This paper reports results from a "natural experiment" taking place in China on the impact of dogs on owners' health. Previous Western research has reported modest health benefits, but results have remained controversial. In China pets were banned in urban areas until 1992. Since then dog ownership has grown quite rapidly in the major cities, especially among younger women. In these quasi-experimental conditions, we hypothesise that dog ownership will show greater health benefits than in the West. Results are given from a survey of women aged 25-40 in Beijing, Shanghai and Guangzhou (N = 3031). Half the respondents owned dogs and half did not. Owners reported better health-related outcomes. They exercised more frequently, slept better, had higher self-reported fitness and health, took fewer days off sick from work and were seen less by doctors. The concluding section indicates how these results may be integrated and suggests further research on the potential economic benefits of pets.