Co-detection of highly pathogenic avian influenza A (H5N1) and SARS-CoV-2 in a bobcat ( Lynx rufus ), Washington, 2025

Highly pathogenic avian influenza (HPAI) A(H5N1) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important One Health pathogens with expanding host ranges. We describe an investigation of a bobcat ( Lynx rufus ) in Washington State in which HPAI H5N1 clade 2.3.4.4b (genotype D1.1) and SARS-CoV-2 were co-detected. Clinical signs, diagnostic findings, and pathology were consistent with H5N1 infection. This report highlights the importance of integrated wildlife surveillance to characterize emerging zoonotic pathogens at the human-wildlife interface. IMPORTANCE This report documents the co-detection of two One Health threats, avian influenza and severe acute respiratory syndrome coronavirus 2, in a bobcat admitted to a wildlife rehabilitation facility. Although rare, the simultaneous detection of these viruses highlights gaps in routine monitoring of mammals and illustrates how wildlife may serve as bridging hosts for pathogens across the human-animal interface. Strengthening coordinated surveillance efforts is essential for understanding disease dynamics, protecting animal and public health, and supporting broader One Health preparedness strategies.