Euparadistomum pearsoni Talbot, 1970
ETYMOLOGY:Eupara = wide and distomum = two mouth along with pearsoni = for Dr. Pearson.
HISTORY: This fluke was recovered from cats in Papua New Guinea. It was originally described as "Euparadistomum sp." (Talbot, 1969) but then recognized as a new species. Other species of Euparadistomum have been described from cats, and a number of species have been described from reptiles. It may be that reptiles are the typical hosts of this group of trematode parasites.
GEOGRAPHIC DISTRIBUTION: New Guinea.
LOCATION IN HOST: Gall bladder, none in the bile ducts.
PARASITE IDENTIFICATION: This fluke is quite discoid in appearance with a color that is pinkish grey when alive. The diameter of the body is about 5 mm. The ventral sucker is centrally placed and has a diameter of 1 to 1.3 mm; the oral sucker is slightly smaller than the ventral sucker. The testes are anterior to the ventral sucker, and each is about one-fourth the diameter of the ventral sucker. The small ovary is at the posterior margin of the ventral sucker. The genital opening is between the oral and ventral suckers. The eggs are operculate, with yellow to brown eggshells, measuring 35 to 52 µm in length by 18 to 26 µm in width.
LIFE CYCLE: Not known. It is suspected that the intermediate host is an arthropod.
CLINICAL PRESENTATION AND PATHOGENESIS: Signs in infected cats have not been described if they are present.
TREATMENT: Probably praziquantel, but not reported.
EPIZOOTIOLOGY: It is not known how cats become infected. It is most likely that they are accidentally ingesting some arthropod that supports the development of the metacercarial stage. Of course, it may be as in Platynosomum (below) in which there is a reptile as the third intermediate host.
HAZARD TO OTHER ANIMALS: None known.
HAZARD TO HUMANS: There have been no records as to the infection of human beings with this parasite. If a person were to ingest the arthropod host, they could perhaps develop an infection.
CONTROL/PREVENTION: This cannot be done until the life cycle has been elucidated.
Talbot N. 1969. Trematodes of the gall bladder of cats in Port Moresby, New Guinea. Austral Vet J. 45:206.
Talbot N. 1970. On Euparadistomum pearsoni n.sp. (Trematode: Dicrocoelidae) from the gall bladder of the domestic cat in Papua. J Helminthol 44:89-96.