Apophallus donicus

Apophallus donicus (Skrjabin and Lindtrop, 1919) Cameron, 1936

(Figure 2-14)

ETYMOLOGY:Apo (away from) + phallus (phallus) [the opening of the genital sinus is anterior to the ventral sucker] and donicus for the Don River.

SYNONYMS:Rossicotrema donicum Skrjabin and Lindtrop, 1919; Tocotrema donicum (Skrjabin and Lindtrop, 1919) Witenberg, 1929; Apophallus donicus (Skrjabin and Lindtrop, 1919) Price, 1931).

HISTORY: This trematode was described by Skrjabin and Lintrop (1919) from specimens collected from cats and dogs in Russia under the name Rossicotrema donicum. There has been considerable debate over the validity of the genus and even the species. However, using the classification of Cameron (1936) (see the history of Apophallus venustus, below), it would appear that there are two distinct species that conveniently fit within the genus Apophallus that was originally created by Lühe (1909).

GEOGRAPHIC DISTRIBUTION: Russia and other parts of Europe. Reported in 1966 from a cat in the Netherlands (Jansen, 1966).

LOCATION IN HOST: Small intestine.

PARASITE IDENTIFICATION: This worm is less than 1.14 mm in length. The ventral sucker is small, the large, globular testes are located obliquely in the posterior of the body, the vitellaria extend only to the ventral sucker. The eggs are 35 to 40 µm long by 26 to 32 µm in width. Supposedly, this species differed from Apophallusvenustus is that the vitellaria in Apophallusdonicus remain lateral while those in Apophallusvenustus are continuous across the body.

LIFE CYCLE: The life cycle was examined by Ciurea (1933). When cats were fed fresh-water fish containing the metacercarial stage, eggs were present in the uteri of the developed adult worms within two and a half days after infection.

CLINICAL PRESENTATION AND PATHOGENESIS Thought to be asymptomatic although it is expected that the small tremeatodes deeply embedded within the small intestinal mucosa may cause some pathology.

TREATMENT: Probably praziquantel, but not reported.

TREATMENT: Probably praziquantel.

EPIZOOTIOLOGY: Cats become infected by eating raw fish. Animals other than the cat that have been shown to serve as hosts of the adult fluke include the dog, fox (Vulpes lagopus), and Mustela sarmatica. It has also been found in numerous piscivorous birds: Mergus merganser, Nycticorax nycticorax, Buteo buteo, and Ciconia ciconia.

HAZARD TO OTHER ANIMALS: None. Although other hosts are infected, the major means of infection is through the ingestion of the fish intermediate host which requires that the appropriate snail also be available. Thus, infection of these other hosts will typically only occur in the wild.

HAZARD TO HUMANS: None. Humans theoretically could become infected if they ingested an infected piscine host.

CONTROL/PREVENTION: Prevention of the ingestion of raw fish.

REFERENCES:

Cameron TWM. 1936. Studies on the heterophyid trematode, Apophallusvenustus (Ransom, 1920) in Canada. Part I. Morphology and taxonomy. Can J Res 14:59-69.

Ciurea I. 1933. Les vers parasites de l’homme, des mammifères et des oiseaux provenant des poissons du Danube et de la Mer Noire. Premier Mémoire. Trématodes, famille Heterophyidae Odhner, avec un essai de classification des Trématodes de la superfamille Heterophyoidea Faust. Arch Roum Pathol Exp et de Microbiol 6:5-134.

Jansen J. 1966. Apophallusdonicus (Skrjabin et Lindtrop, 1919) bij een kat. Tijdschr Diergeneesk 91:614-615.

Lühe M. 1909. Parasitische Plattwürmer. I. Trematoden. Süsswasserfauna Deutschlands Heft. 17. Jena.

Skrjabin KI, Lindtrop GT. 1919. Trematodes intestinales des chiens du Don. don Izvest Donsk Vet Inst 1:30-43.

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