Nematodirus parasites live in the intestine of sheep and infection can lead to profuse watery yellow-green scouring and ill thrift. The concern is that the performance of young lambs that receive an early season check in growth due to nematodirosis may be compromised for the rest of the grazing season and lambs will take longer to reach market weight as a result.
Most losses in the UK occur in the spring when lambs start to graze pastures contaminated with parasite larvae. Once temperatures begin to rise, Nematodirus eggs deposited on the pasture from last year’s lambs will hatch into infectious larvae en mass, posing a significant risk to this season’s lambs.

This disease is commonly diagnosed on the basis of large numbers of Nematodirus eggs in faeces – these faecal sample tests are relatively inexpensive and can be carried out either by your own vet or by us.

Research from the Moredun, suggest that, in high risk seasons, a total of three treatments with an effective anthelmintic given three weeks apart should be enough to control disease. The timing of the first dose depends on the prevailing temperatures and will vary seasonally but would generally be given sometime in early to mid-May. On farms with a reduced risk of nematodirosis, only two treatments may be necessary.

Please ask Kathryn Lawson at the trade desk for advice.