Great Dane Becoming Aggressive: Here’s Why + What To Do

When you know your Great Dane’s personality to be an affectionate dog with good behavior, it can be quite surprising when they start becoming aggressive.

Sudden aggression is unusual behavior that can include behavior such as growling, snapping, biting, barking, nipping, or barking at strangers or other animals.

So what are the reasons behind a Great Dane becoming aggressive?

In this article, we will dive into the reasons for sudden Great Dane aggression, what to do about it and when to seek help.

Why Is My Great Dane Becoming Aggressive?

A Great Dane becoming aggressive is mainly due to illness, fear, injury, resource guarding, punishment, redirected aggression, cognitive dysfunction due to aging, hypothyroidism, or a dental problem. Sudden aggression without provocation is not uncommon however it requires determination of the route cause of the behavior to help your dog.

great dane becoming aggressive

Should I be concerned about my Great Dane becoming aggressive?

Sudden aggression from a usually well-behaved Great Dane is concerning because it can be due to an underlying health condition. 

This means that without being treated or attended to the route cause can worsen and lead to deteriorating health and also unwanted behaviors.

Related: Why is my Great Dane Aggressive?

When To Seek Help

The first thing to do with a Great Dane that is becoming aggressive is to minimize further interaction with other people and pets if the aggression is towards these targets. 

If the aggression is towards you, heed your dog’s warning signs and give them space. Do not force interaction with them.

This reduces the risk of bites and escalation of the behavior.

Consulting your veterinarian is the next step in determining the reasons behind a great Dane becoming aggressive.

The sudden aggression can be a symptom of a serious underlying health problem therefore when you experience this from your Great Dane, have them checked by a veterinarian.

Related: Why is my Great Dane acting weird?

The veterinarian will determine whether there is a health condition or a behavioral problem that is responsible for the unwanted behavior.

If a medical condition is present, treatment will be administered which will also stop the aggressive behavior.

If your Great Dane is found to be in good health and illness is not a reason for the aggression, the veterinarian will recommend a behaviorist.

A behaviorist or dog trainer will help to determine your dog’s triggers and provide solutions that you can implement at home to correct the behavior.

Sometimes in severe cases, if the problem cannot be corrected, euthanasia might be an option because aggressive Great Danes can be dangerous to you and other people.

Related: Why is my Great Dane so annoying?


Great Danes are known to be very affectionate dogs that are people-oriented with the desire to be around people and please them. 

It is certainly out of character for a Great Dane that has been properly trained to suddenly become aggressive. 

When this occurs it is important to evaluate the route cause of the sudden aggression and address it.

Consult your veterinarian to determine the exact route cause and for your Great Dane to get the help they require to resolve the problem.

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