Calodium hepaticum (Bancroft, 1893) Moravec, 1982
(Figures 4-61 through 4-62)
Callodiumhepaticum is better known by its synonym Capillariahepatica. This parasite lives within the parenchyma of the liver of rodents. The female worm deposits eggs in the liver where they remain until the host dies or is eaten. The eggs are not infective for another host, however, until they have spent more than a month undergoing embryonation in the soil. Rats become infected when they ingest embryonated eggs. Three weeks after infection, the females are beginning to lay eggs in the liver of the rat (Campbell, 1991).
The predatory nature of the cat is such that the eggs of Calodiumhepaticum are not uncommonly found in cat feces (Fig. 4-61). The eggs can be recognized by their porous surface (giving them a striated appearance in sections) and by their size 51 to 68 μm by 30 to 35 μm (Campbell, 1991) (Fig. 4-62). Thus, these eggs can be readily distinguished from the eggs of Eucoleusaerophilus and Aonchothecaputorii which will also appear in feline feces.
Callodiumhepaticum occurs on rare occasions in the livers of other hosts. It has been reported from dogs, horses, humans, and other primates. Reports on infection in the liver of cats are rare. There is one report from Slovakia (Mituch, 1968) and one from Brazil (Santos and Barros, 1973).
Campbell BG. 1991. Trichuris and other trichinelloid nematodes of dogs and cats in the United States. Comp Cont Ed Prac Vet 13:769-799, 801.
Mituch J. 1968. Die Helminthenfauna der Hauskatze (Felis domestica L.) In der Slowakei (?SSR). Folia Vet 12:165.
Moravec F. 1982. Proposal of a new systematic arrangement of nematodes of the family Capillariidae. Folia Parasitologica 29 (2):119-131.
Santos MN, Barros CSL. 1973. Capillariahepatica: parasite of dog and cat in Rio Grande do Sol State. Rev Med Vet Sao Paulo 9:133-140.
Figure 4-61. Callodiumhepaticum. The highly striated appearing egg of this worm as it would appear in the feces of a cat that had eaten an infected rodent.
Figure 4-62.Callodiumhepaticum. This is a section of the liver of a rhesus monkey showing the typical eggs of this capillarid.