Behavioral and Physiologic Effects of a Single Dose of Oral Gabapentin in Rabbits (Oryctolagus cuniculus)

Abstract

Stress in rabbits (Oryctolagus cuniculus) may influence veterinarians’ ability to assess their health and can lead to complications such as gastrointestinal hypomotility and poor anesthetic outcomes. Gabapentin has been used as an anxiolytic in various species, but little information is available on its use in rabbits. To assess the effect of gabapentin on stress in rabbits, 5 female and 3 male New Zealand white rabbits, aged 8-12 months, weighing 3-4.5 kg, were administered a single dose (25 mg/kg) of oral compounded gabapentin. Effects on individual behaviors and selected physiologic parameters were assessed by a blinded observer using a human intruder test and tractability score (summed total 0-8, most to least tractable). Heart and respiratory rate, rectal temperature, body weight, and fecal output were also recorded. Baseline measurements for each rabbit were assessed immediately prior to gabapentin administration, and at 1, 2, and 4 hours post-administration. With this method rabbits acted as their own concurrent control group. Rabbits were assessed at 7 AM, 11 AM, and 3 PM. Data were analyzed as continuous, binary, and continuous nonparametric (P ≤ .05). No significant differences in physiologic parameters were observed between baseline and the post-administration timepoints. Fecal output was reduced similar to baseline measurements. Behaviors pressing down decreased (at 2 and 4 hours; P = .05 and P = .013, respectively) and approaching human increased (at 2 hours; P = .022) post-gabapentin compared to baseline. Tractability scores were improved at the 2-hour timepoint compared to baseline (Friedman P = .0461; Wilcoxon P = .0413). These results suggest gabapentin 25 mg/kg orally decreased reactivity with a peak effect at 2 hours, without significant effects on measured physiologic parameters. Oral gabapentin in rabbits should be considered to reduce stress in the presence of humans and to facilitate handling.