Are Jack Russells Aggressive?

are jack russells aggressive

I’ve been the proud owner of 3 Jack Russells for many years and I wanted to share some thoughts about why they can be aggressive, and why it can sometimes be hard if you have an aggressive dog.

What most people don’t know is that early training and socialization can really make a huge difference, even if your Jack Russell has already started fighting with other animals.

First things first, we have to address the elephant in the room.

Are Jack Russells Aggressive?

Jack Russells can be aggressive and this type of behavior is normally caused by fear, lack of socialization, possessive behavior, boredom, and a lack of exercise. Due to their strong prey drive, they might show aggression towards cats and other small animals.

7 Reasons Why Your Jack Russell Might Be Aggressive

As mentioned earlier, Jack Russells might be aggressive because of a few factors. Identifying why your Jack Russell is aggressive is a crucial step in preventing this unwanted behavior.

Let’s explore this in detail.

1.) Fear

Fear is a common contributor to aggressive behavior. A Jack Russell that has been abused, neglected, or not properly trained will most likely show fearful aggression. You should know that fearful aggression is quite common in dogs, and many times it is the result of poor training practices as opposed to innate viciousness.

2.) Lack of socialization

Most people think that their Jack Russell needs to have a lot of human interaction in order to be okay but this isn’t true. Even if your dog has been socialized with other dogs and humans from the time he was little, it doesn’t mean he will accept them instantly.

For example, you might have your Jack Russell out at a dog park and he might be fine with the dogs in the park, but when a strange dog approaches him to say “hi” he will react by showing aggression.

3.) Possessive Behavior or Territorial Behaviour

This may sound silly because it does not apply to all dogs, but some are possessive with things that they consider theirs. With Jack Russells, this can be a common issue as they are can be very possessive of their owners. Before you know it, your Jack Russell sees someone as a threat by simply approaching you.

4.) Boredom and Excess Energy

You might see some aggressive behavior in your Jack Russell if you don’t provide him with enough exercise. Just like humans, dogs need to be active every day. Boredom might cause some dogs to act out and become aggressive.

This is why I often recommend getting a second dog for your Jack Russell so they can play with each other and get exercise at the same time, especially if you can’t be around your Jack Russell all the time.

5.) Lack of Exercise

If a Jack Russell is not getting enough exercise they tend to show aggression. This is because some dogs behave aggressively when they have an excess amount of energy and need a way to release their pent-up energy.

Of course, you should make sure that your dog gets plenty of exercise beforehand so you don’t have to worry about them showing aggression when they are out in public.

Jack Russells enjoy running around, chasing things, and sometimes playing with other dogs very well. It is part of their personality. This type of behavior can be both fun for the owner and the dog but sometimes aggressive dogs need more exercise than others in order to reduce their energy levels.

6.) Lack of Training

This is another situation in which lack of training might result in aggression. The first thing you should do is make sure your Jack Russell knows the basics such as sit, stay, come when called, etc.

These commands will help keep your dog under control and make it easier to manage him if he ever gets aggressive. The key is consistency and making sure your Jack Russell understands what you want from him.

7.) Unsolved Problems

Just like in humans, psychological issues can cause aggression in Jack Russells. This is why you should make sure your dog has a stable life and is comfortable living with you.

If he is struggling to adapt to his environment or if there are a lot of changes in your dog’s life that he doesn’t understand, he might show aggression towards anything that he perceives as a threat, namely strangers walking into your home or other animals.

How to prevent your Jack Russell from being aggressive

Hopefully, by now you’ve identified the cause of your Jack Russell’s aggressive behavior. Let’s have a look at a few ways you can prevent your Jack Russell from being aggressive.

1.) Give him enough exercise

Just like I said above, Jack Russells need a lot of exercise. You should be careful to plan early morning and early evening walks for your dog in order to avoid him from being aggressive.

2.) Train him properly

I recommend all owners take their time to train their dogs when they are puppies. The earlier you start training, the easier it will be later on in life and your Jack Russell will be less likely to act aggressively.

3.) Maintain a stable home environment and lifestyle for your dog

As I said earlier, dogs can become aggressive if they are struggling to adapt to their environment or if there are a lot of changes in their life that they don’t understand. This is often the case with rescue dogs.

You need to make sure that your Jack Russell is not in a situation where there is any conflict in their life and you should maintain a stable environment for them and make sure they are comfortable.

4.) Socialize him from an early age

When you are socializing your Jack Russell from an early age you are making sure that he has the opportunity to get used to different situations, characters, and places.

This will make it easier for him when he moves into adulthood and it will be less likely for him to show aggression if he is used to being around different people.

Socializing your dog also builds a strong bond between you and your dog so they are more likely to listen to you and less likely to show aggression towards anyone else.

5.) Control your dog’s environment

Even if your Jack Russell is used to being around strangers, you can’t just let anyone into your home. If you have a Jack Russell that has shown aggressive behavior, make sure that you control who is allowed in and out of the house and take steps to prevent strangers from walking into your house when you are not there.


As you can see, there are numerous factors that might be contributing to your Jack Russell’s aggression. The key is identifying why your Jack Russell is aggressive and then taking the necessary steps in order to correct the problems.

Even if you have recently adopted your Jack Russell or if you’ve had him for a long time, it is still important to be aware of the signs of aggression so that you can take the necessary measures.


  • Jan Pretorius

    Meet Jan Pretorius, the passionate dog lover and proud owner of the popular canine haven, Born and raised in a small town known for its love of animals, Jan’s journey into the world of dogs began at a young age, fueled by an innate connection with our four-legged companions.