raised hackles in dogs: what does it really mean?
Raised hackles (piloerection) is an involuntary response controlled by the part of the body that reacts automatically to stress, excitement or arousal (the autonomic nervous system). This is just like when humans experience raised goosebumps! When a dog’s hackles are raised, it shows the body is gearing up or getting ready. This can be linked to fear, frustration, excitement, startle or social conflict. To understand what it means, it’s important to read the whole dog, not just the raised hackles. In this blog, find out what it means and how to interpret raised hackles. Raised hackles alone don’t signal a single specific emotion.
What is piloerection?
Piloerection is when a dog’s hair stands up on end, along their back, neck and / or shoulders. This is often referred to a ‘raised hackles’. Tiny muscles at the base of each hair follicle contract, pushing the hairs upright. This is an involuntary response, controlled by the autonomic nervous system. Piloerection is linked to the fight / flight system and is not a deliberate choice. With raised fur, dogs look larger or more imposing, which may be a deterrent to any potential threat.
Raised hackles are a sign of arousal, not a specific emotional state.
Piloerection in response to a cat lurking in a hedge…..
Why do dogs have hackles at all?
Across all mammals, piloerection serves at least two purposes, thermoregulation and visual signalling.
Thermoregulation: making the coat fluffier to trap insulating air in cold or wet conditions.
Visual signalling: making the animal look larger in threatening or tense social moments.
Dogs still use both, although living indoors means you’ll most often notice hackles in social or emotional contexts rather than from the cold!
do raised hackles mean aggression?
Piloerection shows arousal, rather than a single emotion. Raised hackles can certainly accompany fear or defensiveness, frustration, startle, uncertainty, intense interest or offensive behaviour. It is really important to consider the context. Take a good look at the dog’s posture, is there facial tension, tail, ears, mouth, movement and always take into account the situation in order to interpret what is going on.
For example, picture a dog that freezes at the end of the lead, weight shifted forward, hard stare, closed mouth looking towards another dog. In this context, raised hackles may be part of an escalating conflict display.
does location of raised hackles mean something specific?
Currently there’s no solid peer-reviewed evidence mapping hackle location to a specific emotion in pet dogs. Comparative work in canids describes piloerection as part of broader agonistic displays (often with back-arching), which tells us it can appear in conflict, but not that a shoulder-only pattern means X while rump-only means Y. Plenty of training blogs repeat pattern claims without data; take those as hypotheses, not facts.
Breeds, coats and invisible hackles
Short-coated dogs can show quite dramatic hackles, whereas long coats may hide them. Some individuals hackle only in a thin line, yet others display a mohawk from the withers to the tail. The length and density of the dog’s coat and each dog’s individual anatomy change what you can see, which is why it’s important not to just focus on one area - consider the whole picture.
how to interpret hackles safely
When considering why the dog’s hackles are raised, do look at the following to help you interpret what’s going on:
Posture: lower/curved (fear/appeasement) or tall with weight shifted forward (offensive)?
Face: soft eyes and open mouth or fixed stare and facial tension?
Tail: loose or high and rigid vs. tucked?
Movement: fluid and curvy or still/frozen or fast/straight-line?
Situation: is there a trigger, a surprise, a resource or pain?
When seeing raised hackles accompanies by soft, playful body language, this often points to excitement. Whereas raised hackles in a dog who looks to freeze, with weight shifted forward, with hard eye suggests the dog might be about to escalate. When in doubt, create space and support the dog with de-escalation (use a calm voice, move away, try to maintain a loose lead) to create space.
Key takeaways for guardians
Don’t panic! It’s valuable information, learn to look at the whole picture.
Increase distance from things your dog is worried about (triggers) and help your dog to feel safe.
Support decompression with sniffing, foraging and safe, predictable routines.
If hackles show up often accompanied with worry (freezing, tucked tail, growling) reach out for support and get a solid behaviour plan, grounded in positive reinforcement from a qualified Behaviourist.
