If you have been following the long range weather forecasts in the news lately, you would have seen the tabloid papers warning about this winter being the ?worst for more than 60 years?, bringing arctic conditions until next spring. As lambing season approaches, you might be considering housing your flock earlier or for longer than planned with such hazardous weather on the way. However, prolonged housing can increase the risk of other diseases too, including coccidiosis.Caused by the parasite Eimeria, coccidiosis is a widespread disease in lambs. Eimeria is found almost everywhere in the environment and most animals would have been exposed to it early on in life. So why is it worth thinking about this winter?Normally, a healthy lamb in contact with low levels of Eimeria will develop an immune response to protect them from getting the disease in the future. However during a stressful time such as housing due to bad weather, the lamb?s immunity can become compromised and the numbers of infective oocysts in the environment can increase without the animal being able to fight them off effectively. The most susceptible ages are lambs four to six weeks post weaning and signs of disease range from stunted growth and poor weight gain, to full blown diarrhoea and dehydration. So what can you do to protect against it, without compromising development of the lambs? natural immunity?Lambs housed in overcrowded or unhygienic conditions can often spread disease quickly between different age groups, particularly older livestock to younger ?it?s often these older lambs that excrete very high levels of infective oocysts, compared to immune adult animals that only excrete at very low levels. Farmers are advised to keep pens and feed troughs clean and treat for coccidiosis with an effective product such as diclazuril (Vecoxan® 2.5mg/ml Oral Suspension). Given as a single dose, Vecoxan® allows natural immunity to develop while reducing oocyst (parasite) spread in the environment. There are two treatment options available, early or metaphylactically. Early treatment is advised as soon as any sign of disease is noticed and all animals should be batch treated. The second option is recommended for farms with a history of coccidiosis, after a known stress trigger has occurred such as housing. Treatment should be given 14 days after the incident, before any sign of diarrhoea occurs. Prolonged housing may mean that the anticipated pattern changes, so farmers should be alert to this possibility.In a recent study, lambs treated with a single dose of Vecoxan® experienced weight gain increases of 30 grams per day, a shorter fattening period and a feed conversion efficiency improvement of 7%. Farmers must keep in mind that rapid treatment is only half the battle when it comes to tackling coccidiosis. Proper management at housing by keeping lambs age batched, making sure they are not overcrowded and that pen and feed troughs are clean, can all help reduce the stress and overall spread of coccidiosis.For further advice, farmers are recommended to speak to their veterinary surgeon or Suitable Qualified Person for more information.