Okay, "Swine Flu." Why not "Pig Flu" or Hog Flu?"
Swine (n) - Pig. From the Old German word that came down to modern German as Schwein. Schweinhund = pig-dog, clearly a big insult in Germany.
Pig (n) - Swine. This is the Old English word, the origins are lost in the mists of the moors. Pig Latin dates to 1937 college-speak.
Pork (n) - Pig flesh. From the Latin version of pig, porcus.
Hog (n) - Big pig. Possibly Celtic origins.