Assessment of the correlation between the feline Body Mass Index (fBMI) and body composition assessed using dual-energy absorptiometry (DEXA) in a selected feline cohort

Feline veterinary practice could benefit from the use of automated methods or other more immediate strategies to calculate body composition and mass, particularly in consideration of obesity and related metabolic complications. To that purpose, we compared body composition determined by the dual-energy X Ray absorptiometry DEXA with the feline Body Mass Index formula in a feline population in Portugal. Participant outdoor cats(n=20), either from client-owned or cattery, of both sexes were selected after physical examination to confirm their healthy status. This included body mass (3.07 ± 0.83Kg), body condition score (5,2 ± 1,33), sex, reproductive status, age, and breed. For the DEXA evaluation, animals were minimally sedated (medetomidine hydrochloride 100 mg/kg IM). Measurements were taken in the ventral decubitus position, and involved body mass, lean body mass, adipose mass, and bone mass. The feline Body Mass Index (fBMI) was determined for each animal by measuring the ribcage circumference at the point of the 9th cranial rib and the distance between the patella and the calcaneal tuber of the posterior limb (leg index measurement LIM). The experimental protocol was previously submitted to the Institucional Ethics Commission and respected all directives regulating good clinical practice. Under this frame, a significant correlation (r= 0.77) was observed between the percentage of body fat (%BF) measured by DEXA and the fBMI. The correlation between the scale-measured body mass (BM) and the percentage of body fat measured by DEXA was also significant (r= 0.43). Although its sample size was limited, our exploratory study, indicates an interesting positive correlation between the fBMI and the DEXA evaluation. These promising results should be further explored. Funded by FCT—Foundation for Science and Technology, I.P. (Portugal), under the [UIDB/04567/2020] and [UIDP/04567/2020] and ALIES-COFAC. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.