SCIENTISTS at Moredun have developed a novel diagnostic blood test for sheep scab which is now being carried out at the Animal and Plant Health Agency (APHA).

Sheep scab, caused by the mite Psoroptes ovis, is one of the most important parasitic diseases of sheep in the UK and is a notifiable disease in Scotland.

During the early stages infestations are not obvious. Animals often appear clinically normal for several weeks during which time they can infect other sheep.

For control or eradication programmes to be successful, it is crucial that all infested animals are identified as quickly as possible. The Moredun blood test now makes this possible as it can detect infested animals before they show any clinical symptoms.

APHA currently offers veterinary surgeons ectoparasitic examinations of skin scrapings taken from sheep. It is hoped that by integrating the results of the skin scrapings with the new blood test, a more powerful and reliable diagnostic service for sheep scab will be provided. The blood test will be offered free of charge for an initial period.

For this enhanced diagnosis, veterinary surgeons are asked to submit clotted blood samples (Vacutainer, red top) along with skin scraping samples from the same sheep to APHA’s Centre in Shrewsbury. APHA will then report the results to the vet.

Dr Stewart Burgess, leader of the sheep scab research group at Moredun, said: "The development of a sensitive and specific blood test provides an important tool to aid control strategies for sheep scab and, crucially, by using this new test it is now possible to detect the infection much earlier, at the sub-clinical stage.

"We are very pleased to collaborate with APHA to make the test available to support farmers and vets in the control of the disease."

Amanda Carson, Veterinary Lead Small Ruminant Expert Group at APHA said: “We support the efforts of the sheep industry to control sheep scab through effective diagnosis of the disease. We welcome new diagnostic developments such as the Moredun test which will provide a vital tool to improve our diagnostic efforts.”