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Pet Owner Version

Behavior Problems in Dogs


Gary M. Landsberg

, BSc, DVM, MRCVS, DACVB, DECAWBM, North Toronto Veterinary Behaviour Specialty Clinic

Reviewed/Revised Feb 2018 | Modified Oct 2022

Behavior Problems Associated with Aggression in Dogs

The most common behavior problems in dogs are those associated with aggression. Most cases involve a dog's attempt to distance itself from the situation. There are many types of aggressive behaviors with different motivations, but fear, anxiety, uncertainty (conflict), inheritance (genetics), and previous learning are usually involved. Because of the risk of injury and the risk of worsening aggression, it is important to seek help from a veterinarian as soon as any signs of aggression occur. Early on, owners typically need to avoid situations that trigger the abnormal behavior. After implementing treatment techniques, the problematic situations might be slowly reintroduced under the recommendations of the overseeing veterinarian.

Fear aggression occurs in situations that make a dog afraid. Fear causes most types of aggression. Fearful dogs may try to avoid the triggering threat but can become aggressive when they cannot escape (for example, when they are leashed, cornered, or being held), when they are motivated to stay (for example, proximity to a family member, property, or food), or learn that acting aggressively can remove the threat. Animals that learn that aggression "works" to eliminate threats may act aggressively even when they are not threatened. Poor socialization, temperament (inherited from parents), previous punishment, and learning can also lead to fear aggression.

Food-related aggression is shown around pet food, bones, rawhides, biscuits, or human food in dogs that are not starved or abused.

Idiopathic aggression has no known cause. It is unpredictable and unprovoked. This type of aggression is extremely rare.

Impulse control aggression, also called irritable or conflict aggression, is a threat or attack shown by dogs toward people under any circumstance that involves correction of the dog’s behavior by its owner. Diagnosis of this problem is difficult and cannot be based on a single event. Aggression toward family members is often mistakenly called dominance aggression. However, aggression toward family members is most commonly due to fear, possessive aggression, redirected behavior, or conflict (ie, the dog desires two opposite activities at once). Situations that often provoke aggression from the dog include physical restraint and control of food, toys, or resting places.

Inter-dog aggression is aggression that is directed at other dogs. The target can be another dog in the household or dogs that are encountered away from the home.

Maternal aggression is excessive aggression by a mother dog toward people, other dogs, or her puppies. A small amount of aggression may be normal, especially around the time of weaning. High levels of aggression may harm the puppies. The aggression should resolve after the puppies stop nursing. The behavior can also occur in females with "false pregnancies" and should resolve after hormone levels return to normal. This abnormal behavior may be inherited.

Pain aggression is a defensive reaction that occurs when a dog is in pain. It may happen when a dog anticipates being moved or touched. Organ dysfunction (kidney or liver), neurologic diseases, and hormonal disorders (of the adrenal, sex, or thyroid glands) can also lead to aggression. This is why veterinarians rule out medical causes of aggression.

Play aggression occurs along with play behaviors, such as play bows, chases, and charges. In contrast to previously held beliefs, energetic play by humans with dogs (for example, tug-of-war) does not necessarily produce play aggression.

Possessive aggression is constantly directed toward another individual that approaches or attempts to obtain a nonfood object or toy that the dog possesses.

Predatory aggression is behavior associated with predation (for example, stalking, hunting, and catching small animals). It is usually a quiet, sudden attack, and involves a fierce bite and shake of the prey animal.

Protective aggression is an attempt by a dog to guard its owner from an approach by another person, in the absence of a real threat from the other person. The aggression intensifies as the other person gets closer.

Redirected aggression occurs when a dog is prevented from reaching its intended target. The attack is then directed at another dog or person. The aggression is not accidental and the dog will actively pursue the second dog or person, particularly if they are directly associated with the interruption of the dog’s attack on its first target.

Territorial aggression is the protection of a place, such as a yard or a car, from the approach of another dog or person. It includes actions like chasing, growling, barking, or biting. The territorial dog reacts regardless of whether or not the individual approaching acts in any sort of threatening manner.

Other types of aggression can also occur in dogs. In rare cases, aggression can result from infection, toxicity, or side effects from a medication.


Treatment of aggression in dogs is typically complex and should ideally be designed by a specialist. Avoidance of situations that provoke aggression is always a good idea and can help reduce the risk of bites. Almost without exception, physical punishment, including the use of prong collars and electric shock collars can make an already aggressive dog worse. These techniques are not recommended, especially in the absence of professional supervision.

Behavior Problems Associated with Elimination

Excitement urination is the release of a small amount of urine that occurs when a dog is active and excited, but not afraid.

Incomplete housetraining is consistent elimination in undesirable locations that is not associated with a lack of access or an illness. At 8 to 9 weeks of age dogs start to develop a habit of eliminating in certain places, so early attention to housetraining is important.

Marking behavior is urination or defecation that is used to send a social signal. For example, male dogs often lift a leg to urinate small amounts on fences, trees, or other objects. This can be an attempt to claim the area as their territory or just a way of letting other dogs know they’ve been there recently. Some dogs will mark when they visit new households, usually to "cover up" the odors of other animals. Usually, dogs will partially or fully lift their legs when they mark. It is most common in unneutered males, but females (both spayed and unneutered) and neutered dogs can also mark.

Submissive urination occurs in an otherwise housetrained dog only when the dog is showing postures associated with submission (for example, head lowered, ears back). The dog does not show any signs of fear or aggression.


There are two main aspects of housetraining: 1) encouraging a preference for a specific surface (for example, dirt or grass) or location, and 2) encouraging inhibition of urination or defecation until the appropriate location is accessible. The first age at which a dog is able to voluntarily inhibit elimination is at 8½ weeks of age. Appropriate housetraining for dogs involves exposure to the preferred surface for elimination starting at that age, absence of physical punishment, emphasis on positive reinforcement, frequent trips to the desired area, continuous supervision to avoid indoor accidents, quickly and completely cleaning up any accidents, and startling the dog to interrupt it only when the dog is caught in the act of eliminating in an inappropriate place. Punishment is not helpful and may be counterproductive. Dogs with submissive urination should never be startled. These are already anxious, uncertain dogs, and any punishment will worsen the behavior.

Taking dogs outside 15 to 30 minutes after eating and immediately after play, awakening, or if they slow down, can help speed housetraining. Housetraining an older dog is more a matter of fine-tuning the dog’s behavior and encouraging it to select a more appropriate surface or location. The presence of an older dog may help when housetraining a puppy, because the puppy can follow the lead of the older dog. Prevention is important and owners should know that puppies obtained from pet stores are usually much more difficult to housetrain than those obtained from other sources. Puppies in a pet store are generally not taken out of their cages often and do not have to inhibit elimination. They also may have learned to play with or eat feces.

Dogs with medical conditions can urinate and defecate inappropriately. A veterinarian can rule out any underlying medical conditions.

Other Canine Behavior Problems

Some common behavior problems of dogs are identified below. Many can be treated with behavior modification programs that focus on desensitization and counterconditioning ( see Behavior Modification Techniques Behavior Modification Techniques ). This is very important in the early treatment of fears, phobias, and anxieties. Your veterinarian might also prescribe medication to help your pet.

Abnormal ingestive behavior is eating unusual amounts or types of food or nonfood items. This includes pica (eating nonfood items), eating feces (coprophagia), drinking too much water, scavenging (seeking out food in the garbage or off countertops), anorexia (eating too little), overeating, and gorging (eating too fast). These behaviors can be a component of abnormal behaviors (such as compulsive disorders) or due to normal investigative and exploratory behaviors.

Attention-seeking behavior occurs when the dog acts in a way that gets the attention of people who are doing something not directly involving the dog. An example of this would be a puppy that barks to get attention when it is not being actively played with. The owner then reacts to the dog’s bark by giving it attention; both positive (playing with the dog) and negative (yelling at the dog) attention from the owner reinforces this behavior. This may be an undesirable behavior, but it is common and it is certainly a behavior that people unconsciously reinforce in their pets.

Senility, which is also called cognitive dysfunction, is similar in some ways to Alzheimer’s disease in people. Signs include a decrease in social interaction, loss of housetraining, disorientation (getting lost in familiar surroundings), and changes in sleep patterns. Physical and mental stimulation can slow down the signs of senility. Medication and a special diet are also available for treatment. These can delay the progression of signs, but will not reverse them.

Compulsive disorders are repetitive behaviors that occur out of their normal circumstances, or much more often or for much longer periods than is normal (for example, incessant licking). The dog spends so much time doing the compulsive behavior that it does not have time for normal activities. Stereotypies are repetitive behaviors that have no obvious purpose or function.

False pregnancy is a condition during which a dog acts as though it is pregnant, but is not. The dog may make a nest and may gather small objects that it protects as if they were puppies.

Destructive behaviors include chewing, stealing, getting into the trash, and digging. They are normal exploratory behaviors seen in unsupervised dogs that aren't busy doing desirable activities. Exercise, reward-based training, and social enrichment can help when owners are home. When unsupervised, dogs should be confined away from areas they can destroy and given appropriate toys or chews.

Fear is a normal response to a real or perceived threat. Anxiety is a response to fear or apprehension when an animal anticipates a threat. Fear and anxiety have signs that overlap. Some nonspecific signs, such as avoidance, shaking, and trembling, can be characteristic of both fear and anxiety. Phobia is an exaggerated fear response that is sudden and profound and results in panic.

Hyperactivity is an extremely high level of activity that does not respond to correction, redirection, or restraint. True hyperactivity is rare in dogs and is different from overactivity. Overactive dogs are highly energetic and active, but are able to calm down and respond to human control.

Neophobia(fear of new things) is active avoidance, escape, or anxiety directed at unfamiliar objects and situations.

Noise phobia consists of a sudden and profound response to noise that leads to intense anxiety, panic, or attempts to escape confinement. The most common form is fear of thunderstorms, although fear of fireworks or other loud noises is also common.

Separation anxiety is a syndrome in which a dog panics when it is left alone. It causes intense anxiety and may lead the dog to bark, pace, or eliminate inside the house. Dogs that are confined commonly destroy kennels, walls, or doors in an attempt to reunite with their owners. Signs are often most severe within the first 15 to 30 minutes of the dog being left alone.

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