Early weaning in domestic cats increases aggression and sterotypic behaviour says research conducted in Finland.

Early weaning is defined as permanent separation from the mother before the time that it would occur in nature. Feral cats wean their kittens between 4 – 8 weeks of age, but the kittens usually stay with the mother until 4 months of age.  Domestic kittens are routinely weaned and separated from their mother at 8 weeks of age, and this may be too early for the kittens to have learned the full repertoire of social and exploratory behaviours.  Very early weaning ( 2 weeks of age) has been associated with anxiety and aggression in cats, and with stereotypic wool sucking in a separate study. This study investigated effects of early weaning on the behaviour of domestic cats.

This study was conducted in Finland using an online questionnaire survey to collect data on the health, living conditions and behaviour of Finnish domestic cats.  Data was collected on cat demographics, weaning age, problem behaviours, oral behaviours, activity levels, the tendency to seek human contact, aggression and shyness. There were 5,726 home living domestic cat responses in 40 breeds.  Cats weaned before 12 weeks of age were considered to be early weaned, and the behaviour of early weaned cats was compared to late weaned cats using logistic regression.

This study revealed that behavioural problems are common in cats, and that early weaning in domestic cats can have detrimental effects on cat behaviour.  Early weaned domestic cats were more likely to behave aggressively, and late weaned cats were less likely to behave aggressively or display sterotypic wool sucking. Owners were more likely to report a behavioural problem if their cat had been weaned before 8 weeks of age.  The cats weaned in adulthood (16 weeks plus) had the lowest probability for aggression, shyness and abnormal behaviour.  Because cats displaying high levels of aggression, shyness or stereotypy may be experiencing poor welfare, the authors [Ahola MK, Vapalahti, Lohi H (2017)] suggest that increasing the weaning age of kittens may be a simple and inexpensive way of improving cat welfare.

Early weaning in domestic cats source

RSPCA Australia Science Update – Issue 60 – April 2018