Euthanasia

To what extent do chickens suffer when gassed with CO2?

On 9 th June 2025, in an apparent world first, undercover footage of chickens being gassed to death, in the UK in 2024, was publicly released (Carbstrong, 2025). The footage depicts a CO2 gas pit system within which crated chickens...

Year Published: 2026Topics: EuthanasiaAnimal Type: Bird, Chicken

Citation: Mace, J. L., Knight, A. 2026. To what extent do chickens suffer when gassed with CO2? Frontiers in Veterinary Science 12

Factors affecting the effectiveness of captive-bolt stunning of reindeer (Rangifer tarandus tarandus L.) at commercial slaughter in Sweden

Slaughterhouses for all animals, including reindeer, must achieve the goal of high animal welfare. They must carry out regular checks on stunning effectiveness and key parameters to ensure that animals do not display any signs of consciousness, and display the...

Year Published: 2026Topics: EuthanasiaAnimal Type: Other Animal

Citation: Kautto, A. H., Steen, M., Vågsholm, I. et al. 2026. Factors affecting the effectiveness of captive-bolt stunning of reindeer (Rangifer tarandus tarandus L.) at commercial slaughter in Sweden. Acta Veterinaria Scandinavica 68(1), 12.

Potential new biomarkers in pig saliva for differentiating between the effects of different conditions of mixing and density at pre-slaughter: A preliminary proteomicstudy

The intensification of pig (Sus scrofa domesticus) production systems raises concerns regarding animal welfare, particularly during pre-slaughter conditions, a phase associated with significant stress. Saliva is increasingly recognised as a non-invasive matrix for detecting stress-related biomarkers in pigs. This preliminary...

Year Published: 2026Topics: Euthanasia, Welfare AssessmentAnimal Type: Pig

Citation: Botía, M., Muñoz-Prieto, A., Bustillo, A. O. et al. 2026. Potential new biomarkers in pig saliva for differentiating between the effects of different conditions of mixing and density at pre-slaughter: A preliminary proteomicstudy. Animal Welfare 35, e4.

Euthanasia methods in invertebrates: A critical narrative review of methodological and welfare standards

Invertebrates are increasingly consumed and kept as pets, research models, and in zoological exhibits, creating a growing need to better understand their clinical management and welfare. However, the knowledge regarding nociception, pain perception, and euthanasia in invertebrates remains limited, and...

Year Published: 2026Topics: EuthanasiaAnimal Type: Cephalopod, Crustacean, Insect & Spider, Invertebrate, Other Invertebrate

Citation: Bakker, J., Garza, M. A. de la, Morel, M. et al. 2026. Euthanasia methods in invertebrates: A critical narrative review of methodological and welfare standards. Animals 16(2).

Tilapia on-farm welfare assessment protocol for semi-intensive production systems

The aim of this study was to develop and test a tilapia on-farm welfare assessment protocol, based on Brazilian semi-intensive production systems. The study included two mains steps: the elaboration of tilapia welfare protocol and its on-field feasibility test. The...

Year Published: 2020Topics: Euthanasia, Husbandry & Management, Welfare AssessmentAnimal Type: Fish, Tilapia

Citation: Pedrazzani, A. S., Quintiliano, M. H., Bolfe, F. et al. 2020. Tilapia on-farm welfare assessment protocol for semi-intensive production systems. Frontiers in Veterinary Science 7, 606388.

Understanding rat emotional responses to CO2

The aim of this review is to summarize evidence regarding rat emotional experiences during carbon dioxide (CO2) exposure. The studies reviewed show that CO2 exposure is aversive to rats, and that rats respond to CO2 exposure with active and passive...

Year Published: 2020Topics: EuthanasiaAnimal Type: Rat, Rodent

Citation: Améndola, L., Weary, D. M. 2020. Understanding rat emotional responses to CO2. Translational Psychiatry 10, 253.

Welfare impact of carbon dioxide euthanasia on laboratory mice and rats: A systematic review

Background: There has been increased concern about the suitability of CO2 as a method for euthanasia of laboratory mice and rats, including the potential discomfort, pain or distress that animals may experience prior to loss of consciousness; time to loss...

Year Published: 2020Topics: EuthanasiaAnimal Type: Mouse, Rat, Rodent

Citation: Turner, P. V., Hickman, D. L., van Luijk, J. et al. 2020. Welfare impact of carbon dioxide euthanasia on laboratory mice and rats: A systematic review. Frontiers in Veterinary Science 7, 411.

Wireless ‘under the skull’ epidural EEG and behavior in piglets during nitrous oxide or carbon dioxide gas euthanasia

Consciousness is central to animal welfare concerns. Its assessment is most often conducted based on behavior, with a poor understanding of the correspondence between behavior and the neurobiological processes that underlie the subjective experience of consciousness. Recording of brain electrical...

Year Published: 2020Topics: EuthanasiaAnimal Type: Pig

Citation: Rault, J.-L., Lai, A., Hemsworth, L. et al. 2020. Wireless ‘under the skull’ epidural EEG and behavior in piglets during nitrous oxide or carbon dioxide gas euthanasia. Physiology & Behavior 227, 113142.

Evaluation of stress response under a standard euthanasia protocol in horses using analysis of heart rate variability

The effects of a standard protocol for euthanasia on heart rate variability (HRV) as a consequence of stress response were analyzed in this prospective clinical study. The HRV was determined in 40 horses undergoing euthanasia due to various reasons, at...

Year Published: 2020Topics: EuthanasiaAnimal Type: Equine

Citation: Gehlen, H., Loschelder, J., Merle, R. et al. 2020. Evaluation of stress response under a standard euthanasia protocol in horses using analysis of heart rate variability. Animals 10(3), 485.

Review of intraperitoneal injection of sodium pentobarbital as a method of euthanasia in laboratory rodents

Euthanasia is one of the most commonly performed procedures in biomedical research, involving tens of millions of animals in North America and Europe every year. The use of sodium pentobarbital, injected intraperitoneally, for killing rodents is described as an acceptable...

Year Published: 2020Topics: EuthanasiaAnimal Type: Mouse, Rat, Rodent

Citation: Laferriere, C. A., Pang, D. S. 2020. Review of intraperitoneal injection of sodium pentobarbital as a method of euthanasia in laboratory rodents. JAALAS 59(3), 254–263.