After the recent warmer weather, we have seen several cases of lambs with dirty backsides and passing black muck. One farm had some lambs dying as well. Post mortem of these dead lambs showed high levels of immature Nematodirus worms causing siginifcant intestinal damage and dehydration of the lambs with diarrhoea.
We would advise priority being given to dosing your lambs with a wormer effective against Nematodirus battus, to reduce gut damage and avoid reduced growth rates in the lambs. Getting the timing of the dosing right should prevent lamb deaths, as well as reducing the output of eggs from these worms. These eggs are the source of infection in next year’s lambs, so you can help protect next year’s lambs against more severe gut damage by dosing at the right time now.
The warm weather (10 days at greater than 10 oC) has encouraged a rapid hatch of the Nematodirus eggs on the pasture, so we may be seeing a larger sudden worm challenge this year, with more serious effects on lambs.
A benzimidazole wormer (White Drench) will be effective in this situation.
We are still seeing cases of coccidiosis in lambs, so an egg count of lamb faeces (fresh samples from 6 to 10 lambs) will help checking what problem you have, so you can put the most cost-effective treatment in place. If you have any lambs dying, post-mortem will help in identifying the cause. Contact us at the surgery (017684 84258), where we can arrange to examine the right material for you to get a diagnosis.