Effect of doxepin on quality of life in Labradors with laryngeal paralysis: A double-blinded, randomized, placebo-controlled trial.

BACKGROUND Laryngeal paralysis commonly affects older Labrador retrievers. Currently, dogs with severe disease require surgical intervention, most commonly arytenoid lateralization. Anecdotally, doxepin has been proposed to help dogs with laryngeal paralysis. HYPOTHESIS Doxepin will improve quality of life measures assessed by owners of Labrador retrievers with laryngeal paralysis not requiring emergency surgery. ANIMALS Twenty-two Labrador retrievers with laryngeal paralysis. METHODS Dogs were randomized to receive doxepin (3-5 mg/kg q12h PO) or placebo for 28 days. Owners completed quality-of-life assessments before and after completing the study. Data were compared between groups using Rank-Sum tests or Fisher's exact tests. RESULTS The 2 groups of dogs did not differ at baseline except for owner-perceived degree of ataxia (owners of dogs receiving doxepin considered them more ataxic than owners of dogs receiving placebo). After 28 days, owner-assessed quality of life measures did not differ between dogs receiving doxepin or placebo (dogs worsening: doxepin = 2, placebo = 1; dogs unchanged: doxepin = 6, placebo = 7; dogs improved: doxepin = 4, placebo = 2; P = .84). Dogs receiving placebo had a greater improvement in client-assessed overall health than dogs receiving doxepin (mean ranks: doxepin = 4.36, placebo = 6.64; P = .04). The study was terminated at this interim analysis. CONCLUSIONS AND CLINICAL IMPORTANCE Doxepin did not appear to improve any measures of owner-assessed quality of life in Labrador retrievers with laryngeal paralysis.