Viral Hemorrhagic Septicemia Virus (VHSV) is a pathogen that primarily affects fish, particularly species like rainbow trout and European perch. It causes severe disease characterized by hemorrhaging, inflammation, and high mortality rates in infected populations. VHSV is a member of the Rhabdoviridae family and is transmitted through water, making it a significant concern for aquaculture and wild fish populations. The virus can spread rapidly in crowded environments, such as fish farms, leading to outbreaks that can devastate stocks. Control measures include monitoring fish health, implementing biosecurity practices, and managing water quality to reduce the risk of infection.