Are Border Collies Aggressive? (And 9 Causes Of Aggression)

Are you considering adding a border collie to the family? Have you weighed the pros and cons of the breed? Many families tend to get caught up deciding which dog would make the best addition to their home. If you are interested in adopting border collies, you may be asking, “Are border collies aggressive?” In this article, we will discuss the temperament of border collies, why they may be aggressive, and what you can do to stop aggressive behavior. 

Are Border Collies Aggressive? 

Border Collies are not naturally aggressive dogs. Farmers bred border collies to be herd sheep and other livestock, so they are known to be a bit bossy and have an enormous amount of energy. However, they are a medium-tempered dog who is loyal and loving to their family. If you have a border collie that is aggressive, it is not because of its breed. 

Are Male Or Female Border Collies More Aggressive? 

The male border collie tends to be more aggressive than the female. This doesn’t mean they are dangerous or mean; they are just more assertive. If you want a big cuddle bug who will play with the kids, roam the yard without being suspicious of everyone who comes to visit, and form a bond with the whole family, you want a male.  Females are more independent, tend to form a close bond with one person, but are easier to train. 

Why Is Your Border Collie Aggressive? 

The border collie is known to be one of the smartest dog breeds you can get. Thanks to their intelligence, they are easily trainable and very obedient. They also do best when they are always on the go and have a job to complete.  If you do not give your collie the proper exercise and daily tasks, they could be a little overwhelming. 

If your border collie is showing signs of aggression, there is probably an underlying cause at play. This breed is not known for being overly aggressive towards humans, especially their families, and is even known for snuggling at the end of a long day.  


One of the biggest causes of aggression in dogs is pain. If your dog is hurt or sick, they are agitated and in pain and cant relay this to you. In some cases, a dog is going to show signs of aggression to let you know.  

Border collies can be born with health conditions that will grow with them getting worse as they go. You may think that it is just your dog being overly aggressive or mean when they are just in pain and don’t know how to handle it. 

Check your dog for any signs of injuries or illness. Evaluate how they have been acting recently and decide if they have any other unusual behaviors indicating there could be a health issue. Watch for other troubling signs. 

  • Vomiting 
  • Diarrhea 
  • Confusion 
  • Restlessness 
  • Refusing to eat 
  • Refusing to drink 

All of these symptoms may indicate you need to get to a vet as soon as possible. 


Just like humans, dogs can become anxious in certain situations. If your pet is showing signs of aggravation after a significant change, like moving to a new house or having a new person or pet enter the home, this may be the cause of your dog is acting out. 

Other signs to watch for to determine if their issue is due to anxiety are as follows. 

  • Restlessness- Dogs will become restless when they are anxious. You will see this by them getting up and down and never sleeping in one spot for too long. 
  • Pacing- If a dog is overly anxious, they will start to pace the room, house, or yard back and forth because they want to keep an eye on their surroundings. 
  • Shaking- An anxious dog may start to shake or tremble if they are anxious this is due to fear and confusion. 
  • Digging- Excessive digging is a compulsion that dogs will do when they become overly anxious or stressed out. 
  • Excessive licking or chewing- Some vets believe that the act of excessive licking and chewing is a dog’s way of controlling something when they are anxious and feel out of control with their surroundings. 
  • Chewing things they should not- An anxious dog, like a bored dog, will chew things up and destroy things. Chewing is a way to relieve stress for your collie. 

When a border collie, or any other dog for that matter, feels anxious, they do not understand what they are feeling; they know it is not right, and that causes them to panic. 


It is a dog’s basic instinct to behave aggressively when they feel scared or threatened. Your dogs’ ancestors many years ago had to be as scary and ferocious as possible if they were afraid of something they were unsure of; this is how they stayed safe.  

If you got your dog from a shelter or rescue, this could also be a sign of what has happened to them in the past or the fear they have about being rehomed. It is crucial to be patient with rescued collies because you have no idea what they went through before coming into your home. 

Why Is My Border Collie Aggressive To Strangers? 

It can be frustrating when your dog is aggressive towards people outside of the home. The mailman is afraid to drop off your packages, and your neighbors never want to visit. You are probably constantly asking yourself, “Why is my border collie aggressive to strangers?” You are not alone. A lot of pet parents have this same question. Here are some reasons that may answer your question. 

They Are Protecting You 

To a dog, their family is their pack. You are their pack. A border collie is known for being assertive and controlling. If they feel you are in any type of danger, their instincts are bound to kick in and protect you. Like they would in the wild protecting other wolves (distance relatives.).  

When an unknown guest enters the home, your dog is going to be on high alert and go into defense mode immediately. If your collie senses any off behavior, they will feel threatened, and some can become aggressive.  


A territorial dog protects what they consider to be theirs. Examples can include the house they live in, the toys they play with, or even you. This behavior is not the same as protecting you as “their human” but as their property. Territorial dogs are known to become very aggressive.  


A nervous dog makes a dangerous dog. If your dog is scared or nervous about a new person coming near them, they may feel the need to defend themselves or their home.  

Have you heard the saying, “Dogs can sense fear?” This is actually true. However, not in the way you think. Dogs can not technically smell emotions coming from anyone, but they can pick up on other senses.  

Your collie will study any new guests; they will observe behaviors and movements. If your pet sees or senses something that suggests nervousness, anxiety, or fear, this can make them nervous; therefore, they may react in defense. 

Past Experience 

If your dog had a negative experience with someone they didn’t know, they might have a tough time trusting anyone. This reason is a learned behavior and can be easier to correct than the others mentioned above. 

Why Is My Border Collie Aggressive To Other Dogs? 

Your border collie may be acting socially aggressive towards other dogs for the same reasons they act aggressively towards strangers. They are protecting their families, their property, or they feel scared or threatened. However, there are a few other reasons for this nasty behavior. 


If you or someone they love is spending time with another dog, your pet may be getting jealous of you giving away “their attention.” Dogs are very loyal and creatures of habit 


Dominance is one of the most significant factors that cause dog towards dog aggression, especially in males. A dog will use aggression to assert their authority over other dogs, letting them know they are on their turf and they are in charge. 

Dominance is another learned behavior and should quickly be addressed as soon as it starts.  

How To Stop Your Border Collie from Being Aggressive 

It is okay to have a protective dog who will indicate to its owner a stranger is around or to herd animals around the yard with barking and a small nip. It is not okay to have an aggressive dog who shows its dominance towards you or anyone else. If your border collies are aggressive, here are some options you may want to try. 

Positive Reinforcement

Decide what is causing your border collie to be aggressive, and then find a way to reward them for not doing it. As an example, your dog goes insane when the mailman walks up to the door. Pull out a treat and wait for your dog to realize you have it. Once he is calm and quiet,  you can then give it to him. 

Call Your Vet 

If your dog is aggressive because they are hurt or sick, you may never know anything is wrong. All you will notice is their anger. Take your dog to the vet and see if there is a reason behind the behavior, especially if this is new. 

Call In The Professionals

If you cant figure out why your dog is so aggressive and don’t know how to control it, you may want to schedule some obedience classes to get some help from a professional. These are educated trainers that are experienced with these issues and know how to turn them around. 

Want To Train Your Border Collie With Peace Of Mind?

If you haven’t trained your Border Collie properly, then this is the perfect time to start. Whatever bad behavior your shepherd has, whether it’s barking at night or other bad behaviors, using the right training program is the key to having an obedient and happy pup.

The training program I love and highly recommend is Brain Training For Dogs.

With Brain Training For Dogs, you’ll save yourself a ton of time and effort. Instead of banging your head against the wall trying to figure out why your dog won’t listen, you’ll follow a path that has been tried, tested, and most importantly, that’s given proven results. Not to mention the fact, you’ll be able to fit the course around your schedule, not fit your schedule around a trainer or obedience class.

So instead of worrying about whether they’re going to be well-behaved or not, you’ll only have to worry about how much fun you’ll have with them!

And in most cases, it’s still going to be:

  • Cheaper than hiring a professional.
  • Cheaper than replacing everything they might break.
  • And definitely cheaper than a lawsuit against you, if they decide to bite someone.

Just imagine how great it will feel to finally be able to trust your Border Collie completely and never worry whether they’ll be naughty or not. Instead, you’ll have the peace of mind that you have a well-behaved pup, and the boundaries you set for them will always be there, EVEN IF YOU’RE NOT. 

And the best part is it also has a 60-day money-back guarantee! So there’s no reason not to give Brain Training For Dogs a try!

So if you’re tired of your dog’s bad behavior or how they react around other people and pooches, then give it a try! You’ll be amazed by the results!

(You can also check out a full review here to learn exactly what the course has to offer!)

What Should You Avoid Doing? 

Now that you know what you should do to help stop the aggressive behaviors your dog has. It is just as important to know what not to do. Sometimes people do things they think are helping when in actuality, they are making the situation worse. 

Never Yell 

Dealing with an aggressive dog can be very stressful, and at times you may feel like yelling, but that can make things worse than they already are. Yelling at your dog is only going to get them more upset and exacerbate the already aggressive behavior. Never add tension to an already out-of-control situation. 

Do Not Reward Bad Behavior 

Let us use the mailman as our example again. When your dog starts to bark while looking out the window, close the curtain but do not say anything. Never give your dog any attention when they are displaying negative behavior. 

Why Is Your Border Collie Getting More Aggressive? 

A frequently asked question is, “why is my border collie getting more aggressive?” This question comes with a lot of frustration and sadness from the owner. It is tough to see your best friend start to act out in disturbing ways, and you don’t know why or how to stop it. 

For the most part, your dog is not going to just one day choose to become aggressive.  Something is going on with your pet mentally, physically, or emotionally, making them start to change their behaviors. 

Dogs are notorious for being 100% loyal to their owners. No dog would ever purposely do something to make you mad or upset. So, when your furry friend starts to act out, it is up to you to figure out what is going on. Here is a list of the more common reasons for a dog to suddenly become aggressive. 


It can be disheartening to think about, but dogs can become agitated and aggressive as they get older. It gets harder to move around, and they start to develop arthritis and achy joints and bones. 

Border collies are known to develop hip dysplasia as they age, and even when treated with medication, this condition can not only become painful but frustrating. A dog who has gotten used to moving and running regularly, not getting around quickly can make a dog upset, and they may become aggressive. 

Another possibility is that your collie is suffering from the onset of dementia. It is not uncommon for dogs of any breed to start becoming forgetful and confused as they age. If your dog is becoming more aggressive as they get older, they may not even realize they are doing it. 

Health (Physical And Mental) 

Another reason for your Border Collies’ sudden onset of aggression could be a new injury or illness. If your dog starts to act angry and mean for seemingly no reason, they may have gotten hurt at one point, and you never noticed because the pain started small. Dogs are curious creatures and can get into places they shouldn’t be in, making them susceptible to injuries.  

Certain illnesses can also affect a dog’s behavior and temperament suddenly. Border collies are a dog breed known to develop seizures and compulsive behaviors.  

Untreated or uncontrolled seizures are linked to aggressive behaviors in dogs and can continue to worsen until the attacks are under control. 

If your collie’s temper stems from the onset of a compulsive disorder, getting them to a vet quickly can help you control the situation and eventually stop it altogether. 

Are They Being Mistreated (Purposely Or Unknowingly)

Does it seem like your pup is being more aggressive to one person more than the others? Or maybe the anger is brought on when they know you are getting ready to leave the house? If someone is intentionally or unintentionally physically hurting your collie, they will defend themselves and use aggression to do it.  

Watch to see if your dog is specifically directing their anger towards one person more than the rest. If there is a noticeable target, then it’s time to figure out what is going on when you are not around. 

A Change In Their Routine

Dogs are creatures of habit. Keeping a routine can help and improve their moods and behaviors. If they are already on a routine and it gets changed up or completely missed, it can cause some dogs to show signs of aggression. 

If your collie is used to their daily walk every morning, skipping it and putting them on a chain instead or keeping them in the house is not only going to make them bored but aggravate them. Always stick to your collie’s routines. 


Just because your border collie shows aggression doesn’t mean they are a mean dog or dangerous to you and your family. As you can see from this article, collies are family dogs who welcome cuddles and playtime. However, they can have any reasons to get into a bad mood. As a pet owner, it is up to you to figure out what is causing your dog’s aggressive behavior and do whatever you can to fix the issues. 

All dogs want to please their humans and would do whatever it took to make them proud, so if you suspect something is going on with your furry friend, you should take immediate action to make a change. You are all your pet has to look at for help.