The Causes of Dog Aggression

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

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.

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

Predatory Aggression

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

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, they 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.

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 with 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.

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, dog fighting utilizes pain-induced aggressions to keep the fight going.

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

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 their dominance over the dog.

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 would be territorial aggression, but it's not.

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 for 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 That Signals 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 in 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 signalling. Although each dog has its own combination of signalling depending on the breed and what is causing the aggressive behavior, here are some of the physical signs to look for that signifies 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 body lowered
  • pupils dilated

By understanding 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 a loving dog that will become truly man's best friend.

© 2014 Linda Sarhan

Other Canine Behavior Problems

Some common behavior problems of dogs are identified below. Many can be treated with behavior modification programs that focus on desensitization and counterconditioning (see Behavior Modification Techniques). This is very important in the early treatment of fears, phobias, and anxieties. Your veterinarian might also prescribe medication to help your pet.

Abnormal ingestive behavior is eating unusual amounts or types of food or nonfood items. This includes pica (eating nonfood items), eating feces (coprophagia), drinking too much water, scavenging (seeking out food in the garbage or off countertops), anorexia (eating too little), overeating, and gorging (eating too fast). These behaviors can be a component of abnormal behaviors (such as compulsive disorders) or due to normal investigative and exploratory behaviors.

Attention-seeking behavior occurs when the dog acts in a way that gets the attention of people who are doing something not directly involving the dog. An example of this would be a puppy that barks to get attention when it is not being actively played with. The owner then reacts to the dog’s bark by giving it attention both positive (playing with the dog) and negative (yelling at the dog) attention from the owner reinforces this behavior. This may be an undesirable behavior, but it is common and it is certainly a behavior that people unconsciously reinforce in their pets.

Senility, which is also called cognitive dysfunction, is similar in some ways to Alzheimer’s disease in people. Signs include a decrease in social interaction, loss of housetraining, disorientation (getting lost in familiar surroundings), and changes in sleep patterns. Physical and mental stimulation can slow down the signs of senility. Medication and a special diet are also available for treatment. These can delay the progression of signs, but will not reverse them.

Compulsive disorders are repetitive behaviors that occur out of their normal circumstances, or much more often or for much longer periods than is normal (for example, incessant licking). The dog spends so much time doing the compulsive behavior that it does not have time for normal activities. Stereotypies are repetitive behaviors that have no obvious purpose or function.

False pregnancy is a condition during which a dog acts as though it is pregnant, but is not. The dog may make a nest and may gather small objects that it protects as if they were puppies.

Destructive behaviors include chewing, stealing, getting into the trash, and digging. They are normal exploratory behaviors seen in unsupervised dogs that aren't busy doing desirable activities. Exercise, reward-based training, and social enrichment can help when owners are home. When unsupervised, dogs should be confined away from areas they can destroy and given appropriate toys or chews.

Fear is a normal response to a real or perceived threat. Anxiety is a response to fear or apprehension when an animal anticipates a threat. Fear and anxiety have signs that overlap. Some nonspecific signs, such as avoidance, shaking, and trembling, can be characteristic of both fear and anxiety. Phobia is an exaggerated fear response that is sudden and profound and results in panic.

Hyperactivity is an extremely high level of activity that does not respond to correction, redirection, or restraint. True hyperactivity is rare in dogs and is different from overactivity. Overactive dogs are highly energetic and active, but are able to calm down and respond to human control.

Neophobia(fear of new things) is active avoidance, escape, or anxiety directed at unfamiliar objects and situations.

Noise phobia consists of a sudden and profound response to noise that leads to intense anxiety, panic, or attempts to escape confinement. The most common form is fear of thunderstorms, although fear of fireworks or other loud noises is also common.

Separation anxiety is a syndrome in which a dog panics when it is left alone. It causes intense anxiety and may lead the dog to bark, pace, or eliminate inside the house. Dogs that are confined commonly destroy kennels, walls, or doors in an attempt to reunite with their owners. Signs are often most severe within the first 15 to 30 minutes of the dog being left alone.

Aggression in dogs can be caused by behavioral issues, medical conditions or both. If your dog begins to display signs of aggression or hostility, he may be suffering from a condition or problems that should be treated.

Hypothyroidism is a medical condition in dogs that causes the thyroid gland to produce less than normal amounts of the thyroid hormone. Symptoms of hypothyroidism in dogs can include weight gain, loss of energy, hair loss and sudden aggressive behavior. Severity of the condition can vary, as the symptoms can.

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@Latte31 -I agree with you. I think that dog behavior is related to how the animal is treated. The most aggressive dogs that I have ever seen are always chained up.

I think that this fosters aggressive dog behavior because it is an unnatural state for the dog to be in and he is fighting it with his aggression. If the same dog were loose inside of a house or even in the backyard the dog would not be so aggressive.

I think that dogs that are mistreated become conditioned to be aggressive because that is the only way that they can protect themselves which is really how you learn to understand aggressive behavior in dogs.

@Panda2006 -I agree with you. I think that dog problems or aggressive dog behavior is often a result of how the dog is socialized. For example, some breeds have an aggressive and violent reputation but that is not true for every dog representing that breed.

For example, where I live, pit bull dogs are illegal to own because of documented cases of the animal becoming violent and killing or hurting other people.

However, my husband had a pit bull growing up and it was his favorite dog. The dog was very loving and protected my husband from another aggressive dog that was going to hurt my husband.

Since this dog grew up in a loving environment he remained that way through her life so you really can’t ban a breed because some of these dogs were raised to be aggressive.

Aggressive behavior in dogs is really a sort of conditioning that occurs when they are puppies. The dog’s training determines his behavior because no dog is born being aggressive that is something that they are taught to be. panda2006 January 18, 2011

Dogs that have been neglected are often aggressive, and while this relates to their loneliness and lack of training, it can also be a sign that the dog is malnourished or otherwise suffering nutritionally. Dog health can affect aggression in psychological ways as well, such as if an owner goes from being very kind to being violent some dogs would quickly return the favor, being suddenly anxious all the time,much like a child might in that situation.

Watch the video: How to stop Dog Aggression quickly And easily - In a few steps! (May 2021).