Paramphistomum

Paramphistomum Species

• Paramphistomomes are rare in the UK, but can cause severe losses in ruminants in the wet tropics.
• The adult fluke is plump and cylindrical (unusual for a trematode) and attaches to the wall of the rumen without causing serious damage.
• The eggs are like those of Fasciola, but are colourless.
• The intermediate hosts are water snails.
• These shed cercariae that form metacercariae on vegetation.
• Disease occurs if metacercariae are eaten in large numbers.
• Enteritis and diarrhoea result when immature flukes migrate along the small intestine (where the metacercariae excyst) towards the rumen.