Discipline: Veterinary Medicine
Field rats, Rattus mindanensis mindanensis (Mearns, 1905) from Bay, Laguna in Luzon, Philippines were examined at various times for parasites. Among other helminths, five trematodes belonging to two families and three genera and known to infect man were recovered namely: Plagiorchis philippinensis Sandground, 1940 and Plagiorchis potamonides (Tubangui, 1946) Yamaguti, 1958 of the family Plagiorchiidae, and Artyfechinostomum malayanum (Leiper. 1911) Mendheim, 1943, Echinostoma ilocanum (Garrison, 1908) Odhner, 1911 and Echinostoma lindoense Sandground and Bonne, 1940 of the family Echinostomatidae. These are re-described based on the present collection. Plagiorchis philippinensis and Plagiorchis potamonides are illustrated by both drawings and photomicrographs while Artyfechinostomum malayanum, Echinostoma ilocanum and Echinostoma lindoense were illustrated by photomicrographs. Plagiorchis philippinensis is reported for the first time in an animal host since its discovery while Artyfechinostomum malayanum is recorded for the first time from naturally infected rats in the Philippines. Echinostoma lindoense is recorded for the first time in the Philippines constituting a new locality record for the species. The intermediate hosts of these species, when known and their transmission to humans are discussed.