Reduction of repetitive tail chasing in a mixed breed dog using multimodal therapy

A 29.5 kg, 2.25 year old, neutered, male, Rhodesian Ridgeback crossbreed dog presented for excessive spinning and tail chasing. These behaviors occurred exclusively indoors, only when people were present, with 4 different adopters, and in at least 6 different housing situations. The repetitive behaviors ranged from invariant spinning with no apparent function to more goal-directed tail chasing, the latter being the predominant behavior. Approximately 50% of the time, there was a notable trigger, but the other 50% of the time, the behavior appeared to start spontaneously without a discernable trigger.

Physical and neurological examinations were unremarkable. A minimum diagnostic database, including a complete blood count, chemistry profile, total thyroxine level, and common tick-borne disease serology, did not reveal any abnormalities. Further diagnostic testing was recommended to rule out potential medical causes or contributors to the abnormal repetitive behavior (ARB). Additional testing recommendations included spinal and tail radiographs, a pain medication trial, and referral to a veterinary neurologist for advanced diagnostics, including magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) analysis. The clients declined further testing due to financial constraints.

The patient was diagnosed with obsessive-compulsive/compulsive disorder (OCD/CD). Pharmaceutical options included pain and anxiolytic medication trials. The clients elected to initially treat the OCD/CD with anxiolytic medication, with a plan to add a pain medication trial if the response was minimal. Trazodone was chosen for its profile of fast calming and/or mildly sedative effects. Reducing the duration and frequency of the behavior quickly was important as the clients indicated they were contemplating rehoming or euthanizing the patient if improvement could not be promptly demonstrated. Trazodone is a serotonin antagonist and reuptake inhibitor (SARI). It is often used as a hypnotic and atypical anxiolytic medication. Two weeks after initiating trazodone, the clients reported a 25% reduction in the ARB frequency and intensity, with minimal to no sedation. The selective serotonin Reuptake Inhibitor (SSRI), fluoxetine, was added because of its anti-anxiety and anti-obsessional/compulsive/anxiety effects.

Behavioral management strategies were also implemented, including avoiding aversive interactions, minimizing identified triggers of the behavior, and enhancing environmental enrichment to improve overall welfare. Behavior modification using treats and food toys was used to counter-condition the dog to triggers such as noises or stressful situations. The clients were advised to preempt the behavior by redirecting the dog to alternate, incompatible activities for which he was rewarded. If the behavior had already begun, the clients were instructed to ignore the behavior and calmly leave the room. If the dog stopped spinning or followed the clients, they could ask the dog for alternate behavior and reinforce that behavior.

At a three-month follow-up consultation, the clients reported significant improvement, with an 80% reduction in behavior frequency, duration, and intensity. In an email follow-up three months later, the clients reported continued improvement. The behaviors were now infrequent, occurring only two to four times per week.

This patient’s early history, normal laboratory results, unremarkable physical and neurological examinations, and observed repetitive behavior support a diagnosis of OCD/CD manifested as spinning and tail-chasing associated with anxiety owing to early experiences and management.