If your furry friend is resisting certain interactions with people or displaying aggressive behaviors such as threatening barks, growls, and lip-licking with exposed teeth, it’s crucial to recognize these signs of irritability and potential anger in your dog. Also, knowing why your dog is irritable can help you avoid potential dangers.

5 Reasons Dogs Show Aggressive Behavior

5 Reasons Your Dog Is Irritable 1 Classroom, dog class, dog wellness

Illness and Injury:

Dogs that suddenly exhibit aggressive behavior may be experiencing discomfort due to illness or injury. Joint issues, fractures, internal injuries, various tumors, and wounds can lead to pain. Training tools like choke collars and shock collars may exacerbate aggression.

Certain illnesses affecting the dog’s brain, such as cognitive dysfunction, brain diseases, or tumors, can trigger seemingly irrational aggressive behavior. These problems are more likely to occur in older dogs, but age-related hearing and vision loss can also contribute to irritability.

Anxiety or Fear:

Fear is a common cause of aggressive behavior in dogs. When a fearful dog feels trapped – unable to escape – it may resort to aggression as a protective measure. Changes in routine, such as a new job or introducing a new pet at home, can disrupt a dog’s normal life, leading to anxiety or fear. Environmental disturbances, noise, or constant interference from other animals or people can also contribute to irritability.


Dogs exhibit strong resource-guarding instincts, especially regarding their most valued possessions like toys, food, or sleeping areas. Dogs with resource aggression may only display aggression when someone or another pet approaches their favorite items, ranging from warning growls to biting or full-scale attacks.

Showing Dominance:

Dogs maintain a hierarchy within their social groups, determining who eats first, gets the best sleeping spot, and has the first mating opportunity. Dogs may use aggressive threats to maintain order within the group. Household dogs that perceive themselves as dominant may show aggression towards humans and other canine family members.


Dogs restrained for long periods or confined by leashes or wire fences may feel frustrated when wanting to approach other animals but feel restricted. Increased frustration can escalate barking and growling. When approached by the owner, the dog may redirect its frustration by biting. Redirected aggression may also lead to attacks on other family pets, whether canine or feline.

Understanding the reasons behind your dog’s irritability is essential for creating a safe and harmonious environment. If you notice signs of aggression, consult with a veterinarian or a professional dog behaviorist to address the underlying issues and ensure your dog’s well-being.