Larval stages live mostly in the duodenal region of the small intestine and can cause enteritis characterized by diarrhea and dysentry. The common flukes of buffaloes are Paramphistomum sp. They attach themselves to the body of animals and humans while working in the paddy or walking through the forested areas. Land or forest leeches require only the moisture of monsoon rain or damp forest to become active. Some species live in trees and drop onto their hosts as the pass.
Leeches feed solely on the blood of hosts and suck blood to many fold increase their size.
They then detach and fall off. Blood loss caused by sucking and subsequent hemorrhage due to the anti-coagulant nature of the bite can leave animals weak and anemic. Occasionally leeches enter and attach within the nasal cavity or pharyngeal mucosa. In the Himalayan area the leach is by far the most common external parasite of buffalo and people. Chickens are the most practical method of control.