Swine influenza viruses cause significant welfare problems in pig herds and pose potential pandemic risks, with biosecurity and vaccination being the primary prevention approaches.
Swine influenza causes acute welfare impacts through respiratory distress, fever, and the systemic effects of viral infection. Pigs with clinical influenza show classic sickness behaviour: reduced feeding, lethargy, and huddling. In well-managed herds, supportive care and anti-inflammatory medication can reduce the severity and duration of clinical signs. However, in large commercial units where individual monitoring is limited, affected individuals may not receive timely care. The risk of pandemic influenza strain emergence from pig populations creates a public health dimension to managing swine influenza that supports investment in improved biosecurity and welfare.