Avian influenza is an infectious viral disease that affects several species of birds, including chickens, turkeys, quail, and geese. Symptoms of avian influenza can range from mild to severe, with respiratory signs being the most common. Infected birds may show signs such as coughing, sneezing, nasal discharge, decreased egg production, and death. Avian influenza can also affect humans who come into contact with infected birds or their droppings. While vaccination strategies are available to protect poultry against this virus, biosecurity measures such as limiting contact between potentially infected flocks and wild birds should be followed to reduce the risk of infection.