: influenza A of swine that is caused by any of several subtypes (such as H1N1 or H3N2) of the causative orthomyxovirus and in which sporadic transmission to humans has occurred — compare swine flu
: influenza of swine that is marked by fever, lethargy, labored breathing, coughing, and anorexia and that is typically not fatal but may be complicated by development of bronchopneumonia or secondary bacterial infection
Note:
Swine influenza is caused by any of several subtypes (such as H1N1 or H3N2) of an orthomyxovirus (species Influenza A virus of the genus Influenzavirus A). Strains of the virus subtypes have been transmitted to humans, sometimes causing outbreaks.