Company: HYGEIA

FORMULATION: liquid concentrate for dipping sheep

ACTIVE INGREDIENT(S): Diazinon (= dimpylate): 10% = 100 g/L

CHEMICAL CLASS of the active ingredient(s): Organophosphate


PARASITES CONTROLLED (spectrum of activity)

  • For the treatment and control of sheep scab (Psoroptes ovis mites) and blowfly strike in sheep.


To prepare the bath:

Measure the required volume of cold water into the bath. Then add the Dip by following the instructions provided with the dispensing kit for fitting it to the container of dip concentrate and for dispensing the dip concentrate safely to the bath in the proportion of -

  • 2.25 litres (0.5 gallon) of dip concentrate [i.e. 9 x 250ml deliveries from the dispensing pump] to 900 litres (200 gallons) of water, equivalent to 250ppm of Diazinon.
  • Stir the bath thoroughly from end to end before commencing dipping and dip on the day the bath is prepared.

To dip the sheep:

  • Immerse the sheep in the bath for a minimum of one minute. Keep the sheep moving forward and crutch the head under at least once. Care should be taken to see that they do not swallow or inhale the wash.
  • Dip baths of 2250 litres or less must be replenished every 36 sheep. Dip baths over 2250 litres are replenished every 90 sheep. Replenish, as the levels fall, as directed hereunder. This combined with a clean bath, will give best results. If this recommendation is not observed, sheep passing through the bath at a low dip level (or a foul bath) will not be as effectively treated or protected as those passed through earlier.

To replenish the bath:

  • Baths less than 2250 litres (500 gallons): after every 36 sheep dipped, add 1 litre [i.e. 4 x 250ml deliveries from the dispensing pump] into the dip tank and sufficient water to restore the bath to its original volume.
  • Baths greater than 2250 litres (500 gallons). after every 90 sheep dipped , add 2.5 litres [i.e. 10 x 250ml deliveries from the dispensing pump] into the dip and sufficient water to restore the bath to its original volume.
  • When a bath becomes foul, always empty it and refill with fresh dip.
  • For the purposes of the control of sheep scab, sheep must be totally immersed in a bath and all parts of the sheep except the heads and ears must remain immersed for not less than one minute.
  • Plunge the head under at least twice, allowing time to breathe between plunges.

Read the complete product label carefully and ensure thorough accomplishment of all the use instructions.


  • LD50 (acute oral) in rats: for the a.i. 1250 mg/kg
  • LD50 (acute dermal) in rats: for the a.i. >2150 mg/kg
    • Estimated hazard class according to the WHO: III, slightly hazardous.

Suspected poisoning? Read the article on diazinon = dimpylate safety in this site.

Withholding periods (=withdrawal times) in days for meat & milk (country-specific differences may apply: read the product label)

  • Meat & Offal: Ireland 35 days
  • Milk for human consumption: Ireland: Not permitted for use in lactating ewes producing milk for human consumption.

WARNING !!!: Never use on humans, dogs or cats.

Diazinon and all organophosphates (e.g. coumaphosdichlorvos, phosmet, etc.) etc. are highly toxic to birds, fish and aquatic invertebrates.

Organophosphate dips are submitted to very strict operator safety precautions and dip wash disposal regulations. Read the product label carefully and ensure strict accomplishment of all safety instructions.


Risk of resistance? LOW.

There are reports on field resistance of Psoroptes ovis (sheep scab) against some organochlorines and organophosphates in Argentina, and against a few organophosphates and synthetic pyrethroids in the UK. However it does not seem to be a problem elsewhere in Europe.

This means that if this product does not achieve the expected efficacy against the mentioned parasites, it is probably due to incorrect use rather than to a resistance problem. Incorrect use is usually the most frequent cause of product failure.

So far there are no reports on resistance of blowfly maggots, lice, keds or ticks to organophosphates in Europe. However, resistance of blowflies and lice to these and other chemicals has been reported elsewhere (e.g. Australia, New Zealand).

Alternative chemical classes/active ingredients to prevent resistance of external parasites through product rotation:

These alternative products may not be available in all countries, or may not be available for dipping, or may not be effective against all the concerned parasites.

Learn more about resistance and how it develops.


Are the active ingredients of this product ORIGINAL* or GENERICS**?


*Meaning that they are still patent protected and generics are not yet available
**Meaning that they have lost patent protection and may be acquired from manufacturers of generic active ingredients other than the holder of the original patent.

COUNTRIES where this brand/product is marketed: Ireland
GENERIC BRANDS available? YES, but rather few with diazinon in Europe. This brand contains itself generic diazinon.

Click here to learn more about GENERIC vs. ORIGINAL drugs.

For an overview on the most used antiparasitic spray, dip & dust BRANDS click here.


This product is a classic concentrate for dipping sheep with generic diazinon, one of the few ones still remaining in the market. Such products were rather popular in Europe and elsewhere till the 1990s but have been vastly replaced by less toxic and more convenient pour-ons (mainly synthetic pyrethroids or insect hrowth regulators) and injectables (mainly ivermectin and other macrocyclic lactones).

Diazinon (also called dimpylate) is a veteran broad-spectrum organophosphate introduced in the 1950s by GEIGY (later CIBA-GEIGY → NOVARTIS) that has been very abundantly used worldwide in agriculture, hygiene and veterinary insecticides. In sheep, diazinon was particularly appreciated for the control and prevention of sheep scab mites, blowfly strike and lice. It has a high affinity for wool lipids, where it dissolves after administration and remains for a long period of time ensuring several weeks and even months protection against re-infestation.

Usage of diazinon products in sheep strongly declined after several countries imposed very strict safety precautions and dip wash disposal regulations (e.g. the UK & Australia) for all dips in the late 1990s. As a consequence, using these products became rather inconvenient and often also expensive. Soon after, NOVARTIS, the market leader for diazinon products for sheep, divested all its organophosphates for strategic reasons, including its diazinon sheep brands (NEOCIDOL, TOPCLIP). Nowadays, in many countries sprays and dips containing diazinon, other organophosphates and even synthetic pyrethroids have been vastly replaced by injectable macrocyclic lactones (e.g. doramectinivermectin, moxidectin, etc.) that have become affordable, are much more convenient than sprays & dips and as effective. Diazinon is still abundantly used worldwide in insecticide-impregnated ear-tags for fly control on cattle.

Used as recommended this product is highly effective against established infestations of mites (incl. sheep scab), blowfly strike, lice, and keds and ensuresl several weeks protection against re-infestation. Control of ticks is usually less effective. But to ensure efficacy it is crucial to dip the sheep correctly. To learn more about correct sheep dipping click here.

All organophosphates are veteran pesticides developed in the 1950s-1960s and are basically contact insecticides. This means that when the parasite comes in contact with it (e.g. during the blood meal, after landing on a treated host, etc), the active ingredient that impregnates the host's hair coat penetrates through the cuticle (i.e. the "skin" of insects and other arthropods) into its organism and disturbs essential biological processes in the parasite's body, in this case its nervous system.

After administration to livestock or other animals, organophosphates do not have a systemic mode of action, i.e. they are not transmitted to the parasite through the blood or the host. Topically administered organophosphates are very poorly absorbed through the skin of the hosts, and what is absorbed is quickly broken down and/or excreted. Consequently the concentration reached in the blood is too low to kill blood-sucking parasites.


This article IS NOT A PRODUCT LABEL. It offers complementary information that may be useful to veterinary professionals and users that are not familiar with veterinary antiparasitics. 

Information offered in this article has been extracted from publications issued by manufacturers, government agencies (e.g. EMEA, FDA, USDA, etc.) or in the scientific literature. No guarantee is given on its accuracy, integrity, sufficiency, actuality and opportunity, and any liability is denied. Read the site's DISCLAIMER.

In case of doubt contact the manufacturer or a veterinary professional.