With recent increased focus on positive welfare in animal welfare science, there is demand for objective positive welfare indicators. It is unclear whether changes in body surface temperature can be used to non-invasively identify and quantify positive states in mammals. We recorded continuous measurements of tail surface temperature using infra-red thermography (IRT) and concurrent behavioural observations in male and female Wistar rats (Rattus norvegicus). If tail surface temperature can differentiate between positive and negative experiences, we expect a qualitatively different response compared to negative experiences. Three groups of rats were presented with increasing magnitudes of food rewards (neutral/none, one and three rewards). The rats were placed in an arena to which they were habituated and filmed for 30 s before and 30 min after exposure to different rewards. Tail temperature initially decreased from the pre-reward baseline and subsequently returned towards baseline temperature. The overall pattern of the change was the same as for rats subjected to negative stimuli in previous studies. Nevertheless, dynamic changes in tail temperature, specifically the rate of recovery and the behavioural response (exploration), differed between neutral and rewarded rats but failed to distinguish reward magnitude. Sex differences were found in both thermal and behavioural responses, unrelated to reward magnitudes. Female rats exhibited a greater initial response with a slower recovery than male rats, emphasising the value of using of both sexes in animal welfare research. This study improves our understanding of the effects of positive emotions induced by food reward on peripheral body temperature and behaviour.

Killing is often an unavoidable and necessary procedure for laboratory mice involved in scientific research, and providing a humane death is vital for public acceptance. Exposure to carbon dioxide (CO ₂ ) gas is the most widely used methodology despite well proven welfare concerns. Consequently, the continued use of CO ₂ and its globally permitted status in legislation and guidelines presents an ethical dilemma for users. We investigated whether killing with hypobaric hypoxia via gradual decompression was associated with better welfare outcomes for killing laboratory mice. We compared the spontaneous behaviour of mice exposed to CO ₂ , decompression or sham conditions, and used analgesic or anxiolytic interventions to determine their relative welfare impact. Gradual decompression resulted in longer times to unconsciousness and death and the pharmacological interventions support the notion of a minimally negative animal experience, while providing further evidence for pain and anxiety associated with exposure to CO ₂ . Decompression resulted in moderate ear haemorrhage, but our welfare assessment suggests this may happen when mice are unconscious. Hence, gradual decompression could be the basis of significant refinement for killing laboratory mice. Future work should corroborate behaviour with neurobiological markers of loss of consciousness to verify the conscious phase of concern for animal welfare.

Background: Veterinary practices provide exceptional patient care and client support when there is effective teamwork between veterinary nurses and veterinarians. However, the frequency of this interprofessional collaboration has not been measured. Methods: A cross‐sectional online survey, using the Nurse‒Physician Collaboration Scale to measure the frequency of the collaborative behaviours of joint decision making (JDM), cooperativeness (C) and sharing patient information (SPI), was administered to registered and student veterinary nurses. A multivariable logistic regression model was constructed for each behaviour construct. Results: Veterinary nurses ( n = 835) self‐reported collaboration with veterinarians at item level as either ‘good’ or ‘mixed’ (defined as a median item score ≤2 or >2‒3.5). Overall, the median (interquartile range) scores by collaborative behaviour construct were 2 (2‒3) for JDM, 2 (1‒3) for C and 2 (2‒3) for SPI. Multivariable analysis found that role and practice type were significantly associated with participants reporting good experiences in each behaviour construct. Limitations: The survey did not capture the perspectives of veterinarians for comparison. Conclusion: Collaboration between veterinary nurses and veterinarians is good, but improvements in all behaviour constructs could be made. Efforts should focus on improving communication and increasing the opportunities to mutually participate in patient care decision making.