Obsessive compulsive disorder

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Pica.jpg

Obsessive-compulsive disorders (OCDs) or stereotypy is a relatively common behavior disorder of dogs and is physiological and behaviorally similar to the phenomenon in humans.

Specific regions within the brain are involved in OCDs, including the orbitofrontal cortex, dorsolateral prefrontal cortex, anterior cingulate circuit, basal ganglia, thalamus[1] and amygdala[2]. In dogs, significantly lower 5-HT receptor activity are observed in the frontal and temporal cortices in compulsive dogs, as well as abnormal dopamine transporter ratios in the left and right striatum[3].

OCDs may be triggered in dogs by early weaning, separation anxiety, pseudopregnancy, lightening or storm fears, physical or psychological abuse, or juvenile-related traumas. OCD in dogs does not appear to be associated with lack of training, lack of household stimulation, or social confinement. Entire male dogs appear to be more predisposed[4].

Canine OCDs can manifest as pica, excessive tail chasing, repetitive pacing, licking, chasing 'invisible flies', freezing, staring, light/shadow chasing, acral lick dermatitis and masturbation[5]. Stereotypic behavior in dogs are usually exaggerated forms of natural behaviors, such as feeding, locomotion or predation[6] and are thought to represent a coping strategy for environmentally-induced stress and anxiety. These behaviors, usually due to poor or absent psychological stimulation, frequently respond to social enrichment activities and anti-stereotypy medications such as clomipramine.

Pica, an obsessive-compulsive disorder focused on non-nutritional objects, includes sterotypic behavior such as coprophagy, stone chewing, flank sucking, and sucking or chewing on foreign objects such as wool, blankets, toys, etc. This should be distinguished from normal behavior such as bone chewing, which may last for hours but the behavior is sated once the object is consumed.

Although pica may manifest in dogs with frank mineral deficiencies, this is a very rare clinical diagnosis. Most cases of pica are a manifestation of an underlying obsessive compulsive disorder.

Pica is particularly common in densely housed conditions where boredom plays a role in initiating the vice[7]. Once psychological established, OCDs can be difficult to resolve, particularly in young dogs where the behavior becomes 'hard-wired'.

Blanket and flank sucking are relatively common in Dobermans, thought to be related to a breed-specific genetic disorder[8][9].

In some dogs, pica may be an aspect of an multifactorial obsessive-compulsive disorder, where psychosomatic frustration and boredom, particularly in work dogs, manifest in altered behaviors such as

In most cases, a diagnosis is established by first excluding any underlying physical disease that may trigger OCDs, such as:

Blood tests are recommended to detect any underlying electrolyte imbalance. Cobalamin testing should also be considered, especially in cases of iron-loss enteropathies such as ulcerative colitis.

In dogs with obsessive compulsive disorders with no obvious underlying disease process, a decision is usually made on whether the OCD interfers with quality of life to require intervention.

In cases where the disorder is relatively mild, no therapy is necessarily required.

In more severe cases, physical therapy such as regular exercise, environmental enrichment and mood-altering drugs (e.g. fluoxetine) or behavior modification drugs (e.g. diazepam, amitriptyline, clomipramine, buspirone) may be required[12].

References

  1. Stein DJ (2002) Obsessive-compulsive disorder. Lancet 360:397–405
  2. Friedlander LL (2006) Neuroimaging studies of obsessive-compulsive disorder in adults and children. Clin Psychol Rev 26:32–32
  3. Vermeire S et al (2012) Serotonin 2A receptor, serotonin transporter and dopamine transporter alterations in dogs with compulsive behaviour as a promising model for human obsessive-compulsive disorder. Psychiat Res-Neuroim 201:78–87
  4. Overall KL & Dunham AE (2002) Clinical features and outcome in dogs and cats with obsessive-compulsive disorder: 126 cases (1989-2000). J Am Vet Med Assoc 221(10):1445-1452
  5. Tiira K et al (2012) Environmental effects on compulsive tail chasing in dogs. PLoS One 7(7):e41684
  6. Mason G & Rushen J (2006) Stereotypic animal behaviour. Fundamentals and applications to welfare. Oxfordshire, UK. CABI Pub pp:286
  7. Houpt KA (1991) Feeding and drinking behavior problems. Vet Clin North Am Small Anim Pract 21(2):281-298
  8. Moon-Fanelli AA et al (2007) Blanket and flank sucking in Doberman Pinschers. J Am Vet Med Assoc 231(6):907-912
  9. Dodman N et al (2010) A canine chromosome 7 locus confers compulsive disorder susceptibility. Mol Psychiatr 15:8
  10. Bass MC & Schultze AE (1998) Essential thrombocythemia in a dog: case report and literature review. J Am Anim Hosp Assoc 34(3):197-203
  11. Harvey JW et al (1981) Well-differentiated lymphocytic leukemia in a dog: long-term survival without therapy. Vet Pathol 18(1):37-47
  12. Luescher AU (2003) Diagnosis and management of compulsive disorders in dogs and cats. Vet Clin North Am Small Anim Pract 33(2):253-267