Reasons Why Dogs Suddenly Become Aggressive

Dogs are not born aggressive. In fact, most dogs are naturally loving and gentle companions. Unfortunately, there are a number of different factors that can trigger aggression in dogs. Fortunately, there are a number of things you can do to prevent it from happening or stop it after it begins. Here’s everything you need to know about the causes and treatment of dog aggression:

Reasons Why Dogs Suddenly Become Aggressive and How to Stop It

There are many reasons why dogs suddenly become aggressive, and it’s important to know how to stop this behavior before it becomes a problem. The following are some of the most common reasons:

Status Related Aggression

The first type of aggression is status related, and it can be especially dangerous if you don’t recognize it as such. This type of aggression occurs when your dog is unhappy with his place in the pack. If a dog feels threatened by another dog (or human), he may lash out violently because he feels like his territory or status has been threatened.

Status related aggression can happen for a variety of reasons:

  • Your dog may have been bullied by another animal in the past and now has an issue with that animal or animals. This could include being picked on by larger dogs, being singled out for punishment when other dogs are also misbehaving, or simply getting hurt physically as he tries to defend himself against bullying behavior from others.
  • Your dog might not feel comfortable around certain people who are close to home—whether it’s because they make him nervous due to their size, smell, or demeanor; or maybe they just remind him too much of someone else who used to bully him (we’ll talk more about this later).
  • Finally—and probably most commonly—your own body language could be making him feel insecure about where he stands with regard to humans within his own family unit (or even outside of it). This includes sitting down while eating dinner at home together instead of standing up like everyone else; talking loudly during dinner time so no one else gets heard over all the noise; hovering over your food bowl while eating without sharing anything leftovers with Fido when he comes around begging intermittently throughout dinner time too…

Pain or Fear

It’s important to note that dogs can become aggressive if they are in pain or afraid. For example, a dog may bite you if you touch their injured leg because it hurts them and they don’t know how else to get you to stop. In this case, the best thing for you to do is leave the dog alone until after it has been taken care of by a veterinarian. The same could also be true for any other medical condition that causes discomfort or pain in your dog; be sure not to pet them or touch them until after they have been treated by a vet!

Social Instability and Resource Guarding

Here are some of the most common causes:

  • Not enough socialization. It’s important to expose your dog to a variety of people, places and situations in order to prevent social instability later in life. If your dog doesn’t go out often enough, he may become overly protective of his resources (food, toys) or territory (home).
  • Ineffective training methods. If you’ve been using punishment as part of your puppy’s training regimen, this could lead to aggression later down the road as well—punishment is not effective long-term because it makes dogs feel fear instead of respect for their owner(s). Instead of punishing negative behavior with physical means like kicks or slaps on the nose (the latter being particularly risky for small breeds), try rewarding positive behavior instead!
  • Lack of exercise/exposure to other animals/strange noises can also cause aggressive tendencies if left unchecked; without proper stimulation from these sources over time they’ll start acting out aggressively whenever something new comes along that gets them excited about life again!

Frustration-Elicited Aggression

Frustration-elicited aggression occurs when a dog is unable to get what it wants. It could be a ball, a treat or even your attention. When this happens, the dog may become aggressive and try to bite you in order to get its way so that you will give them what they want. Frustration-elicited aggression is most common with puppies who have not yet learned how to deal with frustration and aggression appropriately.

Territorial Aggression

As you may have guessed, territorial aggression is the most common reason for dogs becoming aggressive. It occurs when a dog becomes upset by the presence of an unfamiliar animal or person in its territory and will attempt to drive that animal or person away from their space.

Territorial aggression is most often seen in dogs that are guarding their home or yard. For example, a dog who lives with his family in New York City will likely not demonstrate territorial aggression because he doesn’t spend much time outside alone—and if he does go out alone, he has the entire city as his territory! However, if you were to take your New York-dwelling dog on vacation to Montana and leave him at home while you and your family travel around the state for several days at a time without him…well…it wouldn’t be surprising if he had some issues with strangers approaching his house while you’re away—especially since these people might ring your doorbell!

Preventing Dog Aggression

Keep your dog busy. If they are bored and have nothing to do, a bored dog is more likely to be aggressive.

Don’t leave your dog alone for long periods of time. Dogs need attention and interaction with their owners; if this is not happening on a regular basis, then the dog may become frustrated or upset which could lead to aggression being displayed towards humans or other pets in an attempt to gain attention from that person.

Don’t let your dog get stressed out by having them perform tasks like agility training or another type of training program where they are expected to perform certain actions under pressure such as chasing after something like a ball or treat (which could happen if there were two dogs competing against each other).

Any sort of stress caused by these types of activities might cause some dogs who normally wouldn’t act aggressively do so because it makes them feel threatened about losing their spot within the pack hierarchy system within their household environment

You can stop the aggression.

Once you’ve determined why your dog is behaving aggressively, you can work on stopping the behavior. There are many ways to stop aggression in dogs, including using positive reinforcement (rewards), negative reinforcement (punishment) and punishment combined with positive reinforcement. You can also use training your dog to get him to follow commands and stay calm around other people or animals.

  • Positive Reinforcement: This method involves rewarding good behavior with treats or playtime so that he learns what behaviors are acceptable. For example, if your dog barks at visitors but not when he’s alone with you and then stops barking when given a treat for doing so, this means that you’re able to reward him for good behavior so that he repeats it later on down the road.
  • Negative Reinforcement: This method uses negative stimuli like pain or discomfort until an animal stops doing something undesirable.
  • Punishment: This method uses something painful such as biting or hitting until an animal stops doing something undesirable.
  • Training: Teaching your dog basic commands like sit, stay and heel will help keep him relaxed around other pets because he will have less reason for acting out since he knows how important it is for him act properly in certain situations.
  • Medication: Certain medications like Prozac can reduce aggressive tendencies by reducing fearfulness and stress levels while helping them relax better during stressful situations like thunderstorms or fireworks displays.


Fortunately, there are many steps you can take to deal with aggressive behavior. The first step is to identify what is causing the aggression and then create a plan that involves training techniques, behavior modification, and other tactics.