How dogs communicate with humans and other dogs is quite complex

The methods of communication dogs use incorporate many facets such as eye gaze, body & limb posturing, facial expression, and vocalization. Like humans, dogs also communicate inadvertently through senses such as smell to detect the presence of pheromones. We’ve all heard the expression that “animals can smell fear”. In this respect, that expression is quite true. Humans communicate back to dogs by physical touch, vocalization, hand gestures, body posture, facial expression, and eye gaze as well. Eye gaze is of great importance, as domesticated dogs are the only animal we are aware of that will make, and maintain direct eye contact with humans. This is important because not only do the dogs make and keep eye contact with us, the also read, interpret, and understand social cues related to our eyes shape and orientation at the time of the interaction. An example would be the dog’s ability to interpret the distinction between the ‘wide-eye’ response we display when shocked or enraged versus the quizzical ‘squinty-eye’ response we give when puzzled or in deep thought. If you add the visual cue of ‘squinted-eyes’ and the visual cues of a furrowed brow and clenched jaw, dogs can clearly understand that the human is upset or angry.

Studies of this communicative behavior between dogs and humans suggests that (just as we humans do with each other) dogs read the shape and size of the white part of the eyeballs that is exposed during a given social interaction. It is because of our ability to effectively communicate with dogs that we not only allow them into our homes as part of our families, but have also invited dogs into the workplace as police officers, first responders, rescue workers, therapy animals, etc.

Happiness is communicated from dog to human through a number of visual and verbal cues. Most of us understand the wagging tail, audible yelps, and smiling faces dogs display when happy. These visual cues become quite exaggerated when dogs are excited. The vocal yelps get higher pitched, the tail wags with such vigor that the dogs whole hind-end is often involved, and the smile displayed incorporates heavy panting. In turn, the dog clearly recognizes the beaming eyes, smile, and happy tone of our voices when we humans display our happy emotions.
We too exaggerate these happy expressions when excited. Our smiles become larger showing more teeth, our eyes get wider, our body language more erratic, and like the dogs, our voices pitch higher.

Pain or illness is communicated by dogs through vocal cues and body language as well. But pain or illness may be harder to perceive in our dogs, as they have the ability to tone-down or hide visual cues to their suffering. In an evolutionary sense, dogs tend to mask their pain or illness as not to be perceived as weak or vulnerable to their pack, as this would affect their ranking in the social order. That’s not to say dogs completely hide their pain, as they give cues vocally or physically when particularly distressed by their ailment. Some dogs will openly communicate their pain in the forms of vocalization such as whining, yelping when an injury is touched, or groans when getting-up or laying-down. Visual cues of a dog openly communicating pain include limping, not using a particular limb, licking or ‘tending’ a sore spot or injury, and sad facial expressions to name a few. Dogs that are masking pain will get defensive when disturbed, usually maintain a stoic expression, and will show lack of interest in physical activities. Other visual cues to a dog hiding his pain include heavy panting when at rest, abnormal posturing, and behavioral changes such as abnormal aggression or loss of appetite.

Anger communicated by dogs through social cues is typically direct. The display of anger often involves the vocal cues of loud sustained low pitched growling and continuous aggressive barking. Visual cues to a dog’s anger include lunging movements when tethered or behind a barrier such as a fence or window, bearing or showing its teeth, furrowing it’s brow, and body rigidity including the stiffening of their tail. A full-on display of anger by a dog is commonly described as vicious in nature and is usually unmistakable for any other emotion the dog could be communicating.

Fear communicated by dogs can mimic aggression, but often comes with visual or vocal cues that differ from anger. Visual cues typically include ears pulled back or “flat”, raised hair on the ridge of the dogs back and neck, cowering, and sometimes lip licking or yawning. Vocal cues range from a nervous high pitched barking to a combination of whimpering with growls. Described as ‘skittish’, fearful or nervous dogs are usually jumpy and flinch or dart around as they move about.

Responding to these emotions takes some understanding of the emotions that are being communicated. A playful happy dog welcomes the approach and contact of other dogs or humans, whereas an angry or fearful dog is warning others to keep away. Sick or injured dogs may not understand a person’s intention to help and may often display aggression as a warning to leave them alone. In the case of a ill or injured dog, it’s best to approach with great caution and if need be, heed the dogs warning to keep distance. Angry dogs should never be approached until they have calmed down and are communicating a passive or happy behavior. Often times, when an angry dog is approached it can shift to displaying fear. Dogs displaying fear should not be approached as they may act out of fear or hidden aggression. It’s best to maintain distance from a fearful dog and let it build the courage to come to you. If a fearful dog does gain the courage to approach, be alert, stay cautious, be calm, make slow but deliberate movements, and be reassuring in your tone of voice.