In this paper we examine the use of companion animals (pets) in studies of drugs and devices aimed at human and animal health and situate it within the context of philosophy of technology. We argue that companion animals serve a unique role in illuminating just what it means to use biological technologies and examine the implications for human-animal relationships. Though philosophers have often treated animals as technologies, we argue that the biomedical use of companion animals presents a new configuration of ethical and technological concerns that deserves more attention. Though it seems that companion animals solve many of the ethical dilemmas caused by the use of laboratory animals, the use of companion animals presents its own set of ethical concerns. This paper contextualizes the use of companion animals in research.