Weaning and Feline Behavior: Cats Weaned Early Are Prone to Aggression and Stereotypic Behaviour

A Finnish study* shows that the age at which a cat is weaned has a direct impact on the animal’s future behavior. Early weaning significantly increases the risk of behavioral and socialization problems in adulthood, such as aggression and stereotypic behaviour. Professor Hannes Lohi and his team at the University of Helsinki studied the effects of weaning before 12 weeks of age on the behavior of 5,726 cats of 40 different breeds. Given the frequency of behavioral problems reported by owners, the study suggests that delaying weaning by two weeks is a simple solution to improve the well-being of millions of domestic cats.   In cats—the world’s most popular pet—behavioral disorders are actually quite common and can be a sign of acute or chronic stress. To assess the effects of early weaning (before 12 weeks) on feline behavior, a questionnaire survey collected a wide range of data on the health, living conditions, and behavior of nearly 6,000 indoor cats. Their animal owners rated their pets’ activity levels, tendency to seek human contact, aggression toward family members, strangers, and other cats, as well as fear of strangers and new stimuli, all on a five-point scale. Behavioral problems were more common than expected. Mild behavioral issues were reported in more than 80% of the cats, while 25% exhibited more severe problems. The results show that weaning before 8 weeks of age leads to increased aggression and stereotypic behaviour in adult cats. In contrast, cats weaned at 14 or 15 weeks have a significantly lower risk of exhibiting aggressive behaviour toward other cats, strangers, or family members than cats weaned early, as well as a lower likelihood of exhibiting abnormal behavior (excessive grooming, wool-sucking, etc.) than cats weaned at 12 weeks. The lower likelihood of stereotypic behaviour in cats weaned late is partly explained by a lower likelihood of aggression, which in turn is correlated with stereotypic behaviour. These disorders are linked, the study notes. Increased aggression is thus correlated with an increase in stereotyped behaviors. According to the authors, the effects of early weaning manifest specifically as aggression—often anxiety-induced—and stereotypic behaviour, suggesting dysfunction in the neurotransmitters of the brain’s basal ganglia. The age at which kittens can be separated from their mother and siblings to join a new home is a subject of debate around the world. In Finland, the recommended minimum weaning age is 12 weeks, but in many other countries, such as France and the United States, weaning at 8 weeks is commonly accepted. Based on the study, the Finnish researchers conclude that early weaning has a detrimental effect on the adult animal’s behavior. The recommended weaning age should be extended by at least two weeks, to 14 or 15 weeks of age. They assert that this delay is a simple and effective way to reduce behavioral problems, thereby improving the health and well-being of millions of domestic cats. Adopting the practice of delayed weaning by two weeks could thus have an overall positive impact on the quality of life for cats and their owners worldwide. Although the adverse effects of early weaning have been evaluated in several animal species, no study had yet been conducted in cats. For example, in rodents, monkeys, and minks, early separation from the mother leads to a higher prevalence of stereotypic and aggressive behaviours. A similar phenomenon has been observed in dogs.   * M.K. Ahola, K. Vapalahti, H. Lohi: Early weaning increases aggression and stereotypic behavior in cats. Scientific Reports, 2017, 7 (1)