At a recent event in Haydock in the UK, organised by Bimeda, key leaders and industry experts joined forces with mobile sheep dippers to discuss the issue of sheep scab and how to promote the best practice for its control.

Sheep scab is an issue of increasing concern. This comes on the back of recent reports confirming the detection of resistance of the scab mite to 3ML wormers, which are widely used to treat scab.

Throughout the day, speakers discussed the benefits of dipping for the control of scab and other ecto-parasites.

Benefits of dipping sheep:
  1. It targets external parasites only;
  2. It does not give rise to anthelmintic resistance;
  3. Dipping kills scab mites quickly and helps to reduce the presence of mite antigens present on the skin surface causing inflammation;
  4. The scab mite can survive off-fleece in clumps of wool for up to 17 days. Dipping gives protection against scab for longer than the 17 days, thus allowing for complete elimination in closed flocks;
  5. Dipping is the only way to control scab, ticks, lice, blowfly and keds with one product.

It is estimated that since the elimination of compulsory dipping 26 years ago, there has been a 60-fold increase in sheep scab on UK farms¹; making it important that farmers and animal health professionals plan appropriately for the control of scab.

Speaking at the event, Dr. Peter Bates – a veterinary entomologist and sheep scab expert – outlined the life cycle of the scab mite and discussed dipping as a control measure.

“In the sub-clinical stages of the disease – even though sheep are infected – there may be no visible clinical signs,” he explained.

“This is why scab can be so easily introduced into the flock when buying animals in and adequate quarantine procedures are vital.

Correct dipping technique is necessary to ensure the success of treatment.

He continued: “Diazinon should be used via a plunge dip and not with a shower or jetter and animals must be immersed for 60 seconds with their head dipped under twice.”

Rebecca Mearns – the senior veterinary advisor of Biobest – discussed its collaboration with Moredun to make the sheep scab ELISA blood test available to UK farmers.

This test allows an opportunity to detect scab infection earlier than any other means.

“We must integrate this diagnostic tool into flock health plans, particularly in high-risk situations to fulfil our responsibility to use medicines sustainably. It ensures that a diagnosis is obtained for itchy sheep to allow targeted treatment.

From left to right: Dr. Peter Bates, Lesley Stubbing, Rebecca Mearns and Rachel Mallet

Lesley Stubbings – an independent advisor – discussed issues surrounding resistance of gastro-intestinal roundworms to MLs (sheep scab treatment) and how inappropriate use of these products will increase the rate of development of resistance.

The Sustainable Control of Parasites in Sheep (SCOPS) plan of action to deliver responsible scab control strategies was also discussed. This includes: utilisation of testing; mobile dipping services; education; and the role of markets/abattoirs.

A key part of the day was a discussion on how the use of contract plunge dippers can make dipping both accessible and affordable for farmers.

The event was hosted by animal health company Bimeda and its professional services vet Rachel Mallet outlined that there are a lot of misconceptions about dipping and the barriers to having sheep dipped.

In reality, there is no reason behind preventing sheep farmers from accessing this method of scab and ecto-parasite control.

“For farmers who do not have a licence to dip or dispose of used dip, there are a number of mobile sheep dippers around the country. These provide a way for farmers to avail of dipping without having to carry it out themselves.”

Rachel continued: “In light of potential increases in the cost of dip disposal permits, it is useful to be aware that dipping contractors can even arrange to responsibly dispose of used dip.

“Dipping gives immediate scab and ecto-parasite control and, in fact, dipping is the most broad spectrum method of parasite control. It offers the only way to control scab, ticks, lice, blowfly and keds with one product,” she concluded.


(Source 1: Endemic sheep scab: risk factors and the behaviour of upland sheep flocks: Rose and Wall).