There are two types of problems in dogs; normal behaviors that are unacceptable to the owner (ie, management issues) and abnormal behaviors (or behavioral pathology). The first type requires advice or resource material on normal behavior and learning principles and might benefit from the guidance of a good trainer. The second type requires behavioral counseling to determine the cause and prognosis, and to implement behavior modification, environmental management, and in some cases drugs or supplements.
The process for diagnosing behavior problems and their treatment with behavior modification and drugs is described in the previous chapter (see Treatment of Behavioral Problems). If the problem is determined to be a management issue, the owners will need counseling on how to effectively provide for the pet's needs and how to reinforce what is desirable while preventing what is undesirable. For most canine management problems, counseling from veterinary staff or trainers and quality resources are required, as well as hands-on guidance from a trainer. Trainers should be selected based on their credentials and screened to ensure that they use reinforcement-based training techniques. Positive punishment-based techniques should not be used in training, because at best they only serve to suppress undesirable behavior and can lead to fear, avoidance, and even aggression. Management issues include inappropriate play (eg, nipping or mouthing of people); unruly behavior (eg, pulling, lunging, jumping up, mounting, overactivity); and some forms of barking, destructive behaviors, and housesoiling.
If the problem is determined to be an abnormal behavior or a management issue that is refractory to training, resolution will require a combination of behavior modification techniques, modifications to the environment to prevent further problems, and the use of behavior management products and medications (see Treatment of Behavioral Problems).
Fears and Phobias
Fear is a normal response to an actual or perceived threatening stimulus or situation. Anxiety is a response to fear and agitation, or apprehension when the animal anticipates a threat or fearful situation. Phobia is an exaggerated fear response (see Phobia). The fear response may include panting and salivation, tucked tail, lowered ears, gazing away, low body posture, piloerection, vocalization, or displacement behaviors such as yawning or lip licking. While avoidance and escape is one strategy, some dogs become aggressive to remove the fear-evoking stimulus.
Some of the more common presentations include: 1) fear of other dogs, especially those that are unfamiliar, appear threatening to the dog, or with which the dog has had an unpleasant experience; 2) fear of unfamiliar people, especially those that are novel or look, act, or smell different than what the dog has been accustomed to (eg, young children); 3) fear of inanimate stimuli such as loud or unfamiliar noises (eg, gunshot, construction work, trucks), visual stimuli (eg, umbrellas, hats, uniforms), environments (eg, backyard, park, boarding kennel), surfaces (eg, grass, tile floors, steps), or a combination of stimuli (eg, vacuum cleaners, car rides); and 4) fear of specific situations such as veterinary clinics or grooming parlors. Some dogs have a more generalized anxiety, in which the fearful reaction is displayed in a wide range of situations to which a “normal” pet would be unlikely to react. While there can be a genetic component to fear and anxiety, insufficient early stimulation and handling, lack of socialization (ie, unfamiliarity), or an unpleasant outcome during previous encounters with the stimulus (or similar stimuli) can also be causative factors.
Phobic responses in dogs are generally associated with loud noises (eg, gunshots, fireworks) or a combination of stimuli such as rain, thunder, lightning, and perhaps even static or pressure changes associated with a thunderstorm. Some fears (eg, veterinary clinics, going outdoors, entering certain rooms, or going across certain types of flooring) may become so intense that they meet the definition of a phobia.
It is estimated that ~14% of dogs have separation anxiety. Anxiety may lead to destructive behavior (particularly at exits or toward owner possessions), distress vocalization, housesoiling, salivation, pacing, restlessness, inability to settle, anorexia, and repetitive or compulsive behaviors. The behaviors are exhibited when the dog is left alone and generally arise within the first 15–30 min after departure. A video recording can be an invaluable diagnostic aid to visualize the behavior and determine if there are other concurrent signs of anxiety (autonomic stimulation, increased motor activity, and increased vigilance and scanning). The diagnosis requires that other common causes of the signs be ruled out (eg, incomplete housetraining, exploratory play and scavenging, external stimuli leading to barking, noise phobia leading to anxiety, or confinement anxiety). There is also an association between separation anxiety and noise and thunderstorm phobias, so any dog exhibiting signs of one condition should be screened for the others. Many pets with separation anxiety will begin to exhibit signs as the owner prepares to depart (eg, putting on shoes, getting keys, going to the front door, brushing teeth). When the owner is home, the dog may crave constant contact or proximity to the owner. When the owner returns, the welcoming responses are commonly exaggerated and the dog is hard to calm down.
Compulsive disorders may be repetitive, stereotypic, locomotory, grooming, ingestive, or hallucinogenic behaviors that occur out of context to the time and situation in which they take place, and occur in a frequency or duration that is excessive. Although it can be debated whether animals can obsess, it appears that they perceive and experience concern; therefore, the term obsessive-compulsive has also been used to describe this disorder. The diagnosis should start with a description and observation of the behavior, including video recordings if necessary. Because there is likely a genetic component for many compulsive disorders, the signalment and age of onset is also important. For example, German Shepherds and Bull Terriers are known to spin or tail chase, while a genetic locus for flank sucking has been identified in Doberman Pinschers. The problem may first arise as a displacement behavior when the dog is frustrated, conflicted, or highly aroused. Lack of predictability in the daily routine, alterations in the environment, unpredictable consequences, lack of sufficient outlets for normal behaviors, and chronic or recurrent anxiety might be initiating factors. At this point, if the owners can teach appropriate acceptable alternative responses (eg, sitting before greeting or play as an alternative to spinning) and provide constructive alternatives (eg, feeding from toys), the problem might be resolved. However, as the frequency or intensity increases, the behavior may become compulsive. The diagnosis is considered to be a compulsive disorder when the behavior interferes with normal function or when it becomes independent of (or emancipated from) the inciting stimulus.
Although most dogs respond to drugs that inhibit serotonin reuptake, alterations in other neurotransmitters may play a role (eg, dopamine, endorphins, N-methyl-D-aspartic acid). Therefore compulsive disorders may actually comprise a number of conditions with different pathogeneses. Medical problems can be present with similar signs. If these cannot be ruled out through history, physical and neurologic examination, and appropriate diagnostic tests, then more specialized testing or a therapeutic response trial for a suspected medical or behavioral cause (eg, with drugs for compulsive disorders) might be indicated (see Clinical Presentation and Medical Differentials for Compulsive Disorders).
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|Clinical Presentation and Medical Differentials for Compulsive Disorders
Compulsive Disorder Signs
Medical Rule Outs
Ingestive: Pica, licking, sucking, swallowing (glugging)
Polyphagia, polyuria, polydipsia
GI, food intolerance
Urogenital/renal, hepatic, endocrine
Endoscopy, food trial, steroid trial, GI protectants
Modified water deprivation test
Dermatologic/self trauma: nail biting, flank sucking, acral lick dermatitis, pyschogenic alopecia
Atopic dermatitis, hypersensitivity, food reaction, parasite, infection, neuropathy, pain
Dermatologic tests (eg, skin scraping, biopsy); therapeutic response
Neurologic: spinning, star gazing, pouncing, fly snapping, shadow chasing
Seizure or complex partial seizures, neuropathy
Neurologic tests (eg, MRI); seizure therapy trial (eg, levetiracetam, potassium bromide, phenobarbital)
Aggression is the most common problem in referral practices across North America, approximating 70% of the caseload. It is also a major human concern, because at least 5 million people are referred to hospital each year in the USA alone for treatment of dog bites. Most forms of aggression, except for predation, are distance-increasing behavior (ie, the dog is attempting to actively increase the distance between itself and the stimulus). There are many types of aggressive behaviors with different motivations; however, fear, anxiety, genetics, and learned responses generally play a role in most cases. The effects of early development, socialization, and previous experience all play a role in the development of aggression.
Aggression refers to threatening behavior or harmful attacks, and can range from subtle changes in body posture, facial expressions, and vocalization to biting. Dogs that are easily aroused are at high risk for aggression because their decision-making is affected by their physiologic state (ie, flight or fight). For treatment to be effective, the pet's anxiety and arousal must first be managed by avoiding situations or staying below the threshold at which aggression might arise. A combination of reward-based training, medications, and behavior management devices that calm the pet are also likely to be needed, so that exposure therapy might be successfully implemented.
Before treating aggression the practitioner must assess the potential risk of injury. All stimuli that might incite aggression should be accurately identified to ensure initial safety. Predictability is a critical issue in prognosis both to prevent further incidents and to develop a stimulus gradient for treatment. The signalment, environment, history, and target of the aggression also provide invaluable information as to whether the problem might be safely and effectively managed. The type of aggression is an additional factor—some can be managed and improved, while others require prevention. Finally the clinician must assess the ability of the owner to effectively and safely prevent the problem. Aggression that is unpredictable, arises during relatively benign interactions, involves targets that cannot avoid exposure to the aggressive dog (eg, young children, other household pets), or is performed by a large dog or in an uninhibited manner worsens the prognosis. Any medical condition that might cause or contribute to aggression must be identified, because they are important factors in diagnosis, prognosis, and treatment.
This is the underlying cause for most forms of canine aggression. It is triggered by a stimulus that is threatening to the dog. When the aggression is a direct response to a challenge or confrontation, it might be referred to as defensive aggression. Fearful dogs may try to avoid the stimulus, but become aggressive if they cannot escape (eg, leashed, confined, cornered, or physically grasped), are motivated to maintain their place (eg, on property, between the owner and stimulus, near food or toy), or if they learn that aggression is successful at removing the threat. Genetics, maturity, learning, the stimulus (size, level of threat, previous experience), and ability to escape are all factors in whether a dog is likely to fight or flee. Inadequate socialization, learning, reinforcement of aggressive behavior (eg, retreat of the stimulus), and punishment can all lead to the development of fear-related aggression. The diagnosis is based on identifying signs of fear as well as the history beginning with the first event, because dogs can exhibit fear at the initial exposure but with time may display a more offensive form of aggression (without threats) when they learn it can be successful. (For treatment of fear-related and other types of aggression, see Treatment of Fears, Phobias, Anxiety, and Aggression.)
This type of aggression is most likely to arise when a person or an animal approaches the dog while it is in possession of something that it wants to retain. Pets that are in the process of ingesting or chewing an object might be more likely to display aggression, but the behavior can also be seen in dogs that are near an object. Aggression is most commonly displayed when in possession of highly motivating food, treats, chew toys, or stolen items but can be related to sleeping places, family members, or another pet. While genetics and early experience play a role in development, the relative value of the object to the pet and the threat of losing the object to another dog or person determine whether the pet is likely to be possessive. Items that are novel or scarce may be more desirable. Fear and defensive behavior also play a role if the owners threaten, punish, or confront the pet when it takes an object or has it in its mouth. The dog may also learn that it can successfully retain the object with aggression.
The problem might be prevented by teaching puppies that when their food bowl is removed or when they drop a toy, they will receive something of equal or greater value (treat, play, toy). In adult dogs, the problem should be managed by preventing access to these items or confining the dog when it is given items over which it might be possessive and by training the dog to give and drop on cue (beginning with items of low value for high-value rewards). If safety is an issue (ie, the dog may hurt itself by chewing on the item), it may be possible to trade the object for one of higher value. Providing more toys and multiple small meals (eg, in feeding toys) may reduce the value and novelty of the resource.
Aggressive play is a normal puppy behavior, which may persist into adulthood as a result of genetics (neotinization) and learning. When puppies play aggressively with other puppies, they may nip and bite but will generally resolve the conflicts among themselves. However, if the problem becomes excessive, owner intervention may be required to redirect the dog's activities into other forms of play (eg, feeding toys), or to interrupt the behavior with commands or a leash and head halter. If play with humans escalates to biting, the puppy can be directed to use its mouth in other forms of oral play (eg, fetch, tug games) or the interaction can be immediately stopped (negative punishment) and resumed when oral play ceases (positive reinforcement). Alternately, a leash and head halter or sharp reprimand (off) can be used to interrupt play biting. Punishment should not be used to stop play as it can lead to fear of the owner, defensive aggression, or conflict-induced aggression or serve as inadvertent reinforcement for some puppies.
Aggression is directed toward a third party when the dog is prevented or unable to exhibit aggression to its primary target. This type of aggression is most commonly described when the dog bites the owner as it grasps or restrains the dog when trying to prevent or break up a dog fight. Similarly, dogs that might be aggressive toward a veterinarian might bite the person restraining the dog.
Irritable/Conflict/Impulse Control Aggression
Aggression directed toward family members is often mislabeled as dominance or status-related aggression. However, aggression toward family members generally arises from fearful or defensive behaviors, resource guarding, redirected behavior, or situations of conflict (competing emotional states and unpredictable consequences). In some dogs the problem may be traced back to the owner's attempts to inhibit excessive play aggression (see Play Aggression).
When a dog successfully uses aggression to achieve a goal (retaining a resource) or remove a threat, the pet learns that aggression is successful (negative reinforcement). If the owner continues to threaten, confront, challenge, or punish the pet, some dogs may inhibit their responses, but a large proportion become more aggressively defensive. When dogs are resting or sleeping, chewing on a favored object, or no longer desirous of human affection, they may respond with either deferent displays or threats. However if the owner continues to approach, tries to remove the resource, or attempts to pet the dog despite its signaling, aggression may escalate and future signaling may be lost. The owner-pet relationship can quickly deteriorate as the dog becomes more wary and defensive while the owner becomes more fearful and/or confrontational.
Genetic factors and early experience likely also play a role; many of these dogs are easily aroused, excessively fearful, or may have behavioral pathology (see below). Other cases are primarily a result of learning. Aggression when the collar is grabbed or during bathing, nail trimming, or ear cleaning is a defensive response. Interrupting a pet that is aroused may lead to redirected aggression. Therefore when a dog is presented for aggression directed toward family members it can be difficult to determine the dog's underlying motivation, because each incident has added to prior learning, fear conditioning, and underlying conflict. Simply asserting that the dog is seeking dominance or status over the owner is not a reasonable explanation for aggression to owners. Physical techniques that are intended to assert dominance (eg, pinning, rolling over, verbal discipline) are ill advised and potentially dangerous.
A unique subset of this type of aggression is the dog that responds excessively and impulsively to relatively benign threats. In such dogs the aggressive display is disproportionate to the level of threat. In some lines of some breeds such as the English Springer Spaniel or English Cocker Spaniel, this lack of impulse control has been referred to as a rage syndrome. These excessive and out-of-control responses are likely associated with behavioral pathology in which alteration in serotonin transmission in the CNS has been implicated.
Aggression Toward Other Dogs
Dogs in the same group or household usually avoid conflict without aggression. Communication is based on dominant and submissive signals, with the deference of one of the two individuals to avoid escalation of the encounter. Determining which dog defers can vary between resources, so that dominance is a relative concept. Aggression between individuals living in the same household is generally an abnormal behavior and might be caused by fear and anxiety, redirected aggression, impulse dyscontrol, poor intraspecific communication skills as a result of genetics or lack of early socialization, previous experience and learning, or the relative desire for an individual resource.
Owners may play a role by inadvertently supporting or encouraging a dog during an encounter in which it would normally defer. Age or illness may also play a role, if the way in which one dog signals or responds to the other is altered. Male to male aggression may have underlying hormonal factors that can be improved by neutering.
As young dogs mature, situations may arise in which there are threats, posturing, and inhibited bites with an adult dog either in play or to establish control over resources. If any situations arise in which the dogs are unable to resolve conflicts without aggression or injury, behavioral guidance should be sought. Aggression toward unfamiliar dogs and those that are not members of the family group are likely fearful, possessive, protective, or territorial.
Aggression may be displayed when the dog is approached in its territory. Territory can be stationary (eg, yard, home) or mobile (eg, car). What defines the behavior as territorial is that the dog does not display fear to similar stimuli when outside its territory. Fear, anxiety, defensive, and possessive behaviors may all be components because the pet is most likely to display the behavior toward unfamiliar stimuli and the motivation to escape or avoid (flight) is decreased or removed when the pet is on its own property. Learning (negative reinforcement when the stimulus retreats) and fear conditioning (unpleasant outcomes such as yelling, discipline, and confinement) can also play a role.
This is one of the most dangerous types of aggression because there is usually no warning. The attack is intended to kill prey, and the bite is uninhibited. The sequence of events may include stalking, chasing, biting, and killing. Young children and babies may be at risk because their size and behaviors mimic those of prey. Although extensive socialization to a species might reduce predation toward that species, the behavior may be enhanced when predatory individuals are together in a group. Predation is a normal and dangerous canine behavior; thus, any dog that exhibits the behavior must be prevented from opportunities to repeat it.
Pain- or Medical-Induced Aggression
Any disease that causes pain or increases irritability (eg, dental disease, arthritis, trauma, allergies) can lead to aggression. The dog may become aggressive when it is handled or anticipates handling. Treating the medical problem may resolve the aggression, but the behavior, once learned, may persist.
This aggression may be seen in intact females with a litter of puppies or in females with pseudocyesis. It can be directed toward people or other animals. Signs of aggression arise when the bitch's puppies or toys that mimic puppies are protected, and the aggression should resolve when the hormonal state returns to normal and/or the puppies are weaned. The term maternal aggression has also been used to describe the aggression or cannibalism directed toward the puppies by the bitch. While the problem may have a genetic component, it is reported to occur more frequently after a first litter. Ovariohysterectomy can prevent further incidents.
This term denotes aggression without a clear or identifiable stimulus. It is reserved for aggressive dogs that have been thoroughly evaluated both medically and behaviorally and could not be classified. It may be related to pathologic changes in behavior such as impulse dyscontrol. The prognosis for these cases is usually poor, because management cannot effectively be implemented.
Treatment of Fears, Phobias, Anxiety, and Aggression
Before implementing specific therapy to manage, improve, or resolve a behavior problem, there are some common elements that apply to most cases. The initial discussion should focus on 1) an understanding of normal behavior as it relates to the problem, 2) ensuring that all of the pet's needs are adequately being met, 3) reviewing the principles of learning and reinforcement-based training (predictable consequences), and 4) managing both the environment and the pet to prevent further incidents. The cause, diagnosis, and motivation behind the behavior should be reviewed. Finally, the owner should be given a prognosis with realistic expectations for both short-term and longterm outcomes.
In most cases, treatment focuses on changing the pet's emotional response with the stimulus (counterconditioning) and/or replacing the undesirable response with one that is desirable using reinforcement-based techniques (response substitution). However, dogs that are highly aroused respond with autonomic fight or flight responses and tend to make reflexive responses. Therefore, arousal must be reduced before treatment can proceed. This can be achieved by training the dog to settle on cue, by minimizing the intensity of the stimulus during exposure (desensitization), or by using management devices such as head halters that can change the dog's focus and help it to settle, or with drugs or natural products that reduce anxiety and behavioral pathology. Early intervention with medication may be necessary to achieve success and can be in the best interest of the fearful, anxious, or phobic pet.
There are common elements to the treatment of fear, anxiety, phobias, and most types of aggression. The most essential component is to identify each situation in which the problem might arise, so that a preventive program can first be implemented and a stimulus gradient can be established for response substitution and counterconditioning. Prevention ensures safety (eg, in aggression cases), prevents further damage to the household or injury to the pet, avoids further anxiety-evoking situations for the pet, and ensures no further aggravation of the problem through fear conditioning (ie, unpleasant outcomes) and learning (ie, negative reinforcement if the stimulus retreats).
Prevention can be most effectively achieved by identifying and avoiding any situation in which the dog might be exposed to the stimulus. A leash and head harness, leash and body harness, or verbal commands (when effective) can also prevent access to the stimulus. If avoidance cannot be ensured and aggression is a possibility, then a basket muzzle might be the best alternative.
Because the ultimate goal is to successfully expose, calm, and reinforce the pet in situations when problems presently arise, it is necessary to determine what behaviors need to be trained for effective exposure. For example, if problems arise indoors, the dog may first need to learn a focused sit, a relaxed down, and a mat command (or other location such as room or crate). A drop or give command and a come or recall may also need to be trained. When problems arise outdoors, sit and focus or down and settle may also be useful, but walking forward on a loose leash, backing up, or turning and walking away may be the best options for stimulus exposure. Training should be practiced in a variety of environments with a minimum of distractions until the owners can achieve immediate and consistent success.
By identifying a range of the pet's most favored rewards, the most desirable can be used exclusively when training new behaviors; less-motivating rewards can then be gradually mixed in to ensure immediacy and timing of previously learned commands in a variety of situations. Similarly, a means for controlling the intensity of the stimulus will also need to be designed (eg, volume, distance, location). Exposure exercises can then be implemented by setting up situations in which the highest-value rewards are used to reinforce the desired behavior and condition a positive response beginning with low levels of the stimulus. Setbacks can be avoided by determining the level of stimulus intensity at which a calm and positive outcome can be achieved and reinforced, and with the use of management devices such as a head halter or front control body harness to ensure safety and success. Drug and natural therapeutics might be used concurrently in dogs with excessively intense or abnormal behaviors to enable the successful implementation of behavior modification.
For noise phobias, controlled exposure can best be achieved through recordings that can be gradually increased after each successful session of desensitization and counterconditioning. For separation anxiety, once a regular routine of play, exercise, and training is established, any additional reinforcement should focus on shaping gradually longer inattention sessions when the pet rests or occupies itself with favored chew and food- or treat-filled toys. Any attention- or affection-soliciting behavior should be ignored except when the pet is showing longer and gradually more settled behaviors, preferably in a location such as its mat, bed, crate, or room. Before moving on to short or graduated departures, the dog must first be trained to rest or play with its toys without following the owners when they get up or move around the house. Drugs or natural therapeutics can reduce the pet's anxiety and improve success, and a head halter can help to train and maintain increasingly longer down stays.
The most commonly used medications for fear, generalized anxiety disorders, phobias, and compulsive disorders, are the selective serotonin reuptake inhibitors (eg, fluoxetine) and tricyclic antidepressants (eg, clomipramine). Fluoxetine can be considered for some cases of aggression where impulsivity or intense anxiety is a factor. Carbamazepine has also been used anecdotally as adjunctive therapy in these cases. While the full effect might not be achieved for 3–4 wk, some effect might be noted in the first week. For selective serotonin reuptake inhibitors and clomipramine, doses at the high end of the range may be required for intense fears and phobias and compulsive disorders. For some compulsive disorders, especially those in which there is a self-traumatic component, gabapentin or carbamazepine might be used concurrently.
When an anxiety-evoking event can be predicted (eg, thunderstorms, fireworks, owner departure, visit to the veterinarian, car ride, exposure to dogs or strangers on a walk, visitors coming to the home), a benzodiazepine can be given with the antidepressant ~1 hr before the event. Because benzodiazepines have a varying effects and relatively short half-lives, their efficacy, dose, and duration should be determined in advance of their therapeutic use.
Buspirone, a mild anxiolytic, is another option for ongoing use. Trazodone, in conjunction with other antidepressants, can be considered; it might help to calm if used prior to the anxiety-evoking event or on an ongoing basis. Caution should be exercised when using anxiolytics as some may disinhibit fearful dogs, which could lead to increased confidence and aggression.
Selegiline (licensed in North America for the treatment of cognitive dysfunction syndrome in dogs) is also used for treatment of emotional disorders or chronic anxiety in Europe. Propranolol has been used in conjunction with behavioral drugs to reduce the physical signs of anxiety. Natural options for ongoing use that might reduce anxiety are dog appeasing pheromone, Harmonease® (containing Magnolia officinalis and Phellodendron amurense), l-theanine, α-casozepine, and perhaps melatonin or aromatherapy. The use of L-tryptophan in combination with a low-protein diet may reduce some forms of anxiety and aggression. While drugs may reduce anxiety and impulsivity and work to normalize brain pathology, concurrent environmental management and behavior modification is required to achieve effective and lasting improvement.
Although a hyperactivity disorder has been poorly documented in dogs, there have been numerous cases studies in which dogs are reported to have excessive motor activity, sometimes accompanied by stereotypic behaviors that make it impractical for the dog to focus and learn. It may be difficult to train such dogs to behaviorally settle, and there may be signs of sympathetic activity even at rest (eg, increased heart and respiratory rate, vasodilation). These dogs have been reported to respond to treatment with amphetamine or methylphenidate (0.25–0.5 mg/dog, bid). The dose can be gradually raised every few days to a maximum of ~2 mg/kg if lower dosages are ineffective and there are no adverse effects. However, most dogs that are perceived as hyperactive are actually overactive (ie, not provided with enough stimulation compared with the dog's needs).
Behavioral problems related to ingestion include those in which food intake is excessive (polyphagia), inadequate (hyporexia), or too fast (gorging); water intake is excessive (polydipsia); and nonfood items (pica) or stools (coprophagia) are eaten. Medical causes should be ruled out first. Some dogs that scavenge do so as a normal component of food acquisition and are reinforced by success. Coprophagia may occasionally have a medical cause, and normal maternal behavior includes consumption of stool and urine of young puppies. As part of exploratory behavior, many dogs are attracted to and may ingest stools, compost, and prey (dead or live). During play, dogs may learn that the taste of stools is appealing (especially stools of other species or if food is incompletely digested).
Dogs with hyporexia may have an anxiety disorder, and some may develop specific taste preferences and aversions that reduce what they will eat. Although some dogs with pica and polyphagia have compulsive disorders, many dogs, especially puppies, begin to chew and ingest nonfood items as part of investigative and exploratory behavior.
Many feeding problems can be improved through a work-for-food program in which dogs are given food as reinforcers for training, with the balance placed inside toys that require chewing or manipulation to release the food. This encourages exploration, makes feeding an enjoyable, time-consuming, and mentally challenging activity, and can limit the quantity consumed and prevent gorging.
Elimination Behavior Problems
Dogs may soil in inappropriate locations due to inadequate or insufficient training, as a marking behavior, or as a result of fear or anxiety. However, pain, sensory decline, cerebrocortical disease including cognitive dysfunction, and any medical condition that leads to increased volume of stools or urine, more frequent elimination, pain on elimination, or lack of control, must first be ruled out as potential causes or contributing factors.
A detailed behavioral history is necessary to determine if the dog has ever been housetrained. If not, a housetraining regimen should be reviewed in which the focus is solely on reinforcement of elimination in desirable locations rather than punishment of elimination in inappropriate locations. This requires the owner to accompany the dog to its elimination area (eg, outdoors), reinforce elimination, supervise the pet indoors to prevent or interrupt any attempts at elimination (perhaps with the aid of a leash to ensure continuous supervision), and return the pet to its elimination site at appropriate intervals or if there are signs that the pet is ready to eliminate (eg, sniffing, heading to the door, sneaking away). When the owner is not able to supervise, a combination of scheduling (ensuring that the pet eliminates before departure and having someone return to take the dog to its elimination area before it must eliminate) and confinement training are most effective.
Pets can either be confined away from areas where they might eliminate or kept in an area where they will not eliminate, such as a pen, room, or crate, where the dog eats, plays, or sleeps. Alternatively, the dog can be provided with an indoor elimination area (eg, paper, indoor puppy potty) within its confinement area where it can relieve itself when the owner is gone. Puppies obtained from pet stores or any location where they have been extensively caged are usually much more difficult to housetrain, because they have never had to inhibit elimination and may have learned to play with or eat feces.
Although marking is most often seen in intact males as a form of social and olfactory communication, it is also seen in females (especially when in heat) and in neutered males and females, often as an overmarking of other odors (eg, where other pets have urinated, or on items such as blankets with the residual odor of other dogs, people, or cats). Some dogs will mark when they visit unfamiliar households, especially when another dog's odor is present. There is often a typical posture of a raised or partially raised leg when the surface to be marked is vertical. Stool marking is uncommon.
While marking is likely a component of normal communication, it is unacceptable when it occurs indoors. Neutering intact males will reduce the behavior, and good supervision can prevent or inhibit most marking. As with housesoiling, dogs should be confined away from areas that might be marked when owners are not able to supervise. Marking that is related to anxiety may be reduced by identifying and treating the cause, perhaps with the aid of drugs or natural products that reduce anxiety.
Excitement, Submission, and Conflict-Related Elimination
Dogs may eliminate when they are overly excited, such as when greeting people. Some dogs will urinate when showing submissive postures (eg, crouching to the ground or turning over to expose the belly). Because loss of urine control may be associated with a concurrent desire to both greet and show deferential behavior, many cases may be due to conflicting behavioral motivations. Treatment should focus on avoiding the stimuli (reaching, approach, eye contact) that incite the behavior and avoiding any punishment during greeting, which would add to submissive, fear, and conflict behaviors. Acceptable alternative behaviors that are incompatible with excitable greeting or deferent postures can be taught, such as a relaxed sit or any game or “trick” the pet may have learned such as fetch or giving a paw. Phenylpropanolamine might increase sphincter control, while imipramine may improve control and reduce anxiety.
Other Elimination Disorders
Dogs with separation anxiety or other fears and phobias (eg, thunderstorm phobia, firework phobia, and fear of the veterinary office) may soil during these times. Identifying and treating these conditions can help control housesoiling.
Aging and Cognitive Dysfunction
The aging process is associated with progressive and irreversible changes in body systems that can affect behavior (see Medical Causes of Behavioral Signs and see Medical Causes of Behavioral Signs). In the older pet these might include hepatic or renal failure, endocrine disorders (eg, Cushings disease), pain, sensory decline, or any disease affecting the CNS (eg, tumors) or circulation (eg, anemia, hypertension). In order to diagnose the cause of behavioral signs in a senior dog, a detailed history, physical examination, neurologic evaluation, and diagnostic tests are required to rule out potential medical causes of the presenting signs. Many owners fail to report these signs, perhaps because they are insignificant to the owners or they assume that little can be done. Yet in one study, 30% of dogs 11–12 yr old and nearly 70% of dogs 15–16 yr old had signs consistent with cognitive dysfunction syndrome (CDS).
Aging dogs may exhibit a decline in cognitive function (memory, learning, perception, awareness) that manifests as one or more of a group of clinical signs. These are sometimes referred to by the acronym DISHA and include disorientation, interactions, sleep-wake cycles, housesoiling, and activity changes (which may be decreased or increased and repetitive). In addition, anxiety, agitation, and altered responses to stimuli are frequently reported. The first and most prominent sign of brain aging is a decline in learning or memory, which is difficult and often impractical to assess. However, neuropsychologic testing of older dogs has documented memory decline beginning at 6–8 yr of age and learning deficits by 9 yr of age. CDS in dogs is analogous to the early stages of Alzheimer's disease in people both in clinical signs and brain pathology. As with humans, some pets show minimal to no clinical impairment with age, while others develop varying degrees of deficits.
Veterinarians must be proactive in questioning owners of older dogs about the presence of medical or behavioral signs at each visit and in explaining to owners that early detection provides the best opportunity to improve signs and slow the decline of cognitive function. Treatment should first focus on environmental enrichment (both physical and mental stimulation), which has been shown to slow cognitive decline and improve the signs of CDS. Selegiline is a selective and irreversible inhibitor of monoamine oxidase B and may improve the signs of CDS by enhancing catecholamine transmission and reducing production and increasing clearance of reactive oxygen species. Propentofylline, which may enhance cerebral oxygenation and inhibit platelet aggregation and thrombus formation, is licensed for signs of brain aging in senior dogs in some European countries.
A number of natural products, including diets and supplements, have also been shown to have beneficial effects. A veterinary prescription diet (Hills b/d®), which is supplemented with a combination of antioxidants (including vitamins E and C and dried fruits and vegetables), mitochondrial cofactors such as l-carnitine and α-lipoic acid, and omega-3 fatty acids, has been shown to improve performance on a number of cognitive tasks in older dogs versus in similar dogs fed a standard diet. More recently, another diet (Purina One® Vibrant Maturity 7+), which provides aging neurons with an alternative source of energy from botanic oils containing medium-chain triglycerides, has also been shown to significantly improve cognitive function in senior dogs.
Other natural supplements that have demonstrated efficacy in improving cognitive function include Senilife®, which contains a combination of phosphatidylserine, Ginkgo biloba, resveratrol, and vitamins E and B6; S-adenosyl-l-methionine (Novifit®); and Activait®, which contains phosphatidylserine in combination with α-lipoic acid, carnitine, fatty acids, glutathione, and other antioxidants.
Last full review/revision April 2012 by Gary M. Landsberg, BSc, DVM, MRCVS, DACVB, DECAWBM; Sagi Denenberg, DVM