THE TREMATODES
The trematodes are a group of organisms that are related to the planarian of biology class. The planarian belongs to the free-living form of platyhelminth called the turbellarian. The trematodes differ from their free-living turbellarian relatives in that trematodes are all parasitic and lack the cilia that cover the body surface of the adult turbellarian.
There are two kinds of trematodes: monogenetic and digenetic. This terminology refers to whether or not there is development through morphologically dissimilar stages in some type of intermediate host, i.e., whether or not there is an "alternation of generations." The digenetic trematodes undergo a form of development wherein a larval stage develops in a mollusk and the adult develops in a different host. This dissimilar nature of the larval and adult forms caused the larvae and adults to be considered separate entities until the work of Steenstrup in 1842 showed them to be the same animals. This problem of stage identification did not exist for the monogenetic trematodes that look like adults when they hatch from the egg. The monogenetic trematodes are parasites of amphibians, fish, and other hosts, and are only important if their eggs are found in the feces of a cat that has eaten an infected host. A wide variety of digenetic trematodes, on the other hand, commonly infect cats.
The digenetic trematodes undergo their first larval development in a mollusk, typically a snail. The snail is infected with a ciliated stage, the miracidium, that hatches from the egg produced by the adult trematode. In most cases, after the larva develops through one to several stages within the snail, a proliferative stage is reached that produces the cercaria, the stage that ultimately leaves the snail. After leaving the snail, the cercaria may take one of several routes, it may encyst on vegetation, it may encyst in the tissues of a second intermediate host that will ultimately be eaten by the final host, or it may (in the case of schistosomes only) penetrate directly into the final host. Cats typically become infected by either eating an infected host or via the penetration of the skin. Feline feeding habits are such that cats seldom fall prey to the trematodes that utilize vegetation.
Digenetic trematodes can be classified in several ways. The "Natural" classification used by taxonomists takes into account many characteristics of biology and morphology to place similar organisms into similar groups. Due to the very large numbers of trematodes, this system unfortunately is often considered cumbersome by practitioners. Another means of classification is the mode of infection for the final host. Thus, the adult trematodes could be listed as those from fish, those from crabs, those from lizards, direct penetration, etc. Again, although useful for epizootiology and prevention, this is not of great use to the practitioner. Thus, the trematodes presented herein are given as to where they are typically found within the body of the final host. At the end of the chapter, a table lists how cats become infected and the geographical distribution of the species discussed in this chapter.
Trematodes of the buccal cavity
CLINOSTOMATIDAE
Clinostomumfalsatum Ortlepp, 1963
Clinostomumkalappahi Bhalerao, 1947
Clinostomum abdoni Tubangui and Garcia, 1939\
Trematodes of the intestine
CYATHOCOTYLIDAE
Mesostephanusmilvi Yamaguti, 1939
Prohemistomum vivax (Sonsino, 1893) Azim, 1933
DIPLOSTOMATIDAE
Alariamarcianae (LaRue, 1917) Walton, 1949
Cynodiplostomumazimi (Gohar, 1933) Dubois, 1936
Fibricolaminor Dubois, 1936
Pharyngostomumcordatum (Diesing, 1850) Ciurea, 1922
ECHINOSTOMATIDAE
Echinochasminae
Echinochasmusperfoliatus (Ratz, 1908) Dietz, 1909
Echinochasmus breviviteilus Fahmy, Khalifa, Sakla, 1981
Echinochasmusliliputanus (Looss, 1896) Odhner, 1911
Episthmiumcaninum (Verma, 1935) Chatterji, 1954
Stephanoproradenticulatoides Isaichikoff, 1925
Echinostominae
Artyfechinostomumsufrartyfex (Schrank, 1788) Lühe, 1909
Isthmiophoramelis (Schrank, 1788) Lühe, 1909
Echinoparyphium Dietz, 1909
HETEROPHYIDAE
Apophallinae
Apophallus donicus (Skrjabin & Lindtrop, 1919) Cameron, 1936
Apophallusvenustus (Ransom, 1920) Cameron, 1936
Apophallusmuehlingi (Jägerskiöld, 1899) Lühe, 1909
Ascocotylinae
Ascocotyleascolonga (Witenberg, 1929) Travassos, 1930
Ascocotylelongicollis (Kuntz and Chandler, 1956) Sogandares-Bernal and Lumsden, 1963
Ascocotyleminuta Looss, 1899
Ascocotyleangrense Travassos, 1916
Ascocotylelonga Ransom, 1921
Ascocotyle pachycystis Schroeder and Leigh, 1965
Ascocotylearnoldoi (Travassos, 1928) Soganderes-Bernal and Lumsden, 1963
Centrocestinae
Centrocestuscaninus Leiper, 1913
Pygidiopsisgenata Looss, 1907
Pygidiopsissumma Onji and Nishio, 1916
Pygidiopsoidesspindalis Martin, 1951
Cryptocotylinae
Cryptocotylelingua (Creplin, 1825) Fischoeder, 1903
Cryptocotyleconcavum (Creplin, 1825) Lühe, 1899
Cryptocotylequinqueangularis (Skrjabin, 1923)
Euryheminthinae
Euryhelmissquamula (Rudolphi, 1819) Poche, 1926
Euryhelmismonorchis Ameel, 1938
Euryhelmispacifica Senger and Macy, 1952
Galactosominae
Galactosomumfregatae Prudhoe, 1949
Haplorchiinae
Haplorchispumilio (Looss, 1896) Looss, 1899
Haplorchisyokogawai (Katsuta, 1932) Chen, 1936
Haplorchistaichui (Nishigori, 1924) Witenberg, 1930
Haplorchissprenti Pearson, 1964
Haplorchisparataichui Pearson, 1964
Procerovumvarium Onji and Nishio, 1916
Procerovumcalderoni (Africa and Garcia, 1935) Price, 1940
Stellantchasmusfalcatus Onji and Nishio, 1916
Heterophyinae
Heterophyesheterophyes (Siebold, 1852) Stiles and Hassal, 1900
Heterophyesaequalis Looss, 1902
Heterophyopsis continua (Onji & Nishi, 1916) Tubangui & Africa, 1938
Metagoniminae
Metagonimusyokogawai (Katsurada, 1912) Katsurada, 1912
Metagonimustakahashii Suzuki, 1930
Dexiogonimusciureanus Witenberg, 1929
Stictodoriinae
Stictodorasawakinensis Looss, 1899
Stictodora thapari Witenberg, 1953
MICROPHALLIDAE
Microphalloides vajrasthirae Waikagul, 1983
PLAGIORCHIDAE
Plagiorchis massino Petrov & Tikhonov, 1927
NANOPHYETIDAE
Nanophyetus salmincola Chapin, 1928
Trematodes of the pancreas
DICROCOELIDAE
Eurytrema procyonis Denton, 1942
Trematodes of the gallbladder and bile ducts
DICROCOELIDAE
Euparadistomum pearsoni Talbot, 1970
Euparadistomumbuckleyi Singh, 1958
Euparadistomumheiwschi Buckley and Yeh, 1958
Platynosomumconcinnum (Braun, 1901) Purvis, 1933
OPISTHORCHIDAE
Amphimeruspseudofelineus (Ward, 1901) Barker, 1911
Clonorchissinensis (Cobbold, 1875) Looss, 1907
Opisthorchisfelineus (Rivolta, 1884) Blanchard, 1895
Opisthorchisviverrini (Poirier, 1886) Stiles and Hassall, 1896
Opisthorchischabaudi Bourgat and Kulo, 1977
Paropisthorchiscaninus Stephens, 1912
Metorchisconjunctus (Cobbold, 1860) Looss, 1899
Metorchisalbidus (Braun, 1893) Looss, 1899
Metorchisorientalis Tanabe, 1919
Parametorchiscomplexum (Stiles and Hassal, 1894) Skrjabin, 1913
Pseudamphistomumtruncatum (Rudolphi, 1819) Lühe, 1909
Trematodes of the nasal fossae
ORCHIPEDIDAE
Orchipedumisostoma (Rudolphi, 1819)
TROGLOTREMATIDAE
Troglotrema mustelae Wallace, 1932
Trematodes of the lungs
TROGLOTREMATIDAE
Paragonimuswestermani (Kerbert, 1878) Braun, 1899
Paragonimuspulmonalis (Baelz, 1880) Miyazaki, 1978
Paragonimusmiyazakii Kamo, Nishida, Hatsushika, and Tomimura, 1961
Paragonimusheterotremus Chen and Hsia, 1964
Paragonimussiamensis Miyazaki and Wykoff, 1965
Paragonimusskrjabini Chen, 1964
Paragonimusohirai Miyazaki, 1939
Paragonimuskellicotti Ward, 1908
Paragonimusmexicanus Miyazaki and Ishii, 1968
Paragonimusinca Miyazaki, Mazabel, Grados, and Uyema, 1975
Paragonimusafricanus Voelker and Vogel, 1965
Paragonimusuterobilateralis Volker and Vogel, 1965
Trematodes of the blood vessels
SCHISTOSOMATIDAE
Heterobilharziaamericana Price, 1929
Ornithobilharziaturkestanica (Skrjabin, 1913)
Schistosomajaponicum (Katsurada, 1904) Stiles, 1905
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Intermediate hosts and geographic distribution of the trematode parasites of the domestic cat. |
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|
Family |
Species |
Intermediate Host |
Geographical Distribution |
|
| Clinostomatidae | ||||
| Clinostomum falsatum | Fresh-water fish | South Africa | ||
| Clinostomum kalappahi | Fresh-water fish | India | ||
| Clinostomum abdoni | Fresh-water fish | Philippines | ||
| Cyathocotylidae | ||||
| Mesostephanus milvi | Brackish-water fish (?) | Japan, India, Africa | ||
| Prohemistomum vivax | Brackish & fresh-water fish | Middle East | ||
| Diplostomatidae | ||||
| Alaria marcianae | Frogs, paratenic mammals | N America | ||
| Cynodiplostomum azimi | Frogs (?) | Middle east | ||
| Fibricola minor | Frogs | Australia | ||
| Pharyngostomum cordatum | Toads, Reptiles, shrews | Europe, Africa, China | ||
| Echinostomatidae | ||||
| Echinochasmus perfoliatus | Fresh-water fish | Europe, Middle & Far East | ||
| Echinochasmus breviviteilus | Fresh-water fish (?) | Middle east | ||
| Echinochasmus liliputanus | Fresh-water fish (?) | Middle east | ||
| Episthmium caninum | Fresh-water fish (?) | India | ||
| Stephanoprora denticulatoides | Fresh-water fish (?) | Europe | ||
| Artyfechinostomum sufrartyfex | Snail, frogs | India | ||
| Isthmiophora melis | Frogs | N America | ||
| Echinoparyphium | Frogs | Tasmania | ||
| Heterophyidae | ||||
| Apophallus donicus | Fresh-water fish | Europe | ||
| Apophallus venustus | Fresh-water fish | N America | ||
| Apophallus muehlingi | Brackish-water fish (?) | Europe | ||
| Ascocotyle ascolonga | Brackish-water fish | Middle East | ||
| Ascocotyle longicollis | Brackish-Water fish | Middle East | ||
| Ascocotyle minuta | Brackish-water fish (?) | Middle East | ||
| Ascocotyle angrense | Fresh-water fish | Brazil | ||
| Ascocotyle longa | Brackish-water fish | Americas | ||
| Ascocotyle pachycystis | Brackish-water fish | N America | ||
| Ascocotyle arnoldoi | Brackish-water fish | S America | ||
| Centrocestus caninus | Fresh-water fish | Taiwan | ||
| Pygidiopsis genata | Brackish-water fish | Europe, Middle East, Asia | ||
| Pygidiopsis summa | Brackish-water fish (?) | Asia | ||
| Pygidiopsoides spindalis | Brackish-water fish | N America | ||
| Cryptocotyle lingua | Salt-water fish | N America | ||
| Cryptocotyle concavum | Brackish-water fish (?) | Russia | ||
| Cryptocotyle quinqueangularis | Brackish-water fish | Europe, N Africa, N America | ||
| Euryhelmis squamula | Newt, Toads | Europe, N America | ||
| Euryhelmis monorchis | Frogs | N America | ||
| Euryhelmis pacifica | Salamanders | N America | ||
| Galactosomum fregatae | Brackish-water fish | W Indies, India | ||
| Haplorchis pumilio | Fresh-water fish | Middle East, Asia, Australia | ||
| Haplorchis yokogawai | Brackish-water fish | Middle East, Asia | ||
| Haplorchis taichui | Brackish-water fish | Middle East, Asia | ||
| Haplorchis sprenti | Brackish-water fish | Australia | ||
| Haplorchis parataichui | Fresh-water fish | Australia | ||
| Procerovum varium | Brackish-water fish | Australia | ||
| Procerovum calderoni | Brackish-water fish | Philippines | ||
| Stellantchasmus falcatus | Brackish & fresh-water fish | M East, Asia, Australia, Hawaii | ||
| Heterophyes heterophyes | Brackish-water fish | Mediterranean, India, Japan | ||
| Heterophyes aequalis | Salt, brackish, & fresh-water fish | Middle East | ||
| Heterophyopsis continua | Brackish-water fish | Japan, Korea | ||
| Metagonimus yokogawai | Fresh-water fish | Asia, Spain, Balkans | ||
| Metagonimus takahashii | Fresh-water fish | Asia | ||
| Dexiogonimus ciureanus | Brackish-water fish (?) | Middle East | ||
| Stictodora sawakinensis | Brackish-water fish (?) | Middle East | ||
| Stictodora thapari | Brackish-water fish (?) | Middle East | ||
| Microphallidae | ||||
| Microphalloides vajrasthirae | Crab | Thailand | ||
| Plagiorchidae | ||||
| Plagiorchis massino | Snail (?) | Eurasia, Canada | ||
| Nanophyetidae | ||||
| Nanophyetus salmincola | Fresh-water fish | Northern Pacific coast | ||
| Dicrocoelidae | ||||
| Eurytrema procyonis | Arthropod (?) | N America | ||
| Euparadistomum pearsoni | Arthropod (?) | New Guinea | ||
| Euparadistomum buckleyi | Arthropod (?) | Siberia, Europe | ||
| Euparadistomum heiwschi | Arthropod (?) | Africa | ||
| Platynosomum concinnum | Lizards, frogs, toads | S. Pacific, W. Africa, Caribbean | ||
| Opisthorchidae | ||||
| Amphimerus pseudofelineus | Fresh-water fish | Americas | ||
| Clonorchis sinensis | Fresh-water fish | Asia | ||
| Opisthorchis felineus | Fresh-water fish | Siberia, Europe | ||
| Opisthorchis viverrini | Fresh-water fish | Thailand | ||
| Opisthorchis chabaudi | Frogs | Africa | ||
| Paropisthorchis caninus | Fresh-water fish (?) | India | ||
| Metorchis conjunctus | Fresh-water fish | N America | ||
| Metorchis albidus | Fresh-water fish | Europe | ||
| Metorchis orientalis | Fresh-water fish | Asia | ||
| Parametorchis complexum | Fresh-water fish | N America | ||
| Pseudamphistomum truncatum | Fresh-water fish (?) | Europe, India | ||
| Orchipedidae | ||||
| Orchipedum isostoma | Crabs | Africa | ||
| Troglotrematidae | ||||
Troglotrema mustelaeFresh-water fishN America Paragonimus westermaniFresh-water crabsAsia Paragonimus pulmonalisFresh-water crabs & crayfishJapan, Korea, Taiwan Paragonimus miyazakiiFresh-water crabsJapan Paragonimus heterotremusFresh-water crabsChina Paragonimus siamensisFresh-water crabsThailand Paragonimus skrjabiniFresh-water crabsChina Paragonimus ohiraiBrackish-water crabsAsia Paragonimus kellicottiFresh-water crayfishN America Paragonimus mexicanusFresh-water crabsMexico, C & S America Paragonimus incaFresh-water crabsPeru Paragonimus africanusFresh-water crabsAfrica Paragonimus uterobilateralisFresh-water crabsAfricaSchistosomatidae Heterobilharzia americanaSkin penetrationN America Ornithobilharzia turkestanicaSkin penetrationEurasia Schistosoma japonicumSkin penetrationAsia