Don't overreact to rumen fluke figures in FEC results, urge experts
Cattle and sheep industry experts are urging farmers not to overreact to rumen fluke figures in faecal egg count (FEC) results.
The inclusion of rumen fluke figures in FEC sample results isn’t necessarily a cause for concern, the Sustainable Control of Parasites in Sheep (SCOPS) and Control of Cattle Parasites Sustainably (COWS) groups say.
SCOPS and COWS have been working to encourage livestock producers to use FECs to monitor liver fluke burdens in cattle and sheep.
Experts say the internal parasite has become increasingly unpredictable – and this has brought rumen fluke under the spotlight too.
Diana Williams, of the University of Liverpool and who sits on the COWS Steering Group, says many farmers and their advisers are currently looking at FEC sample results.
"This is an important element within active liver fluke monitoring. But within the SCOPS and COWS industry groups, we are keen to ensure this does not lead to unnecessary treatment of rumen fluke in sheep and cattle.
“Increasingly, laboratories will record the incidental presence of rumen fluke eggs in faecal samples, but this does not indicate a need to treat," she says.
“A positive egg count only indicates the presence of adult rumen fluke in the rumen. On the very rare occasions that disease is caused by rumen fluke, it is due to large numbers of immature rumen fluke in the duodenum (duodenitis).
"There are no specific diagnostic tests for immature rumen fluke, and they would be negative on faecal egg count.”
What's the advice for farmers?
SCOPS and COWS have provided guidance and facts about rumen fluke:
• The detection of rumen fluke eggs only indicates the presence of adults in the rumen. In the majority of cases, it does not indicate any production loss or need to take action.
• Liver fluke remains the more important of the two fluke parasites. Co-infections of liver fluke and rumen fluke are common, but any treatment should focus on the presence of liver fluke.
• Disease due to rumen fluke is not typically caused by adults in the rumen. It is due to a large build-up of immature rumen fluke in the duodenum and is the result of a very high challenge on pasture, leading to large numbers of immature parasites in the intestine.
• If you are concerned about rumen fluke, discuss results with your vet. There are no licensed treatments for rumen fluke and the only active that can kill them (oxyclozanide) has a low safety margin and must be used carefully.
• Oxyclozanide can only be prescribed by a veterinary surgeon for use against rumen fluke and should only be used where there is conclusive evidence that an infestation of rumen fluke is likely to be causing a health/welfare issue.
• Experts say that anecdotal reports of production and/or health benefits in response to treatment of rumen fluke are unlikely to be due to removal of adult rumen fluke and more likely to be as the result of removing a co-infection of liver fluke that may not have been reported.
