It's something you need to think about because according to psychologist Christine Harris at the University of California, San Diego, "Dogs tend to show jealous like behavior when their owner pays attention and affection to another dog-like being."
She came to this conclusion after a simple experiment - in which dog owners, in the presence of their pets, deliberately fawn over various objects including a children's book, a plastic Halloween jack-o-lantern, and a toy dog. The animals had NO reaction to the book or the jack-o-lantern.
"When the owner was showing affection to this potential rival dog, they did things like push on their owner or try to get in between the owner and the object," explains Harris.
In some cases they tried to sniff the toy dog's posterior, to find out what ever it is dogs find out when they do that.
So now, along with everything else, you have to worry whether you're making your dog jealous.
"There is something hardwired, not just in humans, but in dogs that motivates to want to regain that attention from a usurper," says Harris.
I've always figured that this whole "Man's Best Friend" thing is mostly a comfortable illusion; that dogs simply see us as a food dispenser, and we misconstrue that into an expression of affection.
But Dr. Harris believes that she has uncovered a very basic instinct and that dog owners had better take it into account, lest you come home one day to find FiFi blocking the door with a .22 in her teeth.
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