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Why Does Dogs Hair Stand Up? Raised Hackles 101

Why does your Westie’s hair stand up? What does it mean? Is it a sign of aggression? Does it mean they are stressed? Find out here in this guide.

Dogs are great companions. They are often sweet, loving, easy to train, and have their own unique personalities that we adore. But dogs do have some strange behaviors, and if you’re unsure of what they mean, it can be a little confusing as a dog owner.


Why does dogs hair stand up


One of the more common behaviors you may notice is raised hackles. This is when your dog’s hair stands up on end. This can happen for a range of reasons, and you may be wanting to find out why.

In this guide, we’ll go over why your dog’s hair stands up, what raised hackles means, whether it is a sign of stress, and if it’s a bad thing, to help you understand it, and to ease any worries you may have about your canine companion.

Why Does Dogs Hair Stand Up?

When a dog’s hair stands up on their back, this is called piloerection, or raised hackles. This can happen for a number of reasons, and it depends on the dog’s typical behavior, and the environment in which they are in.

Raised hackles typically occur when a dog is startled, fearful, frightened, stimulated, aroused, or excited. It is an involuntary reaction, similar to the notion of goosebumps in humans. So, you can’t be mad at your dog if its hair stands up all of the time; they cannot control it!

To help you understand why your dog has raised hackles, you have to consider the environment in which they are in. For instance, what is happening around them that could have caused this? Is there another dog nearby?

Is there an object that could be spooking them or a person that could make them feel fearful or excited? In addition to considering the situation, you also have to look at your dog’s other body language signals. This could include the posture, position of the ears, tail movements, and if they are baring their teeth or growling.

As mentioned above, dogs can raise their hackles for a number of reasons. In our experience, it is best to think about the overall behavior of your dog, and why this could be happening.

If they are typically fine around other dogs and animals, and their tail is wagging, they are not growling or baring their teeth, then raised hackles could simply be a sign of arousal or excitement.

What Dog Breeds Get Raised Hackles?

All dogs have hackles. Many dog breeds get raised hackles, as it is a natural instinct. However, you may not notice it on some dog breeds much, whereas on others, it is far more noticeable.

For instance, breeds with longer hair can often show their raised hackles without anyone noticing, whereas shorter haired breeds raise their hackles much more clearly. The Rhodesian Ridgeback is a breed that has permanently displayed hackles, and some breeds can have ‘piloerection’ often, but it is unclear to see.

Do Raised Hackles Mean Aggression?

Westie Hair stands up

No, raised hackles does not always mean aggression, but this is what most dog owners believe raised hackles mean. It can convey that the dog is experiencing fear, arousal, insecurity, anxiety, nervousness, surprise, excitement, or defensive and aggressive behaviors.

Is It Bad When My Dog’s Hair Stands Up?

No, not really. The arrector pili are the muscles under your dog’s fur and skin that attach to the hair are controlled by the nervous system. When these muscles become raised, it is an involuntary reaction. It typically happens due to an adrenaline trigger, and the raised hackles are simply a bodily response to this.

There has not been a whole lot of research in this area as to why it happens. But, most dog behaviorists and trainers agree that you have to consider the body posture and other signals to understand why your dog is raising their hackles.

However, for many dogs, where the hair is raised can help to indicate how they are feeling. For instance, if a dog has raised hackles across its shoulders and near the tail, but the hair is not raised down the spine, then this often demonstrates that they are confused or conflicted.

These dogs may be unsure how to respond to certain stimuli, and could be a little reactive to other dogs, objects, animals, or people. If the dog has hair raised along the shoulders, and about a third of the way down the back, then this can demonstrate that the dog is anxious or nervous. It can also indicate that they are fearful.

When the hair is raised all along the back, down the spine, then this means that the dog is confident, and could be displaying signs of aggression or territorial behavior.

Raised hackles are therefore not always a bad thing, but you should consider the signs of stress and anxiety in a dog so that you can get the full picture of why their hackles are raised. This can help you prevent the situation from escalating further.

What Are The First Signs Of Stress In A Dog?

If your dog has raised hackles, you have to consider other body language signs that could help you figure out if your dog is feeling stressed, anxious, or excited. Signs of stress in a dog include:

  • Whale eye (eyes appear large, round, and you can see the whites of the eye)
  • Tucked in tail
  • Tucked in ears
  • Lip licking
  • Yawning
  • Panting
  • Raised hackles
  • Avoiding eye contact
  • Pacing

If your dog appears to have a tucked in tail, raised hackles, and is licking their lips, this could be a sign that they are feeling overwhelmed, nervous, and anxious about something.

While raised hackles does not strictly mean aggression, dogs that are feeling insecure and anxious can escalate into being reactive, or aggressive as a defense mechanism. In these cases, it is vital that you look around your current environment to see what the triggers are, and to eliminate the trigger to calm your dog down.

Remove your dog from that situation. If out on a walk, and another dog is making yours nervous, then change direction, and walk the other way.

If children are in your home and are petting your dog quite heavily, and your dog seems to show signs of stress, then teach them how to respect your dog, and give your dog some space by putting them in their bed or crate, so they feel safe and secure.


To summarize, your Westie’s hair may stand up on end from time to time. In most cases, this is not something to worry about as an owner. It is a natural bodily reaction that your dog cannot control.

Raised hackles are a sign of excitement, stimulation, arousal, nervousness, fear, and sometimes aggression. If your dog has raised hackles, be sure to check the environment and their body language to figure out why and ease the situation before it could escalate or cause your dog stress.

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