Benato, L., Murrell, J., Rooney, N. 2023. Determining a cut-off point for intervention analgesia in rabbits using the Bristol Rabbit Pain Scale. Veterinary Record 193(5), e2995.

Background: The objective of this study was to determine the threshold of the Bristol Rabbit Pain Scale (BRPS) indicating the need for intervention analgesia. Methods: Fourteen members of veterinary staff were recruited to rate rabbits (n = 71) in acute pain. Observers in group A (n = 7) were asked to score each rabbit using the BRPS, while observers in group B (n = 7) independently answered the question ‘In your clinical capacity, do you think this animal requires analgesia?’ with either “Yes” or “No”. The answers from the two groups were then compared. Results: Rabbits for which group B answered ‘No’ (n = 36) had a median BRPS score (range) of 4 (0–10), while those for which group B answered ‘Yes’ (n = 42) had a median BRPS score of 9 (1–18; Z = –7.48; p < 0.001). The area under the receiver operating characteristic curve was 0.85 (95% confidence interval: 0.77–0.93; p < 0.001), indicating excellent discrimination of the BRPS with a cut-off score of 5.5 (sensitivity 88.1% and specificity 69.4%). However, for practicality, a score of 5 was deemed a feasible cut-off. Limitations: The main limitations of this study are the small rabbit sample size and the subjective nature of pain scoring in animals. Conclusions: Analgesic intervention should be considered in rabbits with a pain score equal to or greater than 5 on the BRPS.