Self-directed behaviors in dogs and cats
Although the prevalence of self-directed behaviors is not well-documented in dogs or cats, it is likely underappreciated because animals are not typically presented for evaluation of such behaviors unless the clients think their pets are manifesting a behavior problem or some degree of injury as a consequence of the behavior.
A self-directed behavior is any behavior that an animal directs toward itself repeatedly and consistently in the absence of a primary medical cause. Self-directed behaviors can include a range of activities from excessive maintenance behaviors, such as grooming, to redirected aggression that may or may not be purposeful. Although the prevalence of self-directed behaviors is not well-documented in dogs or cats, it is likely underappreciated because animals are not typically presented for evaluation of such behaviors unless the clients think their pets are manifesting a behavior problem or some degree of injury as a consequence of the behavior.
Self-directed behaviors that result in any degree of self-mutilation or damage are classified as self-injurious behaviors.1,2 Because these behaviors may occur reclusively, an animal may be presented for evaluation of lesions that appear to have developed spontaneously. To identify self-injurious behavior, look for barbering or removal of hair, abrasion, petechiation, or ulcers on any body part resulting from the animal's using its teeth, tongue, claws, or an external substrate (e.g. rubbing against a wall) repeatedly and consistently in the absence of a primary dermatologic or physiologic condition.1,2 Self-injurious behavior is not a clinical diagnosis but an assessment that an animal's condition is the result of a primary behavioral etiology.
Self-injurious behavior may lead to behavioral dermatoses, dermatologic conditions for which a substantive behavioral or emotional component is present.1 In humans, emotional factors affect the management of at least one-third of patients with dermatologic conditions.3,4 For example, chronic dermatoses such as acne, rosacea, and seborrheic dermatitis may be exacerbated by emotional stress. Furthermore, pruritus and pain associated with primary dermatoses may substantially affect emotional reactivity, making an individual more reactive to potentially stressful situations.1 Based on underlying psychoneuroendocrinologic mechanisms common to both humans and animals, it is reasonable to assume that behavioral or emotional factors may contribute to a similar percentage of behavioral dermatoses in companion animals.
NORMAL SELF-DIRECTED VS. ABNORMAL BEHAVIOR
When evaluating animals for self-directed behaviors, it is important to determine whether the behavior falls within the species' normal behavioral repertoire. For example, self-grooming is a normal maintenance behavior that facilitates cleansing, parasite removal, and thermoregulation. Normal grooming behaviors include licking the hair and skin, nibbling, biting, scratching, rolling, and rubbing the face with the forepaws or environmental substrates.
Although normal grooming behaviors are well-recognized, how frequently and for what amount of time healthy household dogs or cats typically engage in such behaviors are not well-documented. Because environmental and social stimuli may affect grooming behaviors, it is likely that the normal range for daily grooming time varies with an animal's living conditions. One study of farm cats reported that grooming occupied 15% of the cats' time.5 Another study of confined indoor cats reported that oral grooming made up 4% of the cats' time (8% of nonsleeping or nonresting time), and grooming by scratching took up 1/50th of the time used for oral grooming.6 Thus, determining what constitutes excessive grooming often depends on an observed predominance of grooming behavior or physical manifestations of injury secondary to grooming.
Once you have assessed that a self-directed behavior is present, consider all appropriate differential diagnoses (Table 1). In concert with a careful review of the animal's behavioral history, directly observing the patient is essential to appreciate potential behavioral etiologies. Although a videotape of the patient's behaviors does not preclude direct observation, it can provide an opportunity to observe the animal engaging in any associated behaviors in its home environment and to study specific behaviors in detail.
Table 1. Differential Diagnoses Associated with Self-directed Behaviors in Dogs and Cats
Primary medical conditions
Although self-directed behaviors by definition exclude primary medical causes, patient evaluation should include a thorough physical examination, a complete blood count, a serum chemistry profile, and any additional diagnostics that may be clinically indicated by other findings (e.g. skin scraping, dermatophyte culture, acetate tape preparation, cytology, histology).7 If clinically relevant abnormalities are noted, you must determine whether the findings are most consistent with a primary or secondary medical cause. Secondary behavioral disorders may result from primary medical conditions that affect an animal's normal behavior patterns and social functioning. As with stressful environmental and social stimuli, medical conditions that cause pain, discomfort, lassitude, or malaise may result in reduced coping strategies, increased reactivity, anxiety, or aggression.
Beyond normal maintenance purposes, grooming in dogs and cats may occur as a displacement behavior. This type of activity is performed out of context as a result of conflict (the tendency or state of motivation to simultaneously perform more than one type of activity), frustration (engagement in a sequence of behaviors that cannot be completed because of physical or psychological obstacles), or anxiety in response to social or environmental stressors. Displacement grooming can distract an animal from stressors, lower its level of arousal, or deflect social conflict or agonistic interactions. Displacement grooming may also occur as a stress response in the absence of sufficient social or environmental stimuli. Displacement grooming is a normal adaptive response to transient stressors; however, with recurrent or sustained stress, excessive grooming (over-grooming) may result.1
Stereotypic behavior and compulsive disorders
Stereotypic self-directed behaviors are characterized by sequences of movements that serve no obvious function and occur repetitively, out of context, or at an excessive frequency or duration. A diagnosis of a compulsive disorder applies when these sequences of movements not only meet the above criteria but also fail to achieve any real or potential goal and interfere with an animal's ability to function normally.1,2 Self-directed compulsive disorders in dogs include a number of syndromes that are descriptive of lesions (e.g. acral lick dermatitis, psychogenic alopecia) or behavior patterns (e.g. flank sucking, tail chewing, tail chasing, self-nursing, preputial licking, excessive chewing of the feet or nails, excessive scratching or rubbing). Self-directed compulsive disorders in cats also include syndromes that are descriptive of lesions (e.g. psychogenic alopecia) or behavior patterns (e.g. hyperesthesia syndrome, tail chewing, excessive chewing of the feet or nails, excessive scratching or rubbing). Correctly diagnosing a stereotypic behavior or compulsive disorder requires evaluating the behavior pattern and frequency, the contexts in which the behavior occurs, and the degree to which such behavior interferes with an animal's ability to function normally.
Redirected behaviors may result when activity directed toward a target is thwarted or interrupted. The redirection may result from a tangible physical obstacle (e.g. a window, confinement to a leash) or a virtual obstacle (e.g. social anxiety, fear). Although redirected behaviors are generally directed toward another individual or environmental objects, I have observed several animals redirect their behavior toward themselves. The redirected behavior may or may not manifest as self-directed aggression. While redirected behaviors may initially occur in the presence of a specific provocative stimulus, over time the animal may generalize and become responsive to a number of different stimuli. A precise behavioral history that identifies specific provocative situations in which the redirected behavior occurs is necessary to confirm this diagnosis.
Cutaneous sensory disorders
Animals with cutaneous sensory disorders experience neurosensory disturbances in the absence of any detectable dermatologic, neurologic, or medical condition. The pathology and clinical signs may be generalized or limited to specific body parts. Because animals cannot verbally report the sensations they experience, consider cutaneous sensory disorder if you observe one of the following responses to specific sensory stimuli:
1. Allodynia—a pain response to non-noxious stimuli
2. Hyperalgesia—an exaggerated response to typically painful stimuli
3. Marked dysesthesia—excessive response to or avoidance of unpleasant stimuli
4. Pronounced self-directed behavior suggesting that the animal may be responding to a sensory stimulus (e.g. by avoidance, withdrawal, arousal to a discrete or focal stimulus).
While attention-seeking behaviors are typically thought of as owner-directed behaviors (e.g. pawing, jumping, nudging, barking), animals can learn to perform self-directed behaviors (e.g. scratching, licking, chewing, sucking) to receive attention. In response to such behaviors, clients often attempt to interrupt the behavior by using physical or verbal correction, comforting the animal, or attending to any lesions present; thus, they reinforce the behavior. Self-directed behaviors occurring only in the presence of selected individuals are strongly suggestive of attention-seeking behavior. In these cases, observing or videotaping the animal in the presence and absence of such individuals will help verify the diagnosis.
In people, psychotic conditions can be associated with self-directed behaviors as a result of hallucinations, delusions, or motor disturbances. Because animals cannot directly report delusional and hallucinatory behaviors, a diagnosis of a psychotic condition in animals is difficult to confirm and must be presumed. Most conditions involving repetitive motor disturbances with possible delusional or hallucinatory components (e.g. fly chasing, shadow chasing) are more commonly classified as compulsive disorders; however, it is still important to consider potential hallucinatory or delusional etiologies when evaluating animals for self-directed behaviors.
Common examples of self-directed behavior include psychogenic alopecia (dogs and cats), acral lick dermatitis (dogs), and hyperesthesia syndrome (cats). These disorders are syndromes with nonspecific causes rather than specific diagnoses. Thus, one dog with acral lick dermatitis may excessively lick as an attention-seeking behavior while another licks as a manifestation of a compulsive disorder. Similarly, one cat presenting for psychogenic alopecia may excessively groom as a displacement activity while another may groom as a redirected behavior. Because many causes result in similar clinical signs, it is essential that a specific diagnosis for the behavior be determined for the most effective management.
Psychogenic alopecia is characterized by excessive self-grooming that is initiated or intensified by nonorganic causes or that persists beyond resolution of an organic cause. Although this syndrome is more prevalent in cats, some dogs do present with psychogenic alopecia (Virga V, Veterinary Healing Arts Inc., East Greenwich, R.I.: Unpublished data, 2005). Clients may not see the behavior because the animals, especially cats, may groom reclusively. The predominant clinical signs of this syndrome in cats are barbering and alopecia, particularly of the medial forelimbs, caudal abdomen, inguinal region, tail, and dorsal lumbar areas. Physical examination of the alopecic lesions should reveal short, broken hairs that do not epilate easily. Broken shafts should be evident on microscopic examination of these hairs. Large amounts of hair in the feces are evidence of excessive self-grooming. Other clinical signs include abrasions or erosions secondary to self-mutilation, secondary bacterial infection, lichenification, hyperpigmentation, and dermatitic lesions (bright-red, elongated, oval streaks or plaques).7
Because psychogenic alopecia has been noted in captive wild cats and is reported to be more prevalent in strictly indoor cats, displacement grooming in response to social or environmental stressors should be considered (Virga V, Veterinary Healing Arts Inc., East Greenwich, R.I.: Unpublished data, 2005).8,9 Other potential causes include anxiety, stereotypic behavior, compulsive disorders, and redirected behaviors.
Acral lick dermatitis
Acral lick dermatitis is characterized by firm, raised, ulcerative plaques that develop because of chronic licking. Single, unilateral lesions of the cranial carpus and metacarpus are most prevalent; additional lesion sites include the cranial radius, metatarsus, and tibia.7 Secondary bacterial infection is common and may contribute to these lesions being intensely pruritic. As such, a sustained course of antimicrobials is often advisable.
Acral lick dermatitis may be organic or psychogenic in origin. Psychogenic associations include displacement activities in response to social or environmental stress, anxiety, stereotypic behaviors, compulsive disorders, and redirected behaviors. Some evidence of familial inheritance and breed predisposition exists, with Labrador retrievers, Great Danes, Doberman pinschers, German shepherds, and some northern breeds being over-represented.9,10
Cutaneous sensory disorders are conditions in which a patient experiences a purely sensory complaint without clinical evidence of a dermatologic, neurologic, or medical condition.1,11 In people, the pathogenesis is typically not identifiable, and the results of diagnostic tests prove unremarkable. Cutaneous sensory disorders occur in both dogs and cats. While dogs may have a disparate array of clinical signs, cats often have a more consistent pattern of signs characterized as feline hyperesthesia syndrome. Behaviors noted in affected cats may include 1) intense grooming behaviors, particularly directed at the tail, flank, anal, or lumbar areas; 2) rippling or twitching of the skin of the dorsum; 3) avoidance behaviors (running, jumping, hiding) in response to no identifiable, tangible stimulus; 4) avoidance or aggression in response to tactile stimulation, particularly of the dorsum; 5) distress vocalizations; and 6) behaviors similar to those observed in estrous females, such as increased motor activity, rolling, and crouching with elevation of the perineal region. Clinical signs may be variable, consistent, or episodic. Affected cats tend to be difficult to distract from the behaviors, or if successfully distracted, they remain so for only a short time.
As noted previously, clinical evaluation of patients presenting with self-directed behaviors should include a thorough clinical examination and minimum database. Potentially important clinical findings should be further evaluated by using appropriate diagnostic tests to rule out any organic causes before considering primary behavioral disorders. Primary and secondary medical conditions should be addressed before or with behavioral management.
A thorough behavioral history, including considering the physical and social environment and directly observing the animal engaging in the self-directed behavior, is critical to effective clinical management. A videotape of the patient's behavior may not only be necessary to observe the behaviors, but may be complementary to direct observation by revealing environmental and social contexts in which the behavior occurs and providing an opportunity for more detailed analysis of behavior.
Effective behavioral management of patients with self-directed behaviors must integrate the treatment of concurrent medical conditions (primary and secondary), environmental management (addressing relevant social and environmental factors), and behavior modification. Pharmacologic support may be incorporated as well and, in my experience, is unlikely to be effective without concurrent medical treatment, environmental management, and behavior modification.
Environmental management and behavior modification
Because an animal's response to its environment may substantively contribute to self-directed behaviors, it is important to attempt to resolve or minimize any social or environmental stressors in the initial management of patients with self-directed behaviors. Behavior modification and pharmacologic support may be substantially hindered or ineffective if the provocative social and environmental factors are not addressed.
Since self-directed behaviors are often associated with emotional states of stress, anxiety, or arousal, behavior modification can minimize the stress response when the animal is exposed to these stimuli. Counterconditioning (establishing a different response to a provocative stimulus by engaging in a competitive behavior or activity) is an effective behavior modification technique to reinforce behaviors that encourage relaxation.12 Appropriate responses are supported with encouragement, affection, and small food rewards as positive reinforcement. Rewards when the patient is relaxed and the problem behavior is absent can augment active counterconditioning. Massage therapy, when the patient is relaxed, can further facilitate relaxation and encourage appropriate interaction between the animal and client.
Desensitization (graduated exposure to a provocative stimulus to minimize a response) may be incorporated to further reinforce relaxed responses. For desensitization to be effective, the patient must accept the direction and leadership of the client. Deference to the client can be established through routine and regular reinforcement of leadership on a daily basis.
Although clients may be frustrated with the problem behaviors, they should avoid expressing it in any way in the presence of the patient. Physical or verbal expressions of the clients' frustration may reinforce any anxiety that the animals are experiencing. Neither should the client provide any measure of comfort—verbal, physical, or emotional—to the patient when it is behaving inappropriately. A client's withdrawal while an animal is engaging in the self-directed behavior (negative punishment) can decrease the incidence of the behavior and prevent the client from inadvertently reinforcing the behavior. In the case of attention-seeking behaviors, client responses to the patient should be minimal while an animal is engaging in the self-directed behavior. Attempts to distract or punish the behavior reinforce the behavior.
Specific protocols using the above noted behavior modification techniques are provided in a number of current veterinary behavioral medicine texts.
Pharmacologic support may be necessary to achieve a change in behavior, particularly in cases for which 1) ongoing exposure to provocative environmental and social stimuli is unavoidable, 2) the animal's degree of arousal is sufficient that behavior modification alone will be ineffective or difficult to accomplish, or 3) the health or safety of the animal or others is at risk. But keep in mind that behavior modification and environmental management are integral to managing behavior problems and may enhance the efficacy of the drugs and effectively reduce the dosage and duration of treatment.12,13 Be sure to consider the animal's motivational or emotional state and the underlying neurophysiology when recommending pharmacologic support. The types of drugs useful for self-directed behaviors include benzodiazepines, tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), and melatonin (Table 2).
Table2. Psychotropic Medications Commonly Used in the Management of Self-directed Behaviors in Dogs and Cats
The benzodiazepines increase neural inhibition as a result of their agonistic effect upon GABA receptors and produce rapid calming and sedative effects. The benzodiazepines act as anxiolytics at low doses and hypnotics at high doses. Benzodiazepines may not only decrease reactivity, but also facilitate social interactions. A primary benefit of benzodiazepines is their immediate onset of action relative to the TCAs and SSRIs. As such, they can be valuable in initially managing situational and social anxieties in pets. Benzodiazepines used in veterinary behavioral medicine include diazepam, alprazolam, clonazepam, and lorazepam.
The benzodiazepines may interfere with short-term memory and learning. Ataxia, lethargy, and somnolence may result from high doses (hypnotic effect) as well as from lower doses, particularly during the initial days of administration or when the dose is increased. Other side effects include increased appetite, physiological dependency, paradoxical excitement, anxiety, aggression, excessive vocalization, and sleep disturbances. Although uncommon, idiosyncratic hepatotoxicity has been reported with diazepam administration in cats.14
TCAs block the reuptake of serotonin and norepinephrine and are variable competitive antagonists at acetylcholine (muscarinic), histamine, and α1- and α2-adrenergic receptors. Amitriptyline and doxepin both have antihistaminic properties because they block H1 and H2 receptors. Amitriptyline affects H1 and H2 receptors equally, while doxepin is more selective for H1 receptors. These antihistaminic properties may contribute to the efficacy of TCAs in treating pruritic conditions refractory to traditional antihistamines, and combined with their noradrenergic effects, these drugs may be valuable in managing inflammation, neuralgia, and pain associated with self-injurious behaviors. Because of the mechanism of action of TCAs in affecting synaptic receptors, allow a minimum of four weeks to observe the onset of clinical effects.
Clomipramine is relatively more serotonergic and less anticholinergic than amitriptyline and doxepin. The veterinary formulation, Clomicalm (Novartis), has been approved by the FDA for use in dogs in treating separation anxiety, although it also can be an effective aid in treating other anxiety-related behaviors. Clomipramine is also the only TCA that has documented efficacy in treating compulsive behaviors in animals.10,15
Potential side effects of TCAs in veterinary patients include transient sedation, increased appetite, weight gain, gastrointestinal disturbances, constipation, cardiac conduction disturbances in patients with dysrhythmias, anxiety, and aggression. Concurrent administration of other TCAs or SSRIs is not advisable, and concurrent administration with monoamine oxidase inhibitors (e.g. amitraz, selegiline) or L-tryptophan is contraindicated. A minimum washout period of two to three weeks is advisable before and after monoamine oxidase inhibitor administration.16,17
Selective serotonin reuptake inhibitors
SSRIs block the reuptake of serotonin with fewer effects on other receptors than TCAs. Of the SSRIs commonly used in veterinary behavioral medicine—sertraline, paroxetine, and fluoxetine—paroxetine does produce some muscarinic anticholinergic effects (primarily constipation, most notable in cats). While TCAs maintain some structural similarity as a group, SSRIs vary substantially in chemical structure, so they may differ substantially in their pharmacokinetic properties. The metabolism of paroxetine is unique in that almost no active metabolites are produced. This feature may favor paroxetine administration in elderly patients or animals with liver or kidney disease. SSRIs are used to treat anxiety disorders, depression, and aggressive behaviors. Despite the specificity of SSRIs for serotonin in comparison with clomipramine, they appear to be equally effective in managing compulsive behaviors. Because of SSRIs' mechanism of action in affecting synaptic receptors, allow a minimum of six to eight weeks to observe the onset of clinical effects.
The specificity of action of SSRIs is associated with fewer side effects than that of TCAs. Adverse effects reported in veterinary patients with SSRIs include increased lethargy, inappetence, restlessness, insomnia, weight loss, gastrointestinal disturbances, anxiety, and aggression. Concurrent administration of TCAs or other SSRIs is not advisable, and concurrent administration with monoamine oxidase inhibitors or L-tryptophan is contraindicated. A minimum washout period of two to three weeks is advisable before and after monoamine oxidase inhibitor administration.16,18
Melatonin is a naturally occurring indole amine hormone produced by the metabolism of serotonin and secreted by the pineal gland. In both nocturnal and diurnal animals, the relative concentrations of serotonin and melatonin in the pineal gland are inversely related within the daily photoperiod (i.e. during daylight hours, serotonin concentrations are high and melatonin concentrations are low; during nighttime hours, melatonin concentrations are high and serotonin concentrations are low). In addition to applications for some primary dermatologic conditions, melatonin may be effective as an anxiolytic. Melatonin has been reported to be serotonergic (possibly as a result of its derivative and inverse relationship with serotonin) and may also function as a GABAergic agonist. Potential adverse effects of melatonin in dogs and cats include somnolence (often transient) and diarrhea.
Vint Virga, DVM, DACVB
Behavioral Medicine for Animals
Veterinary Healing Arts, Inc.
P.O. Box 431
East Greenwich, RI 02818
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