Does it surprise you that Fido may have a jealous side? Researchers find that pooches can turn into a green-eyed monster, too.

Ever met a dog at a park or a market, pet it and said, “When I get home, my dog won’t be happy about this when he smells a strange pooch on me”?

It might be truer than you think.

A new study shows dogs my actually be jealous when you show attention to another dog.

Researchers from the University of California, San Diego tested about three dozen dogs. They had their owner play with a stuffed dog that wagged its tail and ignore their own pup. They then gave the same attention to an inanimate object (a Jack-O-Lantern pail, how very Halloween). Then the owner read out loud from a book that played music and sounds.

Much of the activity from the dogs included pushing the stuffed dog or the owner to get their attention. Some barked or whined. Eighty-six percent even sniffed the stuffed dog’s butt.

One fourth of the dogs actually snapped at the stuffed dog. Researchers found this interesting because they were told by the owners that their dogs wouldn’t act aggressively toward it.

Meanwhile, 94.4 percent of the dogs ignored the pail, and 91.7 percent ignored the book.

The study though actually has less to do with dogs than you might express. Researchers are looking into whether jealousy is a deeper urge than we realize – like going back to prehistoric days. In the study’s conclusion, the researchers say the study supports the theory that there is a “primordial form of jealousy.”

“One possibility is that jealousy evolved in species that have multiple dependent young that concurrently compete for parental resources such as food, attention, care, and affection,” the study said.

Researchers also think that man’s long evolution and co-domestication with dogs has given rise to jealousy because humans and dogs need each other to survive. Gives you something to think about, huh?

Does your dog get jealous when you show attention to another pup? What does he do to show it? Tell us in the comment section below.

[Source: PLOS One]