Euthanasia of pigs 

Ratification date: 16/07/2026 

Purpose 

To provide guidance to veterinarians and industry stakeholders on decision making and methods for euthanasia of pigs on farm.  

To highlight key areas of consideration when developing euthanasia protocols to ensure the highest standards of animal welfare.  

 

Policy 

  1. An effective method of euthanasia that is appropriate for the class of pig and delivers high welfare outcomes must be employed as soon as possible after the decision to perform euthanasia has been made.
  2. Veterinarians must be engaged in the development of on farm euthanasia plans and provide specific training to ensure competency in performing euthanasia. These plans should be reviewed regularly to ensure current research is considered and emerging methodologies are included. 
  3. Development of Australian Animal Welfare Standards and Guidelines for Pigs must reflect current research and include input from veterinarians experienced in pig medicine and animal welfare science. Emerging methodologies should be considered and accepted if they demonstrate high welfare and effective outcomes.
  4. There must be alignment of jurisdictions to develop and regulate consistent Standards and Guidelines to achieve a unified National Standard.  

 

Definitions 

Euthanasia is defined as “ending the life of an individual animal in a way that minimises or eliminates pain and/or distress” (Steiner et al, 2019).  

Killing is a general term for inducing death (Steiner et al, 2019). 

Stunning is the process of inducing unconsciousness prior to killing. This state of unconsciousness should render the pig unaware and unable to experience fear, distress or pain (EFSA, 2004; Gerritzen & Raj, 2009). 

 

Background 

Pigs may need to be euthanised on-farm where it is judged to be in the best interest of the animal for reasons including illness, injury, poor response to treatment, low viability or unsuitability (e.g. for transport). Humane killing may also occur where human interest presides such as a boar who is no longer fertile but is otherwise healthy. These reasons provide an ethical justification for on farm destruction (Hampton et al., 2021). Euthanasia typically involves individual or low numbers of animals and differs from mass destruction events that require tailored decision-making and management strategies (See AUSVETPLAN Operational Manual – Destruction of animals ). This policy considers euthanasia of individual or small numbers of animals to minimise pain and distress, ensuring the highest standards of animal welfare. 

Confirming death is essential. Signs to assess to assist confirmation of death include irreversible absence of breathing, palpebral or corneal stimuli, loss of muscle tone (e.g., jaw, tongue tone), dilated pupils (mydriasis) and no heartbeat on palpation and auscultation (EFSA, 2013). 

Currently there are a limited number of recommended methods, with no single method being appropriate for all classes of pigs. Methods vary in the level of skill necessary to perform them. With the diverse nature of pig farms in Australia, it is necessary to adopt a tailored approach for each farm to ensure the most suitable protocols are adopted, considering parameters including geography, accessibility of veterinary care and services, staffing levels and disposal limitations.  

Persons performing euthanasia must be competent and suitably trained to do so. Training in euthanasia should include how to identify decision points, applicable methods, and when a secondary method is required (EFSA et al., 2020; Nielsen et al., 2020; Thornber et al., 2014). There should be an emphasis on animal welfare, timely (as soon as practicably possible) responses, confirmation of death and work health and safety. It should be recognised that the decision-making process and the act of euthanasia itself are stressful for stock people (Rault et al., 2017). Not all individuals will seek to or should be expected to perform euthanasia, however trained personnel should be available if required.  

Movement, handling and restraint of the animal may also cause pain or distress to the individual and others in that group (Soler et al., 2013; Troeger, 1989). Where possible, pigs should be euthanised in their pens or moved short distances as calmly as possible (Nielsen et al., 2020) and where appropriate be out of the line of sight of other pigs.
  

Methods of euthanasia of individual or small groups of pigs: 

Below provides a summary of methods used highlighting the main considerations and appropriateness of use. A separate more detailed table is available as a separate resource. 

  • Anaesthetic overdose (e.g., barbiturates via intravenous route) Provides a painless death through rapid, smooth anaesthesia leading to unconsciousness and cardiac/respiratory arrest with no awareness of dying. Considerations: Requires appropriate equipment (e.g., flexivac tubing / slapshot extenders), veterinary administration and calm restraint (pre-sedation can reduce stress) (N. J. Kells et al., 2018). Difficult in practice due to the remote geography of many pig farms and the accessibility to veterinary services. Not suitable where meat may be harvested for consumption. Aspirational goal: This method can be used for all pig classes where veterinary expertise is accessible. 
  • Penetrating captive bolt (with appropriate power and placement) Delivers immediate unconsciousness via precise brain penetration and concussion, preventing any perception of pain or distress when correctly applied (AUSVETPLAN, 2015; EFSA et al., 2020). Considerations: Requires accurate positioning/restraint and often a second operator. In smaller pigs and in larger pigs when operated by competent, experience personnel using appropriate charges, can be terminal without requiring a secondary method. However, a secondary (terminal) step (e.g., pithing/exsanguination) should be available for all pigs and required for larger pigs to guarantee death. In healthy pigs, tonic/clonic movements after effective captive bolt application are immediate, can be violent and may continue for several minutes. Requires maintenance of equipment and appropriate storage Aspirational goal: Adopt well-maintained devices with charges appropriate to the size of pig and rigorous training by veterinarians to eliminate secondary steps and achieve rapid, reliable unconsciousness. 
  • Gunshot (free bullet to cranium/head shot) Induces extremely rapid unconsciousness and death from a distance, minimising handling-related fear and stress (Whiting & Will, 2019). Considerations: Firearms expertise and accuracy (head shot) required; noise may distress nearby pigs (Whiting et al., 2011); work, health and safety considerations including unsuitability for indoors use due to ricochet risk. There are appropriate storage and maintenance requirements for all firearms. Aspirational goal: Reserve for trained operators in suitable settings to provide swift relief from suffering where safe to do so. 
  • Non-penetrative captive bolt (NPCB) Causes immediate irreversible unconsciousness through percussive trauma, offering a quick and reliable death for small piglets (Grist et al., 2018). Considerations: Restricted to small piglets (<5 kg); requires restraint, depends on proper training and equipment maintenance. Aspirational goals: A preferred mechanical alternative for small piglets; invest in and appropriately maintain dependable devices for application to piglets. 
  • Blunt trauma to head (manual forceful blow) Aims for immediate death via a single forceful percussive blow to the forehead (EFSA, 2018). Considerations: Risk of incomplete effect, particularly where operators are fatigued or improperly trained. Risk of causing other injuries to the pig (e.g., fractures), repeated blows leading to pain and fear. Distressing for handler and witnesses (Arruda et al., 2020; Dalla Costa et al., 2020; Grist et al., 2017, 2018). Aspirational goal: Replacement of this method should be mandated in updated Standards and Guidelines in favour of other suitable methods, restrict to true emergencies on small piglets (<5 kg). 
  • Carbon dioxide (CO₂) inhalation. Induces hypercapnic hypoxia leading to loss of consciousness then death. May be applied in a group setting, reducing individual isolation and handling fear (Nowak, Mueffling, et al., 2007; Nowak, von Mueffling, et al., 2007; Sutherland et al., 2017). Considerations: aversive sensations (breathlessness, fear, air hunger) occur before unconsciousness – this may be offset if animals can be sedated to the point of insensibility prior to exposure to CO2; loss of consciousness is not instantaneous; recovery risk if mismanaged (N. Kells et al., 2018; Meyer & Morrow, 2005; Nowak, von Mueffling, et al., 2007). Appropriate training is required to mitigate human health and safety risk. Aspirational goals: Continue research into gaseous methods that promote high animal welfare for all classes of pigs (see emerging alternative methods, below). 

All methods should prioritise animal welfare, eliminate avoidable suffering and minimise aversive experiences. Methods should provide rapid unconsciousness, gentle handling in familiar environments and involve veterinary expertise.  

Emerging alternative methods 

Alternative methods of euthanasia have been studied. While a number of these methods are currently aimed at mass destruction, there is potential for application on a smaller scale, and some are currently practiced in jurisdictions outside Australia. 

Research into alternative gaseous methods such as nitrogen (N2), argon (Ar) and nitrous oxide (N2O) have been conducted (Çavuşoğlu et al., 2020; Clark & Brunick, 2008; Lindahl et al., 2020; Nowak, Mueffling, et al., 2007; Nowak, von Mueffling, et al., 2007) however, currently there are no approved methods available in Australia. As new methods arise their consideration as acceptable methods of euthanasia should be assessed. 

An oral agent, microencapsulated sodium nitrite (NaNO2) has been suggested. HOGGONE has been licenced by the APVMA for the reduction of feral pig populations (Cowled et al., 2008; Underwood & Anthony, 2020). It has also been studied in domestic pigs in Australia and overseas in respect of mass destruction (Pepin et al., 2021; Richards et al., 2025) however, further research is required to establish suitability and practical application for euthanasia of domestic pigs. 

Recommendations 

  1. Suitably experienced veterinarians must be involved in developing farm specific euthanasia plans and in delivery of training, to ensure operator competency and that the most appropriate method of euthanasia is used for each specific class of pigs. Euthanasia plans and operator competency should be reviewed annually to ensure currency and include any updates to methods or training. 
  2. The AVA encourages further research into euthanasia alternatives that could deliver higher welfare outcomes and less adverse events for pigs as well as for stock people responsible for performing euthanasia. 
  3. There must be acknowledgement of the differences between individual on farm euthanasia and mass destruction events, requiring different decision-making approaches and management strategies.  
  4. The AVA recommends the development and legislation of Australian Animal Welfare Standards and Guidelines for Pigs that focus on high animal welfare outcomes (rapid loss of consciousness without pain or distress, repeatable effectiveness on the first application, and verified death). These Standards and Guidelines should include:
    a) Appropriateness for the class of pig by providing decision making tools for the individual animal (e.g. weight, age, body condition score, skull characteristics.)
    b)     Timeframes for euthanasia (from identification to euthanasia) to minimise suffering
    c)     Confirmation of death (Nielsen et al., 2020)
    d)     Storage and maintenance of euthanasia equipment
    e)     Appropriate management and movement of pigs to be euthanased prior to euthanasia to optimise welfare outcomes 
  5. Standards and Guidelines and legislative frameworks must include a mechanism that allows incorporation of alternative methodologies as new evidence emerges.  

 

Other relevant policies 

 

References 

Arruda, A. G., Beyene, T. J., Kieffer, J., Lorbach, J. N., Moeller, S., & Bowman, A. S. (2020). A systematic literature review on depopulation methods for swine. Animals, 10(11), 2161. 

AUSVETPLAN. (2015). AUSVETPLAN Destruction manual v3.2. https://animalhealthaustralia.com.au/wp-content/uploads/dlm_uploads/AVP_Destruction_v3.2_2015-1.pdf 

Çavuşoğlu, E., Rault, J.-L., Gates, R., & Lay Jr, D. C. (2020). Behavioral response of weaned pigs during gas euthanasia with CO2, CO2 with butorphanol, or nitrous oxide. Animals, 10(5), 787. 

Clark, M. S., & Brunick, A. L. (2008). Handbook of nitrous oxide and oxygen sedation. Elsevier health sciences. 

Cowled, B. D., Elsworth, P., & Lapidge, S. J. (2008). Additional toxins for feral pig (Sus scrofa) control: Identifying and testing Achilles’ heels. Wildlife Research, 35(7), 651–662. 

Dalla Costa, F. A., Gibson, T. J., Oliveira, S. E. O., Gregory, N. G., Coldebella, A., Faucitano, L., Ludtke, C. B., Buss, L. P., & Dalla Costa, O. A. (2020). Evaluation of physical euthanasia for neonatal piglets on-farm. Journal of Animal Science, 98(7), skaa204. 

EFSA. (2013). Scientific Opinion on monitoring procedures at slaughterhouses for pigs. EFSA Journal, 11(12), 3523. 

EFSA, E. F. S. (2004). Opinion of the Scientific Panel on Animal Health and Welfare (AHAW) on a request from the Commission related to welfare aspects of the main systems of stunning and killing the main commercial species of animals. EFSA Journal, 2(7), 45. 

EFSA, E. F. S. (2018). Identification of elements for welfare risk assessment related to on‐farm killing of animals. EFSA Supporting Publications, 15(8), 1453E. 

EFSA, Nielsen, S. S., Alvarez, J., Bicout, D. J., Calistri, P., Depner, K., Drewe, J. A., Garin‐Bastuji, B., Gonzales Rojas, J. L., Gortázar Schmidt, C., Michel, V., Miranda Chueca, M. Á., Roberts, H. C., Sihvonen, L. H., Spoolder, H., Stahl, K., Viltrop, A., Winckler, C., Candiani, D., … Velarde, A. (2020). Welfare of pigs at slaughter. EFSA Journal, 18(6). https://doi.org/10.2903/j.efsa.2020.6148 

Gerritzen, M. A., & Raj, M. A. (2009). Animal welfare and killing for disease control. In Welfare of production animals: Assessment and management of risks (pp. 191–203). Wageningen Academic. 

Grist, A., Lines, J. A., Knowles, T. G., Mason, C. W., & Wotton, S. B. (2018). The use of a non-penetrating captive bolt for the euthanasia of neonate piglets. Animals, 8(4), 48. 

Grist, A., Murrell, J. C., McKinstry, J. L., Knowles, T. G., & Wotton, S. B. (2017). Humane euthanasia of neonates I: validation of the effectiveness of the Zephyr EXL non-penetrating captive-bolt euthanasia system on neonate piglets up to 10.9 kg live-weight. Animal Welfare, 26(1), 111–120. 

Hampton, J. O., Hyndman, T. H., Allen, B. L., & Fischer, B. (2021). Animal harms and food production: Informing ethical choices. Animals, 11(5), 1225. 

Kells, N., Beausoleil, N., Johnson, C., & Sutherland, M. (2018). Evaluation of different gases and gas combinations for on-farm euthanasia of pre-weaned pigs. Animals, 8(3), 40. 

Kells, N. J., Beausoleil, N. J., Sutherland, M. A., & Johnson, C. B. (2018). Electroencephalographic responses of anaesthetised pigs to intraperitoneal injection of sodium pentobarbital. Animal Welfare, 27(3), 205–214. 

Lindahl, C., Sindhøj, E., Brattlund Hellgren, R., Berg, C., & Wallenbeck, A. (2020). Responses of pigs to stunning with nitrogen filled high-expansion foam. Animals, 10(12), 2210. 

Meyer, R. E., & Morrow, W. M. (2005). Carbon dioxide for emergency on-farm euthanasia of swine. Journal of Swine Health and Production, 13(4), 210–217. 

Nielsen, E. P. on A. H. and, Saxmose Nielsen, S., Alvarez, J., Bicout, D. J., Calistri, P., Depner, K., Drewe, J. A., Garin‐Bastuji, B., Gonzales Rojas, J. L., & Gortázar Schmidt, C. (2020). Welfare of pigs during killing for purposes other than slaughter. EFSA Journal, 18(7), e06195. 

Nowak, B., Mueffling, T. V., & Hartung, J. (2007). Effect of different carbon dioxide concentrations and exposure times in stunning of slaughter pigs: Impact on animal welfare and meat quality. Meat Science, 75(2), 290–298. 

Nowak, B., von Mueffling, T., & Hartung, J. (2007). Can CO2 stunning meet welfare of slaughter pigs? Aland A, Editor2007, 1038–1043. 

Pepin, B. J., Odland, C., Spronk, T., Edler, R., & Williams, T. (2021). Swine behavioral and physiological response to increasing sodium nitrite oral drench administration and resulting tissue residues. Journal of Swine Health and Production, 29(6), 310–318. 

Rault, J.-L., Holyoake, T., & Coleman, G. (2017). Stockperson attitudes toward pig euthanasia. Journal of Animal Science, 95(2), 949–957. 

Richards, K., Pollock, Y., Shankar, R., Staples, L., Marshall, D., Allen, B. L., King, R., Hewitt, R., & D’Souza, D. (2025). Microencapsulated sodium nitrite is a humane solution for domestic grower pig depopulation during an emergency animal disease response. Australian Veterinary Journal, 103(9), 582–591. 

Soler, L., Gutiérrez, A., Escribano, D., Fuentes, M., & Cerón, J. J. (2013). Response of salivary haptoglobin and serum amyloid A to social isolation and short road transport stress in pigs. Research in Veterinary Science, 95(1), 298–302. 

Sutherland, M. A., Bryer, P. J., & Backus, B. L. (2017). The effect of age and method of gas delivery on carbon dioxide euthanasia of pigs. Animal Welfare, 26(3), 293–299. 

Thornber, P. M., Rubira, R. J., & Styles, D. K. (2014). Humane killing of animals for disease control purposes. Revue Scientifique et Technique (International Office of Epizootics), 33(1), 303–310. 

Troeger, K. (1989). Plasma adrenaline levels of pigs after different pre-slaughter handling and stunning methods. Proceedings of the 35th International Congress of Meat Science and Technology, 975–980. 

Underwood, W., & Anthony, R. (2020). AVMA guidelines for the euthanasia of animals: 2020 edition. Retrieved on March, 2013(30), 2020–2021. 

Whiting, T. L., Steele, G. G., Wamnes, S., & Green, C. (2011). Evaluation of methods of rapid mass killing of segregated early weaned piglets. The Canadian Veterinary Journal, 52(7), 753. 

Whiting, T. L., & Will, D. (2019). Achieving humane outcomes in killing livestock by free bullet I: penetrating brain injury. The Canadian Veterinary Journal, 60(5), 524.