Use of trazodone as an adjunctive agent in the treatment of canine anxiety disorders: 56 cases (1995-2007).

OBJECTIVE To evaluate efficacy of trazodone hydrochloride as an adjunctive treatment for anxiety disorders as well as treatment protocol, dose range, concurrent drug use, adverse events, and therapeutic response in dogs unresponsive to other pharmacologic agents. DESIGN Retrospective case series. ANIMALS 56 dogs with anxiety disorders treated at a referral veterinary behavior clinic. PROCEDURES Medical records of dogs with anxiety disorders adjunctively treated with trazodone were retrospectively evaluated with respect to signalment, primary and secondary behavioral diagnoses, physical examination results, hematologic data (CBC and serum biochemical panel), pharmacologic management, and outcome. RESULTS Overall, trazodone, used as an adjunctive agent in combination with other behavioral drugs, was well tolerated over a wide dose range and enhanced behavioral calming when administered on a daily or as-needed basis. CONCLUSIONS AND CLINICAL RELEVANCE Although further controlled studies of dose range, efficacy, and safety are needed, trazodone may provide an additional therapeutic option for use in dogs that are unresponsive to conventional treatment.