Position Statements

Animal Sentience

May 16, 2024

Sentience in this document means having the capacity to experience positive and negative feelings such as pleasure, excitement, fear, hunger, pain, and distress. The number of animal species deemed to show evidence of sentience is increasing. Therefore, the CVMA recognizes the necessity and importance of staying abreast of current and evolving evidence in order to develop best practices and recommendations that prioritize animal welfare.

Position

The CVMA holds that many species of animals are sentient. All vertebrates, and likely many invertebrate animals, are sentient in that they can experience feelings in response to positive or negative stimuli. Consequently, the welfare of sentient animals must be considered as part of ethical decision-making; effort must be made to maximize positive experiences and minimize negative experiences. The needs of the species and the individual must be considered as part of animal care and use practices. Where there may be scientific uncertainty, an assumption of sentience should prevail because it is a key principle in formulating policy on animal welfare.

Summary

  • Sentience is the capacity of an animal to experience feelings in response to positive or negative stimuli.
  • Sentience is not solely limited to an animal’s cognitive abilities.
  • While science supporting animal sentience is incomplete, sufficient evidence exists to suggest that many species are sentient.
  • Because uncertainty exists regarding animal sentience, the Animal Sentience Precautionary Principle must prevail to mitigate unintended harm.
  • The recognition or presumption of sentience in a species must result in efforts to minimize negative states and promote positive ones.

Background

  1. Sentience is the capacity to experience positive and negative feelings such as pleasure, excitement, fear, hunger, pain, and distress. Feelings are subjective experiences that provide animals with information about their internal state in response to external or internal stimuli, allowing them to learn, adapt to situations and environments, and thrive. Feelings cannot be assessed directly in any species but can be inferred from changes in behaviour and physiological indicators. (1-8).
  2. Feelings that allow animals to learn, adapt to situations and environments, and thrive require some level of awareness and cognitive ability, but they are not necessarily related to complex cognitive processes (e.g., self-recognition in a mirror). Thus, the cognitive abilities of certain animals do not preclude sentience (9).
  3. Although the science regarding sentience in non-human animals is incomplete and equivocal, there is sufficient evidence to suggest that many species are sentient. Scientific uncertainty should not be referenced as justification to avoid adopting practices or making recommendations that mitigate animal suffering. The ethical and moral responsibility of society, particularly the veterinary profession, is to interact humanely with all animals irrespective of the certainty about their sentience. All interactions should be guided by the principle that avoidable harm must be precluded. The Precautionary Principle (the Principle) is often used as a guide by policy-makers to reduce risks when the scientific evidence to support a policy is uncertain or incomplete. The Principle was originally developed as a guide to environmental policy (10); it was recently modified to apply to animal sentience. According to the Animal Sentience Precautionary Principle, where there are threats of serious, negative animal welfare outcomes, a lack of full scientific certainty regarding the sentience of the animals in question shall not be used as a reason for not taking intentional and positive steps to prevent those outcomes (1).
  4. Knowledge of what animals are likely to experience and what is needed to ensure that their physical, physiological, and behavioural needs are met is key to addressing their welfare. Due to the subjectivity of feelings and individual/species’ differences in adaptations and needs, what an individual animal experiences is likely to be qualitatively and quantitatively different from humans and other species. Scientific evidence supports that all vertebrates and likely many invertebrates are sentient. For example, cephalopods (e.g., octopus, squids, and cuttlefish), decapods (e.g., crabs, lobsters, crayfish, and shrimps) and insects (e.g., bees) meet several criteria for sentience (2, 11, 12, 13, 14). As such, there is a responsibility to consider their welfare and provide them with a quality of life and a humane death relative to their specific physical, physiological, and behavioural needs (4, 8, 15).
  5. While the prevention and mitigation of experiences leading to negative feelings such as prolonged hunger, fear, pain, and suffering are critical components of good animal welfare (16), it has been recognized that their prevention alone is insufficient; positive experiences and a sense of control over actions and their consequences are also required. (6, 17, 18, 19, 20, 21, 22, 23). The CVMA holds that sentient animals under human care must be provided with opportunities for positive experiences, and negative experiences must be minimized.
  6. As knowledge of animal sentience increases, practices should be carefully assessed and adjusted to maximize positive impacts and minimize negative impacts on animal welfare.
  7. Many countries have recognized animal sentience in their legislation (7) (for example, see the UK Animal Welfare (Sentience) Act 2022 (24)). In Canada, the province of Québec recognizes animals as sentient beings in article 898.1 of the Québec Civil Code (25) and its Animal Welfare and Safety Act (26). The CVMA holds that the recognition of animal sentience should be considered within the Canadian legal system under nationally harmonized animal welfare legislation to ensure consistent application and enforcement. This includes developing and applying regulations; protecting animals used for scientific, commercial, consumption, recreational, or personal purposes; and in interacting with wild and feral animals (27).
  8. The study of animal feelings (or emotions) is a legitimate scientific pursuit in ethology and the behavioural sciences and neurosciences. The CVMA will continue to review new studies on animal sentience as they are published and re-evaluate its position accordingly.

References

  1. Birch J. (2017) Animal sentience and the precautionary principle. Animal Sentience 16 (1). doi: 10.51291/2377-7478.1200
  2. Birch J., Burn C., Schnell A., Browning H., Crump A. (2021) Sentience in decapod crustaceans: A general framework and review of the evidence. The London School of Economics and Political Science. doi: 10.51291/2377-7478.1691
  3. Damasio A., Carvalho, G.B. (2013) The nature of feelings: evolutionary and neurobiological origins. Nature Reviews Neuroscience 14:143–152. https://doi.org/10.1038/nrn3403
  4. Duncan I.J.H. (2006) The changing concept of animal sentience. Applied Animal Behaviour Science 100:11–19. https://doi.org/10.1016/j.applanim.2006.04.011
  5. Mason G.J., Lavery J.M. (2022) What Is It Like to Be a Bass? Red Herrings, Fish Pain and the Study of Animal Sentience. Front. Vet. Sci. 9:788289. doi: 10.3389/fvets.2022.788289
  6. Panksepp, J. (1998) Affective Neuroscience. The Foundations of Human and Animal Emotions. Oxford University Press, New York, NY.
  7. Rowan, A.N., D’Silva, J.M., Duncan, I.J.H., Palmer, N. (2021) Animal sentience: history, science, and politics. Animal Sentience 31 (1). doi: 10.51291/2377-7478.1697.
  8. Yue-Cottee S. (2012) Are fish the victims of “speciesism”? A discussion about fear, pain, and animal consciousness. Fish Physiol Biochem 38:5-15. doi: 10.1007/s10695-010-9449-9.
  9. Broom, D.M. (2019) Sentience in: Choe, J.C. (editor) Encyclopeadia of Animal Behaviour (2nd edition)
  10. United Nations. (1992) Rio Declaration on Environment and Development. Report of the United Nations Conference on Environment and Development, Rio de Janeiro, June 3-14, New York: United Nations.
  11. Crump A., Browning H., Schnell A., Burn C., Birch J. (2022) Sentience in decapod crustaceans: A general framework and review of the evidence. Animal Sentience 32 (1). doi: 10.51291/2377-7478.1691
  12. Gibbons M., Crump A., Barrett M., Sarlak S., Birch J., Chittka L. (2022a) Chapter Three—Can insects feel pain? A review of the neural and behavioural evidence. Editor: Russell Jurenka, Advances in Insect Physiology, Academic Press, 63:155–229. https://doi.org/10.1016/bs.aiip.2022.10.001.
  13. Gibbons M., Versace E., Crump A., Chittka l. (2022b) Motivational trade-offs and modulation of nociception in bumblebees. PNAS, 119 (31) e2205821119. https://doi.org/10.1073/pnas.2205821119
  14. Crook R.J. (2021) Behavioural and neurophysiological evidence suggests affective pain experience in octopus. Science 23;24(3):102229. doi: 10.1016/j.isci.2021.102229. PMID: 33733076; PMCID: PMC7941037
  15. Proctor, H.S., Carder, G., Cornish, A.R. (2013) Searching for Animal Sentience: A Systematic Review of the Scientific Literature. Animals: 3 (3):882–906. https://doi.org/10.3390/ani3030882
  16. Canadian Veterinary Medical Association: What is Good Animal Welfare? https://www.canadianveterinarians.net/about-cvma/cvma-committees/animal-welfare-committee/
  17. Boissy A., Manteuffel G., Jensen M.B., Moe R.O., Spruijt B., Keeling L.J., Winckler C., Forkman B., Dimitrov I., Langbein J., Bakken M., Veissier I., Aubert A. (2007) Assessment of positive emotions in animals to improve their welfare. Physiology and Behavior 92 (3):375–397. https://doi.org/10.1016/j.physbeh.2007.02.003
  18. Fraser D. (2008) Understanding Animal Welfare: The Science in its Cultural Context. 336pp. Oxford UK: Wiley-Blackwell.
  19. Mellor D.J., Beausoleil N.J., Katherine E. Littlewood K.E., McLean A.N., McGreevy P.D., Jones B., Wilkins C. (2020) The 2020 Five Domains Model: including human–animal interactions in assessments of animal welfare. Animals, 10(10):1870; https://doi.org/10.3390/ani10101870
  20. Mellor D.J. (2015) Enhancing animal welfare by creating opportunities for positive affective engagement. New Zealand Veterinary Journal 63 (1):3–8. https://doi.org/10.1080/00480169.2014.926799
  21. Mellor D.J., Beausoleil N.J. (2015) Extending the “Five Domains” model for animal welfare assessment to incorporate positive welfare states. Animal Welfare 24 (3):241–253. doi:10.7120/09627286.24.3.241
  22. Panksepp, J., Biven, L. (2012) The Archaeology of Mind: neuroevolutionary origins of human emotions. WW Norton & Company. New York, NY.
  23. Rault, JL, Hintze, S, Camerlink, I., Yee, J.R. (2020) Positive welfare and the like: distinct views and a proposed framework. Front Vet Sci 7 (370):1–9. doi:10.3389/fvets.2020.00370
  24. The UK Animal Welfare (Sentience) Act 2022, https://www.legislation.gov.uk/ukpga/2022/22/enacted
  25. Québec Civil Code, article 898.1, CCQ-1991, p. 202, https://www.legisquebec.gouv.qc.ca/en/document/cs/CCQ-1991 
  26. Québec Animal Welfare and Safety Act, CQLR c B-3.1, https://www.canlii.org/en/qc/laws/stat/cqlr-c-b-3.1/190341/cqlr-c-b-3.1.html
  27. Canadian Veterinary Medical Association, position statement on Pest Management https://www.canadianveterinarians.net/policy-and-outreach/position-statements/statements/pest-management/

Additional Resources:

  1. New York Declaration on Animal Consciousness https://sites.google.com/nyu.edu/nydeclaration/declaration
  2. Cambridge Declaration on Consciousness https://fcmconference.org/img/CambridgeDeclarationOnConsciousness.pdf