Paramphistomum spp.: Rumen fluke.

General Description: Conical, pear-shaped fluke, 5 to 13mm long and 2 to 5mm wide; light red colour.

Life Cycle: Indirect life cycle with development in a snail. Immature forms leave the snail and encyst on herbage. Ingestion by cattle results in hatching in the small intestine. The immature adults then attach to the intestinal lining for 6 to 8 weeks, causing inflammation and destruction. Thereafter they migrate to the rumen, where they attach as adults and begin to lay eggs. The prepatent period is about 3 to 4 months.

Location: Adult flukes in rumen, immature flukes in small intestine.

Geographical Distribution: Worldwide in standing water and troughs.

Significance: Severe diarrhoea and weakness may lead to death.

Effect on Host: Immature flukes burrow into the lining of the small intestine, ingesting cells and causing tissue death and haemorrhage. Extensive diarrhoea, weakness, and death may result. Inflammation occurs with the destruction of intestinal glands and degeneration of associated lymph nodes.

Diagnostic Information: Clinical signs, previous cases of paramphistomiasis in the area, and the presence of immature paramphistomes in the diarrhoeic faeces. Large numbers of eggs, similar to Fasciola, may also indicate paramphistomiasis.

Control: Improve drainage of wet pastures, or fence cattle away from them.

Paramphistomum - adults