Evaluation of plasma cortisol levels and behavior in dogs wearing bark control collars

On wk 1, 24 healthy mixed breed kennel dogs were screened by physical examination, complete blood count, serum biochemistry, and plasma cortisol measurement. Dogs were tested to ensure they barked at an unfamiliar dog. Dogs were randomly assigned to control, electronic bark collar or lemon spray bark collar groups (n = 8 per group). On wk 0 (acclimation baseline), dogs wore inactivated collars 30 min/day for 3 consecutivedays.On wks1and 2,dogsworeanactivatedcollar 30 min/dayfor 3consecutive days.Controls wore an inactivated collar. The bark stimulus was an unfamiliar dog walked in front of the run, three times, 30 sperpresentation.Plasmacortisolwasmeasuredwk1,wk0d3,wk1d1,wk1d3andwk2d3.ACTH was measured wk 0 d 3 and wk 1 d 1. Barking and activity were measured each session. Results: Dogswearingelectronicorlemonspraycollars barkedless thancontrols (P 0.05). Mean plasma cortisol levels werewithin the reference range for all groups throughout the study. Overall, there was a significant time effect (P 0.05). Activity did not change significantly over time (P > 0.05).