6 min read


Why are Dogs Aggressive?



6 min read


Why are Dogs Aggressive?


An aggressive dog is a scary proposition at any time and seeing a wound-up mutt in your path staring you down with nowhere to run is one of the most terrifying experiences to have. 

Why do dogs feel aggressive? They’ve been domesticated since the last ice age and become a model pet for mankind, so what makes a Mastiff or Bichon suddenly turn into a gremlin with attitude. Perhaps our woofers should be forgiven for getting all racked up, as humans can be a complex species not always kind and compassionate ourselves. 

There are many reasons why dogs become aggressive. Read on to find out!


Signs a Dog is Feeling Aggressive

When we think of a snarly face with barred teeth and drool spilling onto to the ground, a big dog might come to mind - but that’s a misconception, as small dogs can be terror bugs with a vicious mindset just as easily.

Breeds like Pit Bulls are hung out to dry as dogs that will bite you given half the chance, while a Chihuahua hanging off your pants is told not to be naughty as it snaps at your every word.

There’s no doubt humans play their part in the temperament of a dog and if they are treating their pet Bulldog or Doberman with disrespect, they should hardly be surprised if the pooch suddenly turns on their owner. The sad part is the dog is then shipped off to a shelter with an aggressive tag stamped firmly on their collar.

Fear aggression is common in un-socialized dogs who are anxious about everything in their environment, or in mistreated mutts who have been trained with punishment style techniques. All the love in the world can be met with a determined stance when a dog is in total shutdown, looking to make mincemeat of the person trying to help. This dog may have seen the harsh side of human nature and it’s important to understand the body language so you can determine if their aggression is fear or dominance based

A dog that is afraid will appear to cower, with ears pinned back and showing the whites of their eyes. They will growl and bark at you with the message “I’m really scared but I won’t let you hurt me”

A dominant dog wears their body language like a badge with lips curled, twitchy nose, and an overly confident body posture that is visually threatening. Guard dogs can exhibit this style of aggression when defending their property. At first, they will growl and bark at a trespasser and if provoked, they could attack. 

Some woofers who have been spoilt rotten with no boundaries set can be aggressive to members of the family, including children. The hyper-attached mutt guards a favorite pet-mom or dad with a vengeance not allowing anyone to get close. They will snap at the intruding offender with contempt. Friends will stop popping over for coffee, knowing this dog is unsociable.

Some possessive pooches guard their food bowl like a bouncer on a nightclub door. They will have a go at any other dog in the home that tries to play with one of their toys or looks hungrily in their direction. Food aggression is a link back to their wolfy ancestry where guarding resources was part of survival.

Do you have a pooch that takes every opportunity to run the fence-line, chase the postman, or hurl themselves at cyclists and joggers? This is another flashback to the days when dogs were wolves hunting prey. Perhaps your persistent Pug thought a Bison or Elk ran by!

Body Language

Signs a dog is feeling aggressive are:<br/>

  • Barking
  • Guarding
  • Back Hair On Edge
  • Snapping
  • Tail Tucking
  • Ears Back

Other Signs

More signs a dog is aggressive include:<br/>

  • Biting
  • Growling
  • Bared Teeth
  • Attacking Family Members
  • Chasing People Or Other Animals
  • Aggressive Body Language

History of Dogs Being Aggressive


The ongoing debate about dangerous dog breeds has seen a ban on Pit-Bulls in some U.S states - ironic when you think they were once the poster dog for recruitment in the Second World War and some were even highly decorated.

Fight 4 Them tells the heroic tale of Sergeant Stubby who served his country in World War One and was awarded the purple heart for his many counts of bravery. This patriotic Pit Bull went through 17 battles where he captured a German spy (all on his own), alerted his soldier buddies to gas and enemy attacks and when injured, kept the troops in high spirits. Stubby was an all American Pit Bull with a huge heart and gutsy mindset.

American Pit Bulls, American Staffordshire Terriers, and Staffordshire Bull Terriers are all from the same lineage and are English/Irish imports. Here we were all thinking the ancient Romans were the instigators of animal atrocities in the Coliseum when in merry old England, the horrendous sport of bear and bull baiting was a popular amusement for royals up until the 19th century. These poor beasts were tied up so a pack of Pit Bulls could do their worst in the name of human entertainment. Pit Bulls were bred for this blood-thirsty sport and today are still used for illegal dogfighting.

Its increasingly clear the Pit-bull has fallen victim to the outlaws of society who use them to feed an over-sized ego and make money out of dogfights. The RSPCA would like the “Dangerous Dog Act” to be amended so dogs are banned according to their behavior and not their breed,

Pit-bulls are not the only breed with a bad-rep by association. Take the Doberman, whose photoshoots alongside Adolf Hitler gave them the “demon-dog tag”  while Rottweilers were once bred to herd cattle and pull butcher carts but today are considered a risky venture as a family pet.

The Science of Aggression in Dogs


Our wonderful dogs are related to the wolf, who engages in aggressive behavior to protect the pack or bring home the bacon. Seems hard to believe that a wolf would have anything to do with humans, but the story goes that between 14,000 and 30,000 years ago, a coalition was formed which got early man all fired up at the possibility of creating their own super-dog race.

Different breeds were put together to create a dog that was physically designed to perform a task. Careful attention was paid to the physiology of pooches so their body shape enabled them to herd like a Collie or run like a Whippet, popular with poachers wanting rabbits.

Mankind also bred dogs like Pit Bulls to be more aggressive than others and stylized their body shapes to fit with their behavior. Their ability to fight a bear is inherited and has been bred constantly to achieve this anti-social status. The question is, could their aggression be bred out over time?

A Russian researcher says yes, it could be possible, as they managed to breed fear out of foxes over eighteen generations. The foxes were bred under strict control to avoid any of the undesired genes returning. As the breeding program advanced, the foxes' physical appearance also changed, taking on the floppy ears of a pooch. If we were to breed out the aggressive genes of a Pit Bull, it is likely their physical look would be different.

Wide Open Pets brings to light a study carried out at Nationwide Children’s Hospital where they found 12 genes connected to aggression in dogs. Researchers discovered the kind of aggression aimed at familiar people and dogs, is genetically removed from the aggression a dog might show to a stranger and unknown dog.

Tips for Aggressive Behaviour


If your normally-friendly dog suddenly becomes aggressive, they could be in pain, so seek the advice of your vet. Pooches that have been abused are also candidates for aggressive behavior, and understandably so. They are possibly emulating their owner’s harsh treatment by responding with a mirrored view.   

Help is at hand for dogs who are behaving badly with positive ideas from dog trainer, Victoria Stilwell, who believes you have to get to the heart of what is troubling your dog and it can take time to alter this kind of behavior.

Using punishment methods to curb aggression is like putting water on hot oil. The dog might appear to have toned down its snarling and snapping but sooner or later suppressed emotions could explode, seeing the dog headed for the shelter.

If your pooch has a tendency to snap at visitors, a classic baby gate is an effective way to keep people safe. The same pup may growl at other dogs when you are out on a walk making the local dog park a “no-go” zone!

When you go for a stroll, try not to pull on the leash as another pooch approaches. Dogs are tuned into our emotions and will instantly think there is something to be concerned about when their pet-mom or dad tightens the leash. It could send them into protection overdrive and leave you feeling embarrassed by the scowl on the other dog owner's face. Your manic mutt is reactive and needs training to change their view.

If you're totally stressed out by now, grab some treats and take your dog for a walk. The next time you’re Labradoodle gets ready to lunge at a dog on the path, say “Zena look!” If she responds, give her praise and a treat, as the other dog passes by.

Victoria Stilwell recommends calmly turning your dog away from another pooch coming your way. It's possibly fear that makes your mutt act in such a challenging way, so moving away quietly can take the fear with it.

If your dog is aggressive, you might need to muzzle them on walks and contact a renowned trainer who can help you determine the reason and offer tips to change their behavior.

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Safety Tips for Aggressive Dogs:

  1. Muzzle your pooch in public.
  2. Contact a dog trainer.
  3. Have a baby gate installed so visitors to the home feel safe.
  4. Ask the vet advice.
  5. Share your story so other dog owners can learn more about their dog's aggressivity.
  6. Read informative articles about training an aggressive dog.

By a Japanese Chin lover Linda Cole

Published: 04/24/2018, edited: 04/06/2020

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