There are those who affirm that they distinguish different emotions en your dog's facial expressions, something totally logical if we take into account that even the most prestigious experts have carried out studies that show that these animals are capable of expressing feelings. Laughter is one of them.
We tend to see how a kind of smile is created on their faces every time they play, walk or relax after the walk, something similar to what happens in human beings. This fact was first studied by scientist Konrad Lorenz, who stated: "when smiling, the dog opens its jaws slightly and shows its tongue a little. This is what this winner of the Nobel Prize in Medicine affirms in his book "Man meets dog", 2002.
More recently, in 2011, the results of the study led by Professor Nicholas Dodman, from the Cummings School of Veterinary Medicine at Tufts University (Massachusetts). He concludes that these animals can understand emotions and smile, making a face with their lips. He further claims that they have their own sense of humor.
On the other hand, canine behavior expert Patricia Simonet, from the University of Sierra Nevada (USA) studied the "laughter" of dogs using powerful microphones, recording them while they played with each other. He noted that their panting was different when they were having the most fun, being more breathy. «To an untrained human ear, the dog's laugh would make a sound similar to a huh, huh«, Explains Simonet.
If we look closely, we can distinguish these laughter and smiles in our pet. We will see how stretches the lips and raises the corners, slightly opening the mouth and revealing the teeth and tongue. All accompanied by a forward lean and a quick tail movement. It will show itself like this especially in their playtime with us and with other dogs.