Moredun moving forward with new tests and vaccines

New vaccines and diagnostic tests are in the pipeline to help farmers tackle a number of debilitating diseases that cause great distress to cattle and sheep and huge financial losses to the industry.

Scientists at Edinburgh's Moredun Research Institute, this year celebrating its 90th anniversary, are working to develop reliable tests to identify scab in sheep and Johne's disease in cattle and are close to launching a new vaccine to protect sheep from the ravages of caseous lymphadentitis (CLA).

Scab is one of the most important diseases of sheep and has become endemic in the UK since its deregulation as a notifiable disease in 1992 - when it was thought the disease had been eliminated from flocks.

New controls are due to be introduced on Friday in a renewed bid to stamp out the disease.

"Scab is highly contagious, causes considerable irritation to sheep and is a major welfare concern," said Moredun's Dr John Huntley. "Infection is not obvious in the early stages and sheep often appear clinically normal. The sub-clinical stage can last for several weeks when animals can act as a vector for infection.

"Our new diagnostic test can detect infected animals before the onset of clinical symptoms and will be a useful tool to aid control."

Last year a flock of sheep on Moredun's own research farm contracted sheep scab. Only 15 of the 160 sheep in the flock exhibited symptoms but the diagnostic test showed that 106 sheep actually had the disease.

The new test, which detects host antibodies specific to the mite which spreads scab, is protected by patent and is being used on a number of farms in Scotland to determine its most appropriate application. It is hoped to have the test available commercially to farmers within six to 12 months.

A "pen-side dipstick" is also being developed to enable farmers to make an on-the-spot diagnosis of sheep scab.

Progress is also being made on the development of a reliable diagnostic test to identify the wasting condition Johne's disease in cattle at a much earlier stage. Calves pick up the disease at an early age from faeces but the disease can remain sub-clinical for years. Many cows do not show clinical signs of the disease until they are five or six years old.

Scientists are working to improve existing diagnostic tests to overcome the problem of false positives and the detection of sub-clinical animals.

Moredun chief executive Prof Julie Fitzpatrick said the institute was seeking a commercial partner to provide the considerable development funding required to make the test commercially available to farmers.

A patent application is pending for a new vaccine to control CLA in sheep and goats. This chronic disease causes abscesses to form in lymph nodes of affected animals causing distress to the animal and considerable financial loss as a result of impaired performance.

A study to determine the efficiency of the new vaccine developed at Moredun is underway - backed by Scottish Enterprise - which could results in the vaccine being ready to enter the regulatory phase within 18 months.