This chapter focuses on the background of bird flu in Vietnam and delineating a framework for applying the concept of biopower to multispecies relationships. It provides an empirical account of how a particular zoonosis, bird flu, reconfigures biopower by expanding its purview to include both human and animal bodies. The emerging One Health order is particularly visible in Vietnam, where Highly Pathogenic Avian Influenza [HPAI] is decimating poultry populations and causing alarming human fatality rates. The chapter uses the case study of Vietnamese bird flu management in order to develop an approach to biopower that accounts for entanglements between species in contemporary global health. Vietnamese bird flu interventions treat humans and poultry collectively, as living beings connected by biological and social practices related to farming, exchange, consumption and recreation. Bird flu management in Vietnamese poultry farming communities provides an empirical example of the locally situated ethical dilemmas spurred by zoonotic disease control.