Wow! What a great Wikipedia entry. I can't excerpt all the cool stuff, but here's a taste (if you know what I mean)(links within the passage omitted):
In an unusual case, an Oregon teacher was reprimanded after licking blood from wounds on a track team member's knee, a football player's arm, and a high school student's hand. An Oregon public health officer commented that "We do know that animals lick their own wounds, and it may be that saliva has some healing properties. But my very strong recommendation is that you confine yourself to licking your own wounds."...Licked any wounds lately?
The Saint Magdalena de Pazzi is said to have cured a nun of sores and scabs in 1589 by licking her limbs.... Pliny the Elder in his Natural History reported that a fasting woman's saliva is an effective cure for bloodshot eyes....
There are potential health hazards in wound licking due to infection risk... The practice of metzitzah during circumcision is controversial as it can transmit the herpes virus to the infant....
Dog saliva has been said by many cultures to have curative powers in people. "Langue de chien, langue de médecin" is a French saying meaning "A dog's tongue is a doctor's tongue"... appears in a 13th century manuscript....
To "lick your wounds" means to "to withdraw temporarily while recovering from a defeat."
The phrase was spoken by Antony in John Dryden's 17th century play All for Love:
“They look on us at distance, and, like curs
Scaped from the lion's paws, they bay far off
And lick their wounds, and faintly threaten war.”