Sheep scab could no longer be thought of as a problem for the uplands and certain hotspot areas, was the message from independent sheep consultant Lesley Stubbings, speaking at the Sheep Health and Welfare Group conference held at Tamworth.
She said: “The industry has to become more proactive in tackling what has become a widespread issue.
Scab can affect any sheep, anywhere, anytime and is not always easy to detect. In sub-clinical cases the sheep may look fine but they are not.
“There are only two treatments – injectable macrocyclic lactones [3-MLs] or OP plunge dipping. Over the last 25 years there has been a massive decline in dipping, with injectables now accounting for 90 per cent of treatments.
"However, we now have resistance of MLs and, although only a few cases have been confirmed, it reinforces the need to only use them in a targeted way when scab has been confirmed.”
An inexpensive Elisa blood test for scab, which can detect antibodies two weeks after infection, is now commercially available.
Results are available almost immediately, as opposed to results of a skin scrape which may take months.
Ms Stubbings said: “The Elisa test can be used as a diagnostic tool in healthy looking sheep and also as a pre-or post-movement test.
“Isolate the sheep, test and then treat if necessary, rather than blanket treating as a precautionary measure.
This will help take the pressure off MLs which will also help with worm resistance.
“It can also be used to test the efficacy of treatments.
“The good news is that resistance to injectable MLs can be reversed, unlike worm resistance, if you OP dip the flock and kill all the scab mites.”
Ms Stubbings also warned about the use of showers and jetters, she said: “These methods are not effective and OPs are not licensed for use in this way. Using them off label is not legal.”