Self-traumatizing disorders, such as self-inflicted barbering or hair removal and abrasions or ulcerations of a body part, can occasionally start as a behavioral pathology. When presented with an apparently pruritic patient—or any patient that has caused damage to itself with its teeth, tongue, claws or even an external object—perform a thorough history and medical workup to search for the underlying cause. Endocrine, neurologic, musculoskeletal, infectious, immune-mediated, neoplastic, inflammatory, traumatic, dermatologic and behavioral causes can all play a part in an itching, scratching and chewing pet.
Physical examination reveals extensive regions of alopecia without redness, rash or skin thickening. The medical team obtains a standard dermatologic database that includes a skin scrape, skin cytology and fungal culture. The skin scrape and cytology reveal no abnormalities. An oral antihistamine for pruritus and topical antifungal medication for potential dermatophytosis are prescribed.
After two weeks, the dermatophyte culture results remain negative, and the owner reports that topical and systemic medications have not changed Morris' signs. The results of a complete blood count, serum chemistry profile, urinalysis and thyroid profile are normal.
After using a thorough protocol to help identify patients with allergic and endocrine-type skin disorders, the medical team determines that Morris does not appear to be afflicted by either of these conditions. They now must look to other possible causes of his chronic behavior.
Pruritic or other self-mutilatory disorders seen in the behavioral specialty can include compulsive disorders, displacement activities and stereotypic, attention-seeking and other anxiety-related behaviors. These are classified as primary behavioral disorders, with any skin manifestations occurring secondary to the self-induced trauma.
Categorizing, defining self-injurious behaviors
A self-mutilatory behavioral disorder should be diagnosed only after a thorough dermatologic and medical evaluation. Even after a presumptive behavioral diagnosis is made, secondary medical complications may exist that need to be treated (e.g., infection associated with self-induced injuries). Medical problems can be the initiating cause for some compulsive behaviors that later are maintained for other reasons.
The dermatologic workup for these disorders includes skin scrapings, cultures, biopsies, serum chemistry profiles that include endocrine testing, diet trials, tests for parasites, allergy testing, etc. Neurologic and orthopedic examinations and associated diagnostics also are warranted in many cases, as pain and neuropathies can contribute to self-damaging behaviors.
A comprehensive behavioral history should be taken, including:
2. Description or video of the behavior including:
3. Any changes in family, home environment, schedules
4. Concurrent medical conditions and medications
5. Owner's response to the problem
6. Specific types, amount and frequency of exercise
7. Form, duration and frequency of interactions with owners and others.
Beta-endorphins, dopamine and serotonin have been implicated as underlying mediators in compulsive disorders.5 Studies on acral lick dermatitis (ALD) in dogs identified a similarity to human compulsive and impulsive control disorders in that both human and animal models improved with clomipramine or selective serotonin reuptake inhibitor (SSRI) therapies.6
Dopaminergic drugs, such as amphetamines, have been reported to induce stereotypies,7 and dopamine antagonists have appeared to suppress stereotypies.8,9 Support that compulsive disorders are mediated through opioid receptors came from the use of naloxone to treat stereotypic behaviors (e.g., self-licking, self-chewing, scratching behavior).10 Variable neurotransmitters may be involved in different behaviors. A genetic basis is suspected in many compulsive behaviors, with certain breeds being over-represented in some behaviors (e.g., flank sucking in Doberman pinschers, tail chasing in herding breeds).
It has been proposed that patients with clinical atopic disease and other inflammatory diseases may be predisposed to behavioral sequelae, in particular, reduced coping strategies and increased reactivity, anxiety and aggression.11 But this association wasn't apparent in a cross-sectional survey that evaluated 238 dogs classified as pruritic or nonpruritic. No significant difference was found between these groups in aggression, anxiety or fearful behaviors.12
Overall, stress, conflict, anxiety and lack of environmental enrichment have been implicated as initiating or supportive factors in the development of compulsive and stereotypic disorders. Over time, the consequences of these behaviors (i.e., medical, learned, conditioned), changes in neurotransmitters and genetic predispositions help facilitate and sustain these behaviors.
Possible behavioral causes for these disorders include:
Acral lick granuloma (or acral lick dermatitis): ALD is characterized by a firm, raised, ulcerated plaque of the skin secondary to chronic licking. Lesions generally are found on the dorsal aspect of the carpus or metacarpus but also frequently over the metatarsus and tibia. ALD may be dermatologic, neurologic or behavioral in origin or a combination of these.
From a behavioral perspective, a strong association appears to exist between anxiety and licking,13 but inadequate social interactions or lack of environmental stimulation and exercise also have been proposed as psychogenic inciting causes. Displacement licking, which arises out of conflict or frustration, also is cited.5
Certain breeds appear to be over-represented, including Labrador retrievers, Great Danes, Doberman pinchers and German shepherds. This supports a familial inheritance.6,13 Whatever the inciting cause, secondary bacterial infections complicate and continue to potentiate the pruritus through inflammatory mediators and, thus, the persistent stimulus to lick.
Tail chasing in dogs: Tail chasing often happens in play and as an occasional displacement behavior (i.e., in response to conflict or stress). When it becomes more chronic and debilitating by interfering with normal activities or causing damage to the tail tip, it is considered pathologic. Underlying differentials include compulsive disorder, epileptic episodic behavior, a neuropathological disorder or even hallucination.5 In some cases, a familial predisposition (e.g., whirling or spinning in bull terriers) is suspected.
Feline psychogenic alopecia: This condition is characterized by excessive self-grooming that occurs without an underlying dermatologic or physiologic condition.5 Often the owner doesn't see the grooming bouts but notices the alopecia. The affected areas appear primarily on the medial forelimbs, caudal abdomen, inguinal region, tail or dorsal lumbar areas. Physical examination shows short, broken hairs in these areas. In our experience, lichenification, hyperpigmentation or secondary bacterial infection is rarely present in overgroomed areas. It's suspected this disorder may be a displacement activity, as a means of self-appeasement during times of stress, anxiety or conflict.
Although many practitioners diagnose this disorder, it's likely much less prominent than once thought. When pursued correctly, most cases are found to have a medical cause. In one published study, 21 cats were referred to a behaviorist for psychogenic alopecia. Medical causes of pruritus were identified in 16 of the 21 cats, and treatment of the medical condition alone resulted in complete cessation of the excessive licking. Psychogenic alopecia was diagnosed in only two of the cats.14
Clinical management of self-injurious behaviors should take into account the multifactorial origins of the disorders. Treatment should incorporate environmental and social management in addition to treating secondary medical complications. Some stereotypies may serve as coping mechanisms for animals, and the behavior in itself may not be deleterious. Treatment in these cases may not be warranted and may actually be harmful for the patient.
Treatment should be implemented in cases in which the behavior is causing secondary medical sequelae, is affecting the animal's ability to function or is becoming stressful for the owners. In the case of compulsive disorders, treatment is most successful when behavioral management, behavior modification and pharmacologic intervention are combined. Since many of these disorders ultimately are based in anxiety, punishment of the behavior is generally contraindicated. And in the case of attention-seeking behaviors, consistently and reliably removing the reinforcement will eventually cause this behavior to diminish.
If possible, identify the source of the instigating conflict, arousal, stress or frustration, and attempt to eliminate it. Often the underlying stressor may be another pet or family member, so removal is not an option. In these cases, the owner should give the pet its own area of the house or, for cats, various vertical areas to escape confrontations. If a particular situation is identified as a stressor, behavior therapy may involve teaching and reinforcing calm alternative responses or behaviors (response substitution). In these situations, systematic desensitization and counterconditioning to that stimulus may prove helpful.
Inconsistency in the environment or with interactions with the owners is likely a large component in the development of these behaviors. So it's extremely important to stress to owners that they create a consistent, reliable environment and provide predictable daily interactions to address the conflict and anxiety that sustain their pets' behaviors. All interactions between owner and pet should be structured and in a command-response-reward format. The client's response to the pet, especially when it's performing the problem behavior, should be carefully evaluated and counseled. Punishment can lead to exacerbation of the frustration or anxiety. Consoling or inappropriate redirection, distraction or punishment can reinforce the behavior.
Environmental enrichment is also a critical element in eliminating many of these behaviors. Aerobic exercise (e.g., walking, running, agility exercises, flyball) help many patients. Interactive obedience work or play can help mentally stimulate a patient as well as enhance the relationship between pet and owner. Social play with conspecifics can be an important factor for many pets. And owners should rotate interactive food toys or devices.
Suggest that cat owners provide access to elevated sites or window perches and encourage marking, rubbing, rolling and scratching. Also suggest they provide meals in interactive food toys and offer cardboard boxes, paper bags and catnip or cat grasses. A birdfeeder can be placed outside a window where the cat lays, or cat videos can be played to provide visual stimulation.
A medical team should develop a thorough protocol to make a diagnosis in a behavioral patient. Obtain a medical and behavior history, identify dermatologic lesions on physical examination and develop a clinical diagnostic plan. This will aid in differentiating among the allergy, endocrine and behavioral patient. With these results, you can then develop a comprehensive treatment plan.
Editor's Note: A chart outlining the differences among allergy, endocrine and behavioral patients is available at dvm360.com/DermChart.
Dr. Moffat is a board-certified behaviorist at VCA Mesa Animal Hospital in Mesa, Ariz. Dr. Rosenfeld is the founder and president of VTEC. He is a general practitioner and runs a mobile ultrasound practice in Cape Cod, Mass.
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