Abstract Obesity results from excessive body fat accumulation. Leash-walking is a practical way to increase activity in treating obesity; however, limited studies have focused on the frequency and duration of dog leash-walking. There is few research reporting on whether initiating exercise or increasing physical activity in obese dogs can induce stress. Therefore, the present study conducted a clinical trial of the leash-walking effect on weight management and identified the relationship between stress and weight management. Thirty-one dogs participated in a 4-week weight management and were divided into four groups according to their leash-walking frequency and duration. Low walking group (LW): approximately 30 min, 3 times per week; Group 1: approximately 60 min, 3 times per week; Group 2: approximately 30 min, 5 to 7 times per week; Group 3: approximately 60 min, 5 to 7 times per week. Body weight and hair cortisol concentrations of participated dogs were also evaluated. There were significant ( ) differences in the weight loss rate between the Group 2 (−1.08 ± 0.34%/week) and Group 3 (−1.26 ± 0.54%/week) compared to the LW (−0.13 ± 0.49%/week). However, there was an increasing tendency of hair cortisol concentration in Group 1 (0.15 ± 0.10 μg/dl to 0.20 ± 0.19 μg/dl) and Group 3 (0.19 ± 0.19 μg/dl to 0.45 ± 0.76 μg/dl) which are approximately 60 min of leash-walking duration groups. The results of this study suggest that it is more efficient to increase leash-walking frequency than duration for weight loss. However, suddenly increasing leash-walking may be a stress-inducing factor during weight management in overweight dogs. Therefore, it is important to start weight management with appropriate frequency and manageable duration of leash-walking and gradually increase the leash-walking times step by step.