Fear aggression in dogs happens when a dog’s fear causes them to demonstrate aggressive behavior.
Fear aggression can be directed at people, other dogs, or animals. It can also be generalized, which means the dog is afraid of anything and everything.

The most common cause of fear aggression is a lack of socialization during the critical period (between 3 and 12 weeks old). This is when puppies should be exposed to as many different people, animals, and situations as possible so they learn to cope with new things and don’t become fearful.
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Other causes of fear aggression include prior traumatic experiences, such as being attacked by another animal or being abused. Fear aggression can also be caused by health problems, such as brain damage or an injury that makes the dog sensitive to pain.
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Fear aggression is a serious problem because it can lead to bites and other injuries. It can also make it difficult for the dog to be around people or other animals, which can make their life very stressful.
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But, a fearful dog can be helped and there are an abundance of resources and tools for pet parents to navigate aggression in dogs related to fear.
FEAR AGGRESSION IN DOGS
Fear aggression happens when a dog has a fear response.

Typically, a dog is not fear aggressive the first time they experience anxiety related to that specific fear.
For example, if a dog has a trigger fear of loud noises, they are not going to show aggressive behaviors the first time they experience a loud noise.
Instead, as a dog’s exposure to their fear continues without being handled or helped, and the dog feels threatened more and more, these behaviors will escalate.
Dog aggression does not happen overnight. Many dogs will demonstrate one small behavior at the first sign of their uncomfortability.
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Next, they will begin progressing in their behavior more and more until fear related aggression might take place, as a top tier escalation of the dog’s fear.
WHAT DOES FEAR RELATED AGGRESSION LOOK LIKE?
Fear aggressive dogs might be described by any of the following:
- Barks excessively (Barking Dogs)
- Growls
- Lunges
- Snaps
- Bites
It is important to know that a dog can show any or all of these behaviors, and that not every aggressive behavior is indicative of fear.

For example, a dog who is acting out of dominance is not going to show the same behaviors as a dog who is afraid. A dog who is feeling threatened by someone or something might bark, growl, lunge, and snap, but a dog who is feeling dominant might just bark and lunge.
EARLY WARNING SIGNS OF A FEAR AGGRESSIVE DOG
A fearful dog might also show other signs of stress prior to showing aggression or demonstrating actual fear biting, such as:
- Panting
- Trembling
- Whining
- Ears back
- Tail between legs
- Lip licking
- Cowering
- Avoidance
- Rigid posture or body language
- Lack of eye contact
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A dog who is feeling dominant might also show some of these signs, but not in the exact same way as a fearful dog. Any of these signs can be early warning signs that your dog is afraid and could potentially become fear aggressive if the root cause of the fear / stressful situations are not addressed.
The BSAVA created a great demonstration of the ‘dog aggression ladder’, as shown below.
This ladder demonstrates that dogs do not just wake up one day and decide to bite. Instead, they travel through an entire series of communicative body language signs and signals before eventually snapping.

THE MAIN CAUSES OF CANINE AGGRESSION RELATED TO FEAR

Dogs experience fear for all sorts of different reasons.
Aggression in dogs happens when a dog’s fear causes them to demonstrate aggressive behavior. Fear aggression can be directed at people, other dogs, or animals. It can also be generalized, which means the dog is afraid of anything and everything.
The most common cause of fear aggression is a lack of socialization during the critical period (between 3 and 12 weeks old).
Other reasons dogs demonstrate fear aggression are:
- Interactions with people
- Interactions with unfamiliar dogs or dogs in general
- A dog’s environment is stressful or chaotic
- Something that is new might be a scary thing
- Things that the dog associates with something scary such as the Vet’s office
- Small children
You may not be able to fully understand the things that your dog is afraid of, but if their behavior is demonstrating that they are afraid than you should listen to what your dog is communicating with their body language.
Fear is an irrational feeling and with feelings comes behavior. Dogs cannot communicate verbally, thus some dogs become fear aggressive as a means of coping with and communicating their fears.
IS ALL AGGRESSION IN DOGS CAUSED BY FEAR?

Although fearful dogs can react in aggression, some dogs will react in aggression for other reasons.
Some reasons that dogs can show aggressive behavior are:
- Fear
- Anxiety (ANXIOUS DOG)
- Excitement
- Chronic pain or new pain (TREATING PAIN)
- Possessiveness
- Dominance
- Protective Instincts
- Socialization Issues (SOCIALIZATION GUIDE)
- Heredity
Dogs that are acting out of excitement or socialization are not going to show the same signs of fear as a dog who is feeling anxious or threatened. A dog who is feeling pain is also not going to show the same signs of fear.
Dogs who are acting out of dominance or possessiveness might show some similar behaviors to a fearful dog, but not all of them. For example, a dog who is feeling dominant might lunge and bark, but they are not going to cower or avoid.
SOCIALIZATION AND AN AGGRESSIVE DOG

A lack of socialization will seriously impact a dog’s behavior. A well socialized dog should be comfortable with new people, new places, and new experiences.
A dog who is not socialized might be fearful of anything that they haven’t experienced before. This can include men, women, children, other animals, cars, bikes, and more.
A dog who is not socialized is also going to have a harder time learning how to behave properly around people and other animals. This can lead to a number of problems, including fear aggression.
Click to view our socialization guide:
CHRONIC PAIN AND AGGRESSION ISSUES

A dog who is in pain might begin to show behavioral problems.
Dogs who are typically well-mannered and have positive behaviors that suddenly begin to demonstrate aggression might be experiencing pain.
This is especially true if the dog is beginning to show aggression towards people or animals that they previously got along with.
If you think that your dog’s sudden aggression might be due to pain, it is important to take them to the vet as soon as possible.
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DOMINANCE AGGRESSION

Dominance aggression can be a serious problem in dogs. This type of aggression is often seen in dogs who have not been trained or socialized properly.
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Dominance aggression can be directed towards people or other animals. A dog who is feeling dominant might lunge, bark, and growl. They might also try to mount other animals or people.
A dog who is trying to demonstrate dominance might try to stand between their owners and other dogs.
HOW TO HELP A FEARFUL DOG
If you think that your dog is displaying signs of fear aggression, there are things that you can do with your dog to help their fearful behavior.

SEEK PROFESSIONAL HELP OR A PROFESSIONAL TRAINER
It is always best to seek a qualified professional when it comes to a dog that is fear aggressive. Fear aggressive dogs can be unpredictable. Fearful dogs are not bad dogs, but they can be dangerous if not properly trained.
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A professional can help you to understand your dog’s fear and work with you to help your dog overcome their fear.
A certified professional dog trainer (find one here) can also help you to learn how to properly manage your dog’s fear aggression. This might include teaching you how to read your dog’s body language, how to properly provide correction, and how to prevent your dog from getting to the point of fear aggression.
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PROVIDE SOCIALIZATION
One of the best things that you can do for a fear aggressive dog is to provide socialization. Socialization helps dogs to become comfortable with new people, new places, and new experiences.
You can socialize your dog by doing things that your dog enjoys first.
For example, if your dog enjoys walks, start by taking them on more walks in different places. As your dog becomes more comfortable, you can start to introduce new experiences.
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As your dog’s progress becomes comfortable with that one task, begin introducing them to new things, but make sure you are going very slowly, as your pup’s behavior might regress if you push too hard, too fast.
USE POSITIVE REINFORCEMENT TRAINING
Positive reinforcement training is a great way to help a fearful dog overcome their fear. This technique is also called balanced training.
POSITIVE REINFORCEMENT AND YOUR DOG
With positive reinforcement training, you will provide your dog with a treat or toy whenever they display desired behaviors.
Check out our favorite treats for using positive reinforcement training below.



For example, if your dog is afraid of men, you can begin by having a man stand outside while you are walking your dog. When your dog sees the man, give them a treat. As your dog becomes more comfortable, you can have the man move closer to your dog while they are receiving their treat.
It is important to make sure that your dog is always comfortable and never feels forced into a situation.
You should also make sure that you are using positive reinforcement in other areas of your dog’s life, as this will help them to feel more confident and less fearful overall.
MANAGE YOUR DOG’S ENVIRONMENT
As much as possible, try to manage your dog’s environment to prevent them from feeling fear.
For example, if your dog is afraid of kids, try to avoid situations where your dog will come into contact with kids. If you must take your dog to a place where there will be kids, make sure that you keep your dog on a leash and under control at all times.
You can also try to desensitize your dog to their fear by exposing them to small amounts of their fear in a controlled environment.
MUZZLE TRAINING AND DOG BITES
If your dog has demonstrated behavior of territorial aggression, biting, or snapping at other people or dogs, it is important that you muzzle train them for their own safety.
With a muzzle, they will be protected from potentially biting and hurting others, which could put them at risk for being put down.
Muzzle training can be a difficult process, so it is important to seek professional help from a qualified dog trainer or behaviorist.

CRATE TRAINING AND FEAR AGGRESSION
Since fear aggression stems from feeling ‘out of control’, crate training is one of the best coping mechanisms for fear aggression in dogs.
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A crate provides a place for your dog to ‘escape’ to when they are feeling overwhelmed or frightened.
Crate training takes time and patience, but it is worth it to help your dog feel safe and secure.
Crate training is not a physical punishment and you should not make the crate a scary thing- but rather help your pet find comfort in their ‘den’.
CONCLUSION
Fear aggression in dogs is a serious problem that should be addressed with the help of a professional. With proper training, socialization, and management, you can help your dog to overcome their fear and become a happy, well-adjusted dog.