A good culture of care, empowering individuals within organisations to care and reflecting wider social expectations about care, is now a well-documented aspiration in managing practices of laboratory animal research and establishing priorities for patient and public health. However, there is little attention to how different institutional cultures of care interact and what happens to the accountabilities of caring roles and the entanglements of caring practices when institutional cultures meet. Drawing on research exploring the increasing practices of patient and public involvement (PPI) within animal research in the UK, we identify three ways in which cultures of care are changing in encounters between biomedical researchers and people affected by health conditions. Firstly, patient involvement in animal research brings additional bodies to care for within research facilities. Secondly, patient and public groups are seen as an increasingly important group to convey a culture of care to. Thirdly, involvement brings opportunities for patients and publics to connect care for both human and animals. However, more attention is required to understand how shifts towards cultures of care distribute power and responsibility to care within institutions and at their boundaries, where responsibilities to care may be disconnected from the power to effect meaningful changes.