Exploring the sources of aggression in canines, and looking at ways to effectively manage your pet.



Aggression is a significant issue and while the types of aggression may vary, the underlying root causes of aggression are usually consistent: insecurity, fear and anxiety.

A dog can show aggression by growling, lunging or baring teeth. If your dog shows these tendencies it can be frustrating to manage.

One of the most important steps in dealing with dog aggression is to find the cause of the aggression. This will help you to figure out the best plan to stop this behaviour.


Some illnesses can cause a dog to become aggressive. If a dog has never shown signs of aggression before and suddenly starts growling, snapping or biting, it may be caused by disease or illness.

Pain is a common cause of aggression. Brain tumours and thyroid disease can also cause aggression. You should speak to your vet to determine whether a health issue may be the cause of your dog’s aggression.


At the centre of dog aggression is the dog’s need to increase distance from a perceived danger. This can include growling or lip curling. Usually the dog only shows aggression when they feel in danger and needs to defend themselves.

A fearful dog usually only bites when he feels he/she is unable to escape some impending harm and defend him/herself. When a dog feels threatened by something, the first safest option is to run away from the threat; this is called the flight response, if the dog can’t get away from the threat, the only alternatives are to either submit in the hope the threat goes away, or fight (the fight response). The most common cause of fear aggression is inadequate socialisation as a puppy.

A dog with fear aggression will often adopt body postures that signal fear, while retreating, such as cowering, lip licking and baring teeth. If the dog is cornered and has nowhere to run it might growl, lunge, snap or bite in an attempt to dispel the threat. Dogs with fear aggression might retreat as someone approaches but then nip them as they turn to walk away.



These are a series of actions and behaviours your dog can practice any time they are in the situation that makes them feel uncomfortable. For example, if the dog fears new people coming to the front door, have a ritual you can follow every time somebody comes to the door.

  • Put the dog on their lead and take them outside to see the people at the door
  • Have the person at the door stand with a bag of treats or the dog’s favourite toys
  • Go for a walk down the street (at no time should the guest try to engage with the dog)
  • Come back inside the house and get your dog to sit or down as the guest comes in
  • Get your guest to take the treat or toy out of the bag and place on the floor at a safe distance (dog is still on a lead)
  • Let your dog get the treat
    Then leave the dog in a safe quiet place eg. crate or separate room
  • Practice this with friends and neighbours who are happy to help until your dog feels comfortable with the doorbell ringing and people coming in
  • Once the dog no longer feels fearful, you can cut out the walk down the road and let your guest in still with the bag of treats. making the greeting less time consuming
  • Always tell your guests to give the dog space and limited attention

You can make up any ritual as long as its something your dog enjoys. The secret to success with this one is to keep your dog thinking and working, which keeps them under their stress threshold.

Though fear aggression is a serious issue which can take a considerable amount of time and effort to address, it is possible to manage. Be sure to avoid all punishment-based training and instead help your dog become more confident and secure using the power of positive training.


Resource guarding is when a dog controls access to food, beds, sofas, things that are important to him/her through defensive body or aggressive body language. It is a relatively common canine behaviour and is influenced by a number of environmental and situational stimuli, including a dog’s natural instinct to survive.

Guarding resources is usually from a deep rooted insecurity and inability to cope well in social situations, even with people or dogs they know.


  • Begin by changing the physical picture and provide a new bowl in a different location
  • Vary feeding times so that your dog never has the chance to become tense when his body clock tells him/her it’s time to eat
  • Use the empty bowl method. Pick up the bowl and make it look like you are filling it
  • Place an empty food bowl on the ground in front of the dog. Wait for the dog to investigate, see there is nothing to eat and wait for him/her to look at you. As soon as the dog looks at you, praise him/her and add a bit of food to the bowl
  • After your dog has finished the food wait for him/her to look at you again; praise the dog and add more food to the bowl
  • Repeat this until all the food is eaten. Walk away from the bowl and then back and add some more food. This shows your dog that your approach and presence at his food bowl is a positive part of his feeding experience
  • Feed your dog like this for a week; as your dog becomes more relaxed, gradually add larger handfuls of food until you get to the point you can put a full meal down and your dog stays relaxed with you standing next to it
  • The next stage is to practise walking past the empty bowl and throwing in a tasty treat to reinforce to your dog that you are a positive
  • The last stage is to throw a tasty treat into his bowl as he/she is in the process of eating. By this time, your dog should be much more relaxed with your presence and be able to accept you being close as they eat

You should not punish your dog for resource guarding, as confrontation increases the competition and causes the dog to guard the contested resource even more.

For further information or help, you can contact Nicola Edwards at our South Shields surgery on 0191 456 4209.


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