- Dog owners often regard their dogs as family members that provide companionship and feelings of security and of being loved. The loss of a dog may be experienced as a stressful life event and lead to bereavement. The aim of this study was to explore the contribution of a Conservation of Resources (COR) theory to the understanding of the effects pet dogs might have on their healthy adult owners' stress. We performed a cross-sectional study of 110 current dog owners and 103 bereaved owners, all females. Veterinarians from 48 private clinics from central Israel referred the researchers to owners who euthanized their pet dogs in 1-month period. The control group included owners who had lived with the dogs for more than 2 years. Based on the COR theory, 2 new instruments to measure resource losses and gains of owners were assembled. The level of stress was assessed by the Perceived Stress and the Somatic Complaints scales. Stress was stronger for bereaved owners (statistically significant). In multivariate regression, for current owners, the factors correlated with stress were: number of cigarettes, performing or not performing sports activity in previous 2 weeks, and dog-related losses. For bereaved owners, the factors that correlated with stress were number of cigarettes and losses owing to a dog's death. The findings of the study supported the hypothesis that stress among bereaved owners is higher than that among the current owners. It seems that the death of a dog is a stressful life event.