Previously it was thought that chimpanzees and other humans were the only creatures capable of being affected by "contagious" human yawns.
But scientists at the School of Psychology at the University of London put 29 dogs through their paces to discover just how close their links with man really are.
Writing in the journal, Biology Letters, they said they got each of the dogs to watch a human yawning and making ordinary mouth movements.
The research team found that 21 of the 29 dogs yawned straight after the human yawned - but none reacted to the mouth movements.
This suggested that dogs are more closely attuned to humans than chimpanzees and even other humans.
When the man in the experiment yawned 72 per cent of the dogs responded compared to 33 per cent of chimpanzees and between 45 and 60 per cent of humans, as reported by other studies.
"The current study demonstrates that human yawns are possibly contagious to dogs," The Daily Express quoted the researchers, as saying.
"The study is the first to demonstrate that the observation of yawning elicits yawning in a non-primate species, as well as the first demonstration of possible contagious yawning between different species," they added.
But one mystery remains - no one really knows why yawns are contagious.
The researchers said: "It may indicate that dogs possess the capacity for a rudimentary form of empathy."