Dogs are devoted companions who offer unwavering loyalty to their humans, and even new research exposed the full extent of their green-eyed inner monster.
Anecdotal evidence from owners is now backed by scientists who have found that these companion animals get jealous when their human strokes another dog.
But the study, published in the journal Psychological Science, has also found that dogs can get jealous just by imagining that their owner is petting another dog, even when they can't see the interaction.
"The research supported what many dog owners strongly believe . . .