Research into parasitic diseases produces more questions than answers, finds Peter Green MRCVS
Liver fluke is a large parasite that lives in the liver of grazing animals. Animals catch the infection on damp or marshy pasture where the intermediate host, a small snail, thrives. Cattle, sheep, goats and deer can be severely affected, and farmers regularly have to dose their stock to treat liver fluke.
In one survey in Ireland, 9.5% of horses at an abattoir were infected with liver fluke; in Spain, 60% of horses were found to be positive on a blood test. We know how cattle and sheep get the infection: they ingest the early stage of the parasite as they graze. It seems obvious that horses are infected this way, too.
{"content":"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"}
