Use of memantine in treatment of canine compulsive disorders

Abstract

Medication plays an important role in the treatment of canine compulsive disorders (CCD). Not all cases can be managed with the current medications, and new pharmacological options are needed. This case series assesses the efficacy of the NMDA receptor blocker memantine as a possible new treatment option for CCD. Thirteen dogs with different manifestations of CCD were enrolled in the study, and data from 11 dogs were available for analysis. A behavioral and clinical history was obtained for each dog. Further medical tests were performed if deemed necessary. The main presenting complaints in the included cases were light/shadow chasing, spinning/circling, and tail chasing. All dogs were either treated with memantine alone or memantine was added to ongoing fluoxetine treatment. All owners of dogs included in the study were provided with a specific behavior modification plan in addition to the pharmacological treatment. Memantine was administered orally twice a day at a starting dose of 0.3-0.5 mg/kg. The dose was increased over time if necessary, and side effects permitting, to a dose not higher than 1 mg/kg. The owners were asked to use a clinical global impression scale (CGI) on a daily basis to assess the severity of their dog's compulsive behaviors. This score was obtained daily for up to 4 consecutive weeks, and average weekly scores were calculated. Seven (64%) of the dogs included in the study showed a reduction in the severity of CCD, with CGI scores reduced by the second week of treatment. Only 1 out of 11 dogs showed a side effect (increased frequency of urination) that was potentially related to the medication. The results suggest that memantine may be an effective, well-tolerated option for the treatment of CCD either as a sole treatment or as an add-on to fluoxetine. Further studies are needed to investigate the efficacy of memantine in the treatment of CCD.