Inter-Rater Reliability of the Feline Grimace Scale in Cats Undergoing Dental Extractions

Ryota Watanabe, Graeme M. Doodnaught, Marina C. Evangelista, Beatriz P. Monteiro, Hélène L.M. Ruel, Paulo V. Steagall

Research output: Contribution to journalArticlepeer-review


This study aimed to evaluate the inter-rater reliability of the Feline Grimace Scale (FGS) in cats undergoing dental extractions and the effects of the caregiver's presence on the FGS scores. Twenty-four cats (6 ± 3.3 years old; 4.9 ± 1.7 kg) undergoing oral treatment were included in a prospective, blinded, randomized, clinical study. They underwent treatment under general anesthesia (acepromazine-hydromorphone-propofol-isoflurane-meloxicam-local anesthetic blocks) at day 1 and were discharged at day 6. Images of cat faces were captured from video recordings with or without the caregiver's presence at 6 h postoperatively (day 1), day 6, and before and after rescue analgesia. Images were randomized and independently evaluated by four raters using the FGS [five action units (AU): ear position, orbital tightening, muzzle tension, whiskers change, and head position; score 0–2 for each]. Inter-rater reliability and the effects of the caregiver's presence were analyzed with intraclass correlation coefficient [single measures (95% confidence interval)] and the Wilcoxon signed-rank test, respectively (p < 0.05). A total of 91 images were scored. Total FGS scores showed good inter-rater reliability [0.84 (0.77–0.89)]. Reliability for each AU was: ears [0.68 (0.55–0.78)], orbital tightening [0.76 (0.65–0.84)], muzzle [0.56 (0.43–0.69)], whiskers [0.64 (0.50–0.76)], and head position [0.74 (0.63–0.82)]. The FGS scores were not different with [0.075 (0–0.325)] or without [0.088 (0–0.525)] the caregivers' presence (p = 0.12). The FGS is a reliable tool for pain assessment in cats undergoing dental extractions. The caregiver's presence did not affect FGS scores.

Original languageEnglish (US)
Article number302
JournalFrontiers in Veterinary Science
StatePublished - May 29 2020


  • Feline Grimace Scale
  • analgesia
  • dental pain
  • dentistry
  • facial expression
  • feline
  • pain assessment
  • periodontal disease

ASJC Scopus subject areas

  • veterinary(all)


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