What Are Triggers for Aggressive Dogs?

A hard stare with a stiff, forward body posture reliably indicates a high level of arousal.
i Jupiterimages/Photos.com/Getty Images

Owning a dog who is aggressive is frustrating and difficult, especially if you don't know the reasons behind the behavior. If you learn the triggers for your pooch's aggressive displays, you can diffuse and prevent incidents from occurring and help your aggressive dog feel more comfortable in her everyday environment.

Physical Illness

thenest article image

George Doyle & Ciaran Griffin/Stockbyte/Getty Images

If your beloved pooch is showing signs of aggression, your first stop should be a veterinarian. There are many physical illnesses that can cause increased aggression such as loss of eyesight, hearing loss, thyroid cancer and arthritis. While medical-based aggression is typically easy to treat, it has to be properly diagnosed. If your dog is flinching away and showing her teeth, growling when touched or snapping when startled, she may be suffering from joint pain, blindness, deafness or changes in brain chemistry.


thenest article image

John Foxx/Stockbyte/Getty Images

Fear-based aggression is common in dogs of all breeds, sizes, backgrounds and ages. If a dog is afraid enough of a situation, she will not hesitate to use her teeth in order to enforce her personal boundaries. Common fear-based triggers include unfamiliar people, large or loud objects and new situations. This pooch is easy to identify by the scrunched-down body position, slicked back ears, wide eyes and excessive drooling or panting. These pups are often referred to as "fear biters" and they need patient, calm, positive handling to help them learn to cope with the source of their anxiety.

Resource Guarding

thenest article image

Ablestock.com/AbleStock.com/Getty Images

If your dog grumbles, shows teeth or bites when another person or dog comes near her while she's enjoying a meal, toy or bone, she's likely demonstrating resource-based aggression. Resource guarding is an instinctive behavior shown by dogs who view other animals or people as a threat to what they consider to belong to them, whether that's their favorite person, a spot on the sofa, food, toys or the backyard. If your pooch resource guards from other dogs, keep her separated while she's enjoying meals, treats, toys and family time. If she's resource guarding from members of your family, you should consult a professional for guidance. Resource guarding from people is a dangerous situation prone to rapid escalation.


thenest article image

Goodshoot/Goodshoot/Getty Images

Surprisingly enough, frustration can cause an otherwise calm, even-tempered dog to lash out at other dogs, people and objects. We've all been told or have told children, "Don't tease the dog." Dogs dealing with frustration-driven aggression have a point at which they get so excited and aroused by whatever they want, be it food, another dog or a toy, they have to diffuse their anxiety and tension. They then turn on and direct their frustration towards the closest target, typically the person at the other end of the leash. Exposing these dogs to their "frustration trigger" at a distance where they can be calm and rewarding them for proper behavior helps desensitize them to the object. Inch them closer and closer to the target, always rewarding calm behavior and moving away from the object if your dog begins to get aroused.

Dogs or People

thenest article image

Fox Photos/Valueline/Getty Images

If your dog tries to attack every dog she passes, she's liking dog-aggressive. While people-aggressive dogs are far more rare, they crop up on occasion. Dogs who demonstrate attack-based aggression lock in visually on a target and lean towards it with their body stiff and rigid. They may or may not give a warning growl before launching at the person or dog. A dog who attacks people without warning is truly dangerous and will require professional evaluation. For dog-aggressive dogs, keep your pup safely away from all other dogs and very gradually, decrease the proximity between your dog and other dogs while rewarding calm behavior. Use a basket muzzle for safety.


If your pup growls or bites while being picked up, examined, groomed or moved and there isn't a medical reason, your pooch is probably being controlling. Dogs who nip or snap when being handled are trying to convey their displeasure with the situation and get you, the groomer or the vet to stop doing whatever it is they're doing. Control-based aggression is best handled (no pun intended) by desensitizing your pooch to touch and rewarding her enthusiastically for non-aggressive behavior.

the nest