# Sheep Dipping (DD-602)

> Sheep scab is an intensely itchy skin disease caused by the mite Psoroptes ovis. The UK's National Animal Disease Information Service (NADIS) says the mites' droppings trigger an allergic reaction that leads to rubbing, wool loss, scabs and rapid weight loss. In severe cases it can kill. NADIS says compulsory treatment was enforced in Britain from 1928. Eradication failed and control was deregulated in 1992, but England and Wales still legally require infected flocks to be treated, and Scotland made the disease notifiable again in 2010. According to the UK sheep-parasite group SCOPS, there are now only two treatments for scab in the UK: plunge dips containing the organophosphate diazinon, and injectable macrocyclic lactones. Organophosphate dips work only as a proper plunge dip, never through jetters or showers. NADIS says dips kill scab mites within 24 hours, keep working for several weeks, and also control blowfly, lice, keds and ticks. Synthetic pyrethroid (cypermethrin) dips were once the other option. NFU Scotland reported in 2010 that the Veterinary Medicines Directorate suspended them in 2006 over water pollution and manufacturers then stopped making them. Organophosphates are highly toxic to people too. The UK Health and Safety Executive requires anyone buying OP dip to hold a certificate of competence and sets rules for protective clothing, storage and disposal. NFU Scotland notes that concerns have been raised about effects on human health. The footage shows sheep being pushed through a dip, with a metal tipping cradle and frame over the swim bath. The country isn't identified.

- Department: Tech (also Nature)
- First published: 2025-06-23
- Last updated: 2025-06-23
- Permalink: https://detailenjoyer.com/case/sheep-dipping/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## On the timeline

- **1928**: Compulsory sheep scab treatment begins to be enforced in Britain
- **1992**: Britain deregulates sheep scab control after eradication fails
- **2006**: The Veterinary Medicines Directorate suspends cypermethrin sheep dips over water pollution
- **2010**: Scotland makes sheep scab notifiable again

Full timeline: https://detailenjoyer.com/timeline/?case=sheep-dipping

## Quick facts

- **DD-602-F01**: Sheep scab is caused by the mite Psoroptes ovis. _(Write-up · Exhibit A (The mite))_
- **DD-602-F02**: Organophosphate sheep dips only work as a full plunge dip. _(Write-up · Exhibit C (Plunge only))_

## Write-up

A full-body bath against mites. Plunge dips treat sheep scab, lice and ticks.

1. **The mite**: Sheep scab is caused by the mite Psoroptes ovis, whose droppings trigger an intense allergy.
2. **Two options**: UK scab treatment is now either a diazinon plunge dip or an injectable macrocyclic lactone.
3. **Plunge only**: OP dips work only as a full plunge dip, never through jetters or showers.
4. **Pyrethroid dips gone**: Cypermethrin dips were suspended in 2006 over water pollution and later abandoned.
5. **Rules for people**: Anyone buying OP sheep dip must hold a certificate of competence.

## Related case files

- [Hungarian Herding Dogs (DD-691)](https://detailenjoyer.com/case/hungarian-herding-dogs/): Another case about sheep farming
- [Fish Fattening (DD-723)](https://detailenjoyer.com/case/fish-fattening/): Another look at how animals are farmed
- [Shear Delight (DD-178)](https://detailenjoyer.com/case/shear-delight/): I linked more about sheep
- [Trocar Cows (DD-585)](https://detailenjoyer.com/case/trocar-cows/): I paired it with another livestock health practice

## Reel vs. record

- **Note**: 'Typically organophosphates or synthetic pyrethroids': in the UK, synthetic pyrethroid (cypermethrin) dips were suspended in 2006 and later abandoned, so diazinon (an organophosphate) is the only dip option. Pyrethroid dips may still be used elsewhere.
- **Note**: 'Protection against reinfestation for weeks': yes. NADIS says OP dips kill mites within 24 hours and keep working for several weeks.
- **Note**: 'Ticks, lice and psoroptic mites': yes, and dips also control blowfly and keds.
- **Missing**: OP dips are highly toxic to people too. UK users need a certificate of competence and must follow rules on protective clothing, storage and disposal.
- **Missing**: injectable macrocyclic lactones are the main alternative to dipping, but heavy use has been linked to resistance in worms and a 2018 study confirmed moxidectin-resistant scab mites in Wales.

## Video: Sheep Dipping: A Full-Body Bath Against Mites

- Duration: 22.2 s · Published: 2025-06-23
- File: https://detailenjoyer.com/assets/videos/DLQ96jZxBeK.mp4

### Transcript

DID YOU KNOW? Sheep dipping is a vital process to eliminate external parasites like ticks, lice and psoroptic mites causing sheep scab. Sheep are fully submerged in a concrete or metal plunge dip containing a diluted solution of insecticides, typically organophosphates or synthetic pyrethroids. These chemicals disrupt the parasite's nervous system, ensuring rapid kill-off and protection against reinfestation for weeks. NOW YOU KNOW!

## Questions & answers

**Q: Which mite causes sheep scab?**  
A: Its droppings trigger an allergic reaction. _(Source: Write-up · Exhibit A (The mite) · NADIS: Sheep scab)_

**Q: Which organophosphate is used in UK scab dips?**  
A: SCOPS lists diazinon plunge dips. _(Source: Write-up · Exhibit B (Two options) · NADIS: Sheep scab; SCOPS: Sheep scab treatment and quarantine)_

**Q: How must OP dips be applied?**  
A: Jetters and showers don't work and aren't allowed. _(Source: Write-up · Exhibit C (Plunge only) · NADIS: Sheep scab; SCOPS: Sheep scab treatment and quarantine)_

**Q: Why were cypermethrin dips suspended in 2006?**  
A: Per NFU Scotland. _(Source: Write-up · Exhibit D (Pyrethroid dips gone) · NFU Scotland (Mar 3, 2010): Cypermethrin dip withdrawal to hit Scottish sheep scab initiative)_

**Q: What must UK buyers of OP sheep dip hold?**  
A: Per HSE and SCOPS. _(Source: Write-up · Exhibit E (Rules for people) · SCOPS: Sheep scab treatment and quarantine; HSE AIS41: Sheep dipping, advice for farmers and others involved in dipping sheep)_

## Sources

- [NADIS: Sheep scab](https://nadis.org.uk/disease-a-z/sheep/ectoparasites-of-sheep/sheep-scab)
- [SCOPS: Sheep scab treatment and quarantine](https://www.scops.org.uk/external-parasites/scab/treatment-and-quarantine/)
- [NFU Scotland (Mar 3, 2010): Cypermethrin dip withdrawal to hit Scottish sheep scab initiative](https://www.nfus.org.uk/news/news/cypermethrin-dip-withdrawal-hit-scottish-sheep-scab-initiative)
- [HSE AIS41: Sheep dipping, advice for farmers and others involved in dipping sheep](https://www.hse.gov.uk/pubns/ais41.pdf)

## Cite this case file

Easterling, Marcus. "Sheep Dipping." The Detail Department (DetailEnjoyer), case file DD-602, last updated Jun 23, 2025. https://detailenjoyer.com/case/sheep-dipping/