Leech

Leeches have been used in medicine for over 2,000 years. Recently, however, medical researchers have begun to look more closely at the medicinal benefits of leeches, and these investigations have proven fruitful.

In the early 1980's, a French surgeon began to use leeches to stimulate circulation in reattached fingers. These animals are now being increasingly used with microsurgery, especially following replantation or transplantation of a severed body part. Surgeons performing these procedures have found that an operation can fail because tiny blood vessels become clogged. The leech prevents painful swelling and blood clotting, not only by draining off fluid, but also by secreting an anaesthetic to ease the pain and anticoagulants to reduce clotting. These anticoagulants may have value in treating cardiovascular disease.

In addition, medical researchers studying the leech have found that leech saliva contains a host of desirable substances, including antibiotics and possible anti-cancer agents. Leeches are also being used increasingly in neuroscience research.