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Many dogs attack people or other dogs, but what triggers the attacks in the first place?

 Whether the attack is directed towards a human, or other dog, often, dog attacks are often poorly understood, but dogs always attack for a reason. 

These underlying reasons for dog attacks may be difficult at times to comprehend by those not familiar with the way dogs behave and communicate with humans and other dogs.

 While the causes of why dogs attack may be several, we can list a few common reasons. Following are several reasons why dogs attack. 

Underlying Medical Issues

Medical problems can sometimes lower a dog's threshold for reactivity which leads to an increased chance for attacking.

 A painful ear infection may cause a dog to lash out when he's pet over the head. A dog with hearing or vision problems may startle if you approach him unexpectedly.

 Older dogs with mobility problems may no longer be able to remove themselves from an overwhelming situation which may lead to them choosing to react instead of moving away.

Dogs with low thyroid levels suffering from hypothyroidism may develop behavior changes and an increase in aggressive behavior is not unusual.

 According to Nicholas Dodman, a board-certified veterinary behaviorist, even borderline-low thyroid levels are thought to trigger mood alterations that may exacerbate anxiety-based behaviors, including aggression.

 When dogs attack out of the blue, it's therefore important to consider whether a medical problem may be the culprit.

Lack of Socialization

For a good reason dog trainers and behavior consultants tend to emphasize the importance of socializing puppies with people of all ages, other dogs and animals.

 According to the American Veterinary Society of Animal Behavior, incomplete or improper socialization during the puppy's first three month of life may lead to significant behavioral problems later in life such as fear, avoidance, and/or aggression.

History of Punishment

When people use punishment to try to solve behavior problems, they often end up raising the bar for defensive behaviors in dogs which may lead to biting.

 One of the biggest mistakes is punishing a dog for growling. Once you take away the dog's warning system, you'll end up with a dog who bites without warning. 

On top of that, consider that when punishment is applied, it tends to suppress most behavior without addressing the underlying problem, that is, the fear or anxiety, explains board-certified veterinary behaviorist Andrew Luescher. 

Punishment is completely inappropriate for most types of aggression and any behaviors involving anxiety, he claims. Which brings us to the next section.

Fear-Based Reaction 

Fear may trigger lunging and biting behaviors

Fear may trigger lunging and biting behaviors in dogs.

A great majority of dogs attack out of fear, claimed the late veterinary behaviorist Dr. Sophia Yin in her blog on Cattle Dog Publishing. 

The fear may occur because of a genetic predisposition, lack of socialization, negative experiences or a combination of some or all of these. 

A dog may lash out because he is not comfortable being pet, is cornered or feels threatened by somebody perceived as intimidating. 

One common cause of fear towards other dogs is a traumatic experience that dates back to early life. A dog who has had a negative experience with a dog may generalize such fear to other dogs that appear similar to the dog generating the fear in the first place.

Guarding Resources

A predisposition to guard resources is linked to survival and can still be seen in the domesticated dog. 

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Resources that are protected can be anything the dog perceives as valuable such as food, toys, bones, sleeping places and sometimes even other dogs and people.

 Territorial behavior, can also be somewhat relative to protecting resources as dogs are sending people, other dogs or animals away from perceived territory, but territoriality may often stem from fear.

A mother with puppies is sometimes guarding her litter, but in this case the behavior is triggered by hormones. According the Merck Veterinary Manual, maternal aggression should resolve once mother dog's hormonal state returns to normal. 

This type of aggression can sometimes be seen in intact female dogs when going through a false pregnancy, also known as phantom pregnancy. 

In this case though, instead of guarding puppies, the dog may act protective of toys that may be perceived as puppies.

High Arousal and Frustration

When a dog gets overly aroused, it's easy for the excessive arousal to spill into aggression. 

A typical cliché' are two dogs who are highly excited to greet the owner and then end up fighting or two barking dogs who are anxious or frustrated by people and dogs passing by a fence who end up fighting. 

Another scenario are two dogs who are fighting and highly aroused, then, when the owner gets in between to separate them, he or she risks becoming the victim of a re-directed bite. Read more on this phenomenon here: Discovering redirected aggression in dogs. 

People who place their hands in between fighting dogs are almost guaranteed to get bitten, warns Dr. Jeff Nichol veterinarian and member of the American Veterinary Society of Animal Behavior.

Yawning can be a sign of stress.

Yawning can be a sign of stress.

Our Failure to Read Dogs

Often, dogs attack because we fail to read them. Dogs are naturally prone to give signals when they are getting uncomfortable in a certain situation.

 A lip lick, a yawn, turning the head, showing the whites of the eyes are just a few of the many stress signals dogs give. 

A child cannot read these signals. The child therefore may be hugging a dog and fail to read the dog's body language which is saying to be left alone. After several attempts for the dog to communicate, the dog may decide to leave or to bite.

Unfortunately, parents also miss important warning signals such as a dog's attempts to escape, stressed body language, and growling . 

Those parents though who heed such warning signals have higher chances of keeping their kids safe, suggests board-certified veterinary behaviorist Lisa Radosta.

 This is why a parent should teach a child how to properly interact with the dog and must intervene at the earliest signs of trouble.

Now That You Know...

As seen,  dogs attack for several reasons. Dogs who are often blamed for attacking for no reason are often misunderstood. This doesn't necessarily mean that these dogs don't pose a danger to people or other dogs, but it means that often dogs may be put into situations that could have been prevented if only they were better understood.

How to Prevent Dogs From Attacking 

If your dog attacks, it's important to play it safe and prevent putting your dog into situations that evoke the attacking behavior. 

This can be accomplished through management strategies such as walking the dog on leash at a distance from other dogs if he attacks other dogs, not giving toys or bones if a dog attacks when in possession of such resources or not putting dogs in too overwhelming situations that may cause excessive arousal to spill into aggression.

 Consulting with a dog behavior professional at the first signs of trouble, is important, so the dog's triggers can be identified and, if feasible, behavior modification can be applied as needed.

Did you know? Veterinary behaviorist Ilana Reisner in an article on Psychology Today explains how dogs can sometimes quickly change their minds in regards to their interactions with people or with other dogs. 

For example, some dogs may do fine accepting a visitor who is sitting on the couch, but might jump and bite the moment the visitor is standing.

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