An overview of canine communication

Dogs communicate visually using movement and a wide range of body postures, which can be overtly expressive or incredibly subtle, such as an ear or tongue flick.

Gestures are controlled by voluntary muscles and convey information about how the signaller feels and what their intentions are.

Although each body part may be examined in isolation, it is important to observe the entire body, wherever possible, to interpret the emotional expression of the individual.

Challenges to visual communication

Artificial selection and human intervention have resulted in a wide variety of dog breeds and types, plus their crosses, with hugely differing morphology. For example:

• The subtleties of facial and body movements might not be clear in dogs with longer or wrinkled coats, or those with darker-coloured coats
• Dogs without tails, or tails that are carried high or twisted over the body, create differing silhouettes to those with tails which naturally hang downwards, and mean they are not necessarily able to be tucked beneath the body.
  This limits the individual’s ability to communicate anxiety or fear by tucking their tail beneath them
• Dogs with limited mobility or anatomical abnormalities might be unable to adopt certain postures or movements. As well as potentially causing frustration, this risks them not being able to communicate as quickly as they desire and might therefore result in more overt vocal communication, such as growling, to maintain feelings of safety.
• Limb amputees, as well as dogs with docked/short tails or cropped ears, have altered silhouettes which can restrict visual communication ability
• Dogs are able to learn that some forms of communication work out well for them and might therefore begin to perform these more often in contexts other than their original intention, for example:
  • some dogs have learned to bare their teeth toward humans as an affiliative gesture
  • some dogs have learned to enjoy having their stomach area stroked and will roll onto their backs to solicit this type of human-dog interaction
  • However, in both of these examples, the positive emotion of the dog will be displayed across the rest of their body, remaining relaxed and tension-free.

The above illustrates why carefully considered puppy socialisation is so important. It helps a puppy learn to interact with a variety of different types and breeds.

Under-socialised puppies, with minimal exposure to dogs other than their own litter, might therefore miss out on valuable learning about how different types of dogs communicate, as well as the subtle nuances of individuals.

The range of dogs’ vocal-signalling repertoire appears to have expanded during domestication, which suggests that social interaction with humans has been influential in regulating vocal expression.

Barking is the most typical vocalisation. Barking is generally performed in short-range interactions, in a wide variety of contexts such as warning/alerting, greeting, attention-seeking and play.

Barks convey functional information expressing the signaller’s emotional experience within a specific context. For example, a dog might bark with a lower pitch when worried by an approaching stranger, but with a higher pitch during isolation.

Growling is mainly performed as a warning or threatening signal during combative situations, or during play. Dogs can differentiate between growls produced in different contexts, so can work out if they are ‘positive’ or ‘negative’.

Growling might increase in duration and volume according to an escalation in discomfort. It might also be accompanied by other signals, such as a lip-curl to display the canine tooth and widened eyes with ears held backwards.

Whining may indicate pain, stress or excitement. Whining might be performed specifically to gain attention, especially where a dog has learned that this vocalisation results in their owner attending to them.

Howling is a form of reunification behaviour, aimed at maintaining social unity.

Other forms of vocalisation include groans, yelps, grunts, sneezes and puffing out air from one’s cheeks. Grunts and groans may indicate pleasure or pain depending on the context in which they are performed.

Tactile communication is a typical feature of human-human communication. However, between dogs, it appears to generally occur within specific contexts such as during mating, during agonistic interactions to intimidate an opponent or to maintain a unique social bond.

Social cohesion appears to be maintained by specific activities in particular, such as resting in close contact, sexual approaches preceding mating, and social grooming. However, this context-specific tactile behaviour tends to be short-lasting.

Humans tend to initiate and seek to maintain physical contact with a higher frequency and for a longer duration than dogs. For this reason, some dogs may appear less relaxed during human-dog tactile interaction and tolerate –rather than solicit and enjoy – physical contact.

Some dogs might even attempt to avoid or withdraw from such interaction, but this will likely depend on which specific part of their body is being touched, as well as the manner in which they are being touched.

For example, a dog’s reaction could be different to different types of tactile contact such as lying on a lap, being stroked, being hugged and being picked up.

Just as dogs learn that making eye contact with humans can have positive outcomes for them, dogs can learn to enjoy physical tactile interactions with humans, especially when carefully introduced from early puppyhood.