The Sustainable Control of Parasites in Sheep (SCOPS) has warned that much of England, Wales, and lower-lying ground in Scotland and Northern Ireland is at high risk for nematodirus.

SCOPS offers a free online forecast where farmers can check the predicted hatch rate in their area. Its works via a traffic-light system that is updated daily using data from 140 weather stations across the UK.

At present, it is showing red – representing high risk – and black – very high risk – for parts of the Midlands and southern England.

For areas at very high risk, SCOPS recommends immediate treatment to avoid losses.

SCOPS forecast on Friday, April 14

Nematodirus

Nematodirus battus is a parasite found in the small intestine of lambs which can cause diarrhoea, ill thrift and death.

Its eggs typically need a period of cool temperatures followed by warmer temperatures in order to hatch.

SCOPS has said that spring 2023 has so far seen variable temperatures, with cool spells followed by warmer periods.

When temperatures exceed 10° is the opportune time for the eggs of Nematodirus battus, the to hatch.

SCOPS is reminding farmers that young lambs have no immunity to these worms and thus are susceptible to disease, particularly if there is a sudden increase in temperatures causing a mass hatch of the nematodirus eggs.

This can have “devastating consequences” for lambs that are six to 12 weeks of age, it said.