The effects of observer gender on feline acute pain assessment using three pain scoring instruments

The objective of this study was to investigate whether observer gender affects acute pain scores in cats using the Feline Grimace Scale© (FGS), the UNESP-Botucatu multidimensional feline pain assessment scale-short form (UFEPS-SF), and the Glasgow Composite Measure Pain Scale-Feline (CMPS-Feline). Fourteen veterinarians (7 male, 7 female participants) evaluated 24 standardized and randomized videos of cats before and after ovariohysterectomy using the three pain scales. Mixed-effects models tested the effect of gender on item scores and total scores. The association between gender and rescue analgesia was assessed using mixed-effects logistic regression. Interobserver reliability was assessed using the intraclass correlation coefficient (ICC). Total UFEPS-SF and CMPS-Feline scores were higher for female than male observers (P = 0.0005 and P = 0.0013, respectively). Female observers assigned significantly higher scores than male observers for 3/5 FGS action units, 2/4 UFEPS-SF items, and 3/8 CMPS-Feline items. Female observers had 4.88, 3.84 and 3.73 times higher odds than male observers of reaching the threshold for rescue analgesia for the FGS, UFEPS-SF, and CMPS-Feline, respectively. Interobserver reliability was excellent for both genders (ICC 0.935–0.962). Observer gender influences acute pain assessment in cats, with female veterinarians systematically generating higher scores. These findings underscore the need to consider human-factor biases when interpreting feline pain scores and highlight opportunities for enhanced training and implementing pain scoring in feline practice. © The Author(s) 2026.