In production animals, treatment focuses on group management, environmental or housing modifications, and in some cases removing individual animals out of or to other groups. Specifics are covered in the relevant sections for each species.

In companion animals, the treatment of behavior problems varies with diagnosis and prognosis. In general, the program begins with prevention and avoidance of problems, while the owner develops effective strategies to modify the pet's behavior so that it might gradually be reintroduced to the problem situations while achieving a desirable outcome. Modifications to the environment may be required so that the pet can be kept away from the stimuli (or the sights or sounds of the stimuli) that incite the problem or from the areas in which the problem occurs. Modifying the pet's behavior can be accomplished by applying the principles of learning and behavior modification and combining these with products that improve safety, reduce anxiety, or help to achieve the desired response more effectively (eg, muzzles, head halters, no-pull harnesses, calming caps, etc). Drugs and natural products may also be indicated for certain problems.

Behavior Modification Principles

The most commonly used behavioral techniques include habituation, extinction, desensitization, counterconditioning, response substitution, and shaping. Flooding is often talked about but seldom used because it is likely to make most animals worse. While it is claimed that punishment is frequently used, with varying degrees of success, few people correctly employ punishment. For punishment to be successful, the aversive stimulus (eg, startling the dog with a loud noise, spraying water at a cat, etc) must occur sufficiently close to the onset of the behavior that the probability of the behavior occurring in the future is lessened. Most aversive stimuli are inappropriate in context, duration, or time of application and are more about the client's anger than about changing the behavior. In fact, recent studies have confirmed that punishment-based training and confrontational techniques are more likely to lead to increased aggression and avoidance behaviors.

Most of the humane, passive, or positive techniques involved in behavior modification are not hard to learn and are equally successful as preventive techniques. The following is a short review of the basic principles involved in the techniques and their associated strategies.

Classical Conditioning

The pairing of an unconditioned stimulus with a neutral stimulus results in a conditioned stimulus and a conditioned response. Classical conditioning can occur in both positive and negative ways. Examples of a positive conditioned emotional response are the pairing of a clicker with favored treats (for clicker training) or a doorbell signalling visitors (for pets that are enthused about meeting new people).

Problems arise when a fearful conditioned emotional response is established toward a previously neutral stimulus (visual, odor, auditory, animate, inanimate) by repeatedly pairing it with a fear-producing stimulus. Once this occurs, the stimulus itself will elicit the fear response, eg, a doorbell that becomes paired with the visit of unfamiliar people (for pets that are fearful of visitors), or the pairing of the doorbell with verbal or physical discipline applied by the owner for barking or jumping up (pinning, leash corrections). Similarly when a pet lunges or jumps up to greet new people, pairing of punishment (such as choke collars, prong collars, shock, pinning, verbal corrections) may lead to a conditioned fearful response toward new people. An owner that is nervous or fearful about the situation further enhances the pet's fearful emotional state. A visit to the veterinary clinic that may begin as a neutral situation may quickly become fear evoking if it is associated with unpleasant outcomes or is further enhanced by owner anxiety.

Counterconditioning and Desensitization

Counterconditioning involves the consistent and repeated pairing of a stimulus that evokes an unpleasant response with something that is highly positive until a positive association is made. To be successful, counterconditioning should be coupled with desensitization, (ie, minimizing the intensity of the stimulus to a level that does not incite the fear response such as by reducing volume, increasing distance, changing the environment, or modifying the stimulus to something that is less threatening).

Desensitization and counterconditioning are extremely time-consuming. The exercises must be constantly repeated so that the response lessens and is altered to one that is positive. All of the animal's communicatory signals must be considered. Clients often want both quicker fixes and less work. However, moving too quickly provokes anxiety and sabotages any behavior modification program.

Operant Conditioning

Operant conditioning is how one's actions result in consequences. The results either increase or decrease the likelihood of future responses. There are 4 types of behavior-consequence relations: positive and negative punishment and positive and negative reinforcement. Reinforcement increases the likelihood that a behavior will be repeated, and punishment leads to a reduction in behavior. Negative refers to the removal of a stimulus, and positive refers to the application of a stimulus.

Positive reinforcement occurs if behavior is increased by something applied (generally something pleasant or appealing); negative reinforcement occurs if behavior is increased by something removed (generally something unpleasant). In positive reinforcement training, a reward should be given immediately and consistently until the behavior can be reliably repeated. If the behavior is to be trained on command or cue, a word or hand signal should then be added prior to the behavior-reward sequence. Once learned, behavior can be reinforced on a variable schedule, so that the period of time or number of responses before the reward is given is varied. Rewards are used for positive reinforcement but a reward is not synonymous with positive reinforcement. A reward is anything that is desirable to the pet, from an activity such as petting, walking, or play to an item such as a toy, food, chew, or treat. However, unless there is a clear relationship between the behavior and the reward (timing, consistency, contiguity) then the reward does not achieve the goal of positively reinforcing behavior.

Negative reinforcement must not to be confused with punishment because punishment decreases behaviors and reinforcement increases behaviors. One example of negative reinforcement is escape behavior. If an animal anticipates an aversive outcome, such as a reprimand from the owner, the aversive outcome will not occur if the pet escapes. Similarly, if the owner puts pressure on a head halter until the desired behavior is achieved, the release of tension is negative reinforcement. One potential consequence of negative reinforcement is that if a pet's threats or aggression lead to removal of a stimulus (eg, dog, delivery person, owner) the behavior is reinforced and increased by the retreat of the stimulus.

Positive punishment occurs when a behavior decreases when something is applied (generally something unpleasant) and negative punishment occurs when a behavior is decreased when something is removed (generally something pleasant or appealing). In positive punishment, if behavior does not decrease after the first few applications, then the punishment is not being appropriately timed or the behavior is too strongly motivated to be deterred by punishment. Positive punishment that is applied by a person (owner, trainer) is intended to cause the pet to become fearful of repeating the behavior. However, a potential consequence is that the pet becomes fearful of the punisher, which can lead to defensive aggression or fear of an approaching hand. Also, if the unpleasant consequence only occurs when the owner is present, the behavior may continue in the owner's absence. Another problem with positive punishment is that if the pet receives an unpleasant consequence for undesirable behavior toward a stimulus (eg, barking at cars, lunging to greet people on the street, jumping up on strangers), this may lead to a conditioned fear of the stimulus (see above).

Punishment that unnecessarily leads to pain or discomfort is inhumane. Punishment cannot be used for training desirable behaviors, only for stopping what is undesirable. If the goal is to make the pet fearful of repeating a behavior (eg, garbage raiding, taking things from counters, chewing plants) or to keep the pet away from an area (room, couch, bed), then environmental punishment (booby traps) or remote punishment (eg, spraying water while remaining out of sight) might be most appropriate. If consistent and sufficiently aversive, this type of punishment can lead to avoidance. However, before focusing on how to stop what is undesirable, the owner should first focus on providing a desirable alternative (eg, where to sleep, where to climb, what to chew). Pet-activated devices such as motion detector alarms or compressed air, unpleasant substrates (double-sided tape), aversive tastes, or remote activated devices (compressed air) can be effective deterrents without being associated with the owner's presence.

Negative punishment is the reduction of a behavior by the removal of something pleasant. For example, if the pet is receiving affection or play when an undesirable behavior begins (eg, play biting, mouthing, mounting) the immediate removal of the play or affection will punish the pet. Unless the pet can determine what behavior leads to the removal of play, the behavior may actually intensify due to frustration at not receiving its reward.

Second-Order Reinforcers

Signals that can be used at a distance to convey that the reward is coming are second-order reinforcers. Commonly used second-order reinforcers are words (“Good dog!”), clickers, or whistles. By repeatedly and continuously pairing these with a primary reward such as a toy or treat, second-order reinforcers can elicit the same response that the reward would, as long as the pairing is repeatedly maintained. Clicker training requires frequent practice and excellent timing, but once achieved the animal can be reinforced each time the desired behavior is observed. Clicker training is an excellent way to immediately “mark” desirable responses, gradually shape new or more desirable behaviors (eg, longer, more relaxed), or associate a positive emotional response with the stimulus.

The Premack Principle

When a more desirable behavior is made contingent on a less desirable behavior, the less desirable behavior is more likely to be repeated. Thus, the more desirable behavior serves as the reinforcer. For example, if a pet wants to go out or cross the street for its walk, the owner can train a sit-stay before each of these behaviors. A horse or dog that wants to walk ahead can be taught that walking on a slack rein or leash will result in this behavior.

Overlearning

Overlearning is the repeated evocation and expression of an already learned response. It is a phenomenon that is frequently employed in training for specific events, but may be underused in preventing fearful responses in dogs. Overlearning accomplishes 3 things: it delays forgetting, it increases the resistance to extinction, and it increases the probability that the response will become a “knee-jerk” one, or response of first choice, when the circumstances are similar.

Shaping

Shaping works through gradual approximations and allows the animal to be rewarded initially for any behavior that resembles the desired behavior. For instance, when teaching a puppy to sit, following a slight squat with a food reward will increase the probability that squatting will be repeated. This squatting behavior is then rewarded only when it more closely resembles a sit, and finally, when it becomes a true sit. Shaping can also be used to reward an increase in the duration of a behavior.

Extinction

The eventual ending of a behavior once all reinforcement is removed is termed extinction. For example, if people pet a dog that jumps up on them for attention, the behavior continues; if they stop, the dog will eventually extinguish its response because the reward is no longer there. However, any form of intermittent reinforcement—even occasional petting of the dog in response to its jumping—will prolong the performance of the response. Valuable rewards, a long history of performance, and intermittent reinforcement all increase resistance to extinction. Owners also must be prepared for the intensity of the behavior to initially increase before it is extinguished. Giving in will make extinction even more difficult as the animal learns that higher intensity behaviors achieve the desired outcome.

Habituation

Habituation is a gradual lessening of a response to a stimulus. Usually this occurs with repeated presentation of a stimulus whereby the animal learns that it does not signal anything important. For example, horses placed in a pasture bordering a road may at first run away when traffic passes, but eventually learn to ignore it. Stimuli associated with potentially adverse consequences are more difficult to extinguish with habituation than other stimuli. In prey species, responses to sounds associated with predators would be difficult to habituate because they have been selected for and generally are adaptive. If the fear response is too intense, instead of habituation the pet may become increasingly more fearful of the stimulus (sensitization).

If an extended interval has occurred since the time an animal last experienced a stimulus to which it had habituated, the animal may again react when re-exposed to the stimulus. This is known as spontaneous recovery.

Flooding

This is used to treat fears of harmless stimuli by forcing the animal to stay in the presence of the stimuli until the fear is extinguished. This procedure is seldom effective in dogs because it initially enhances fear and cannot be stopped until all physiologic and emotional signs of fear are gone. If done improperly, flooding may therefore increase problem behaviors. In practice, a controlled level of flooding is quite often used as a component of behavior modification, in which the stimulus is presented at a level that is low enough to cause fear and the pet is restrained calmly in place until it habituates. This can then be combined with reinforcement (ie, pet is reinforced or the stimulus removed when the fear response subsides or abates).

Response Substitution

This involves the replacement of an undesirable response with one that is desirable. For example, high value rewards can be used to train desirable target behaviors that are alternatives to the undesirable behavior. However, if the behavior is part of the pet's natural repertoire (eg, greeting, barking) it can be particularly difficult to train alternative behaviors. Specific examples of response substitution include training a dog to sit or lie down as an alternative to jumping up, mounting, or play biting; or to sit, walk on loose leash, or back up for dogs that are forging ahead or running out the door. Training should begin in a variety of environments where success can be most readily achieved. The desired endpoint is for the animal to be quiet and calm. Therefore the owner must learn to read the look in the eyes, body posture, facial expressions, and breathing to be able to gradually shape the desired behavior. Training could then move to environments with increasing distractions and locations where the problem is most likely to arise.

To replace the undesirable behavior with one that is desirable, response substitution should be coupled with desensitization (see above) by setting up exposure to low levels of the stimulus and practicing the target behaviors and relaxation exercises while reinforcing with the most valued rewards. If the pet is fearful or anxious, the focus should also be on counterconditioning, so that each exposure to the stimulus is associated with only highly positive outcomes and no negative outcomes.

Last full review/revision March 2012 by Gary Landsberg, BSc, DVM, MRCVS, DACVB, DECVBM-CA