Correct use of OP dip

Organophosphate (OP) dips are not authorised for use in showers, jetters or sprayers. It is illegal to apply OP dip via one of these routes and it is illegal to prescribe OP dip for application via one of these routes. The Veterinary Medicines Directorate (VMD) takes a firm stance on OP dip only being authorised for use as a plunge dip, as per this VMD statement.

Why is this so important?

Parasitologists advise that showering or jetting against scab does not work. It may damp down problems for a while, but won’t help in proper control or eradication. Therefore, showering or jetting with OPs …

  • Is a waste of money.
  • Could lead to resistance against diazinon developing, by exposing scab mites to a sub-lethal dose.
  • Could be contributing to the spread of sheep scab, as sheep ‘treated’ with a shower or jetter may appear to be clear of scab of sold/moved immediately after application even if they are not.

To (anonymously) report someone prescribing or using OP through a jetter or shower, go to  or contact one of the organisations that supports the Code of practice for mobile dippers.

Warning to prescribers

Prescription by SQPs for off-label use of an OP through a jetter or shower is a breach of the SQP Code of Practice, which says SQPs must take into account the requirement for the person receiving the product to use it for an authorised use. When supplying an OP dip, prescribers are recommended to stress to the buyer that it must not be used in a shower or jetting application. They should not assume they will know this or that using an OP in this way could render them liable for prosecution under the Veterinary Medicines Regulations. AMTRA will consider disciplinary cases and/or reporting to VMD when made aware of any SQP or business supplying sheep dip contrary to the code or the regulations. Any cases of a vet supplying dip for use in showers/jetters will be notified to the VMD and RCVS.