Dog aggression: how to spot it and what to do about it

Aug 22, 2022

As much as we love our dogs, there is no denying that their ancestry as fierce predators is still within them. Numerous triggers may cause a dog to exhibit aggressive behavior. The inability to cope with these behaviors leads many dog owners to surrender their pets to the nearest shelter. And without proper socializing and training, a dog with aggressive tendencies has very poor prospects of finding a fur-ever home.

Dog behaviorists, trainers and obedience coaches have a wide variety of techniques for keeping a dog’s behavior friendly, safe and cooperative. Let’s begin by understanding what dog aggression is, and why your dog may be experiencing it.

Defining dog aggression

Aggression is defined as threatening to harm or actually harming another individual. It may be offensive, when a dog initiates hostile behavior to protect territory, or defensive, when a dog has been challenged or threatened by a rival.

How to spot dog aggression

There are a number of ways a dog that is feeling threatened or stressed may behave before becoming aggressive. Watch out for the following behaviors and body language:

  • Growling, snapping, lunging, nipping, baring teeth and biting
  • A quickly twitching tail
  • Raised, bristly fur along the back
  • Stiff legs, ears laid down flat against the head, arched spine and unblinking eyes
  • Cowering and tail-tucking; while these are submissive postures, a dog can quickly flip the switch and become aggressive.

These body language signals may also indicate anxiety and fear, and these are signs of a dog in acute distress that needs to be handled carefully.

Types of aggression in dogs

Take note of the following types of aggressive behavior so you can better understand and spot them before it’s too late to intervene.

  • Territorial dog aggression — The dog defends their space from a perceived intruder.
  • Protective aggression in dogs— The dog protects members of their pack against another animal or a person. Mother dogs with pups frequently display this behavior.
  • Possessive aggression in dogs— The dog protects their food, toys, or other objects of value. Trainers call this “resource guarding.” Some puppies learn resource guarding from their mothers or littermates. And dogs that have spent a long time in a shelter sometimes display possession aggression over space. They literally, want to possess a space to rest or sleep. Possessive behavior toward food bowls and toys can be a result of trauma and deprivation.
  • Fear-based dog aggression — The dog is frightened, retreats, but lashes out when cornered.
  • Defensive aggression in dogs — Usually the behavior of a dog that really does NOT want to fight, but feels trapped and desperate. This dog will usually give warning signs before becoming aggressive, by turning their face away, and crouching down to avoid confrontation with a perceived attacker.
  • Social aggression in dogs — Dogs with poor social skills begin leveraging for the top-dog spot when put into contact with other pets or people. Some dogs are perfectly docile when they’re secure in the role of top dog in your household, but suddenly display aggression when a new pet is introduced.
  • Frustration-elicited dog aggression — Also called the “short leash” syndrome. This is often a dog that’s restrained or restricted too harshly, and experiences an outburst of misdirected energy.
  • Redirected aggression in dogs — This is often a case of simply being in the line of fire when a dog is feeling hostile toward something or someone else. Breaking up a fight between two dogs is a perfect example of this! A dog may also become aggressive toward an innocent bystander or passer by when there’s an unreachable target, like a dog on the other side of the fence.
  • Pain-elicited dog aggression — When a pet is injured or in pain, lashing out is a predictable response. If your dog is aggressive without any apparent reason, consult your vet. The source may be something as simple and correctable as a toothache or an ear infection.
  • Sex-related dog aggression — Two rivals competing for a mate can trigger hostile altercations, generally between intact animals. Females will fight other females, and males will fight other males under these circumstances, an excellent argument for spaying and neutering all pets.
  • Predatory dog aggression — Chasing a squirrel or other prey animal triggers the behavior in this dog. Dogs are hunters, and this is natural, but here’s the problem: small pets and even our children may behave as “prey” to a dog who’s tuned in to this type of deep-seated aggressive behavior.

Sometimes aggression escalates over time, so be mindful of your dog’s behavior. A dog who growls slightly when their food bowl is approached may begin biting to protect their dish if the early warnings are ignored.

How and when to intervene in aggressive dogs

In the wild, these are all useful behaviors. But when it comes to our domesticated companions, these tendencies clash with what we want in a happy, relaxed family pet.

Growling Dogs

When confronted with a growling dog, don’t try to take the role of the dominant alpha by forcing him to give up the toy or food he’s protecting. Try the command to “drop it” — a good one to teach if you haven’t already. But be sure to reward this behavior with a better treat or toy as positive reinforcement.

Behavioral modification for aggressive behavior in dogs

Behavioral modification techniques may be helpful to reduce aggression in dogs. One approach is to reduce the focus on the objects that your dog is guarding.

Dog aggression around food

If your dog is aggressive about food, diffuse the situation by placing several bowls of food around your space. Place bland food in one dish, and as your dog is eating from that bowl, serve up a portion of an even more delicious food into a different bowl a few feet away. Add desirable food to the other bowls, demonstrating that food is abundant, and that there are options. This may help your dog relax and stop fixating so obsessively on “their” dish.

Dog aggression around toys

The same may be done with toys. Begin by hiding your dog’s favorite toys where she can’t find them. In fact, lock them away. Offer your dog other toys that don’t carry the same degree of possessive value. The goal is to create a safe new universe of abundant alternatives for your dog, which reduces the need to possess and defend the only dish or the only toy available.

Dog aggression around strangers

If your dog is only aggressive toward strangers, you can try the desensitizing technique described earlier. Begin by standing near someone your dog doesn’t know. You should be far enough away so that your dog doesn’t start to growl or snap. Then, reward your dog with lots of treats and praise as you gradually decrease the distance between your dog and the stranger, continuing to use positive reinforcement.

Aversion training doesn’t work for aggressive dogs

Every good trainer will tell you that aversion training for an aggressive dog does not work, and leads to escalating aggressive behavior. This means that yelling, scolding, shaming, striking, isolating, withholding contact (food, love), or otherwise punishing your dog will never produce the desired behavior.


And, punishment often antagonizes a pet into even more violent aggression next time. Responding to a dog’s threatening behavior with threatening behavior of your own sends the message that aggression is okay. Even if punishment eliminates the specific “problem behavior,” it’s inevitable that your dog will suffer consequences in other ways, because the bond of trust between you and your dog has been broken. Dogs which are trained with violence frequently become highly stressed and agitated. They may act depressed and withdrawn, and may develop physical symptoms as a result.

Dog aggression is a usually a symptom of something else

Aggression may seem sudden, but it comes from somewhere. Consult with Airvet and explain how and when your dog exhibits aggression. Make note of when your dog gets aggressive, and share any other unusual changes in your dog.

Medical conditions can trigger aggressive behavior in dogs

The source may be an underlying medical condition. A dog with hypothyroidism, a hidden injury, or a neurological issue including encephalitis, epilepsy or a brain tumor may behave in ways that are difficult to understand. Even the presence of a toxic substance or a metabolic problem can produce a range of behaviors from nervousness and restlessness to jerking, twitching, incontinence, and compulsively snapping at the air (sometimes called “fly biting”).

Trauma can trigger dog aggression

Trauma in your dog’s past may also be a factor, especially if you adopted your pet without knowing a great deal about their early life.

Identifying the sources of aggression

Begin by eliminating all of the possible physiological sources for aggressive behavior by taking your dog in for an exam. When your vet has given your dog a clean bill of physical health, it’s time to look more deeply into the psychological and emotional state of your pet.

Dog training for aggressive behavior

Contact a trainer who focuses on positive reinforcement techniques. The trainer will need to visit your home, and seek out clues for stress including interactions with other pets. Find a trainer who has been certified by a reputable organization, such as the Certification Council for Professional Dog Trainers.

Aggressive dogs and children

You may discover that your dog cannot interact safely with children. This is because some dogs are triggered by noise or sudden movements. While painful to learn, it’s essential to know to avoid tragic incidents. If you know your dog is aggressive toward children, take appropriate precautions to avoid contact with kids. And always have the ability to control your dog on a leash or harness when out in a public setting.

Understanding your dog inside and out is an ongoing process. Dogs are complex, sentient beings. Patience and a reward-based system will bring out the best in your canine companion.

Do you have an aggressive dog? If so, contact us today. We’re here for situations exactly like this (and more)! Our team will be happy to listen to your concerns and then provide meaningful recommendations for your dog.