Reliability of body condition scoring using the Rabbit Size-O-Meter in companion rabbits (Oryctolagus cuniculus).

Overall inter-rater reliability of the Rabbit Size-O-Meter (RSOM) across all rater groups was poor.

• Overall inter-rater reliability was assessed using Krippendorff's alpha across 7 raters of varying experience levels.
• Overall inter-rater reliability yielded a Krippendorff's alpha of 0.58, classified as poor.
• 205 rabbits were scored by veterinary professionals (n=3), master's students (n=2), and laypersons (n=2).
• The five-point Rabbit Size-O-Meter (RSOM) scale was the instrument used for scoring.

Inter-rater reliability among veterinary professionals was moderate, but decreased for students and laypersons.

• Agreement among veterinary professionals was moderate, with Krippendorff's alpha of 0.72.
• Agreement decreased when master's students or laypersons were included in the analysis.
• Rater experience level was a differentiating factor in inter-rater agreement on the RSOM scale.

Intra-rater reliability of the RSOM was high, ranging from substantial to almost perfect.

• Intra-rater reliability was assessed in a subset of 10 rabbits.
• Intra-rater reliability ranged from substantial to almost perfect across raters (Cohen's kappa = 0.69–0.90).
• Cohen's kappa was used as the statistical measure for intra-rater reliability analysis.

Body condition score decreased with age in the study population.

• The effect of age on body condition score was statistically significant (p = 0.043).
• A linear mixed-effects model was used to evaluate the effects of age, sex, and breed on rated body condition.
• Body condition score decreased as rabbit age increased.

Breed significantly affected body condition scores in companion rabbits.

• The effect of breed on body condition score was statistically significant (p = 0.012).
• Sex was also included in the linear mixed-effects model but breed was identified as a significant factor.
• A diverse rabbit population of 205 rabbits was included in the study.

The RSOM was not validated against objective measures of adiposity, representing a key limitation of the study.

• The study explicitly states that 'the RSOM was not validated against objective measures of adiposity.'
• The authors recommend 'modifying the body scoring system and validating the RSOM against objective measures of adiposity.'
• Body condition scoring systems are commonly used to monitor adiposity in companion animals, but their reliability in rabbits remains unvalidated per the study background.