Fibricolaminor Dubois, 1936

(Figure 2-9)


ETYMOLOGY:Fibri = fiber + cola = colon and minor for the small size


HISTORY: This worm was originally described from Australian rodents, Hydromys chrysogaster, by Dubois (1936).

GEOGRAPHIC DISTRIBUTION: Seven specimens of this species were collected from a cat in Ross, Tasmania, Australia (Dubois, 1978). Four of 59 cats (6.8%) collected from the Tasmanian midlands were found to be infected with this parasite (Gregory and Munday, 1976).

LOCATION IN HOST: Small intestine.

PARASITE IDENTIFICATION: These are small trematodes about 0.5 to 0.75 mm long. Fibricola differs from Alaria and Cynodiplostomum in that it has no pseudosuckers on either side of the oral sucker and the testes are tandem

LIFE CYCLE: The life cycle of this species is not known. It has been described for the related American species Fibricolatexensis (Chandler 1942; Leigh, 1954). Eggs passed into the environment in the feces of the natural host, the raccoon, require about 2 weeks of development before they hatch. The miracidium penetrates a snail of the genus Physa wherein it produces sporocysts. The cercaria that is produced is pharyngeate and longifurcate with colorless eyespots; the body is covered with small spines. The cercaria penetrates tadpoles and develops to the metacercarial stage. The metacercariae have been experimentally passed to chameleons and frogs by feeding of metacercariae from tadpoles. In the raccoon, the adults developed in 10 days after being fed metacercariae. Feeding metacercariae of Fibricola texensis to kittens did not result in patent infections. In Korea, metacercariae of Fibricola seoulensis harvested from the viscera of a snake, Natrix tigrina lateralis, have been shown to be capable of developing to the adult stage in cats (Hong et al., 1983).

CLINICAL PRESENTATION AND PATHOGENESIS:: There are no reports of clinical disease in cats. The only report is from the necropsy of stray cats in Tasmania without any mention of clinical presentation.

TREATMENT: Probably praziquantel, but not reported.

EPIZOOTIOLOGY: The rodents serve as the major host of this parasite, and cats are probably only incidentally infected.

HAZARD TO OTHER ANIMALS: None. Although other hosts are infected, the major means of infection is through the ingestion of the intermediate host which requires that the appropriate snail also be available.


CONTROL/PREVENTION: It is not known what intermediate host harbors the larval stage, although frogs and other paratenic hosts are possibilities.


Chandler AC. 1942. The morphology and life cycle of a new strigeid, Fibricolatexensis, parasitic in raccoons. Trans Am Mic Soc 61:156-167.

Dubois G. 1978. Notes helminthologiques IV. Strigeidae Railliet, Diplostomidae Poirier, Proterdiplostomidae Dubois et Cyathocotylidae Poche (Trematoda). Rev suiss Zool 85:607-615.

Gregory GG, Munday BL. 1976. Intestinal parasites of feral cats from the Tasmanian Midlands and King Island. Austral Vet J 52:317-320.

Hong SJ, Lee SH, Seo BS, hong ST, Chai JY. 1983. Studies on Intestinal trematodes in Korea. IX. Recovery rate and development of Fibricola seoulensis in experimental animals. Korean J Parasitol 21:224-233.

Leigh WH. 1954. notes on the life history of Fibricolatexensis (Chandler, 1942) in Florida. J Parasitol 40:45.

Figure 2-9.Fibricolatexensis collected from the small intestine of a raccoon in Texas.