Dog owners have long noticed and joked about canine behavior that looks a little like jealousy, e.g., the way a dog will bark when its owners embrace each other and seem to ignore the dog. But a 2008 study by Austrian scientists showed that dogs really do feel a primitive form of jealousy. After giving a pair of dogs treats when they performed handshakes, scientists stopped giving one of the dogs the treats, and that dog quickly stopped playing along and even expresses stress and physical annoyance when the other animal kept getting fed. We've always projected emotions onto our pets, but the truth is that they've got their own emotions to express.

           It is real fact that dogs become jealous, and I know it through the experience. For example, when in the family, where there is a dog, an infant appears, the dog becomes jealous because the family pays all attention to the newborn, and dog tries to do  everything to draw their attention.