Glossary of Behavioral Terms for Veterinary Medicine

The term "abnormal behavior" can mean behavior that is atypical for a species. However, the term is often used synonymously with the term "pathological behavior," referring to action and behavior that is dysfunctional, such as that arising from a behavioral disorder (ie, pathologically abnormal behavior). These can be likened to mental health disorders or emotional disorders.

Notably, many behavior problems are actually normal behaviors for particular species that are undesirable to owners (eg, garbage raiding, jumping up, predation, herding, guarding).

The term "abnormal repetitive behavior" is a descriptive term for maladaptive, repetitive or fixed, and pathologically abnormal behavior, irrespective of any underlying medical conditions that might cause or contribute to the behavior.

Abnormal repetitive behaviors are a heterogenous group of behaviors that include both stereotypies and compulsive behaviors. Categories of abnormal repetitive behaviors include oral/ingestive (eg, pica, polyphagia, licking, gulping), neurological/hallucinatory (eg, fly snapping, light chasing), locomotory (eg, spinning, pouncing), and self-directed (eg, acral lick dermatitis, psychogenic alopecia). These categories are not mutually exclusive.

Aggression can be defined in a narrow sense (eg, a single attack) or in a broader sense (eg, as agonistic behavior). In the latter case, aggression can be appropriate or inappropriate, in context or out of context, inter- or intraspecific, or it can be a challenge or contest that results in deference or in combat and resolution.

Anxiety is the apprehensive anticipation of future danger or misfortune, which can be accompanied by both behavioral and somatic signs (vigilance and scanning, autonomic hyperactivity, increased motor activity and tension). Anxiety can occur without an identifiable trigger or threat. In some individuals, anxiety can be situational or can become generalized. Although the terms are often used interchangeably, anxiety is distinguished from fear in that anxiety is a response to an anticipated or imagined threat or danger, whereas fear is a response to an actual, present stimulus.

Emotional arousal can be defined as a state of increased physiological activation. When emotionally aroused, an animal might not respond as they would under normal circumstances. The emotional arousal state can substantially impact the animal's ability to learn.

Compulsive behaviors are abnormal and repetitive, variable in form, and often fixated on a goal. They can be exaggerated, sustained, intense, and difficult to interrupt or have an element of dyscontrol in either the initiation or continuation of the behavior or its inhibition, or in switching between behaviors. They are generally derived from normal behaviors such as grooming, predation, ingestion, or locomotion.

Compulsive disorders might initially arise from situations of frustration or conflict but become compulsive when they persist or occur outside the original context. Certain breeds appear to be genetically predisposed to compulsive behavior. There is likely an alteration in serotonergic activity, but involvement of other neurotransmitters (eg, dopamine, opiates) also has been implicated. Compulsive disorders may arise when the primary cause of a behavior has changed over time, manifesting in the compulsive disorder, or when there is more than one cause for the compulsive behavior. Associated brain areas include the prefrontal cortex and amygdala.

Conflict arises when a pet has competing motivations or is motivated to perform more than one opposing behavior. This might occur when a dog is motivated to greet but is fearful of approach, perhaps because of previous unpleasant experiences (eg, yelling, hitting, pinning). The resultant behavior might be either a displacement behavior or aggression (when fear is an overriding factor).

Displacement behavior is generally a normal behavior that is performed out of context, or is “displaced,” because the animal is unable—physically or behaviorally—to execute another activity or otherwise occupy itself. This type of behavior is less specific than redirected behavior. When displacement activity occurs, the behavior may be out of context with the situation (eg, circling, air snapping, or even urination). A displacement behavior can arise from conflict or frustration or be a vacuum activity.

Dominance is a concept frequently misapplied. The ethological concept of dominance refers to competitive control over a limited resource and to the ability of a higher-ranking animal to displace a lower-ranking animal of the same species from that resource.

Rank is usually defined by an ability to control the resource or by access and presumed ability to restrict matings.

Dominance is not interchangeable with hierarchical rank. Ranks, particularly those that are linear and in which a dominant animal is identified, are largely artifacts of experimental or manipulated situations. A dominant animal is not the one engaged in the most fighting and combat; most high-ranking animals seldom have to contest their right of access to a resource.

Instead, high-ranking animals are usually better identified by the character and frequency of deferential behaviors exhibited by others in their social group and by their ability to respond appropriately to a variety of social and environmental circumstances. Thus, confident and assertive postures and signaling by one individual in a pair might be described as dominant behavior if the response of the second individual is deferential or subordinate. However, the terms dominant and subordinate only describe the relationship of the pair in one context and do not describe their relationship overall, unless this kind of response is consistent across all resources and interactions.

Although the terms dominance and rank apply to communication and signaling between members of a species (eg, dog-dog), they do not translate to communication between species (eg, dog-human).

Fear is a feeling of apprehension associated with the presence or proximity of an object, individual, or social situation. In contrast, anxiety is a response to an anticipated threat or danger. However, the terms are often used interchangeably.

Fear is part of normal behavior and can be an adaptive response. Whether the fear or fearful response is abnormal or inappropriate must be determined by context. For example, fire is a useful tool, but avoidance of fire is an adaptive response. If a pet is fearful of stimuli that are innocuous, such as walking on certain types of surfaces or going outdoors, such fear would be irrational and, if it were constant or recurrent, probably maladaptive.

Fears usually occur as graded responses, with the intensity of the response proportional to the proximity of the stimulus. Most fearful reactions are learned and might be unlearned with gradual exposure, although a lack of sufficient previous exposure, consequences of previous exposure, and genetic factors all play a role in how quickly or completely unlearning might be achieved.

Frustration arises when an animal is motivated to engage in a sequence of behaviors that it is unable to complete because of physical or psychological obstacles in the environment. When pets are frustrated—such as a cat that cannot gain access to an outdoor cat that it sees through the window or a dog that cannot get to a stimulus on the other side of a door or fence—the resultant behavior can be a redirected behavior (eg, attack of another family pet or owner), a displacement behavior (eg, stereotypic pacing), or clinical signs associated with fear or anxiety (eg, whining or howling).

Another example of goal frustration is the dog or cat that chases a laser light toy but is unable to finish the sequence or achieve any goal. This frustration can lead to compulsive chasing of other lights and shadows.

Phobias involve sudden, all-or-nothing, profound, abnormal responses that result in extremely fearful behaviors (catatonia, panic). Phobias can develop over time—some animals develop increasingly more-intense fear responses with repeated exposure (eg, storm phobias). Once established, phobias are associated with immediate and intense fear when the stimulus is presented.

Once a phobic event has been experienced, any event associated with it or the memory of it (eg, wind, rain, or darkening sky and storm phobias) can be sufficient to generate the response. Although fears can diminish after repeated exposure without untoward consequences, phobias can remain at or exceed their former high level for years, even without reexposure.

The genesis of such events in dogs is usually either an extremely frightening or traumatic experience or the presence of profound internal problems with fear (eg, genetic predisposition), such that responses to unfamiliar stimuli are excessive. Owners' responses might inadvertently aggravate the problem, either by further encouraging the behavior or by adding to the fearful emotional state if the outcome for the pet is unpleasant (eg, owner anger or punishment). Phobic situations are either avoided or, if unavoidable, are endured with intense fear or distress.

Redirected behavior activities are directed away from the principal/appropriate target and toward another, secondary/less appropriate target (eg, when the animal is in a state of emotional arousal and is unable to reach the principal target, or if the animal is interrupted).

A stereotypy is a perseverant repetition of behaviors that is unvaried in sequence and has no obvious purpose or function. Stereotypic behaviors usually derive from contextually normal maintenance behaviors (eg, grooming, eating, walking).

Stereotypic behaviors have been reported commonly in farm, zoo, and laboratory animal species and arise in situations of conflict or frustration related to confinement or husbandry practices. They can arise under a variety of conditions:

• barren or stress-evoking environment

• limited opportunity to display a full range of species-typical behaviors

• maternal deprivation

• attendant neurological disorders

Some stereotypic behaviors, at least in their early stages, may provide a coping mechanism for the animal. For example, nonnutritive suckling in calves may assist digestive processes.

Vacuum activity may be exhibited when an animal is highly motivated to perform an instinctive behavior but there is no available outlet (eg, flank sucking, licking). These activities have no apparent useful purpose.