Abstract
BACKGROUND: Neutered cats are more predisposed to obesity. However, limited research has explored whether body condition score (BCS) and bodyweight vary across lifestages as a function of age at neutering. METHODS: Longitudinal clinical records of BCS (n = 2410) and bodyweight (n = 2073) were paired with age at neutering and other owner-reported auxiliary information before analysis using cumulative link mixed-effects models and linear mixed models to explore which factors influence BCS and bodyweight as cats age. RESULTS: BCS and bodyweight were age dependent, increasing until 9 years of age and then declining. No differences in BCS or bodyweight were found between cats neutered at 4 months or younger, 5 months or 6 months. Cats neutered at 7‒12 months experienced a less rapid age-related increase in bodyweight and BCS. Females had lower bodyweight and BCS than males, with differences more pronounced in the summer and autumn. Longhaired cats had a lower BCS than shorthaired cats, but hair length was not significantly associated with bodyweight. LIMITATIONS: It was not possible to measure welfare impacts or incorporate diet and lifestyle measurements. CONCLUSION: Cats neutered prepubertally showed no difference in bodyweight or BCS as cats aged compared to cats neutered at 5 or 6 months. Cats neutered at 7‒12 months had a lower risk of bodyweight and BCS gain overall. Postneutering weight management advice is recommended for all cats, and monitoring should utilise a combination of both BCS and bodyweight, particularly for longhaired cats.