Pigs can have more than one type of flu at the same time. This means that viruses can mix genes and become a type of flu that could cause a pandemic.

Swine influenza virus is a virus that is common in pigs. This type of influenza virus can also infect humans and birds. Swine influenza virus is sometimes called SIV or swine flu.

Swine flu is common in pigs. Normally, it only infects people who have been in close contact with pigs. However, the disease can spread from one person to another. Swine flu can cause fever, disorientation (not being clear-headed), stiffness of the joints, vomiting, and loss of consciousness. Sometimes this ends in death. There are different types, or strains, of swine flu. They are called H1N1,H1N2,H3N1,H3N2, and H2N3.