Farm Ireland

Thursday 18 January 2018

Increased threat from rumen fluke

John Donworth

Rumen fluke (paramphistomosis) is becoming a serious animal health concern on Irish farms. I know we have all heard of liver fluke, but rumen fluke was certainly new to me.

It had been thought that rumen fluke wasn't to be of any significance in countries with a temperate climate like ours, but in the wet year of 2009 rumen fluke seemed to be present in significant numbers in dairy cows.

Under the microscope, rumen fluke looks like a worm, and it has a life cycle similar to liver fluke. It is picked up by the grazing dairy cow as immature fluke, but, once in the cow, it attaches itself to the walls of the small intestine.

It later moves to the rumen to become an egg-producing adult. In light infections, young rumen fluke migrate to the rumen within four to six weeks and normally no clinical infections occur.


However, in heavy infestations the development of the young fluke is slowed and they can stay in the small intestine for more than four months and cause severe disease associated with the destruction of the line of the small intestine. In a severe outbreak, as many as 70,000 immature rumen fluke may be present in the small intestine.

Eggs are passed from the small intestine in the manure. These eggs hatch in a wet environment and the larvae develop in snails. Once developed, the larvae leaves the snail, attaches itself to the grass plants, and, once eaten by the cow, the cycle starts all over again.

Heavy infections with rumen fluke can cause animal deaths in severe cases, but more moderate infection can cause reduced weight gains, lower milk production or just plain ill thrift. Severe diarrhoea can also be a feature.

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We had a wet summer in 2008 and last year was worse again. Conditions for survival of the rumen fluke eggs could not have been better and maybe this was one of the reasons this problem appeared in July/August last year. Cows were constantly grazing wet paddocks.

If you have cows coughing with nasal discharge, and if IBR has shown up negative, then I would take a dung sample to check for the presence of fluke. You will find liver fluke, but you may find that you have rumen or stomach fluke. The test should give you an indication of how severe the infestation levels are.

How do you control rumen fluke? Any product containing oxyclozamide will do the trick. Zanil was the product of choice but this cannot be used on milking cows. Its availability at the moment also seems to be an issue.

Irish Independent