Free laboratory testing for sheep scab in Scotland is available from SAC Consulting Veterinary Services following confirmation that resistance to moxidectin in the mite, which causes sheep scab, has been found in England and Wales.

The notifiable disease significantly impacts on the welfare and productivity of the animals during winter, with investigation of itchy sheep results showing a peak in sheep scab during January and February (see below graph).

If left untreated, the disease can cause intense irritation to the sheep, lead to reduced quality of sheepskins and wool and also affect the growth rate of lambs.

An early diagnosis is particularly relevant in the run-up to lambing, when it is easier to treat the flock prior to the birth of any lambs.

The disease is caused by Psoroptes ovis mites and confirmation of infection requires microscopic examination of skin samples from affected animals.

Sheep scab has been notifiable in Scotland since 2010, with annual notifications ranging from a high of 150 in 2011 to a low of 81 in 2014. The first three months of 2017 saw 34 notifications.

Over the last five years, SAC Consulting examined more than 300 samples with scab mites detected in almost a third (32%) of these samples and lice in 17%.

"The resistance the sheep scab mite has shown to moxidectin makes an accurate diagnosis essential," said George Caldow, head of SAC Consulting Veterinary Services. "It will allow vets and farmers to select the correct treatment and avoid the overuse of macrocyclic lactone injections. I would encourage farmers to work with their vets to promptly investigate the cause of itchy sheep, and to take advantage of the free testing available," he said.