11 April 1997


NEW injectable sheep scab treatments are currently under assessment. One of these is moxidectin, a milbemycin-based product. It is expected to receive its licence within a month.

Laboratory and field studies carried out by the Department of Agriculture in Eire have shown a double or single subcutaneous injection of a 1% moxidectin formulation are effective at not only curing existing sheep scab, but also at preventing reinfection for 28 days.

Its protective capacity of 28 days following a single injection has also been proven at the Central Veterinary Laboratory. These trials were backed by a further study on the Lleyn peninsula, north Wales, during 1993.

Trials on the other product, Doramectin, are not as advanced. However, some work at CVL has shown a single injection can eradicate scab.

"These new products will have an important role if they are licensed but I do not think they will be used exclusively by farmers against sheep scab," says Dr Dermot OBrien, senior veterinary research officer at the Department of Agriculture in Dublin.

"Farmers will continue to use OPs for as long as they can, as well as SPs, because many prefer to dip their sheep. However, I can see moxidectin being used on commonage to prevent the spread of sheep scab as it is a proven prophylactic against scab infestation and reinfestation."n

New injectable sheep scab treatments promise one shot control against the highly infectious parasite.