Correspondence

Animal Sentience Committee: welfare implications of legislative differences in the definition of ‘animals’

Published 3 February 2026

The Animal Welfare (Sentience) Act 2022 recognises certain animals as sentient beings and established the Animal Sentience Committee (ASC). The ASC’s purpose is to support accountability to Parliament in relation to consideration of animal welfare in government policy decisions. The ASC also helps to increase recognition and application of animal sentience principles and responsibilities across government. Animals defined as sentient under this act include all vertebrates (other than humans), cephalopod molluscs and decapod crustaceans, which reflects the latest scientific evidence relating to assessment of animal sentience and capacity to suffer. The list of animals included in the act may expand with further developments in our understanding of sentience. 

The ASC recognises that the definition of ‘animals’ is not consistent across legislation relating to animals that pre-dates the Animal Welfare (Sentience) Act. This raises concerns that the welfare of sentient animals may be adversely impacted, principally by non-inclusion of certain animal orders, or species, in primary and secondary legislation that affords welfare protections. Such protections include duty of care requirements ^{[footnote 1]} and prohibition of animal cruelty, including unnecessary suffering, mutilation or poisoning. They also include regulation to control, and minimise harms to animals during the administration of procedures or treatments including acts of veterinary surgery and prescription of medicines, harmful scientific procedures, slaughter and transportation.

Summary definitions from key animal welfare legislation are listed in Table 1 below: 

Table 1. A comparison of the definitions of ‘animal’ in UK animal welfare legislation 

Legislation	Definition of ‘animal’	Life stage
Animal Welfare (Sentience) Act 2022	‘Animal’ means all vertebrates other than humans; cephalopods, decapods.  Note: “Vertebrate” means any animal of the Sub-phylum Vertebrata of the Phylum Chordata and “invertebrate” means any animal not of that Sub-phylum.	Not defined
Animal Welfare Act 2006	‘Animal’ means all vertebrates other than humans. Free-living wild animals are excluded from the further definition of ‘protected animal’.  Note: “Vertebrate” means any animal of the Sub-phylum Vertebrata of the Phylum Chordata and “invertebrate” means any animal not of that Sub-phylum.  The act contains the provision to extend the definition of ‘animal’ to include invertebrates of any description by regulations.	Excludes foetal and larval forms
Animals (Scientific Procedures) Act 1986	The definition of ‘protected animal’ means all vertebrates other than humans; cephalopods	Mammals, birds and reptiles are protected only after they have reached 2/3 gestation or incubation period. Other vertebrates are protected from when they can feed independently. A cephalopod in embryonic form is not a ‘protected animal’.
Zoo Licensing Act 1981	Animals of the classes Mammalia, Aves, Reptilia, Amphibia, Pisces and Insecta and any other multicellular organism that is not a plant or a fungus; “wild animals” means animals not normally domesticated in Great Britain	Not defined
Dangerous Wild Animals Act 1976	‘Dangerous wild animals’  are defined species of mammals, birds, reptiles and invertebrates (spiders and scorpions)	Not defined
Wildlife and Countryside Act 1981	Specifies individual wild species in various Schedules, which include invertebrates, amphibians, reptiles, birds, and mammals	Not defined
Veterinary Surgeons Act 1966	Act states that “animals” includes birds and reptiles.  This is consistently interpreted by the Royal College of Veterinary Surgeons (RCVS) as intentionally not including fishes (as recorded in Hansard, 1966) or invertebrates. Inclusion/exclusion of amphibians is not explicit, but RCVS opinion is that, as not specifically mentioned they are not covered. However, it is ultimately for the courts to determine the meaning.	Not defined
Veterinary Medicines Regulations	All animals other than humans, including birds, reptiles, fishes, molluscs, crustacea and bees	Not defined
Welfare of Farmed Animals (England) Regulations 2007	‘Farmed animal’ means an animal bred or kept for the production of food, wool or skin or other farming purposes. It does not include fish, reptiles, amphibians or animals living in the wild.	Not defined
Welfare of Animals at Time of Killing Regulations 2015 (WATOK)	There are different definitions for ‘animal’ throughout the Act, and different provisions apply to different types of animals. The following are covered at some point in the legislation: Vertebrates including reptiles and amphibians, invertebrates, fish Note: Assimilated Council Regulation (EC) No 1099/2009 defines animals as vertebrates excluding reptiles and amphibians that are bred or kept for farming purposes; Schedule 4, WATOK includes reptiles, amphibians and invertebrates (and poultry, hares and rabbits killed elsewhere than a slaughterhouse) with reference to not permitting/sustaining avoidable pain, distress or suffering and operators having the  knowledge and skill necessary to perform those operations humanely and efficiently.	Not defined

The discrepancies listed in Table 1 are not only unjustifiable on scientific grounds, they also reflect an important matter of principle. The ASC believes that all animals deemed to be sentient should receive equivalent levels of protection, regardless of the context in which they are used by, or interact with, humans. The London School of Economics (LSE) Review of the Evidence of Sentience in Cephalopod Molluscs and Decapod Crustaceans, sponsored by Defra, concluded there is strong scientific evidence that decapod crustaceans and cephalopod molluscs are sentient, hence their inclusion in the Sentience Act. There is thus a strong case for including these animals within the scope of other laws that aim to protect animals from avoidable suffering.  

As an example of potential suffering due to the inconsistencies in Table 1, decapod crustaceans are currently not included in the Animals (Scientific Procedures) Act 1986. This means that they can be subjected to procedures that cause pain, suffering, distress and lasting harm, with no requirements for project or personal licences, a harm-benefit assessment, refinement of painful procedures, ethical review, regulatory oversight or adequate training for those using or caring for them. There are also no Codes of Practice for housing and care, or for euthanasia. Similarly, the Welfare of Animals at Time of Killing (WATOK) Regulations do not include cephalopods and decapods, thus there is no guidance on humane and efficient killing or what constitutes avoidable suffering in these or other invertebrates. To provide another example, the Animal Welfare Act only applies to wild animals when they are held captive or restrained (such as when trapped or held in the hand), or if they have escaped from captivity. This means that free-living wild animals are not within the scope of the Act, posing risks to their welfare, particularly regarding hunting and ‘pest control’. Examples of protections for some species of free-living wild animals, including specified mammals (deer, seals, badgers), are provided in Appendix 1 below. 

Furthermore, the non-inclusion of fishes and invertebrates in the Veterinary Surgeons Act enables non-veterinarians to treat these animals, with attendant welfare risks. Veterinary surgeons are arguably uniquely equipped by their training to carry out diagnosis. However:  

• non-vets such as marine scientists can currently diagnose illnesses in fishes and invertebrates  
• fishes in fish farms can be anaesthetised weekly by non-vets for signs of disease and  various sampling procedures  
• the implantation of tracking devices, and other procedures that would be considered acts of veterinary surgery in other species, can be carried out by unregulated individuals in fishes and invertebrates  

These anomalies could have implications for both public assurance and animal health and welfare assurances. 

The Royal College of Veterinary Surgeons (RCVS) is calling for legislative reform and a replacement for the Veterinary Surgeons Act 1966 (VSA 1966).  Both the Fish Veterinary Society and the British Veterinary Association have called for the definition of ‘animal’ in the VSA to be amended to include fishes. The inclusion of fishes in the definition of ‘animal’ would likely require new Exemption Orders to allow appropriately trained non-vets to carry out some of the procedures named above. Recent correspondence with the RCVS in collating this report makes it apparent that the VSA also likely excludes amphibians. It is suggested that any new bill to replace the VSA (1966) includes provisions for the minister to be able to amend the definition of ‘animal’ to bring it into line with other legislation (noting that this would first require some thought on new Exemption Orders and other measures), and to allow the definition to be further amended in future in the light of new evidence and societal views on animal health and welfare, in consultation with the Animal Sentience Committee. Such a change in the definition would ensure that veterinary surgeons played an appropriate role in assuring animal health and welfare in species not currently covered by the 1966 act. 

ASC conclusions 

The ASC recommends that Parliament gives due consideration to ensuring that the definition of ‘animals’ be applied consistently in animal-related legislation, to reflect the recognition of animals as sentient beings. The Animal Welfare Act itself should also be updated to explicitly define animals as sentient beings, as opposed to only implicitly acknowledging this by emphasising welfare. 

To achieve a consistent approach to the definition of animals within all relevant laws, the ASC recommends that legislative amendments refer to the definition of animals as laid down within the Animal Welfare (Sentience Act) 2022: all vertebrates other than humans, cephalopods and decapods.    

The ASC has identified the following Acts with an inconsistent definition of animals. Application of the definition as laid down in the Animal Welfare (Sentience) Act 2022 would result in: 

• The Animal Welfare Act 2006 – inclusion of cephalopods and decapods  
• Welfare of Farmed Animals Regulations 2007 – inclusion of fish, reptiles, amphibians, cephalopods, decapods 
• The Animals (Scientific Procedures) Act 1986 – inclusion of decapods 
• The Veterinary Surgeons Act 1966 – inclusion of fishes, amphibians, cephalopods, decapods  

The ASC considers that such amendments would enhance animal welfare protection. The Committee understands that human interests (primarily economic) will inevitably be brought to bear in practice, with respect to expanding legislative scope. However, it is essential that the interests of humans and other animals are considered and weighted fairly.  

It is also timely to review the scope of all the legislation listed above, given that the LSE review of cephalopod and decapod sentience was published in 2021. Discussions around animal sentience, including which species and developmental stages are sentient, are also gathering momentum, for example in relation to some insects and arachnids. The Committee recommends that clear processes are established to review evidence for animal sentience, so that legislations can be updated in a timely manner and risks to the welfare of sentient animals effectively minimised. Referral to the Animal Welfare (Sentience) Act 2022 would enable concurrent updates to be enacted across all relevant legislation. 

Professor Anna Meredith OBE 
Dr Penny Hawkins  

8 January 2024

Appendix 1: Legislation protecting wild animals 

Legislation which protects wild animals	Summary of the legislation
Wildlife and Countryside Act 1981	Protects certain wild animals by creating a range of offences. For example, it prohibits intentionally killing, injuring or taking certain animals, selling the animal (dead or alive), and having possession of items capable of being used for committing offences under the Act.
Wild Mammals (Protection) Act 1996	Makes it an offence to mutilate, beat, impale, burn, crush, drown etc any wild mammal with intent to inflict unnecessary suffering. Exceptions include acts of mercy, a reasonably swift and humane killing if due to lawful shooting and pest control, and lawful use of poison, snare, trap or dog etc.
Protection of Badgers Act 1992	Gives special protection to badgers. Makes it an offence to wilfully kill, injure or take a badger or attempt to do so. Badger tongs and certain firearms are also banned, as well as damaging, disturbing or obstructing access to a sett.
Deer Act 1991	Regulates the circumstances in which deer can be taken or intentionally killed and controls the sale of venison derived from unlawful killing. Creates associated criminal offences.
Conservation of Seals Act 1970, Antarctic Act 1994, Seal Products Regulations 2010	Collectively regulate the killing of seals and the trade in seal products.
Pests Act 1954	Regulates the use of traps used for pest control and their sale. Includes provisions about failure to inspect traps at specific intervals.

1. The 5 welfare needs according to the Animal Welfare Act are: a suitable environment, a suitable diet, to be able to exhibit normal behaviour patterns, any need to be housed with, or apart from, other animals, and to be protected from pain, suffering, injury and disease.  ↩