Separating puppies from their litter too early can turn them into aggressive dogs, say scientists.
They are significantly more likely to display problematic behaviour as adults than those who stay for at least two months.
This raises the risk that they will be abandoned by their owners.
Researchers studied 140 dogs aged between 18 months and seven years. Half had been taken from the litter and adopted between the ages of 30 and 40 days, and half had been taken at 60 days. The dogs’ owners were asked to complete a questionnaire about their pets including their provenance, breed and a range of potentially problematic behaviours.
These included destructiveness, excessive barking, possessiveness around food or toys, attention seeking, aggressiveness, play biting, fearfulness on walks and reactivity to noises.
The scientists found that these behaviours were all more common in dogs who had been separated from their litter at between 30 and 40 days old.
Behaviour was also worse in dogs who had been removed early and placed in pet shops than those who had been removed later and placed in such a shop.
Dr Federica Pirrone, who led the research at Milan University, wrote in Veterinary Record: “Early separation from the dam and littermates, especially when combined with housing in a pet shop, might affect the capacity of a puppy to adapt to new environmental conditions and social relationships later in life.” - Daily Mail