Why Do Dogs Bite?

The report of a 10 year old boy being killed by a dog while on holiday in Cornwall is horrifying and shocking.  While little is known of the circumstances of this attack, it may be useful to reflect on why dogs might bite in the first place.

Predation behaviour

Border Collie stalkingGroups at risk of predation behaviour from dogs include:

  • babies or young children
  • small dogs
  • cats
  • other small furry creatures

Predatory behaviour often has few warning signs but may be preceeded by intent watching and stalking of the victim.  It is usually caused by poor socialisation at a young age and may be triggered by exciting movements of the ‘prey’.

While predatory behaviour has been greatly reduced in some breeds, dogs as a species are predators so it is sensible to take precautions and never leave young children or small pets alone with a dog.


Black puppy biting handPlay biting is normal behaviour in puppies and is important for them to learn bite-inhibition, where the force of their bite is reduced.  Punishment of play biting is usually ineffective as the attention given increases the dog’s arousal.  It is important not to encourage the sort of play that encourages your dog to bite, and stop play as soon as the mouth becomes involved.  Making sure that your dog is on a good-quality diet that is not too high in energy, and ensuring they have plenty of exercise and stimulation will help to reduce your dog’s arousal.


dog lying down with toyDogs can act aggressively in defending resources such as food, chews, toys, resting places, attention or puppies.  This is an area where children often come into conflict with dogs and can lead to bites.  This is not caused by ‘dominance’ – that theory has been completely debunked – rather, it is the dog’s way of saying “back off, this is mine”.

To prevent resource guarding it is important to train your dog that good things happen when someone comes near their food bowl, or touch their toys.

It is also important to teach children to stay away from dogs when they are eating, or resting.

Dogs guarding resources will normally give plenty of warning signs before they progress to biting – e.g. ears back, growling.  However if these warning signs have been ignored in the past, or punished, the dog may resort to biting much earlier.

Anxiety-related aggression

German Shepherd lying down looking anxiousThese bites occur when a dog is in a stressed state and feels that there is no other option.  Dogs are more anxious when they are in pain, and if they anticipate that an encounter is going to be painful, they may resort to biting.

Dogs who are stressed will usually be giving plenty of warning signs, but these may be very subtle and missed.  The more these early signs are ignored, the more the dog will resort to more drastic measures to prevent what they perceive as a threat.  This is known as ‘The Ladder of Aggression’.
Ladder of aggression

How to prevent dog bites

  • Be aware of potentially risky situations and avoid them where possible, or put measures in place to stop the dog being able to bite the at-risk person (e.g. put in a separate area, muzzle the dog)
  • Teach children to interact with dogs in a safe way.  The Blue Dog Project has some great resources.
  • Be aware of the warning signs and never punish your dog for warning you that they are getting stressed.
  • Never leave children unsupervised with a dog.

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