Reasons Why Dogs Become Aggressive

If your dog is becoming aggressive with other animals and people, there are several steps you can take to determine what the problem might be. Some causes for aggression involve medical issues while others are based on specific behaviors learned by the dog due to its environment or current living conditions.

Although some breeds tend to be more aggressive than others, aggression in dogs can occur in any breed. It’s important to address the issue immediately before it affects not only your pet but also those around him as well.

Reasons Why Dogs Become Aggressive

The causes of dog aggression are numerous. Some dogs are born with certain genes that make them more likely to become aggressive. Others are more likely to become aggressive because of their life experiences. However, even dogs who have a wonderful temperament and are never known to be aggressive can develop aggression problems later in life.

Illness and Injury

It’s easy to rule out illness as a cause of aggression because there are usually other symptoms that occur along with the aggressive behavior. If your dog is suddenly aggressive and has no prior history of violence, you should take him to the veterinarian for a checkup. Your vet will run basic blood and urine tests and possibly an MRI or CT scan to look for the root cause of your dog’s aggression problems.

Injury to a limb or a tooth can be an underlying cause of aggression in dogs. The injured area may become very sensitive, and the dog might bite anytime someone tries to touch it. If you suspect that injury is the reason behind your dog’s sudden hostility, take him to the veterinarian for an exam.


Dogs are social animals who usually live in packs or pairs. If they are not living with other dogs, they will often bond to the first animal they live with, whether it’s a human or another dog. Dogs who do not have companionship of any kind while they’re left alone may become aggressive because of loneliness.

Dogs who are not properly trained will sometimes become aggressive out of frustration at their inability to communicate what they want. If your dog is always being attacked by another animal when he’s off the leash, it may be because he has no way to defend himself or ask for help.


Some dogs will become aggressive if they feel that someone is trying to take something away from them. Possessiveness can be exhibited in several ways, including keeping others at a safe distance while chewing on an object, growling when someone tries to touch the dog’s food or toys, and snapping at people who try to get too close.


Some dogs will become aggressive when they are afraid. This is a very common reason for a dog to suddenly bite someone without any warning signs. If your dog has been attacked by another animal before, it may cause him to fear other animals as well as people.

Fearful dogs usually react by running away or cowering, but if they can’t get away, they might lash out and bite.


Dogs are naturally territorial animals. If your dog doesn’t have a way to tell others that his territory has been invaded, he may try to scare the intruder away by being aggressive. Dogs who have been allowed to protect certain areas of the house from other animals or people may turn aggressive if someone tries to go into that area.

If you have another dog, territoriality is very common when it comes to food. If your dogs are not trained to eat at different times, the dominant dog may try to keep the other away from his bowl while he eats.


Dogs are social animals who want to please their owners. If your dog doesn’t have any other outlet for his energy or drive, he may become frustrated and try to release the extra energy by being aggressive. This often happens when a dog is left alone, especially if he’s used to being around people all day.

He may turn into an aggressive maniac if left alone, even for just a few hours. Signs of frustration in dogs include constant barking or whining, chewing objects that are not appropriate to chew, digging holes around the house, and jumping at people when they come home.


Dogs who try to claim dominance over their owners can become aggressive because they fear reprisals if they act submissively. This type of aggression is usually displayed by dominant dogs who growl or bare their teeth at people they don’t know, like delivery men and strangers on the street.

Your dog may try to bite you if he feels that you are challenging his place as the alpha in the household. He may also become aggressive if you discipline him.

Certain breeds are more likely to become aggressive than other breeds. Some of the most common aggressive dog breeds are pit bulls, Rottweilers, German shepherds, Siberian huskies and Doberman pinschers. Not all dogs in these breeds have violent tendencies but they often have problems with aggression due to their history of being bred for these traits.

How to Stop a Dog from Biting

If your dog is aggressive toward family members, you may think that the only solution is to get rid of him and find another canine companion.

Don’t give up on your dog just yet. Many cases of aggression in dogs are due to simple misunderstandings on the part of humans rather than a lack of training for the animal. If you can identify the cause of your dog’s aggression, there is a good chance that you can help him to become less aggressive.

There are several things you can do if your dog becomes hostile with family members.

The first thing to remember is that it probably isn’t entirely his fault – he may be feeling threatened. When your dog displays aggressive behavior, you should make sure that you aren’t intimidating him in any way.

Here are some tips to keep in mind:

Don’t allow your dog to intimidate you. Stand tall and hold your ground when you see aggressive signs. Draw on your inner strength! If you feel overwhelmed, back off slowly until he relaxes. Don’t give him the upper hand. Stay calm and collected at all times. If you react with fear, your dog may feel that he has the advantage.

Respect your dog’s space. If you are forcing him to sit on your lap or accept affection from someone he doesn’t like, you are showing him that you are an intimidator who is trying to control his life. This will only cause him to become more hostile toward you and anyone else who tries to touch him.

Avoid eye contact. When your dog becomes aggressive, avoid looking into his eyes and making direct eye contact because this can be seen as a challenge or threat.

Do not show fear or even the smallest hint of it because dogs can smell fear and will use that against you. Your body language is just as important as your tone of voice.

Spend time with your dog. Dogs who are neglected and isolated from the family tend to be more aggressive because they feel threatened by their own lack of control over the household. Your dog needs your companionship just as much as you need his so make sure he is included in all family activities.

Curing Dog Aggression: Behavior Modification

Do not allow the dog to intimidate you, even if he is growling or snarling. Dogs will typically stop their aggression if they sense the human is not backing down. Keeping a calm demeanor and forcefulness to show that you are in control of the situation can help prevent an injury.

Persevere! It may take weeks or months before you see any improvement in your pet’s behavior. Be consistent with your training techniques and maintain a positive attitude to encourage success.

Avoid making sudden movements near the dog as these actions may trigger an aggressive response from him, so always walk backwards when moving toward him for play time or food treats

In some cases, the aggression doesn’t have a specific trigger and your dog is just constantly hostile toward everyone. In these cases, you should look to professional help from a veterinary behaviorist or a certified trainer who has experience with dealing with aggressive dogs if other training methods don’t work.

If your dog’s aggression is caused by fear or anxiety, he can be treated with behavior modification that will help him to become used to the things that scare him.