Abstract This study was designed to separate the physically induced effects of activity from the psychologically induced effects of anticipation of activity. The purpose of this study was to determine if a psychological experience (i.e., activity anticipation) would cause a significant physiological reaction in athletic and working dogs. Physiological reaction to a psychological experience was determined by measuring physiological parameters (rectal temperature, pulse and respiration, TPR) of Greyhounds who were watching or running in a desired event comprised of intense work of short duration. The study was a cross-over design; twelve Greyhounds were split into two groups of six. On Day 1, a group of dogs chased a lure for 50 m (i.e., Run Group), while other dogs watched (i.e., Watch Group) the Run Group dogs chase the lure. On Day 2, the previous day's Watch Group became the Run Group and the previous day's Run Group became the Watch Group. This procedure was repeated daily until each dog completed two running trials and two watching trials. Physiological parameters were obtained during resting, pre-exercise, post-exercise and 30 min post-exercise. For all dogs of either group the anticipation of activity was associated with an increase in rectal temperature and heart rate from resting to pre-exercise. For the Watch Group, pre-exercise, post-exercise, and recovery heart rates were all significantly increased when compared to observations taken at rest ( P < 0.0001, P = 0.0002, and P = 0.0210). For the Watch Group, pre-exercise, post-exercise, and recovery respiratory rates were not significantly different than observations taken at rest ( P = 0.614, P = 0.190, and P = 0.0676). For both Watch and Run Groups, pre-exercise, post-exercise, and recovery rectal temperatures were significantly increased when compared to resting observations ( P < 0.0001). Heart rates were not significantly different between Watch and Run groups ( P = 0.475). This study demonstrated that both activity and anticipation of activity had significant effects on the vital signs of dogs bred and trained to perform a selected activity. Of the TPR measurements, heart rate was most associated with anticipation of activity. Respiratory rates appeared to be largely dependent on activity and therefore did not provide a sufficient marker for anticipation of activity. Of the three TPR measurements, rectal temperature demonstrated the least variation.