Eurytrema procyonis Denton, 1942
ETYMOLOGY:Eury = wide and trema = trematode along with procyonis = for the original raccoon host.
SYNONYMS:Eurytrema vulpis Stunkard, 1947; Concinnum procyonis of Schell, 1985.
HISTORY: This fluke was originally described from specimens recovered form the pancreatic duct of a raccoon in Texas, USA (Denton, 1942). Burrows and Lillis (1960) discovered the same parasite in the pancreatic ducts of two cats in New Jersey, USA.
GEOGRAPHIC DISTRIBUTION: This species of Eurytrema has only been reported from the eastern United States of America. In a survey of 290 cats from St. Louis, Missouri, USA, 31 were found to be infected with this parasite (Fox et al., 1981). A survey of 36 cats within a 250 mile radius of Fort Knox, Kentucky, USA, reveal that 5 of these cats had pancreatic flukes (Sheldon, 1966).
LOCATION IN HOST: Pancreatic duct; in one of the cases described by Burrows and Lillis, the cat had over 300 of the flukes in the pancreatic duct and an additional 67 flukes in the bile ducts and gall bladder.
PARASITE IDENTIFICATION: This fluke is 1.7 to 2.5 mm in length, and 0.73 to 1.3 mm wide at mid body. There is a well developed ventral sucker that is about one-fourth of the body length towards the posterior end, and the testes are large, paired, and just posteriad to the ventral sucker. There is a cirrus present behind the genital pore that opens anterior to the ventral sucker. The eggs are 45 to 53 µm long by 29 to 36 µm wide.
LIFE CYCLE: The life cycle of this trematode is only incompletely described. Embryonated eggs are eaten by a land snail, Mesodon thyroidus. The cercariae develop within sporocysts within these snail, and when developed, the cercariae have very short tails. The sporocysts, containing numerous cercariae, are extruded from the snail. Viable cercariae are still present within the extruded sporocysts after 5 days. It is believed that the second intermediate host is most likely an arthropod (Denton, 1944).
CLINICAL PRESENTATION AND PATHOGENESIS: Cats infected can develop pancreatic atrophy and fibrosis (Anderson et al., 1987); the inflammatory pancreatic disease can lead to clinical signs of weight loss and intermittent vomiting. The pancreatic ducts become thickened, and the main duct can be enlarged with numerous flukes. Infected cats may show a reduction in the protein and carbonate content of pancreatic fluid, and an overall reduction in the volume of fluid produced. (Fox et al., 1981).
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.
HAZARD TO OTHER ANIMALS: Raccoons and foxes are quite often infected with this parasite.
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. One of the naturally infected cats was a four-and-one-half year old spayed, female American indoor-outdoor cat (Anderson et al. 1987). It is not known how this cat became infected or how the infection could have been prevented.
Anderson WI, Georgi ME, Car BD. 1987. Pancreatic atrophy and fibrosis associated with Eurytremaprocyonis in a domestic cat. Vet Rec 120:235-236.
Burrows RB, Lillis WG. 1960. Eurytremaprocyonis Denton, 1942 (Trematoda: dicrocoelidae), from the domestic cat. J Parasitol 45:810-812.
Denton JF. 1942. Eurytremaprocyonis, n. sp., (Trematodea: Dicrocoelidae), form the raccoon, Procyon lotor. Proc Helm Soc Wash 9:31-32.
Denton JF. 1944. Studies on the life history of Eurytremaprocyonis Denton, 1942. J Parasitol 30:277-286.
Fox JN, Mosley JG, Vogler GA, Ausitn JL, Reber HA. 1981. Pancreatic function in domestic cats with pancreatic fluke infection. JAVMA 178:58-60.
Sheldon WG. 1966. Pancreatic flukes (Eurytremaprocyonis) in domestic cats. JAVMA 148: 251-253.
Figure 2-32. Eurytremaprocyonis recovered form the pancreatic duct of a cat in New Jersey. Note the lateral vitellaria, the testes that are anterior to midbody, the large anterior and ventral suckers, and the uterus filled with eggs that extends posteriad between the vitellaria to fill the body with dark eggs.