Research says singling out sheep will save 1.3 million from lameness

Around 1.6 million of the UK's sheep are afflicted with lameness and 80% of that is due to the disease footrot. Footrot is infectious, caused by the bacterium Dichelobacter nodosus. Previous studies have shown that the rapid treatment of a sheep with footrot increases its rate of recovery and decreases transmission of the infection to other sheep yet lameness figures in many flocks seem to persist around the 10% level and 80% of that lameness is due to footrot.

The Warwick researchers wanted to find out why the disease seemed to persist at that level when they had found that cheap treatments are available that can produce a rapid recovery. The researchers first looked if sheep farmers were facing problems in identifying lame sheep.

Warwick researchers Professor Laura Green and Dr Jasmeet Kaler asked more than 230 farmers and sheep specialists to watch video clips of individual sheep and then say whether they thought the sheep was lame or not. They were then asked about when they would catch the sheep for inspection and treatment, or whether they would wait until more sheep in the flock displayed a similar severity of lameness.

In fact they found that almost all the study participants correctly identified lame sheep in need of further investigation, eg those with an uneven posture, a shorter stride in one leg or a slight nodding of the head as they moved. However they found a surprising split on how farmers then treated lame sheep. The researchers did find that 50% of farmers did move to catch, investigate and treat individual lame sheep within 72 hours of them exhibiting lameness however the remaining 50% took significant longer to respond leading to increased opportunities for the infection to spread. When farmers did act quickly disease rates fell dramatically and overall flock lames fell from around 10% to 2% of the flock.

Why then do 50% farmers and sheep specialists take longer to respond? The researchers believe this is simply down to different philosophies of flock management. Some farmers, put their efforts into more interventions treating all or a large section of a flock at the same time, other farmers might not have the right equipment or skilled dogs to isolate and catch individual sheep on a regular basis. Now that this research has identified the value of early identification and treatment of footrot it is hoped those farmers will ensure that they have the resources to intervene quickly to regularly inspect and treat individual lame sheep

Professor Laura Green said "Our study indicates that farmers have the skills to follow the current advice about how to minimise lameness in sheep and prevent the spread of footrot among their flock. They should inspect – and treat appropriately – the first mildly lame sheep in a group within one to three days of it first being lame"

Source: University of Warwick