Did you know your dog could get jealous?

Does your dog seem to act up when he sees you petting your friend's pooch? Does he clamor for your attention even more when there are other canines nearby?

A new study revealed that this increased excitement might actually be how Fido lets you know he's jealous of these other animals, the first time evidence has been found to prove jealousy is not an emotion reserved for humans.

Dr. Christine Harris, who studies emotion at the University of California at San Diego, told NBC News that her interest was piqued after playing with her parents' pooches.

"As I was petting the dogs, what happened is that one dog would push the other dog's head from out underneath my hand so that both hands were on him," Harris explained to the news source.

So she, along with fellow researcher Caroline Prouvost, set out to learn more about this behavior. They studied 36 dogs while their owners paid attention to three separate objects while ignoring them. One of these objects was a stuffed dog that barked, and humans were asked to treat the toy like a real animal. The other two objects were inanimate, and jealousy with the first toy. They would snap their jaws, push the owner and the object, and try to put themselves in between the two.

This content is brought to you by the pet experts at Hartz.