![]() ![]() The damage from sub-acute fluke has a huge effect on growth rate, milk yield, finish weights and body condition. Losses usually occur from December onwards but may be seen much earlier (October) with a severe challenge. Typically, some sheep present with severe depression, inappetance, weakness and may be unable to stand. ![]() Sub-acute fluke presents with rapid loss of body condition and poor fleece quality despite adequate flock nutrition. Sudden death caused by acute liver fluke. Sheep with acute fluke die suddenly from severe bleeding and liver damage.įigure 3. Sudden deaths may affect up to 10 percent of sheep at risk causing grave financial loss.įigure 2. Gathering may be difficult because sheep have abdominal pain and are reluctant to run. Others in the group may be lethargic and have reduced grazing activity. Sudden deaths are the usual first indication of acute fluke. It causes severe disease due to massive blood loss in the liver or from secondary infection of the damaged liver by clostridial bacteria (Black Disease). The timing of disease depends on the timing of infestation of the snails but acute is usually seen from August to October, sub-acute from October onwards and chronic from December onwards.Īcute cases occur from three weeks after high numbers of immature fluke are eaten by the sheep. Liver fluke causes three types of disease - acute, sub-acute and chronic depending upon the level of challenge and the animals’ resilience. It takes 10 to 12 weeks after ingestion for the fluke to reach maturity and start to lay eggs.įigure 1. The immature fluke migrate through the liver structure causing damage as they develop into adults. The fluke develops in the snail,hatches out onto pasture and forms a cyst on the grass which is eaten by sheep. This stage requires wet and warm conditions above 7 to 10☌ occurring from late spring to mid-autumn. The eggs hatch and enter a specific species of snail, Galba truncatula. Adult fluke are 2 to 3cm in size and live in the bile ducts laying eggs which enter the animals intestinal tract and end up on pasture. The liver fluke parasite, Fasciola hepatica, infects the liver of both cattle and sheep. Fluke is the second highest cause for abattoir condemnations. Losses are estimated at £3 to £5 per infected sheep. Chronic disease could halve profits by reducing the lamb crop and increasing ewe mortality. Fasciolosis can have a serious financial impact on a sheep farm with immediate losses of up to 10 per cent caused by the acute or subacute form of disease. ![]()
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