Controlling sheep scab has always been a problem in the hills, which, coupled with recent reports confirming the detection of resistance of the sheep scab mite to 3ML wormers1, is resulting in flockmasters now being encouraged to revert back to plunge dipping.

Since the elimination of compulsory dipping 26 years ago, it is estimated that there has been a 60-fold increase in sheep scab on UK farms, which in turn, led to what is believed to be an industry first event totally dedicated to sheep scab, and how to promote best practice to control the disease.

Speaking to industry leaders, representatives of the various breeds, academia, vets and veterinary medicine manufacturers at the event in Haydock, Dr Peter Bates, a parasitology specialist, told delegates one of the biggest problems with the disease is it can be easily introduced into a flock when buying in animals. This is because purchased sheep in the sub-clinical stages, may be not show any visible clinical signs of sheep scab, but are infected. Hence, he said adequate quarantine procedures are vital.

He also stressed that farmers should never use a shower dipper or jetter to control scab and that successful treatment is based on using diazinon in a plunge dipper. Animals must also be immersed for 60 seconds with their head dipped under twice.

It was a point echoed by veterinarian, Rachel Mallet of Bimeda, who pointed out that contract plunge dippers can make dipping both accessible and affordable for farmers.

"There are a lot of misconceptions about dipping and the barriers to having sheep dipped. In reality, there is no reason 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, who provide a way for farmers to avail of dipping, without having to carry it out themselves.

"In light of potential increases in the cost of dip disposal permits it is useful to be aware that sheep dipping contractors can even arrange to responsibly dispose of used dip. Any farmer who is having trouble finding a local mobile dipper can contact Bimeda for a list of dippers in their area."

Rachel added: "Dipping gives immediate scab and ecto-parasite control. In fact, dipping is the most broad spectrum method of parasite control for sheep as it offers the only way to control scab, ticks, lice, blowfly and keds with one product."

Rebecca Mearns of Biobest, also encouraged producers to take up the sheep scab ELISA test which is able to detect for sheep scab infection earlier than any other means and often as soon as two weeks post-infection and before any clinical signs appear.

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

Lesley Stubbings discussed issues around resistance of gastrointestinal roundworms to MLs and how inappropriate use of these products to treat sheep scab will increase the rate of development of resistance.

Benefits of dipping sheep for the control of scab and other ecto-parasites:

• Dipping targets external parasites only

• Dipping does not give rise to anthelmintic resistance

• Dipping kills scab mites quickly and helps to reduce the presence of mite antigens present on the skin surface causing inflammation.

• The scab mite prefers to spend its entire life cycle on the animal, but can survive off-fleece in clumps of wool for up to 17 days. Dipping gives protection against scab for longer than the 17 days that the mite can survive in the environment, thus allowing for complete elimination in closed flocks

• Dipping offers the only way to control scab, ticks, lice, blowfly and keds with one product