With farms increasingly looking to sheep dipping as the most effective method to control scab, making sure this is achieved needs attention.
Sheep scab has arguably moved up the agenda in the past few years, most recently on the back of the detection of resistance of sheep scab mites to 3-ML injectable products.
The UK Sheep Health and Welfare Group report 2016 states the annual estimated cost of sheep scab in the UK is £8.3 million.
Now, in the knowledge that some sheep scab mites are resistant to injectable products, the pressure to preserve the effectiveness of organophosphate (OP) dips, the only other treatment for sheep scab, is being ramped up.
Recent Animal Medicines Training Regulatory Authority advice states OP products should not be used in jetters and showers.
Lesley Stubbings, of the Sustainable Control of Parasites in Sheep group, explains: “There are no veterinary products licenced in the UK for use through jetters or showers.
“This use has gone widely unchallenged in the past, but the hurdles we face in controlling sheep scab are now so great it is more important than ever to preserve the efficacy of the organophosphate dips.
“Exposing scab mites to a sublethal dose of OP in jetters and showers is an ideal way to encourage resistance to develop and we cannot afford to continue taking that risk.
“Plunge dipping is the only way to get the OP down to the skin so it can kill all the mites and showers and jetters simply cannot achieve that.”
OP product manufacturer Bimeda is reporting a ‘surge in interest in sheep dipping’ in recent months.
In response to this, it has recently launched a training video outlining some of the key points to consider for those who may have little prior experience with sheep dipping.
Causes and identifiers of sheep scab
ALL sheep at any age are at risk of being infected with sheep scab. It is a disease caused by mite psoroptes ovis which lives on the skin surface where it feeds.
The faeces produced by the sheep scab mite cause a severe allergic dermatitis, resulting in the scabby lesions seen in the later stages of the infection.
The mites are transferred from animal to animal by direct contact, or by pieces of wool containing sheep scab mites.
They can also be transferred on clothing worn by people when they move between flocks or groups of sheep.
In the early stages of the disease, there are often no obvious signs of infection until inching and wool loss sets in, so good biosecurity plans on-farm are key – particularly quarantining bought-in sheep for at least three weeks on arrival.
A blood test to detect whether sheep have been exposed to sheep scab is available.
It can detect sheep scab two weeks after exposure and can be used even when sheep are showing no signs of infestation. Contact your veterinarian to find out more.
OPTIONS FOR DIPPING
DR Renee Lodder, Bimeda technical veterinarian, says: “Farmers can use their own dipping tank on their property if they have completed a course of competence for sheep dipping, which is generally done via local agricultural colleges.
“They also need to obtain a permit for dip disposal from their local environmental agency, the requirements for which vary in different parts of the UK. It is best to contact a local environmental officer for more specific information.
“Another option is to use the services of a mobile plunge dipping contactor, who already has the necessary permits and training as well as disposal facilities in some cases.”
Although not strictly a seasonal problem, the risk of scab in the approaching autumn and winter months is heightened.
“Although sheep scab is generally present in winter, the changing seasons mean the risk is there from late autumn to early spring,” Dr Lodder says.
“While we see fewer of them in summer, mites could still be present. As autumn approaches, many will be looking to dip to get sheep in good condition pre-tupping and as a pre-treatment for winter, but dipping in summer as a fly control measure is also on the rise.”
■ Farmers looking for a contract mobile plunge sheep dipper can find contractors in their area online at sheepdippers.co.uk, and many are willing to travel nationwide