The purpose of this cross sectional study was to examine whether dog ownership increases the amount of the carer's physical activities and reduces cardiovascular risk. The amount of physical activities and risk factors for cardiovascular diseases were obtained from 1189 subjects (aging 24-88, 85.6% response rate) who agreed to participant in of the study at the time of medical check-up at Ogano Central Hospital. Ogano is a small town located in the mountainous area of Saitama Prefecture. We extracted 696 subjects (age 40-69) ; some were owners and the main carers of their dogs (dog owners) and the others had no pets (non-owners). As for the amount of physical activities, the dog owners had significantly higher energy expenditure of exercise and leisure time physical activities than those of non-owners for either sex. Accordingly, the dog owners had significantly higher physical activity level than non-owners for either sex. However, the prevalence rate of cardiovascular diseases risk factors was not significantly different between the two groups for either sex. We concluded that dog owners benefited from owing dogs in increasing their physical activities. However, no evidence was found from our subjects that dog ownership per se was associated with cardiovascular health status, probably because of the significant but small difference in the physical activities.