Excerpted from Lecture notes from continuing education seminar, Mesa Arizona, 2000

Self-directed traumatic disorders in dogs and cats may be a result of behavioral or medical causes. Compulsive disorders, conflict induced displacement behaviors, and conditioned or reinforced behaviors are all-important considerations. However, in order to make these diagnoses, not only must the history be consistent with these disorders, but also all underlying medical causes must first be ruled out, controlled, or resolved. It is also possible for a medical problem to develop into a compulsive disorder or for medical problems to coexist with a behavioral problem.

Examples of self directed traumatic disorders or self-injurious behaviors in dogs include acral lick dermatitis, flank sucking, spinning and tail chasing, self-directed licking or chewing, nail biting and checking of the rear end.¹ In cats, compulsive licking or hair pulling, (psychogenic alopecia), tail attacking, pawing at the face, and perhaps hyperesthesia might all have a behavioral cause.¹ In some cases there can be breed predilections such as flank sucking in Dobermans, spinning in English Bull Terriers, and tail chasing in German Shepherds.¹

Possible behavioral causes

Compulsive disorders often arise out of situations of conflict or frustration. Conflict occurs when the pet is motivated to perdorm two opposing behaviors (such as approach to greet and fear of punishment). Frustration refers to a situation in which the pet is motivated to perform a behavior but is not able to do so (such as when the pet is confined behind a barrier but is motivated to chase). The pet's response may be a displacement behavior, where the behavior is an abnormal or out of context response to the stimulus (e.g. tail chasing), or a redirected behavior, where the response to the stimulus is appropriate but directed toward different target (e.g. redirected aggression). When the conflict, frustration, or reinforcement persist or regularly recur, the behavior may become compulsive. Compulsive disorders are those in which the behavior is exhibited outside or independent of the original context, and have no apparent goal¹. Compulsive disorders may be repetitive, exaggerated, sustained or so intense that they might be difficult to interrupt.

Compulsive disorders in dogs and cats have also been referred to as stereotypes,² obsessive-compulsive disorders³, and various types of seizure foci.⁴ They are similar to the stereotypes described in other species, such as the repetitive or ritualized pacing seen in zoo animals (e.g. canids, polar bears), cribbing, self-mutilation or weaving in horses, or bar biting in pigs. These have traditionally been considered to be a response to conflict arising out of confinement or husbandry practices.¹ Stereotypic behaviors are described as being repetitive, constant, and serving no apparent purpose. However, this is not entirely accurate for all of the compulsive disorders seen in dogs and cats since some of these behaviors involve no repetition (e.g. freezing, staring), and there can be some variability in their expression.

In humans, the term obsessive-compulsive disorder is used to describe a group of behaviors with repetitive excessive motor features such as trichotillomania (hair pulling) and onychophagia (nail biting). Obsessions are intrusive thoughts that are often related to checking (e.g. appliances, security devices) or concern for contamination (e.g. excessive washing). Because of similarities in some of the signs in pets and humans, and the fact that serotonin reuptake inhibitors are effective for the treatment of both, it has been proposed that the term OCD be used to describe the syndrome in pets.⁵ However since it is unknown whether animals have obsessive thoughts, this author and others prefer the term compulsive disorders.⁶

Compulsive disorders may be associated with states of anxiety and may affect health (weight loss, self-trauma), but there may be no apparent effects on mental or physical well being.

Diagnosing the Cause of a Compulsive Disorder

The diagnosis is based on first ruling out all possible medical causes for the presenting clinical signs. A minimum database would usually include a physical examination and laboratory tests including a complete blood count, urinalysis and biochemistry profile. Additional tests may also be required based on the signalment, clinical signs, and results of the examination and initial laboratory tests. For example, a more comprehensive profile or additional diagnostic tests might be needed for pets exhibiting picas, while additional dermatological tests would be needed when there are signs of licking or self-trauma. Neurologic diseases, organ dysfunction, metabolic diseases and diseases of the special senses may also need to be ruled out. Seizure foci differ from compulsive disorders in that seizures arise independent of any specific stimuli or events, they do not appear with any degree of regularity or predictability, cannot be interrupted, may have a recognizable pre and or post ictal phase and often improve with anticonvulsant therapy.

Hyperkinesis, although uncommon might be another cause of repetitive or stereotypic behaviors, and might improve with methylphenidate therapy. Based on history and signalment, cognitive dysfunction may also be a consideration. In some cases, it might even be advisable to assess response to therapy, to rule out some medical problems. For example, a steroid trial or food trial might be indicated for compulsive licking to rule out an underlying pruritic condition, while antibiotics and perhaps anti-inflammatories might be required to resolve the infection and pruritus associated with acral lick dermatitis. Treatment to relieve any possible underlying pain or a drug trial for cognitive dysfunction might also be warranted based on the clinical signs and signalment.

Once underlying medical problems have been ruled out or treated, the behavioral history will be needed to confirm the diagnosis and work out an appropriate treatment plan. Although the examination and observation of the pet may provide valuable information, seldom will the pet display the behavior in the veterinarian's presence. Having the owners make a video of the problem can therefore be a valuable tool. The history should include a description of the problem (if it cannot be viewed) and details about the onset of the problem, including any changes in the household, and the stimuli and situations in which the problem arose. This should then be compared to the current presentation of the problem; whether it has changed in frequency, expression, intensity, or the type of stimuli that set off the problem. The owner's response to the problem, the pet's reaction, what has been successful and what aggravates the problem must also be determined. The amount and type of training, exercise and play, relationships with family members and other pets, the environment, daily schedule and the rewards that best appeal to the dog should be reviewed.

Pathophysiology of compulsive disorders

There may be a common pathophysiology for all compulsive disorders but it also possible that the neurotransmitters involved may vary between presenting complaints, or that there may be changing involvement as the problem progresses.⁷ In addition, locomotory compulsive disorders such as tail chasing or jumping in place tend to develop after repeated conflict, are displayed most commonly in situations of high arousal, and are often so intense that it may be difficult to calm the dog or interrupt the behavior.¹ By contrast oral self-directed compulsive behaviors (such as flank sucking and acral lick dermatitis) may develop more acutely, are most likely to displayed in situations of minimal (or even insufficient) stimulation, and may actually help to calm the dog down.¹

Beta-endorphins, dopamine, and serotonin have all been implicated primarily based on evidence of response to therapy. Dopaminergic drugs such as amphetamines may induce stereotypes⁸ and dopamine antagonists such as haloperidol may result in suppression of stereotypes.^9,10 Another possibility is that compulsive disorders are mediated through opioid receptors since opioid antagonists (drugs that block central endorphin receptors) such as naltrexone have been successful at reducing "stereotypes" in some cases.^{11, 12, 13, 14} In one report however, naloxone was associated with increased pruritus in a dog.¹⁵ In addition, drugs that supply an exogenous source of opiates such as hydrocodone have also been reported to be effective in the treatment of acral lick dermatitis.¹⁶

Serotonin depletion has also been suggested to be a mechanism by which stereotypes are induced,¹⁷ Based on human models for the treatment of obsessive-compulsive disorders, drugs that inhibit serotonin reuptake appear to be most effective in the treatment of many cases of canine and feline compulsive disorders. In one study of the effect of selective serotonin reuptake blockers on acral lick dermatitis, improvement was seen with clomipramine (43%), fluoxetine (39%) and sertraline (21%) in comparison to placebo, desipramine (a noradrenergic tricyclic antidepressant) and fenfluramine (a serotonin releasing agent).⁴ Clomipramine has also been shown to be effective in the treatment of canine compulsive disorders including spinning (n=17) and acral lick dermatitis (n=12) in a double blinded placebo-controlled study. The authors concluded that behavior modification was also likely to be necessary to manage canine compulsive disorder as clomipramine therapy alone for 4 weeks was not curative.¹⁸ In 12 compulsive tail chasing terriers, 75% were reported to have improved with clomipramine administration in conjunction with behavior management,¹⁹ while a number of studies have shown improvement in acral lick dermatitis at doses ranging from 1 mg/kg daily to 3 mg/kg bid.^20,21,22 A month or longer may be required before improvement is seen in these cases.

In Europe, it is believed that stereotypes arise in a number of behavioral conditions and that the other clinical signs associated with the stereotypy should be used as diagnostic criteria and in deciding what treatment to use. Stereotypes themselves are defined as having no obvious function, no obvious stop, seeming to have no internal regulation and interfere with normal behavioral function. The following classifications by Dehasse have been proposed, in addition to compulsive and hyperactive disorders.²³

• Hypersensitivity-overactivity disorder: The puppy does not show any bite control and there is hypervigilence to routine, everyday stimuli. Selegiline may improve these conditions.

• Unipolar disorder (dysthmia). These dogs may be hypervigilant, overexcitable, agitated, and unable to stop behavioral sequences and have hyposomnia. They may exhibit stereotypes, ingest their food quickly, reingest, develop a fixed gaze toward objects and have possessive aggression. Selegiline may improve this condition.

• Dissociate disorders: Between 5 months and 5 years, the dog becomes increasingly less receptive to the environment, and may have hallucinatory events. There is dilation of the brain ventricles and peaks on the EEG occipital region and sometimes demodicosis. These dogs may respond to respirodone at a dose of .5-1 mg per meter squared, or an SSRI.

Treatment of compulsive disorders

In general, treatment for most compulsive disorders should include behavioral modification and management, environmental modification, and concurrent drug therapy. For displacement behaviors that are exhibited in response to stressful events or stimuli, the stimuli must first be identified. Desensitization and counterconditioning is then needed so that the pet learns to respond appropriately when exposed to the stimuli. Reinforcers must be identified and removed, and if drug therapy is to be used anxiolytics such as buspirone, benzodiazepines or perhaps amitriptyline or clomipramine (rather than SSRI's such as fluoxetine) may useful. Concurrent medical problems must also be addressed. For compulsive disorders associated with self-trauma, dermatologic lesions may require concurrent treatmentstimulationirst step in treatment is to identify and resolve any underlying anxiety or conflict. In some cases the cause cannot be entirely resolved, so that the treatment will then need to focus on desensitizing the dog to the stressful situation (e.g. planned departures). It should also be determined whether the owner's response to the problem is in any way reinforcing the behavior, or aggravating the anxiety (e.g. punishment) so that this too can be corrected. For most cases, the treatment program will involve a more intensive and structured program of interaction and stimulatimn for the pet, and modifications to the pet's environment. Stimulation might be increased by providing additional or more intense training sessions, interactive play and exercise sessions and a variety of motivating and interesting toys to keep the pet occupied when it is spending time on its own. Some pets are interested and stimulated by pet videos. Play sessions with another pet can also prove productive (or sufficiently distracting) for some animals. A change in the pet's environment may provide enough new stimuli and distractions to resolve the problem, separate the pet from the site of the problem, as well as remove some of the conditioned factors that were present in the "problematic" environment. The goal is for the pet to receive sufficient stimulation so that it remains calm and secure at all other times.

If the pet performs the compulsive behavior when unsupervised, some form of prevention will initially be necessary. Although cage confinement or Elizabethan collars can be useful for some problems, these techniques alone merely prevent the expression of the problem and may actually serve to further increase the pet's level of anxiety. If the pet displays the behavior in the owner's presence, the goal is to ensure that no reward is given and to interrupt the pet so that it can then be directed to perform an appropriate alternative. Distracters might be a horn, citronella spray, water rifle or can of compressed air.

Punishment, whether verbal or physical, should be avoided, as it will further increase stress, anxiety and often conflict. However, studies have shown that with a sufficiently intense aversive applied remotely and consistently until the problem ceases, some compulsive behaviors may be useful.²⁴ Therefore remote devices that deter the pet each time he or she performs the behavior may be effective.

Although general suggestions can be made for the treatment of most canine compulsive disorders, more specific therapy will need to be implemented on an individual case basis. For some problems, such as flank sucking in Dobermans, if the compulsive disorder is causing no apparent physical harm to the pet, it might be best to consider this a relatively benign mechanism for coping and to allow the pet to continue the behavior. Of course, any conflict and understimulation should first be identified and resolved.

Drug therapy

Clomipramine may be effective for a variety of compulsive disorders in dogs,^{4,20,21,22,23,24,25} It is licensed for this use in dogs in Canada and although it is not licensed for use in cats (although there is a label claim for urine spraying for cats in Austalia), it has also been shown to be effective (in conjunction with environmental management) in some cats with compulsive disorders such as psychogenic alopecia^{25, 26, 27, 28} Clomipramine is the most selective inhibitor of serotonin reuptake of all of the tricyclic antidepressants. Its intermediate metabolite, desmethylclomipramine also inhibits noradrenaline reuptake. For the treatment of compulsive disorders 2 mg/kg bid might be more effective than once daily dosing.²⁰ If improvement has not been significant within 3 to 4 weeks and there are no adverse effects a dose can of 3 mg/kg bid might be effective. If the owner achieves satisfactory control the drugs can be weaned by approximately 25% every 1 to 2 weeks to avoid any rebound effect, and to determine the lowest effective dose that will control the problem.

Alternately, SSRI's such as fluoxetine, fluvoxamine or sertraline may be effective, with less sedation and anticholinergic effects.²⁹ In one study of 63 dogs with acral lick dermatitis treated with fluoxetine at 20 mg per day or placebo for 6 weeks, there was statistically significant improvement in the fluoxetine group.³⁰ Compared to tricyclic antidepressants, SSRI's cause little or no hypotension, have few anticholinergic effects, and cause less sedation and fewer cardiac conduction disturbances. They may occasionally lead to increased restlessness, agitation, insomnia, weight loss and gastrointestinal upset in humans. The use of paroxetine may be more problematic.

For acral lick dermatitis a number of other therapeutic options have been suggested. Hydrocodone has been shown to be effective in some cases, perhaps to reduce pain and discomfort or perhaps to supply an exogenous source of opiates. In some cases, especially those of early onset, opiate antagonists such as naltrexone or naloxone may be effective, but they are seldom practical due to cost and dosing. Haloperidol at 1 to 2 mg/kg bid has also been suggested to augment other pharmacologic therapy in refractory cases.³¹

DRUG	DOGS	CATS
Clomipramine	2-3 mg/kg bid	.5-1 mg/kg q24h
Fluoxetine	1 mg/kg sid or 1-4 mg/kg q 24 h (Europe)	.5 mg/kg sid
Fluvoxamine	.5-2 mg/kg bid
Paroxetine	1 mg/kg sid	.5 mg/kg sid
Selegiline	.5 - 1 mg/kg q 24h	.5 -1 mg/kg q 24 h

1. Bradshaw JWS, Neville PF, Sawyer D. Factors affecting pica in the domestic cat. J App An Behav Sci, 52, 373-379, 1997.

2. Luescher UA, McKeown DB, Halip J, Stereotypic or obsessive-compulsive disorders in dogs and cats. Vet Clin N Am Sm Anim Pract 21, 401-413, 1991

3. Overall KL. Clinical Behavioral Medicine for Small Animals, Mosby, St. Louis, 1997, 219-220

4. Dodman NH, Knowles KE, Shuster L, et al. Behavioral changes associated with complex partial seizures in Bull Terriers. J Am Vet Med Assoc, 208, 688-691, 1996

5. Rapaport JL, Ryland DH, Kriete M. Drug treatment of canine acral lick, an animal model of obsessive-compulsive disorder. Arch Gen Psychiatry, (49), 517-521, 1992

6. Hewson CJ, Luescher UA. Compulsive Disorders in Dogs. In: Voith VL, Borchelt PL, Readings in Companion Animal Behavior, Veterinary Learning Systems, Trenton, NJ, 153-158, 199⁶

7. Luescher UA. Compulsive behaviour in dogs. Veterinary International, 10 (2), 7-12, 1998

8. Hartgraves SL, Randall PK. Dopamine agonist-induced stereotypic grooming and self-mutilation following striatal dopamine depletion. Psychopharm, 90, 358-363, 1986

9. Kennes D, Odberg FO, Bouquet Y, DeRycke PH. Chanegs in naloxone and haloperidol effects during the development of captivity induced jumping stereotypy in bank voles. J Pharmacol, 153, 19-24, 1988

10. Iglauer F, Rasim R. Treatment of psychogenic feather picking in birds with a dopamine antagonist. J Small Anim Pract, 34, 564-566, 1993

11. Dodman NH, Shuster L, White SD et al. Use of narcotic antagonists to modify stereotypic self-licking, self chewing and scratching behavior. J Am Vet Med Assoc, 193, 815-819, 1988

12. Dodman NH, Shuster L, Court MH, et al. Investigation into the use of narcotic antagonists in the treatment of stereotypic behavior patterns, (crib-biting) in the horse. Am J Vet Res, 48, 311-319, 1987

13. White SD, Naltrexone for treatment of acral lick dermatitis. J Am Vet Med Assoc, 196 (7), 1073-1076, 1990

14. Brown SA, Crowell-Davis S, Court MH, et al. Naltrexone responsive tail chasing in a dog. J Am Vet Med Assoc 190, 1434, 1987

15. Schwartz S. Naltexone-induced pruritus in a dog with tail-chasing behavior. J Am Vet Med Assoc, 202 (2), 278-280, 1993

16. Brignac MM. Hydrocodone treatment of acral lick dermatitis. Proceedings of the 2^nd World Annual Congress of Veterinary Dermatology. Montreal, Quebec, 1992

17. Vanderbroek I, Odberg FO, Caemert J. Microdialysis study of the caudate nucleus of sterotyping and non-stereotyping bank voles. Proc Int Soc Appl Ethol, 245, 1995

18. Hewson CJ, Luescher UA, Parent JM, et al. Efficacy of clomipramine in the treatment of canine compulsive disorder. J Am Vet Med Assoc, 213 (12), 1760-1765

19. Moon-Fanelli AA, Dodman NH. Description and development of compulsive tail chasing in terriers and response to clomipramine treatment. 212 (8), 1252-1257, 1998

20. Paterson S. A placebo controlled study to investigate clomipramine in the treatment of canine acral lick granuloma. Third World Congress of Veterinary Dermatology Proceedings, Edinburgh, Scotland, UK, September 1996

21. Mertens PA, Dodman NH. Medical treatment of acral lick dermatitis in dogs. Kleintierpraxis 41: 313-392, 1996

22. Goldberger E, Rapaport JL. Canine acral lick dermatitis: response to the antiobsessional drug clomipramine. JAAHA, 27, 179-182, 1990

23. Dehasse J. Clinical management of stereotypies in dogs. Presented to the AVSAB annual conference, AVMA, July 1998

24. Eckstein RA, Hart BL. Treatment of acral lick dermatitis by behavior modification using electronic stimulation. J Am Anim Hosp Assoc, 32, 225-230, 1996

25. Sawyer LS, Moon-Fanelli AA, Dodman NH. Psychogenic alopecia in cats: 11 cases (1993-1996). J Am Vet Med Assoc, 214 (1), 71-74, 1999

26. 6 Seksel K, Lindeman MJ. Use of clomipramine in the treatment of anxiety-related and obsessive-compulsive disorders in cats. Aust Vet J, 76 (5), 1998, 317-321

27. Dehasse J. Feline urine spraying. Appl Anim Behav Sci 52, 365-371, 1997

28. Marder A. Presentation to the American Veterinary Society of Animal Behavior, Baltimore, 1998

29. Overall KL. Drugs, Pets and Prozac. Can Pract, 21 (5), 20-24, 1996

30. Wynchank D, Berk M. Fluoxetine treatment of acral lick dermatitis in dogs: a placebo-controlled randomized double blind trial. Depress Anxiety 1998; 8 (1): 21-3

31. Luescher UA. Pharmacologic treatment of compulsive disorder. In: Psychopharmacology of Animal Behavior Disorders. Dodman NH, Shuster L (eds.). Blackwell Science Inc., Malden, MA, 203-221, 1998

8909 Iverleigh Court Potomac, Maryland 20854
301-983-8387 800-755-4738 Fax 301-365-0191
E-mail dermapet@aol.com

Products || Protocols || Shampoo Therapy
Skin Diseases || 7 Steps to Treating Ears || Articles of Interest
About DermaPet || Newsletter || MSDS Sheets || Home