Combined enrichment and pharmaceutical intervention reduces excessive arousal in shelter dogs in a randomized controlled trial.

INTRODUCTION

Environmental stressors in animal shelters may lead to development of excessive arousal, posing risks to adoptability and behavioral euthanasia. Recommendations regarding excessive arousal in shelter dogs include providing pharmaceuticals and enrichment.

METHODS

A randomized controlled trial was conducted to assess the influence of enrichment and pharmaceutical interventions on shelter dogs (N = 50) displaying excessive arousal from a municipal animal shelter in Texas, United States. Data were collected during 1 week of baseline conditions (days 1-7) and 1 week of treatment (days 8-14). Dogs were randomly assigned to a treatment group: (1) baseline (5-min walk, 2x/day), (2) calm enrichment (15-min walks 2x/day,15-min human-animal interaction), (3) active enrichment (15-min play 2x/day, 15-min human-animal interaction), (4) pharmaceutical (20 mg/kg gabapentin, 6 mg/kg trazodone, 5-min walk 2x/day), and (5) pharmaceutical and calm enrichment (20 mg/kg gabapentin, 6 mg/kg trazodone, 15-min walk 2x/day, 15-min human-animal interaction). Arousal scores (0 = no arousal, 4 = extreme arousal) and ease of transition out of kennel scores (0 = no difficulty, 4 = extreme difficulty) were assigned. Behaviors were assessed before, during, and after enrichment provision. All assessments occurred on days 1, 3, 7, 10, and 14.

RESULTS

During post-enrichment, the baseline group had higher arousal scores compared to active enrichment (p = 0.041), pharmaceutical (p = 0.001), and pharmaceutical and calm enrichment (p < 0.001) groups. Arousal scores were lower day 10 (p < 0.001) and day 14 (p = 0.003; vs. day 1). The pharmaceutical and calm enrichment group exhibited had less lip licking (p = 0.004), panting (p = 0.032), vocalizations (p = 0.003), and jumping (p < 0.001) compared to all treatments. The pharmaceutical group (vs. baseline) had less jumping (p < 0.001) and more body shaking (p = 0.003). Post-enrichment (vs. pre-enrichment) observations had less paw lifting (p < 0.001), yawning (p = 0.011), vocalizations (p < 0.001), and more lip licking (p < 0.001), environmental scanning (p = 0.002) and panting (p = 0.002). Dogs in kennels near exits had less paw lifting (p = 0.013) compared to dogs housed in between high arousal dogs. Longer stays were associated with more alert behavior (p = 0.001) and less environmental scanning (p = 0.04), lip licking (p = 0.013), and vocalizing (p = 0.029).

DISCUSSION: Results suggest enrichment and pharmaceutical interventions may reduce excessive arousal in shelter dogs and can be used to inform shelter intervention protocols aimed at promoting welfare and adoptability.