Most often a dog's aggression is motivated by fear, anxiety, conflict about what to expect and what to do and the anticipation of possible punishment (see Aggression – Diagnosis and Overview, (Dominance, Alpha, and Pack Leadership – What Does It Really Mean?, and Canine Communication – Interpreting Dog Language).
Growls, barks, snarls, snaps or lunges at people on walks. Shows aggression toward visitors to your home. Shows aggressive behaviors in your back yard, including aggression toward children or adults on the other side of the fence or the meter reader. Has killed one or more cats.
As a dog ages, it's common to have some health concerns. Something like dental pain, arthritis, or vision and hearing loss can trigger aggression in a senior dog. If a dog is experiencing dementia or confusion, these can also trigger aggression.
Territorial behavior usually appears as puppies mature into adolescence or adulthood, at one to three years of age. Dogs may show aggressive behavior when they think that one of their family members or friends is in peril. Dogs are a social species.
Dogs will give a warning growl in situations involving things like resource guarding, stranger danger, feeling cornered, or feeling stressed.
Don't push your dog over his tolerance threshold. Whatever you're doing, just stop. If your dog's growl threshold is near his bite threshold – that is, if there's not much time between his growl and his bite, get safe. If his growl doesn't mean a bite is imminent, stop what you're doing but stay where you are.
First, it's important to realize that the sudden onset of aggressive behavior may not be a sign of a significant personality change. Instead, it usually indicates a developmental stage of a dog's life. Every day, your dog learns new things and responds to new stimuli.
Puberty's Effect on Dog Behavior
Once dogs reach puberty and start getting larger and more mature, they learn they can use aggression to control their environment and therefore feel safer. Using aggression to keep scary things away (e.g., unfamiliar dogs and humans), makes dogs feel less afraid.
The behavior associated with Rage Syndrome includes outbursts of aggression that are intense and at times unpredictable. These episodes also tend to be large dramatic responses relative to a seemingly benign situation. Affected dogs often freeze, stare, and may rapidly escalate to biting.
But as dogs age, they can become more aggressive. This is often due to a decline in cognitive function and can be a difficult phase for both the dog and his owner. There are ways to help manage an ageing dog's aggression, but it is important to understand the root of the problem and take steps to address it.
Behavioral euthanasia is humanely ending a dog's life because of severe behavioral issues, such as aggression or extreme anxiety. Humane euthanasia is done by a veterinarian. Dogs who are put down due to behavior problems are often young and healthy, which makes this outcome so difficult for many to understand.
Aggression
Older dogs may become more aggressive due to a variety of factors, including pain, fear, and frustration. Pain can cause a previously gentle dog to lash out when touched or handled. They could be experiencing pain from a number of things.
If your dog is showing any changes in their behaviour, especially if they have started showing aggression suddenly, you should contact your vet as soon as possible. Aggression tends to get worse over time and can lead to serious injuries to you, your dog or other people and pets so getting help is essential.
Instead of screaming, or yelling at the dog, speak to him in a soothing tone as you slowly back away. Don't make direct eye contact. Staring in the eyes of an aggressive dog may prompt him to attack. If the dog gets too close or lunges at you, place a jacket, handbag or backpack, etc., between you and the dog.
An aggressive dog poses a danger to us and other humans. It tells us the dog is unhappy. Even in a mild form or in a small dog, aggression typically signals the dog is tense and not enjoying his life at that moment – or, sometimes, not at all.
Can a Dog That Bites Ever Be Trusted Again? With enough patience and care, many dogs can learn how to manage their stress levels more effectively. As you build better communication skills with your dog, you'll also start to rebuild your trust with them.
Health issues that can change your dog's behavior include arthritis, hip dysplasia, luxating patellas, sore teeth, thyroid problems, epilepsy/seizures, ear infections, digestive issues, skin or environmental allergies, yeast infections, hearing loss, eyesight loss, and cancer.
Fear- and anxiety-related aggression are commonly manifested in the veterinary hospital or in situations of social approach and handling. Dogs that display aggression are not mean or bad dogs. They are simply afraid/fearful and anxious/nervous about a perceived or anticipated threat or unpleasant outcome.
A few widespread types of anti-anxiety medications used for treating dog aggression include Anafranil, Clomicalm, and Buspirone. For dogs with less extreme cases of anxiety, Buspirone is generally the go-to medication.
For this reason, I advise all my clients and students that it is NEVER wise to punish a dog for growling, even by saying “No.” Dogs that are repeatedly punished for growling eventually may not give a warning and immediately escalate to biting.
Growling is a very normal behavior for dogs. It simply shows that something is too much for them or that they feel distressed. Still, you shouldn't take it lightly, but think about how you can avoid it next time. If your dog growls at you, be sure to stay calm and never scold him.
Best case scenario if you growl at your dog — you'll get his attention because you've made a novel noise. Worst case scenario – you'll get bitten in the face. I used another example to illustrate the fact that growling at your dog is not only silly, but dangerous advice.
Growling is an emotional response. It is not a "disobedient" behavior. You cannot punish an emotion out of a dog (or a human). Growling is just your dog's way of trying to tell you something important, and you should listen and genuinely thank your dog for the honest feedback.