Early weaning increases aggression and stereotypic behaviour in cats

Ahola, Vapalahti and Lohi analyzed a large survey of pet cats to test whether the age at weaning influences adult behaviour. They found that cats weaned early, before the natural age, showed higher rates of aggression toward people and stereotypic behaviours such as excessive wool sucking and over-grooming, while later weaning, including beyond the conventional age, was associated with reduced problem behaviours. The association held across breeds and after accounting for other factors, suggesting that prolonging the natural weaning and maternal period benefits behavioural development. The study, drawing on data from thousands of cats, challenged common breeding practices of early separation and indicated that allowing kittens to stay with the mother and littermates longer can lower the risk of behaviour problems, with implications for breeder and shelter weaning and rehoming practices.