Could Greater Time Spent Displaying Waking Inactivity in the Home Environment Be a Marker for a Depression-Like State in the Domestic Dog?

When pet dogs experience long-term stress, such as when deprived of their owners or after the loss of a social companion, they can become inactive and unresponsive. Dogs in this condition are commonly referred to as being “depressed”, but this remains an untested hypothesis. One hallmark of human clinical depression is anhedonia—a reduction in the experience of pleasure. Here we tested the hypothesis that shelter dogs that spend greater time inactive “awake but motionless” (ABM) in their home-pen would also show signs of anhedonia, as tested by reduced responses to a treat filled Kong. We also explored whether dogs being rated by experts as disinterested in the Kong would spend greater time ABM (experts did not know the dogs’ actual inactivity levels). Fifty-seven dogs from 7 shelters were tested in total.

Dogs relinquished by their owners spent more time ABM than strays or dogs seized in legal cases, and one association was found between the ABM and the dogs’ response to the filled Kong, which was in the opposite direction that expected, so does not support the hypothesis that waking inactivity indicates a depression-like state in dogs. However, dogs rated by experts as “depressed” and “bored” when exposed to the Kong spent greater time ABM, and we discuss whether ABM could tentatively indicate “boredom” in dogs.

This article contains a comprehensive background on 'depression' and 'boredom' in animals along with discussion around the implications of both for pet dogs and how future studies might go about further evaluating them.

Harvey, N.D.; Moesta, A.; Kappel, S.; Wongsaengchan, C.; Harris, H.; Craigon, P.J.; Fureix, C. Could Greater Time Spent Displaying Waking Inactivity in the Home Environment Be a Marker for a Depression-Like State in the Domestic Dog? Animals 20199, 420.

Full article / DOI can be found here.