Dogs Get Petty About Treats

Dec. 9 -- MONDAY, Dec. 8 (HealthDay News) -- It's a dog-envy-dog world, and a jealous dog isn't likely to take it lying down.

According to new research in this week's issue of the Proceedings of the National Academy of Sciences, dogs who sense that another canine is getting better treatment will go on strike, er, make that a paw strike. They refused to "shake hands" if they weren't getting equal "pay."

For this experiment, dogs and their owners were divided into pairs. The paired dogs sat next to each other, with owners behind them, and were asked to put their paw into the researcher's hand. Once the "shake" was successfully completed, each dog was rewarded with either a piece of sausage or a piece of bread.

But if the dog who "shook" was denied its treat and the partner was not, resentment seemed to build up, with the denied dog eventually refusing to lift its paw.

Dogs stopped cooperating earlier if another dog was present than if they were on their own in the same scenario. They also appeared more stressed if a partner was getting a reward and they weren't than if they were denied rewards in a solo setting.

The quality of the reward itself didn't matter to the canine subjects.

The immediate good news for dog owners is that you don't have to feel guilty if one dog is getting liver and the other a regular dog biscuit (as long as both pooches are getting something).

Of course, it's not truly clear if "envy" is the right word to describe these patterns. "Envy implies a certain emotional state and a thought process, at least by the classic definition," said Bonnie V. Beaver, a professor in the department of small animal clinical sciences, College of Veterinary Medicine & Biomedical Sciences at Texas A&M University in College Station. "We don't know what they're thinking. We know that at least without appropriate rewards, they're not willing to continue working. This gives us a scientific procedure that allows us to give better evaluation."

But precise definitions don't really matter, as the potential significance of the findings goes beyond that.