Wound licking

The enzyme lysozyme is found in many tissues and is known to attack the cell walls of many gram-positive bacteria, aiding in defense against infection.

Salivary tissue factor, associated with microvesicles shed from cells in the mouth, promotes wound healing through the extrinsic blood coagulation cascade.

[12][13] Nitrates that are naturally found in saliva break down into nitric oxide on contact with skin, which will inhibit bacterial growth.

In a recent study, scientists have confirmed through several experiments that the protein responsible for healing properties in human saliva is, in fact, histatin.

Indeed, a dog's saliva is bactericidal against the bacteria Escherichia coli and Streptococcus canis, although not against coagulase-positive Staphylococcus or Pseudomonas aeruginosa.

[42] Pliny the Elder in his Natural History reported that a fasting woman's saliva is an effective cure for bloodshot eyes.

[46][47] "Langue de chien, langue de médecin" is a French saying meaning "A dog's tongue is a doctor's tongue", and a Latin quote that "Lingua canis dum lingit vulnus curat" or "A dog's saliva can heal your wound" appears in a thirteenth-century manuscript.

[48] In Ancient Greece, dogs at the shrine of Aesculapius were trained to lick patients, and snake saliva was also applied to wounds.

[50] The Assyrian Queen Semiramis is supposed to have attempted to resurrect the slain Armenian king Ara the Beautiful by having the dog god Aralez lick his wounds.

Allowing pet cats to lick open wounds can cause cellulitis[53][54] and sepsis[55][56] due to bacterial infections.