The objective of the present study was to utilise an accurate canine pedometer methodology and to assess the relationship between activity and body condition score (BCS) in dogs. Initial methodology validation used videography and pedometer step measurements to assess actual steps taken in comparison with pedometer readings for twenty large, medium and small dogs. During the validation, dogs considered to be medium or large breed showed no significant difference between pedometer readings and actual steps taken. A total of seventy-seven obese and non-obese dogs over 35 cm (14 inches) shoulder height and over 10 kg were recruited from a dog obesity clinic and a community sample to assess daily walking activity. Body condition scoring and pedometer steps were assessed on three separate weeks during a 10-week period. During the activity monitoring, daily step counts ranged from 5555 to 39 970 steps/d among the seventy-seven medium and large dogs. Dogs’ BCS were inversely correlated with average daily steps (Spearman's ρ = − 0·442, P < 0·0001). The present study identified a significant inverse correlation between daily walking steps and BCS over a range from 4 to 9 out of 9 (P < 0·0001).