expert believes she has uncovered  secret of what dogs dream about. Dr Deirdre Barrett,  psychologist at Harvard Medical School, conducted research into dog dreams and concluded that, among other things, dogs dream about their owners. Dr Barrett said canine dreams were comparable to those we have: "Humans dream about  same things they're interested in by day….There's no reason to think animals are any different. Since dogs are generally extremely attached to their human owners, it's likely your dog is dreaming of your face, your smell and of pleasing or annoying you."  psychologist even advised pet owners to give their pets "happy daytime experiences" to make sure they have nice dreams. 
Dr Barrett stated that there is no way of knowing for certain what dogs see when they dream. Research isn't even close to disclosing that mystery with human dreams. Her conclusions are based on  fact that canines and other mammals have  sleep cycle that is similar to  human cycle. This includes  period of activity called REM (Rapid Eye Movement), which is  part of  sleep cycle when humans dream. She said: "That certainly makes it  best guess that other mammals are dreaming too." Dr Barrett also explained  reason that dogs move their legs while they are asleep. She said they are probably acting out their dreams so their legs move in  running motion in their sleep.