Dog Body Language: Interpreting Facial Expressions, Body Language, and Vocalizations

What does "expressive behavior" mean in dogs?

Expressive behavior is the ethological term for all observable signals through which a dog reveals its internal state and communicative intentions to other dogs, humans, and the environment. This includes facial expressions, body posture and gestures, vocalizations, and chemical signals (pheromones, scent marks). The term refers to the sender’s side of communication—that is, what the dog displays outwardly.

This should be distinguished from the more common term “body language,” which refers more to the recipient’s perspective: what owners, other dogs, or veterinarians interpret from the dog’s behavior. In practice, the two concepts overlap—anyone who wants to understand canine communication must consider both sides together.

Background + Scientific Context

Dogs communicate multimodally: they combine multiple channels of communication simultaneously. Siniscalchi et al. (2018, Animals) summarize the current state of research: visual signals (facial expressions, body posture, tail position), acoustic signals (barking, growling, whining), tactile signals (nudging, placing a paw), and olfactory signals (marking, anal gland secretions) work together.

A key research finding in recent years: Through domestication, dogs have developed anatomical adaptations that facilitate communication with humans. Kaminski et al. (2019, PNAS) demonstrated that, compared to wolves, dogs have a more developed medial levator anguli oculi—the muscle that creates the famous “puppy dog eyes” (inner brow raise). This facial expression does not exist in wolves. A previous study (Kaminski et al. 2017, Scientific Reports) demonstrated that dogs display more facial expressions when a human pays attention to them—meaning that canine facial expressions are not only emotional but also, in part, socially directed.

Quaranta et al. (2007, *Current Biology*) demonstrated that tail wagging is not one-dimensional: dogs wag their tails more to the right in response to positive stimuli and more to the left in response to negative stimuli—a consequence of brain lateralization. Tail wagging is therefore not a reliable signal of "joy," but rather a signal of arousal that conveys directional information.

The DogFACS system (Caeiro, Burrows, Waller 2017) has standardized the scientific study of canine facial expressions: 23 distinct action units that can be recorded individually or in combination.

Vitomalia-Position

Dogs communicate constantly—the question is whether owners can read their signals. We reject the common interpretation of canine behavior based on dominance theory ("he's trying to provoke me," "he's showing me who's boss"). Behavioral research shows that dog behavior depends on context, emotions, and past experiences; it is not a status game.

We are particularly critical of training dogs not to growl. Growling is one of the clearest early warning signals a dog can send. Punishing a dog for growling deprives it of the ability to communicate in advance—the next conflict will then escalate without warning. We recommend: Take growling seriously as valuable information, defuse the triggering situation, and work on the underlying emotion.

When does a dog's expressive behavior become significant?

• Whenever dogs encounter other dogs—conflict escalation can often be recognized and prevented by early calming signals
• During visits to the vet, grooming, or handling—signs of stress (licking lips, yawning, turning away, lifting paws) indicate that the animal is overwhelmed
• For reactive or anxious dogs—the subtle cues that occur just before a behavior "explodes" are the starting points for training
• During the socialization phase and when developing bite inhibition
• When assessing whether play situations among dogs are still relaxed or are starting to turn sour
• Before bite incidents — most "sudden" bites were preceded by clear warning signs that were overlooked

Practical application

If you want to learn to read an animal's body language, you should observe the animal as a whole, not just a single detail.

Facial expressions: Eye shape (round vs. almond-shaped, visible white sclera [“whale eye”]), lips (relaxed, pulled up, tense), forehead, mouth opening. A tense, closed mouth with a hard gaze is a clear indicator of stress or conflict.

Body posture: weight shift (forward = approach/conflict, backward = retreat/fear), overall body tension, raising or lowering the tail, raising the hairs on the neck (piloerection).

Tail: Position is usually more revealing than movement. Held high with short, fabric-like wags = often excitement, not joy. Held low or tucked in = insecurity/fear. Loose, wide wags at medium height = relaxed, positive excitement.

Voice: Pitch, frequency, and context are key. A low growl accompanied by a stiff posture = a demand for space. A high-pitched whine = stress, frustration, or excitement. The context-free notion that "a bark is just a bark" doesn't tell the whole story.

Calming signals such as licking one’s lips, yawning, turning one’s head away, moving slowly, or approaching in a semicircle are attempts to reduce tension in a situation—they deserve a response, not to be ignored.

Common Mistakes & Myths

• “Wagging means joy.” Not necessarily. Wagging indicates excitement; whether that excitement is positive or negative depends on the height, speed, and side of the wagging (Quaranta 2007), as well as the dog’s overall body posture. A dog wagging its tail high and fast with a stiff body may be on the verge of an escalation.
• “The dog feels guilty.” What looks like remorse (tucked tail, averted gaze, crouched posture) is well documented as a reaction to the owner’s tone of voice and body language—not to any “wrongdoing” committed (Horowitz 2009, Behavioural Processes). Dogs associate the anger with their own presence, not with the long-past act.
• “You have to train the dog out of growling.” Growling is a warning signal and therefore a safety mechanism. Punishing the behavior removes the warning, not the underlying emotion—the next conflict will then escalate silently.
• “My dog is smiling.” An open, panting mouth with the lips pulled back can be a sign of relaxation—or stress panting. Research based on DogFACS shows that owners often misinterpret stress panting as a “smile.”

Current State of Research (2026)

Canine communication is one of the most active fields of research in behavioral biology. Well-established findings include the lateralization of tail wagging (Quaranta et al. 2007, replicated), domestication-related anatomical adaptations of canine facial expressions (Kaminski et al. 2019), and DogFACS as a standardized observation system (Caeiro et al. 2017). Current lines of research focus on eye-tracking studies of dogs’ visual attention toward human faces, the role of olfactory communication (still limited systematic data), and individual stylistic variations across breeds and learning histories. Limitations of current knowledge: The extent to which individual micro-signals reliably indicate specific emotional states varies depending on the signal—generalized tables of unambiguous interpretations found in dog training literature go beyond the scientific consensus.

Frequently Asked Questions

What is the difference between facial expressions and body language in dogs?

"Expressive behavior" is the scientific term for all the signals a dog sends—facial expressions, body language, vocalizations, and chemical signals. "Body language" is a colloquial term that usually refers to the visual perception of these signals from the owner's perspective. In practice, both terms describe the same phenomena from two different perspectives.

Does my dog always wag its tail when it's happy?

No. Tail wagging indicates arousal—joy is just one possible cause. Quaranta et al. (2007) demonstrated that dogs wag their tails more to the right in response to positive stimuli and more to the left in response to negative ones. A raised tail with short, stiff movements is often associated with tension and conflict, not joy. To interpret tail wagging correctly, one must always consider the dog’s overall body posture as well.

Should I try to stop my dog from growling?

From our professional perspective, the answer is clearly no. Growling is a warning signal—it signals discomfort or an impending escalation. Anyone who punishes or suppresses growling deprives the dog of the ability to communicate, but does not eliminate the underlying emotion. The result: the next conflict escalates without warning. It makes more sense to identify the triggering situation, defuse it, and work on the trigger with professional guidance.

Related terms

• Dog Body Language
• Dog Calming Signals
• Signs of Stress in Dogs
• Calming Signals
• Dog Reactivity
• Dog Aggression
• Bonding with a Dog
• Puppy Communication

Sources & Further Reading

1. Kaminski, J., Hynds, J., Morris, P., & Waller, B. M. (2017). Human attention affects facial expressions in domestic dogs. Scientific Reports, 7, 12914. https://www.nature.com/articles/s41598-017-12781-x

2. Kaminski, J., Waller, B. M., Diogo, R., Hartstone-Rose, A., & Burrows, A. M. (2019). Evolution of facial muscle anatomy in dogs. PNAS, 116(29), 14677–14681. https://www.pnas.org/doi/10.1073/pnas.1820653116

3. Quaranta, A., Siniscalchi, M., & Vallortigara, G. (2007). Asymmetric tail-wagging responses by dogs to different emotive stimuli. Current Biology, 17(6), R199–R201. https://pubmed.ncbi.nlm.nih.gov/17371755/

4. Caeiro, C. C., Burrows, A. M., & Waller, B. M. (2017). Development and application of CatFACS / DogFACS . Behavioural Processes. https://pubmed.ncbi.nlm.nih.gov/27693172/

5. Siniscalchi, M., d'Ingeo, S., Minunno, M., & Quaranta, A. (2018). Communication in dogs. Animals (MDPI), 8(8), 131. https://pubmed.ncbi.nlm.nih.gov/30087270/

6. Bloom, T., & Friedman, H. (2013). Classifying dogs' (Canis familiaris) facial expressions from photographs. Behavioural Processes, 96, 1–10. https://pubmed.ncbi.nlm.nih.gov/23485707/