Farmers can spot lame sheep, but fail to prevent footrot spread

October 14, 2008

Sheep farmers are highly able to spot even mildly lame sheep, but many do not take steps to prevent the spread of lameness in their flocks by catching and treating these animals. A study in the open access journal BMC Veterinary Research is the first to provide evidence for the accuracy of farmers' reporting of lameness, suggesting that farmers have one of the skills required to minimise footrot and other infectious foot conditions in their flocks.

Footrot, one of the most common causes of lameness, 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. But are sheep farmers able to pick out sheep in the early stages of the disease?

Dr. Jasmeet Kaler and Professor Laura Green, researchers at the University of Warwick, 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 level of lameness.

More than 90% of the study participants correctly identified mildly lame sheep, that is, those with an uneven posture, a shorter stride in one leg or a slight nodding of the head as they moved. However, the treatment of lame sheep varied considerably between farmers. Nearly 20% said they would treat lame animals on the first day, whilst about 70% said they would do so within a week. Farmers and sheep specialists were more likely to catch and treat a sheep as the severity of its lameness increased. The majority said they would catch a single lame sheep at the point where it would not bear its weight when standing and showed discomfort when moving. However, 25 farmers said they did not catch individual sheep at all and only treated lame sheep at routine gatherings. These farmers had highest prevalence of lameness in their flock (15%).

The authors say, "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 if necessary treat – the first mildly lame sheep in a group within one to three days of it first being lame"

Source: BioMed Central