Perinatal mortality can be very high and limit sheep production and viability. Limiting perinatal mortality in lambs is therefore an important part of sheep production. David McFarlane in New Zealand and his seminal paper in 1965 describing an autopsy method for the investigation of perinatal losses, represents a huge study on the changes that occur in lambs in the perinatal period. McFarlane (1965) defined perinatal mortality as death during or within seven days of birth. This definition appears to be widely accepted. Dr Kevin Haughey and Dr Stan Dennis published widely on perinatal mortality also, and wrote many publications on the topic in the 1970s. Despite the ease and high economic advantage of limiting perinatal mortality, it is often overlooked.