aggressive dog

6 Causes of Aggression in Dogs

Medical Contributor:

Dr. Chelsie Narito

Nov 8, 2023

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If you have a dog, you probably know a little bit about her normal behavior and personality. You likely know how to recognize changes in her personality, and you know how much aggression is too much for your pet, as well.

Although some dogs are naturally slightly aggressive, most dogs don’t show extreme aggression without a reason. If your dog has suddenly become more aggressive than normal, it’s very important to figure out why. In the article below, you’ll find a quick list of some of the most common causes of aggression in dogs to help you get started.

1. Boredom

Although aggression may seem like a strange result of boredom, many bored dogs turn to aggressive tendencies to relieve their pent-up energy. If your dog spends most of her day in her crate or at home without anything to do, she may become aggressive when you finally interact with her at the end of the day.

To combat this problem, enroll your dog in training or work with her yourself so she has something to spend her mental energy on. Make sure you take her on walks and play with her to burn off some physical energy, too.

2. Anxiety

Anxiety can quickly lead to aggression in dogs who are very afraid. If your dog is nervous or easily frightened, she may become aggressive when she feels like she needs to defend herself. Although this response is instinctive, it can often happen even in situations when you know your dog is safe—such as when fireworks are going off outside.

Additionally, if you’ve recently experienced any major changes in your household, your dog may become aggressive due to this type of anxiety instead. New pets, new babies, new partners, and new homes can all lead to temporary anxiety and aggression in dogs.

3. Pain

Dogs who are in pain may become aggressive because they are trying to defend themselves from further injury. If your dog is in a lot of pain due to an acute or chronic problem, she may growl and snap at you when you try to touch her. Even if you’re trying to help your dog, her pain may make her lash out.

It is important to take your dog to the vet if she is being aggressive due to pain. She may have a serious underlying health problem or a life-threatening injury that needs to be treated right away.

4. Pregnancy

If you have an intact female dog, and especially if she has been around any male dogs recently, there is a chance she could be pregnant. Aggression goes along with pregnancy in many dogs because they feel the need to protect themselves and their unborn puppies from real or perceived threats in the surrounding environment.

After a dog gives birth, she may be aggressive toward anyone who tries to bother her or her puppies, too. It is important to provide your pregnant dog with a comfortable, safe place to give birth and raise her young puppies.

5. Neurological Problems

Neurological problems can happen as a result of health problems like brain tumors or as a result of injury. Any illness or injury that affects your dog’s nervous system can potentially change her personality, leading to aggression and other issues that were not there before.

If your dog is diagnosed with a neurological problem, understand that aggression and personality changes may be part of her life moving forward. Work with your veterinarian to determine which issues you can manage or treat, and which ones you need to learn how to live with instead.

6. Rabies

Finally, rabies is always a risk in unvaccinated dogs with sudden aggression. Although rabies is extremely uncommon, especially compared to other items listed here, any dog who hasn’t been vaccinated against rabies may potentially contract this fatal and very dangerous disease.

Among its many other symptoms, rabies often causes dogs to become very aggressive. They may also become confused, exceptionally clingy, or prone to mood swings. Rabies also causes foaming at the mouth, inability to drink water, and seizures, before it eventually leads to paralysis and death. It can be spread from dogs to humans, so keeping your pet vaccinated against rabies is extremely crucial.

Contact VEG if Your Dog is Aggressive 

If your dog is extremely aggressive and has experienced sudden behavioral changes without an explanation, take her to the vet or emergency vet right away. There is always a risk she could be very sick with an illness or condition causing these behavioral changes, and it’s important to rule out rabies in an unvaccinated dog, too.

Remember that you should work with a professional trainer or a vet if you have a dog who is always aggressive toward you or your family members. It can be difficult living with an aggressive dog, but training and vet care can often help resolve the problem.

At VEG, we have compassionate and experienced team members available around the clock to help guide you in the best direction. When you call any of our locations, you’ll speak directly with an emergency veterinarian who’s just as concerned about your dog as you are. If you’re concerned about your pet’s health, or have any questions about aggression in dogs, call us right away so we can help.