C01 - Hemodynamic, Echocardiographic, Electrocardiographic, and Behavioral Effects of Oral Gabapentin in Healthy Dogs

Abstract:

Background: Gabapentin has been used prior to veterinary visits in dogs to reduce signs of anxiety; however, its effects on cardiac diagnostics have not been evaluated in dogs.

Hypothesis/Objectives: To investigate the effects of gabapentin on blood pressure, echocardiography, electrocardiography, and behavior scores in healthy dogs.

Animals: 15 healthy, client-owned dogs aged 1-8 years.

Methods: Dogs were enrolled in a prospective, double-blinded, placebo-controlled, crossover study. They were randomized to receive placebo or gabapentin (30-31.5mg/kg) orally 90 minutes prior to visit. Physical examination, Doppler blood pressure, echocardiogram, electrocardiogram, and 24-hour Holter placement were performed. After a minimum 7-day washout period, diagnostics were repeated with the alternate treatment. Anxiety was assessed by blinded review of video obtained during visits. Results were described with mean +/- standard deviation, and linear mixed effects models were performed.

Results: Left atrium to aorta ratio measured in long axis was smaller following gabapentin (2.11+/-0.14 vs. 2.19+/-0.17, p=0.017), but the difference was considered clinically unimportant. Normalized left ventricular internal dimension in systole and diastole, ejection fraction, blood pressure, corrected QT interval, 24-hour average heart rate, and number of ventricular premature complexes were not statistically significantly different. Video scores assessing stress following gabapentin were not significantly different from placebo (2.16+/-0.50 vs. 2.35+/-0.67, p=0.16). Adverse effects reported with gabapentin were sleepiness (3/15), incoordination (1/15) and urinary incontinence (1/15).

Conclusions and Clinical Importance: A single, oral, pre-visit dose of gabapentin was well-tolerated and caused a clinically unimportant reduction in left atrial to aortic ratio without significant effects on other parameters.