals used in chronic, palliative, and euthanasia care. Environmental challenges include the persistence of barbiturates, NSAIDs, antibiotics, chemotherapeutics, and telmisartan in the environment, and the consequences of after-care decisions such as home burial or cremation. The analysis expands on ethical decision-making between euthanasia and palliated death, addressing alignment with professional guidelines, mental-health implications, and sustainability. By integrating One Health principles, VPM can foster collaborative solutions among veterinary professionals, human-health practitioners, and environmental scientists. The paper concludes with recommendations for responsible drug use, owner-centered communication, environmental safeguards for after-care, and the development of biodegradable euthanasia agents. A One Health approach ensures that compassionate animal care promotes human resilience and ecological stewardship.

Graphical abstract

1. Introduction

Veterinary palliative medicine (VPM) is a rapidly developing field driven by longer animal lifespans, advances in clinical care, and evolving ethical expectations of the human–animal relationship (AVMA, n.d.). Within the One Health paradigm, palliative care is not limited to alleviating animal suffering but extends to supporting owners’ emotional health and mitigating the environmental impacts of veterinary practice. The One Health approach— linking animal, human, and environmental health—has been increasingly recognized as a guiding framework for contemporary veterinary medicine. Veterinary organizations now encourage clinicians to establish interdisciplinary collaborations, including with human medical and environmental experts, to enhance both local and global health outcomes (AAHA, n.d.). Although VPM, caregiver outcomes, and environmental contamination have been examined independently in the literature, few reviews explicitly integrate these domains within a unified One Health framework. This narrative synthesis addresses the gap by systematically connecting animal welfare, caregiver well-being, and ecological sustainability in the end-of-life veterinary practice. This manuscript attempts to analyze current challenges and opportunities in aligning VPM with One Health principles, focusing on animal welfare, owner well-being, and ecological sustainability.

2. Methodology

This narrative review integrates evidence from peer-reviewed literature, professional guidelines, and regulatory frameworks. Searches were conducted in PubMed, Scopus, and ScienceDirect between May and October 2025, and used keywords related to “veterinary palliative medicine,” “One Health,” “euthanasia,” “caregiver burden,” “grief,” and “environmental contamination.” The exclusion criteria were based on access to full-text information and relevance to the conceptual framework. Consistent with PRISMA guidance for transparent reporting in review studies, the databases searched, timeframe, search terms, and general inclusion considerations are described to enhance clarity, while recognizing that this work constitutes a narrative rather than a systematic review. Relevance was determined by conceptual alignment with One Health principles and documented implications for animal welfare, caregiver psychological outcomes, or environmental sustainability. Relevant policy and legal documents from European and American regulatory authorities were included to frame environmental aspects of aftercare. Contradictory findings were retained for transparency, and practice-based insights were synthesized to highlight clinical implications and gaps requiring empirical research.

3. The human–animal bond

The human–animal bond is one of the cornerstones of veterinary medicine and cannot be over- or underestimated, regardless of the specific field in which veterinary professionals are working. Multiple studies have demonstrated the beneficial impact of pet ownership on human physical and mental health, including improvements in cardiovascular outcomes (Mubanga et al., 2017), evidence of shared endocrinopathies between owners and pets (Wallis, Rafan, 2020), and reductions in symptoms associated with depression, anxiety disorders, and grief (Mubanga et al., 2017). Some research has been done linking immunological and psychological ageing biomarkers to pet ownership (Batty et al., 2017), but more investigation is required. Further studies have since been published, and the benefits of pet ownership have been amply evidenced in peer-reviewed literature (Barker, Wolen, 2008; Gan et al., 2020; Mrtins et al., 2023; Opdebeeck et al., 2021; Scoresby et al., 2021; Zhao et al., 2025).

However, the inverse is also true when caring for a chronically ill, aging, or otherwise medically fragile pet. Owners frequently report a lack of proper resources—such as access to adequate care and time to meet caregiving demands—leading to feelings of hopelessness, frustration, and anxiety and, after the pet’s death, disenfranchised grief (Hendrix, 2022). Published studies documenting the negative effects of pet ownership on human health in this context focus on caregiver-burden syndrome (Charry-Sanchéz, Pradilla, Talero-Gutiérrez, 2018; Kuntz et al., 2023; Spitznagel et al., 2017; Van Hooser et al., 2021) as well as exacerbated grief manifestations and poorer psychosocial functioning after bereavement (Ahn et al., 2023,Akiyama, H. et al., 1987; Stallones, 1994; Van Hooser et al., 2021). One study comparing criteria for classifying grief as a disorder following human bereavement found that the same criteria apply following animal bereavement (Lee, 2020).

Given these findings, pet ownership and the human–animal bond should be considered as relevant to a One Health approach, as seen in Table 1, since the risk of zoonoses, particularly when ample evidence demonstrates their contributions to human health and well-being. Deepening studies in veterinary palliative medicine is especially important, as end-of-life care for companion animals can have profound impacts on owners’ lives and overall health.

Table 1.

Comparison of documented benefits and risks of pet ownership.

Dimension	Documented Benefits	Documented Risks or Challenges	Key References
Physical Health	Lower blood pressure, improved cardiovascular outcomes, increased physical activity	Risk of injury, zoonotic exposure	Mubanga et al., 2017
Mental Health	Reduced anxiety and depression; emotional support; improved life satisfaction	Caregiver stress, anxiety, burnout during illness; grief after loss	Mubanga et al., 2017; Spitznagel et al., 2017; Lee, 2020; Van Hooser et al., 2021
Social Connection	Enhanced social interaction, decreased loneliness	Social isolation after pet loss or in long-term caregiving	Akiyama et al., 1987; Kuntz et al., 2023
Cognitive / Neurological	Possible reduction in biomarkers of inflammation and cognitive decline	Not clearly evidenced; stress of care may offset benefits	Batty et al., 2017; Charry-Sanchéz, Pradilla, Talero-Gutiérrez, 2018
Economic / Practical	Routine promotes structure and physical activity	Financial burden of medical and palliative care	Hoffmann, Dickinson, 2021; Spitznagel et al., 2017
Post-Loss Effects	Enhanced empathy and meaning making	Complicated or prolonged grief, depression	Stallones, 1994; Lee, 2020; Ahn et al., 2023

4. Palliated death in the one health context

“Palliated death” refers to the non-immediate, stress and distress free dying process supported by comfort-focused care rather than active euthanasia. This approach mirrors the human hospice model, which emphasizes symptom control, dignity, and family presence at the end of life (Hartnack et al., 2016). In veterinary practice, palliated death acknowledges that euthanasia is not always the owner’s preferred or ethically acceptable option, even when it may be medically indicated (Hendrix, 2022). Studies indicate that owners who choose this route often do so to honor the human–animal bond, preserve spiritual or moral congruence, or allow for natural closure following a life shared with the animal (Van Hooser et al., 2021).

From a One Health perspective, palliated death integrates animal welfare, human psychological resilience, and environmental stewardship. For the animal, the focus is on symptom palliation, including pain control, nutrition, hydration, and comfort, ensuring that distress is minimized while avoiding unnecessary interventions (Hartnack et al., 2016). For caregivers, the process may provide an opportunity for emotional adjustment and anticipatory grief but also carries substantial psychological risk. Caregiver burden, fatigue, and guilt are common, especially as the owner witnesses progressive decline (Charry-Sanchéz, Pradilla, Talero-Gutiérrez, 2018; Spitznagel et al., 2017). These responses are consistent with the compassion fatigue documented in human hospice caregivers and can be mitigated through effective communication, emotional support, and shared decision-making between the veterinary team and the family (Chur-Hansen, 2010; Pihkala, Aaltola, 2025).

Grief following palliated death can still evolve into complicated grief, particularly when owners experience uncertainty about whether continued care prolonged suffering or delayed a more humane death (Lee, 2020; Van Hooser et al., 2021). To minimize these risks, veterinary professionals are encouraged to incorporate structured bereavement support and follow-up after death, in alignment with One Health’s psychosocial dimension (Chur-Hansen, 2010; Pihkala, Aaltola, 2025)). Such follow-up can include referrals to mental health resources, veterinary social workers, or online grief networks to prevent prolonged grief disorder and to foster recovery (Akiyama et al., 1987, 2020; Kuntz et al., 2023).

Environmentally, palliated death may reduce immediate risks associated with euthanasia solutions such as pentobarbital, which are known to persist in soil and groundwater (Bean et al., 2022; Eckel, Ross, Isensee, 1993; Patel et al., 2019). However, long-term administration of palliative pharmaceuticals, including NSAIDs, antibiotics, chemotherapeutics, and telmisartan, can still contribute to chronic environmental contamination (Johnson et al., 2008; Kravos, Gotvajn, Prosen, 2024; Li, 2014; Monteiro, Boxall, 2010). These agents, excreted or eliminated post-mortem, may enter ecosystems through burial or wastewater pathways.

Consequently, responsible pharmaceutical management—such as tapering or discontinuing unnecessary medications during palliative phases, ensuring safe drug disposal, and choosing less persistent compounds—represents a critical intersection between palliative ethics and environmental protection (Li, 2014). Development of shorter half-life analgesics and biodegradable alternatives could enhance environmental sustainability without compromising patient comfort (Dodds, 2025; Raditic, Bartges, 2014).

Ultimately, the decision between euthanasia and palliated death should reflect an integrated understanding of animal welfare, human emotional needs, and environmental impact. Within this One Health framework, palliated death provides a valuable model of compassion that recognizes the interdependence of these dimensions. By aligning symptom management, emotional support, and ecological consciousness, veterinary professionals can uphold the ethical commitment to minimize suffering across species and ecosystems alike (Chur-Hansen, 2010; Hartnack et al., 2016; Hendrix, 2022).

5. Environmental considerations

Environmental responsibility is a cornerstone of the One Health framework. In VPM, this includes managing pharmaceutical residues, ensuring occupational and public safety, and selecting environmentally sound body-disposition methods.

5.1. Euthanasia

Pentobarbital remains the primary agent for euthanasia due to its reliability and minimal distress when properly administered. However, it is environmentally persistent, with residues detectable in soil and groundwater for extended periods (Bean et al., 2022; Eckel, Ross, Isensee, 1993; Patel et al., 2019). Such residues can pose lethal risks to wildlife scavengers and contaminate water supplies, particularly after improper carcass disposal.

Cooney, Robertson and Kogan (2025) examined lidocaine and mepivacaine for euthanasia of anesthetized dogs and cats as potential barbiturate-sparing agents. While physiologic indicators suggested rapid death, visible reflexes—agonal gasping, myoclonus, opisthotonus—were frequent. These signs, though not indicative of consciousness, can be misinterpreted by observers as suffering. According to the Bishop (2016) and the AVMA Guidelines for the Euthanasia of Animals (2020)), an acceptable euthanasia technique must induce “rapid loss of consciousness followed by cardiac or respiratory arrest and subsequent loss of brain function” without distressing reflexive activity. The presence of such movements therefore fails to meet established welfare criteria (AAHA, 2016; AVMA, 2020). Furthermore, witnessing these responses may exacerbate owner trauma and clinician distress, violating AAHA (2016) recommendations to minimize psychological burden during euthanasia.

While lidocaine and mepivacaine may offer environmental advantages, they currently lack compliance with professional welfare standards (AAHA, 2022; AVMA, 2020). Their use should remain experimental until validated against both physiological and psychological metrics. A One Health–aligned euthanasia approach requires balancing ecological sustainability, animal welfare, and human emotional well-being (AAHA, 2022; AVMA, 2020). Research priorities include the development of biodegradable agents that meet AVMA welfare standards and refinement of communication training to help veterinarians prepare clients for physiological reflexes and reduce distress (AAHA, 2022). The authors’ built Table 2 as a quick reference guide of the aforementioned drugs, including some other commonly used in the euthanasia of companion animals.

Table 2.

Environmental risk ranking of pharmaceuticals used in veterinary euthanasia and palliated death.

Pharmaceutical or Class	Primary Use in VPM	Environmental Risk Level	Approx. Environmental Half‑Life*	Key References
Pentobarbital (barbiturate)	Standard euthanasia agent	Very High – Persistent in soil and groundwater; toxic to wildlife	Weeks to months	Eckel, Ross, Isensee, 1993; Bean et al., 2022; Patel et al., 2019
Chemotherapeutic agents	Palliative/oncologic treatment	High – Persistent and hazardous residues	Months	Johnson et al., 2008; Monteiro, Boxall, 2010
Telmisartan	Cardiovascular/palliative therapy	High – Long environmental half-life and ecotoxic potential	10–40 days	Schwarz et al., 2020; Kravos, Gotvajn, Prosen, 2024
NSAIDs (e.g., diclofenac)	Analgesia/anti-inflammatory	Moderate to High – Documented toxicity to scavenger species	Days to weeks	Li, 2014
Antibiotics	Palliative infection control	Moderate – Contribute to antimicrobial resistance and water contamination	Days to weeks	Li, 2014
Lidocaine	Experimental euthanasia agent	Low to Moderate – Lower persistence than barbiturates; welfare concerns remain	1–2 days	Cooney, Robertson, Kogan, 2025
Mepivacaine	Experimental euthanasia agent	Low to Moderate – Similar environmental profile to lidocaine	1–3 days	Cooney, Robertson, Kogan, 2025

^⁎Half‑life estimates reflect environmental degradation ranges reported in published environmental and pharmacological studies; values are approximate.

5.2. Home burial

Home burial provides emotional connection and ritual comfort (Adams et al., 2020), yet presents environmental risks through leaching of barbiturates, pharmaceuticals, and pathogens (Bean et al., 2022; Eckel, Ross, Isensee, 1993). Research on human cemeteries has demonstrated leachate movement and groundwater contamination where drainage is inadequate (Charry-Sanchéz, Pradilla, Talero-Gutiérrez, 2018; Dent, Knight, 1998).

The EU Regulation (EC) N 1069/2009 on animal by-products and Directive 2000/76/EC on waste incineration specify criteria to prevent groundwater contamination through burial or cremation of animal remains (European Commission, 2009; European Parliament, 2000). Member states, such as the United Kingdom and Portugal, have additional national regulations—The Environmental Protection (Disposal of Animal Carcasses) Regulations 2003 (UK Defra, 2003) and Decree-Law No 73/2011 (Government of Portugal, 2011)—which impose minimum burial depths and restrict proximity to water sources.

The U.S. Environmental Protection Agency (EPA) regulates solid waste management under the Resource Conservation and Recovery Act (RCRA), establishing standards for burial sites to protect groundwater (U.S. EPA, 2019). State-level laws, including the California Environmental Protection Agency (CalEPA) and New York State Department of Environmental Conservation (NYSDEC 2021) regulations, mandate zoning and soil suitability assessments for animal carcass disposal.

Veterinarians should provide evidence-based aftercare guidance consistent with these legislative standards. Environmentally safer alternatives include cremation and alkaline hydrolysis (aquamation) (Veterinary Sustainability Alliance, 2025). When home burial is legally permitted, recommended precautions include a minimum depth of 1.5 m, at least 250 m from wells or surface water, and avoidance of burial after barbiturate euthanasia to prevent secondary poisoning (Patel et al., 2019). Establishing regulated pet cemetery zones within municipal cemeteries, equipped with liners and leachate control systems, aligns with EU and U.S. environmental frameworks and cultural practices, while promoting also mental health (Fig. 1).

Fig. 1.

Home burial for Companion Animals. Legend:: This flowchart summarizes how environmental risks associated with home burial inform national and international regulatory frameworks, which in turn guide veterinary recommendations for safe disposal of companion animal remains. The chart then branches into two possible outcomes: conditions required when burial is permitted, and environmentally safer alternatives such as cremation or alkaline hydrolysis.

6. Discussion and conclusions

Integrating One Health principles into veterinary palliative medicine (VPM) reframes end-of-life care as a multidisciplinary, ethically grounded, and environmentally responsible practice. While euthanasia remains a cornerstone of compassionate veterinary care, its broader implications, including environmental contamination, psychological effects on owners, and ethical deliberation within the veterinary team, require systematic evaluation (AAHA, 2022; AVMA, 2020; Hartnack et al., 2016).

From a clinical standpoint, euthanasia protocols using barbiturates such as pentobarbital are still considered the most reliable for ensuring rapid and peaceful death, yet their persistence in the environment presents ongoing hazards. Studies have documented barbiturate residues in soil and groundwater and secondary toxicity in scavenger species (Bean et al., 2022; Eckel, Ross, Isensee, 1993; Patel et al., 2019). The exploration of alternative euthanasia agents—including lidocaine and mepivacaine—has demonstrated potential environmental advantages, but current findings indicate noncompliance with AAHA (2022) and AVMA (2020)) welfare criteria due to observable reflex activity and risk of owner distress (Cooney et al., 2025). Therefore, any transition toward environmentally safer euthanasia methods must be supported by rigorous clinical validation that upholds both welfare standards and psychological considerations.

The human dimension of VPM remains equally vital within the One Health framework. Owner distress, caregiver burden, and prolonged grief have all been recognized as significant psychological challenges linked to companion-animal illness and death (Akiyama et al., 1987; Kuntz et al., 2023; Lee, 2020; Spitznagel et al., 2017). Bereavement reactions may be exacerbated by moral uncertainty about euthanasia decisions or the physical decline of the animal during palliated death (Chur-Hansen, 2010; Pihkala, Aaltola, 2025). This underscores the necessity of communication training, shared decision-making, and post-loss support programs to mitigate mental health impacts on owners and veterinary professionals alike (Adams et al., 2020).

The environmental component of One Health palliative practice extends beyond euthanasia to the use, storage, and disposal of pharmaceuticals. A wide range of agents commonly prescribed in palliative care, including NSAIDs, antibiotics, chemotherapeutics, and telmisartan, have been identified as emerging environmental pollutants (Johnson et al., 2008; Kravos, Gotvajn, Prosen, 2024; Li, 2014; Moneiro, Boxall, 2010; Vulliet, Cren-Olivé, 2011; Schwarz et al., 2020). These compounds can enter ecosystems through wastewater, excretion, or improper carcass disposal, contributing to antimicrobial resistance, endocrine disruption, and bioaccumulation in aquatic and terrestrial species. Addressing these risks necessitates interdisciplinary collaboration between veterinarians, environmental toxicologists, and regulatory authorities to establish responsible drug-use and waste-management protocols consistent with EU Regulation (EC) No 1069/2009 and U.S. EPA RCRA (2019)) standards.

The environmental consequences of aftercare practices, particularly home burial, also demand ongoing attention. As noted in Section 5.2 existing European and American legislation provides regulatory frameworks for safe burial and incineration of animal remains (CalEPA, 2020; European Commission, 2009; European Parliament, 2000; UK Defra, 2003; Government of Portugal, 2011; U.S. EPA, 2019; NYSDEC 2021). Implementing these standards more consistently in veterinary settings would help reduce soil and groundwater contamination. Additionally, emerging technologies such as alkaline hydrolysis (aquamation), have been recognized as low-impact alternatives to cremation and burial.

Within this comprehensive perspective, veterinary professionals serve as crucial mediators between medical science, client psychology, and ecological sustainability. An One Health approach calls for the following actions:

• 1Integration of One Health education into veterinary curricula to raise awareness of environmental and psychosocial consequences of palliative practices (Hartnack et al., 2016).
• 2Development of standardized communication and grief-support protocols to protect the mental health of clients and clinicians (Chur-Hansen, 2010; Pihkala, Aaltola, 2025).
• 3Adoption of eco-responsible pharmaceutical management, including selective prescribing, safe drug disposal, and preference for short half-life or biodegradable compounds (Li, 2014).
• 4Promotion of interdisciplinary research to evaluate new euthanasia and palliative agents that balance efficacy, welfare, and sustainability (AAHA, 2022; AVMA, 2020).

Future research should prioritize empiric evaluation of caregiver psychological outcomes associated with palliated death pathways, environmental monitoring of commonly prescribed palliative pharmaceuticals, and the development of euthanasia agents that meet established welfare criteria while reducing ecological persistence (AAHA, 2022; AVMA, 2020).

Ultimately, the One Health model redefines palliative veterinary medicine as a synergistic system linking animal well-being, human emotional resilience, and environmental protection. By embracing this integrative vision, veterinary professionals can move beyond isolated clinical outcomes to achieve truly compassionate, scientifically responsible, and ecologically sustainable palliative and/or end-of-life care for animals and the humans who love them.

Disclosure

ChatGPT (OpenAI) was used solely to assist in editing and formatting tables for clarity and presentation. No AI tools were used to generate scientific content, interpret data, or produce original analysis. All conceptual development, synthesis, and interpretation were performed by the authors..

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Title: One Health Considerations in Veterinary Palliative Medicine

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Corresponding author’s name: J. Maria da Costa

Date: 14/nov/2025

CRediT authorship contribution statement

J. Maria da Costa: Writing – review & editing, Writing – original draft, Methodology, Formal analysis, Data curation, Conceptualization. Joana Correia Prata: Writing – review & editing. Felisbina Queiroga: Writing – review & editing. Teresa Barroso: Writing – review & editing, Writing – original draft.

Declaration of competing interest

The authors of the paper “One Health Considerations in Veterinary Palliative Medicine”, submitted for publication to Veterinary and Animal Science, declare there was no support for the reported work, no relevant support outside this work, nor any other activities that merit disclosure, under the rules of transparency and ethical publication of scientific work.