Accurate sheep-scab diagnosis ‘essential’

Farmers and crofters have been reminded that free laboratory testing for sheep scab is available from SAC Consulting Veterinary Services.

Sheep scab is a notifiable disease, hitting the welfare and productivity of the animals during winter.

It is caused by Psoroptes ovis mites. Confirmation of infection requires microscopic examination of skin samples.

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

Data from SRUC, which runs SAC Consulting Veterinary Services, reveals the peak time for identifying and diagnosing sheep scab is January and February.

The rural college says early diagnosis is particularly relevant in the run-up to lambing as it is easier to treat the flock prior to the birth of any lambs.

It said it was concerned about news, reported by colleagues in England and Wales, that resistance to moxidectin in the mite which causes sheep scab has been confirmed.

“The resistance the sheep scab mite has shown to moxidectin makes an accurate diagnosis essential,” said George Caldow, head of SAC Consulting Veterinary Solutions.

“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 in the past five years SAC Consulting had examined more than 300 skin samples from sheep and scab mites were detected in 32% of all samples and lice were present in 17%.

Iwould encourage farmers to work with their vets to promptly investigate the cause of itchy sheep. GEORGE CALDOW