page_title: Hirudo medicinalis
section_title: Beneficial secretions
hierarchical_section_title: Hirudo medicinalis / Range and ecology / Beneficial secretions
caption_attribution_description: English: treating mastitis with leach
context_page_description: Hirudo medicinalis, the European medicinal leech, is one of several species of leeches used as "medicinal leeches".
  Other species of Hirudo sometimes also used as medicinal leeches include H. orientalis, H. troctina, and H. verbana. The Asian medical leech is Hirudinaria manillensis, and the North American medical leech is Macrobdella decora.
context_section_description: Medicinal leeches have been found to secrete saliva containing about 60 different proteins. These achieve a wide variety of goals useful to the leech as it feeds, helping to keep the blood in liquid form and increasing blood flow in the affected area. Several of these secreted proteins serve as anticoagulants (such as hirudin), platelet aggregation inhibitors (most notably apyrase, collagenase, and calin), vasodilators, and proteinase inhibitors.  It is also thought that the saliva contains an anesthetic, as leech bites are generally not painful.
caption: Treating mastitis of a cow with leech
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