The purpose of this study was to learn more about the relationship between pet attachment, the ability to care for a pet, and depression in older adults. One hundred and seventeen Caucasian, older, adult dog owners in rural, south-central Pennsylvania were recruited using non-random sampling methods through veterinary offices and dog grooming salons in south-central Pennsylvania, USA. They completed an anonymous, self-administered questionnaire, which was returned by mail. Half of the respondents were female, 74% were married, and 27% were employed. Attachment to pet dogs was measured by the Lexington Attachment to Pets Scale. Regression analysis revealed that higher levels of pet attachment and widowhood were associated with higher levels of depression, and the ability to care for the dog and satisfaction with human relationships were associated with lower levels of depression. Higher levels of pet attachment may indicate that the pet plays a central role in the older adult's life and may substitute for human companionship.