When a dog chooses to guard an item in his possession, by using his body language and perhaps his teeth to keep others at bay, he is resource guarding, a type of aggression with potentially dangerous consequences.

Most resource-guarding dogs will guard food or treats; some will guard empty food bowls or locations where food is frequently offered; a few will guard their people; and occasionally, a dog will guard random objects.

It is imperative that dog owners get help from a canine behaviour counsellor qualified to handle aggression-when-guarding behaviour is present, due to the possibility of the dog biting someone. Although it is a treatable behaviour, it should not be attempted without the supervision of a professional.

Like all behavioural problems, it is important to treat the real issue rather than the symptoms. A dog that freezes over a rawhide, stops chewing when you approach, gives a hard-eye stare, tries to move the item out of your reach, growls, lunges or snaps is clearly telling you that he doesn’t want you near his object, and these are all symptoms of the underlying cause – resource guarding.

A dangerous way to deal with this problem is to attempt to correct or punish the symptoms when they appear. This may seem like the most logical route to the dog owner: If the dog growls or snarls, punish the dog and take the item away. But this is actually the worst possible course of action.

Dogs that have been punished when behaving in this manner will often suppress some of the outward signs of resource guarding, but it doesn’t solve the problem. In fact, it makes the dog more unpredictable, as he learns to skip the eye stare or the growling because he’s been punished for those things, and instead goes from zero to bite, making him much more dangerous.

From the dog’s perspective, resource guarding is a clear way of defining to other family members that they are to leave his items alone – perfectly natural among a family of dogs, but clearly undesirable behaviour when living with humans. The dog resents anyone coming near him or his item for fear of losing it, and when we go in and take the item away, we justify the dog’s concerns. Over time, the dog learns to get better prepared for a fight when we approach.

Solving this problem consists of various exercises that teach the dog there is no need to guard his resources, or fear the approach or hands of a person. This is done by gradually desensitising the dog to the presence of people when he is given high-value items.

We commonly teach the dog that the presence of people equal more or even better items offered than the item he already has, and that people are happy to trade up or just offer higher-value items when they approach. This directly addresses the cause of the guarding behaviour – the anxiety, suspicion and offensive stance the dog takes – and seeks to change it to stress-free, welcoming, even encouraging people contact due to the higher rewards.

Although this behaviour occurs with many types of dogs in a variety of circumstances, it is more common in dogs that have a prior history of having to compete for resources – food, space or even attention: the starving dog that has been rescued, the weaker puppy of the litter competing for an insufficient milk supply, the puppy-mill dog born and raised in an over-crowded environment, the shelter dog competing for attention or food with his kennel mates.

Once a dog with this history gets into an environment where resources are plentiful, one would think that any resource guarding would naturally go away. But this is not the case; these dogs need careful, specific behavioural modification to help them recognise that guarding items is unnecessary. With specialised exercises, and with the aid of a qualified behaviour counsellor, this is a fixable problem. – The Modesto Bee/Tribune News Service/Lisa Moore