The number of lambs reared per ewe is still one of the most important single factors affecting the productivity of sheep flocks. Some loss of lambs is unavoidable; however, an improvement in lamb numbers reared of as little as 1% can make a significant difference to the profitability of any sheep enterprise.



Whist abortion is often regarded as the most common cause of pre-natal losses, the number of ewes that are lost at or before lambing has a significant impact on flock performance and is a loss of lambs which is often under-estimated. Chronic cases of abortion are often masked by numbers of stillborn or weakly lambs. Whilst these may be put down to bad luck, chronic losses can lead to steady and persistent financial losses.

There are many causes of abortion in sheep and appropriate treatment can prevent further problems. Diagnosis often requires veterinary expertise and early diagnosis is often cost-effective. Any abortion level above 2% requires investigation. Since the cause of the abortion can only be determined by analysis of the dead lambs, afterbirth or by blood tests, it is essential that advice is sought and that any aborted ewes are isolated. It is also important that hygiene standards remain high in the lambing shed. Enzootic abortion (EAE) and toxoplasma are the most common types of abortion but are not the only cause. Other infectious organisms can also cause abortion as can poor nutrition and rough handling of ewes during pregnancy.