Ascocotyle angrense Travassos, 1916
This parasite was originally described from a heron, Butorides striata, in Brazil. The only report of this parasite from the small intestine of a cat is from an experimental infection (Sogandares-Bernal F, Lumsden RD. 1963. The generic status of the heterophyid trematodes of the Ascocotyle complex, including notes on the systematics and biology of Ascocotyleangrense Travassos, 1916. J Parasitol 49:264-274). The parasite is distributed along the east coast of North America, Yucatan, and Rio de Janeiro, Brazil. This small fluke is 0.46 to 0.79 mm in length with an oral sucker bearing approximately 20 hooklets. The eggs are 16 to 24 µm long by 16 to 20 µm in width. Cats were experimentally infected with this trematode by feeding fish (poeciliid and cypriodont) gills that contained metacercariae in their filaments. The prepatent period in cats is not stated, but rats passed eggs within 48 hours after exposure. Clinical signs in the experimental animals were not monitored. Natural hosts include a long list of fish intermediate hosts, e.g., Fundulus, Lucania, Mollienesia, and a as final hosts, a long list of birds and mammals, e.g., wood duck (Aix sponsa), egret (Casmerodius albus), muskrat (Ondatra zibethicus), raccoon, and rat (Rattus norvegicus).