Resource Guarding in Dogs

Some dogs display excessive anxious and aggressive behaviors to protect possessions. How much of these behaviors can be considered normal? Resource guarding can describe behaviors ranging from normal and fairly benign to pathological and risky to others. It is normal for an animal to attempt to keep a valued possession. In a situation perceived as threatening, some dogs will try to run and hide with the object, hold it tightly in their mouth, or offer submissive gestures to appease humans or other dogs. Most owners will recognize these behaviors as what they are: efforts to keep the possession. Owners may only consider the situation problematic if the dog is swallowing or hiding potentially harmful items or is excessively aggressive.

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As with other behavior evaluations, two major questions should be answered first:

1. Is this normal behavior?
2. How much of a risk does this pose to other pets, people, or the patient?

A certain amount of resource guarding is normal. Individual cases may require a thorough history to help delineate normal from abnormal resource guarding.

A dog that occasionally guards an extremely special item is behaving normally. Such high-value items might be given as a treat, stolen or found (eg, bones from garbage), or seemingly inconsequential (eg, used napkin). Similarly, a dog in a high-pressure situation guarding something it would not usually may also be behaving normally. These dogs typically calm down quickly following the situation’s resolution.

Some dogs may exhibit disturbing signs of resource guarding (eg, frequent biting or lunging toward and pursuing a target that approaches or touches a particular item) and may need time to calm down after an incident; in some cases, interaction can be risky for several minutes to hours afterward.

Dogs that are anxious when they have high-value items and others are nearby often have additional anxiety-based behavior problems resulting in aggression (eg, conflict based, fear based, stranger induced).

Some dogs fall into the middle of this spectrum. They may try to bite but will warn by growling, snarling, or snapping. They are less likely to exhibit other forms of anxiety-based aggression than are the more extreme resource guarders.

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There seems to be an innate tendency for some dogs to be more possessive than others. All behavior is the result of a combination of genetics and environment.

If coupled with insecurity related to resources, the tendency could blossom into resource guarding. Insecurity may arise from neglect or abuse. For example, starvation or competition with other dogs for truly limited essential resources while maturing or for extended periods in adulthood could teach a dog to guard food. However, it is incorrect to attribute all resource guarding to a history of deprivation; the problem is also seen in dogs with no history of starvation, abuse, or neglect.

Many dogs with excessive resource guarding have a history of owner-exacerbated aggression. This can include seemingly benign attempts to establish leadership with a puppy by taking away the bowl while the puppy eats and then returning it. For many puppies, this may be a bewildering act, but it will not lead to anxiety and aggression. However, puppies with a genetic predisposition toward anxiety or aggression may respond by growling.

Owners may escalate aggression by repeatedly returning and taking away food or using so-called dominance gestures (eg, scruff shaking, alpha-rolling, holding the puppy’s mouth closed) to teach the puppy not to growl. This human behavior has the opposite intended effect and teaches the puppy to be more protective of valued resources.

If punishment teaches a dog to guard resources, what do we tell owners to do?

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Conditions that can cause or worsen resource guarding include anything that can trigger pain (eg, osteoarthritis) or polyphagia (eg, diabetes, hyperadrenocorticism). Asking clients what they are giving their dog, not just checking the prescription record, is important, as some drugs can cause polyphagia. For dogs with a history of food guarding, veterinarians should avoid treatment with steroids or other drugs that can cause polyphagia.

Avoidance is typically the first step. Dogs that only guard specific items should not be provided those items or should be alone when the items are given. For example, a dog that guards its food can be fed outdoors and only given highly valued treats when it is secured in a crate or kennel. For many dogs with resource guarding issues, this alone is sufficient.

In some cases, owners may be told to embrace the growl. A dog that does not guard resources or growl is usually preferred, but if the problem exists, a growl is better than a bite. Growls are warnings to stay away and change the situation. The dog should not be praised for growling, nor should it be scolded or otherwise punished.

Although the preferred method is to trade the guarded object for a more valued treat, high-level distraction (eg, ringing a doorbell or offering to go for a walk) that causes the dog to abandon the guarded item should also be considered. With this method, follow-through is important to avoid issues with trust. If the dog abandons the guarded resource when a walk is offered, it is important to follow through and take the dog for a walk, even a short one. Otherwise, the dog will learn to ignore these offers.

Desensitization and counterconditioning can help reduce a dog’s tendency to guard an item. These basic procedures can also be used with puppies and newly adopted dogs (without a history of resource guarding) to reduce the likelihood of problems.

With puppies and nonaggressive dogs, it is important that the resource is not simply taken away and the dog expected to accept the behavior; the dog should be rewarded for allowing the resource to be removed. For example, the owner should pick up a food bowl, put a treat in it, and return it to the dog. If the dog seems uneasy, the owner should instead approach the bowl and drop a treat inside so that the dog associates the action with a treat. Teaching a reliable release–drop command is also a beneficial way to start the process with a puppy or newly adopted dog.

For clients who want to proceed beyond avoidance, a full behavior consultation is recommended. Some dogs may have underlying behavior problems and may show aggression in other situations.

In these cases, the human–animal bond may be less than ideal because of misguided attempts to break the dog of its behavior problems. A comprehensive behavior modification plan may begin with relationship-building. The behavior modification involved in lessening these dogs’ resource guarding, especially for intense cases, can be involved and require a working knowledge of canine behavior and behavior modification.

Some shelters have initiated programs to address resource guarding in dogs that are up for adoption. Although to date there is not much evidence regarding the success of these programs, they do show promise.¹

Like urine marking, mounting, and coprophagia, resource guarding can be considered within the range of normal canine behavior in some cases. But like other normal behaviors, it can become a significant problem that results in a dangerous situation and considerable stress.

 Case in Point 1

Misty, a 12-year-old female cocker spaniel, had one mild episode of resource guarding 9 years ago.

History After her owners placed a steak bone in her crate, Misty began to crack the bone and growled when her owners attempted to retrieve it. The owners were able to lure Misty from the crate with a piece of steak and remove the bone. After the bone was out of sight, Misty’s behavior returned to normal.

Treatment: Avoidance Misty was never given another steak bone, and no episodes of resource guarding were noted afterward.

Assessment Misty gave an appropriate warning when she was threatened with losing a high-value item. But she was easy to lure from the crate and abandoned the bone when a more valued possession was offered. Her behavior returned to normal immediately following the bone’s removal.

Diagnosis: Mild Resource Guarding

Case in Point 2

Mikey, an 8-year-old castrated shih tzu, had a 1-month history of food guarding.

History Mikey lived with another shih tzu (approximately the same age) and an elderly owner. Mikey had no prior history of aggression.

According to medical records from the referring veterinarian, a recent physical examination found no abnormalities, and CBC and serum biochemistry profile findings were within reference ranges. History included mild seborrhea and pruritus controlled for 4 months with prednisone at 5 mg PO. The drug had been prescribed for a recently deceased dog; the owner began treating Mikey at the recommendation of her groomer.

Mikey had bitten the owner when she tried to stop him from attacking the other dog during feeding times. The owner was managing the situation by separating the dogs at feeding times.

Treatment: Taper Medication The owner was advised to continue separating the dogs at feeding times and to contact the primary veterinarian for instructions for tapering the prednisone dose.

Assessment The owner was advised to bring both pets’ medications to her primary veterinarian for review. After prednisone was discontinued, Mikey’s resource guarding stopped.

Diagnosis: Iatrogenic Resource Guarding

LAURIE BERGMAN, VMD, DACVB, owns Keystone Veterinary Behavior Services, a behavior house-call practice in Villanova, Pennsylvania, and is an active lecturer and consultant on small animal and wildlife behavior. Dr. Bergman completed a behavior residency at University of California, Davis, and an internship in wildlife medicine at Tufts University. She has been involved in wildlife practice on Cape Cod and consulted with local zoos and animal shelters in San Diego.