The behavioural effects of dog appeasing pheromone (DAP) continuously administered over a 7-day period, were evaluated in adult dogs housed in a public animal shelter. Barking amplitude (dB) and the frequency of discrete behavioural responses to two temperament tests associated with fear, separation and excitable behaviour (Arrowsmith, unpublished data) were recorded in 37 treatment and 17 control dogs. Mean barking amplitude (L-eq) and barking frequency were significantly reduced in dogs subject to DAP exposure for 7 days (P < 0.001, < 0.04, respectively), though peak values (L-peak) were not significantly altered. There was also some reduction in the barking amplitude of dogs during the I min recovery period, following a distraction. Following 7 days of DAP exposure, there were significant differences in resting (P = 0.03), barking (P < 0.04) and sniffing frequency (P = 0.01) in response to a friendly stranger. There were no highly significant differences in response to a neutral stranger. The preliminary tests indicate that DAP is a useful palliative tool for reducing some behavioural indicators of stress in dogs. Further tests are necessary to investigate the use of DAP in canine stress reduction in conjunction with traditional behavioural therapy programmes. (c) 2005 Elsevier B.V. All rights reserved.