Enrichment in puppyhood and its effects on later behavior of dogs

Enrichment of the captive environment is becoming more common, but little is known about the consequences of early enrichment on later development. Sixty pups from the breeding colony at Pfizer UK were assigned either to a control group or to one of two groups which received enrichment between the ages of 5 to 14 weeks: 1) a group receiving extra human socialization or 2) a group provided with chewable items suspended in the pen and a length of plastic pipe within the pen. The dogs' behavior was observed after two changes in husbandry: at 15 weeks of age after being placed in same-sex groups of five and after removal from these groups to pair-housing in a laboratory block. Rawhide was the most popular of the tested items. The litters with toys spent an average 64% of their time interacting with them, indicating that, given the choice, pups will make extensive use of such items. Enrichment did not have any measurable effect on the development of stereotypes, but 6 to 11 months after enrichment, dogs given increased human socialization were slightly more approachable than dogs from the other groups. Male dogs from this group spent 37% more time than did controls at the front of the pen, sitting and monitoring the room, a behavior that could be interpreted as an attempt to seek human contact. Early enrichment is easy to achieve and can improve the quality of life for pups.