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7 Causes of Dog Aggression: Fear, Pain, Predators, and More

L Sarhan has degrees and certifications in the areas of veterinarian medicine.

Causes of Aggression in Dogs

Causes of Aggression in Dogs

Types of Dog Aggression

Many animals show aggressive behaviors for a variety of different reasons. Originally, aggression in domestic dogs was actually a positive trait, because owners wanted dogs to protect them and their property. However, these aggressive traits are very unpredictable and often lead to problems. To understand why canine aggression is so unpredictable, let's first look at the types of canine aggression.

7 Types and Causes of Dog Aggression

Type of AggressionCause of Aggression


hunting prey for food or sport


fear of something, such as the vet


injured, sick


negative reinforcements


Alpha mentality; wanting to show that it is the one in charge


to show something is theirs and to back off, such as food, family, and their yard


dog fighting, negative reinforcements

1. Predatory Aggression

Many dogs have a natural instinct to hunt. With this type of aggression, dogs will not give any warning signs before they strike. Unfortunately, many times children and other pets fall victim to this type of behavior.

2. Fear-Induced Aggression

Many veterinarians and their staff have to deal with aggression that is caused by fear. Animal hospitals aren't the only place fear-induced aggression is displayed. Any time an animal feels trapped with no means to escape, it will automatically fight back. This is a survival instinct.

Other reasons may include sudden, loud noises and children. One common reason is when the dog fears other people. It could even just be characteristics of other people such as wearing a hat, a uniform, or even the site of a rolled-up newspaper being delivered. These may be triggered by past experiences.

3. Punishment Aggression

Punishment aggression can be similar to fear-induced and pain-induced aggression. If an owner chooses physical punishment, such as spanking the hindquarter, this could cause an aggressive reaction from the dog. No physical punishment is ever recommended for any animal, especially dogs. Some owners take physical punishment too far by kicking, slapping, or punching the animal. This is considered abuse and is strongly unacceptable if not illegal.

Even if you use the isolation method, such as crating or isolating in a room, some dogs will act out because they do not want to be isolated. More often this occurs from using crates that are simply too small and uncomfortable for the dog.

The most common body language used in animals is to show aggression or displeasure at something.

The most common body language used in animals is to show aggression or displeasure at something.

4. Pain-Induced Aggression

Most animals display aggression when they are in pain. This is why you should always approach an injured animal with the utmost caution. In fact, dogfighting utilizes pain-induced aggression to keep the fight going.

Injury isn't the only reason for this type of aggression. Sometimes dogs may have painful skin irritation, an internal medical condition, or simply be afraid of a veterinary procedure, such as vaccinations.

5. Dominance Aggression

Canines naturally have a pack hierarchy mentality. One dog will be more dominant and be considered the leader of the pack whereas the other dogs are considered subservient and will follow the dominant dog. For domestic dogs, humans serve the dominant role of the pack leader. However, there are times when dogs will challenge the pack leader whether it is canine or human.

Dominance aggression has warning signs such as growling, snapping, or biting before it escalates to a full fight. Many times this occurs when a human persists to assert its dominance over the dog.

6. Territorial Aggression

Dogs can be quite territorial. Some dogs may growl, bark, or bite anyone unfamiliar to them that gets too close to the yard, house, or their human family. Many times, dominance aggression is mistaken for territorial aggression. You would probably think that when a dog growls when you come too close to their food bowl while they are eating it would be territorial aggression, but it's not.

7. Learned Aggression

Some owners unknowingly reinforce aggressive behaviors. These owners will give into the dog by allowing the dog to have what it wants at the first sign of aggression. Unfortunately, some owners even teach or encourage aggressive behaviors, especially in dogfighting.

Another example of learned aggression is responding to a dog's aggression with negative punishment techniques. This will reinforce fears and create phobias in the dog. Nonetheless, the dog's aggression problems will worsen.

Body language signs that signal a dog is exhibiting hostility and aggression.

Body language signs that signal a dog is exhibiting hostility and aggression.

Signs and Signals of a Dog's Aggressive Behavior

Animals often use body language to communicate. In fact, the most common body language used in animals is to show aggression or displeasure at something. Dogs are no exception. Dogs have many ways in which they give warnings of aggression and a possible impending attack. This is referred to as dog signaling. Although each dog has its own combination of signaling depending on the breed and what is causing the aggressive behavior, here are some of the physical signs to look for that signify that your dog is upset or angry.

  • Growling
  • Lips curled; snarling teeth
  • Nose wrinkled
  • Ears back
  • Fur, also known as hackles, raised along their back, especially between the shoulders and right before the tailbone
  • Tail tucked
  • Front half of the body lowered
  • Pupils dilated

By understanding the different types of aggressions dogs display, you will be better equipped to correct the behavior. Many dogs will be grateful to have an understanding owner that is better equipped to help them learn and grow into loving dogs that will truly become a man's best friend.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

© 2014 Linda Sarhan