Treatment of CD can include providing owner education, minimizing repetitive behavior, reinforcing alternative behavior, and/or alleviating patient stress.
Punishment-based training should not be used, as it can increase aggression, the likelihood for injury,15 and anxiety, which may exacerbate CD behavior.2 Pet owners may be less likely to use punishment-based training if educated that CD is associated with anxiety, not dominance behavior or lack of training.
To prevent unintentional reinforcement of CD behavior, pet owners should not provide or remove positive reinforcements (eg, attention, food, toys) when the dog engages in repetitive behavior. Because CD behavior becomes more ingrained the more frequently it is practiced, treatment should focus on behavior prevention. Pet owners can identify situations in which CD behavior is likely to occur to help with avoidance (eg, restricting yard access to prevent the dog from repetitively running laps around the perimeter).
Dogs should be taught an alternative behavior that can be cued and reinforced when the compulsive behavior is likely to occur. Dogs that pace may be encouraged to fetch an object. Dogs that shadow chase may be rewarded for lying down with their chin on the floor. Dogs with pica may be fed exclusively from puzzle toys, which also provide mental enrichment.
Pet owners should not interact with their pet in an inconsistent manner (eg, when a dog jumps in greeting and is alternately praised and punished). Inability to predict how a human will respond may cause the dog to feel anxious, confused, and/or frustrated; consistent, predictable interactions can help alleviate stress. A cue–response–reinforcement pattern in which a cue (eg, sit command) is given, the dog responds (eg, dog sits), and the desired behavior is reinforced (eg, a treat is given) is recommended. The consequence of undesirable behavior should be withdrawal of attention (eg, owner walks away when the dog jumps up).
Environment modification and/or physical restraint may be necessary to prevent engagement in CD behavior. Opaque privacy film on reflective surfaces can reduce light chasing. Dogs that pace in the yard can eliminate while on a leash. Barriers (eg, baby gates, pens, crates, tethers) can prevent access to trigger environments and restrict movement, which can minimize repetitive locomotor behavior. Dogs with self-injurious behavior may require basket muzzles, bandages, or Elizabethan collars, although the CD behavior may recur once these are removed.2
Because CD is associated with anxiety, psychopharmaceuticals that affect serotonin can reduce the frequency and intensity of CD behavior. Clomipramine (1-2 mg/kg PO q12h), a primarily serotonergic tricyclic antidepressant, has been the drug of choice to treat CD and has shown efficacy in the treatment of tail chasing in terriers and other repetitive behaviors.8-11 Fluoxetine (1-2 mg/kg PO q24h), a selective serotonin reuptake inhibitor, has been shown to be as effective as clomipramine in the treatment of tail chasing in dogs11 and more effective than placebo in the treatment of acral lick dermatitis.13 In a placebo-controlled clinical trial, owners of dogs given fluoxetine were significantly more likely to report a reduction in the perceived severity (ie, absent, mild, moderate, severe, very severe) of their dog’s CD behavior than owners of dogs given placebo; however, a significant difference in frequency and duration of CD behavior between fluoxetine- and placebo-treated groups was not found.12 Doses of clomipramine and fluoxetine used to treat CD varied between studies.9-13 One study reported that, although not definitively determined in dogs, clomipramine at 3 mg/kg PO q12h significantly reduced the severity of CD behavior.10 In another study, clomipramine was increased above the initial starting dose (1-2 mg/kg PO q12h) in 3 of 18 dogs to reduce tail chasing.9 In humans, treatment of obsessive-compulsive disorder typically requires higher doses of pharmaceutical agents as compared with other anxiety disorders.16
There are no FDA-approved medications for CD treatment in dogs. Because medications to treat CD behavior are extra-label, informed owner consent should be obtained, particularly because higher doses may be necessary in some patients and there may be a higher risk for adverse effects. Caution should be taken in dogs with cardiovascular disease. In humans, tricyclic antidepressants (eg, clomipramine) are associated with adverse cardiovascular effects (eg, arrhythmias) and prolongation of the QT interval on ECG.17 In a study of dogs, serum clomipramine concentration was positively correlated with an increase in P-wave duration but was not significantly correlated with QT interval.18 However, in a drug safety study, bradycardia and arrhythmias were observed in some dogs that received ≤20 mg/kg/day for 6 months.19