Brand: CYPERGUARD Concentrate for Dip Emulsion

Company: BIMEDA

FORMULATION: liquid concentrate for dipping animals

ACTIVE INGREDIENT(S): Cypermethrin high-cis (80:20) 10% = 100 g/L

CHEMICAL CLASS of the active ingredient: Synthetic pyrethroid


PARASITES CONTROLLED (spectrum of activity)

  • Prevention and treatment of blowfly strike, lice, keds and ticks on sheep by plunge dipping after dilution of the product with water.
  • For the prevention and treatment of sheep scab caused by pyrethroid sensitive mites..


For Blowfly, Keds, Lice and Ticks

  • Initial Dilution Rate: 1 lt product in 500 lt water (equivalent to 200 ppm=mg/L); Replenishment: 1 in 500

For Sheep Scab

  • Initial Dilution Rate: 1 lt product in 500 lt water (equivalent to 200 ppm=mg/L); Replenishment: 1 in 500

A single treatment will provide up to 9 weeks control of Blowfly Strike. Occasionally retreatment may be necessary after 4-9 weeks depending on the level of challenge, weather conditions and the timing of the first dipping.

Do not dilute the product until it is actually required.

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


  • LD50 (acute oral) in rats: Cypermethrin a.i. 250 (oily vehicle) to 5150 mg/kg (aqueous vehicle)
  • LD50 (acute dermal) in rats: Cypermethrin a.i. >4920 mg/kg
  • Estimated hazard class according to the WHO: U unlikely to present acute hazard

Suspected poisoning? Read the article on cypermethrin safety in this site.

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

  • Meat: Ireland 14 days
  • Milk for human consumption: Ireland: Not for use in sheep producing milk for human consumption.

WARNING !!!: Never use on humans or cats. Synthetic pyrethroids are toxic to cats!

All synthetic pyrethroids (e.g. cyhalothrin, cypermethrin, deltamethrin, permethrin, etc.) are extremely toxic to fish and aquatic invertebrates. Do not contaminate dams, streams or waterways with product or used containers.

You may be interested in the following articles in this site dealing with the general safety of veterinary products:


Risk of resistance? YES, moderate. Biting lice developed high resistance to synthetic pyrethroids in Australia and New Zealand in the 1990s. In Australia they were eventually withdrawn from the market for biting lice control on sheep. Several cases have been reported in the UK as well, but so far it seems to remain a limited problem. Nevertheless it is a warning, and the more synthetic pyrethroids are used against biting lice, the higher the risk for resistance to develop.

This also means that if this product does not achieve the expected efficacy against the mentioned parasites, it can be due to resistance and not to incorrect use, which is usually the most frequent cause of product failure.

Resistance of blowfly strike, keds, mites an ticks of sheep to synthetic pyrethroids is usually not a problem in most European countries. But biting lice resistance to these chemicals is very high in Australia and New Zealand.

Alternative chemical classes/active ingredients to prevent resistance development by lice through product rotation:

These alternative products may not be available in all countries, or may not be available as pour-ons, 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 not very frequent for dipping anymore, because most dipping product have been replaced by pour-ons in many countries.

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 one of the few concentrates for dipping against ectoparasites of sheep left in a European country. Elsewhere in the world they are still used a lot. Besides cypermethrin, numerous other synthetic pyrethroids are used worldwide in such products, e.g. cyhalothrindeltamethrin, flumethrin, fenvaleratepermethrin, etc. They all have a similar spectrum of activity and a comparable safety profile.

Cypermethrin is one of several veteran type-II synthetic pyrethroids. It was introduced by ICI & SHELL in the 1970s. Worldwide it is massively used in veterinary products as well as in agricultural and hygiene pesticides.

Insecticide concentrates for spraying and dipping such as this product often represent the cheapest option for iectoparasite control on animals. More modern and often more effective active ingredients for the control of external parasites are often not available as concentrates but only as ready-to-use pour-ons and  injectables. They are often more effective, more convenient and with a longer protection period than the concentrates, but are also more expensive and often not approved for the control of as many pests as the concentrates.

All synthetic pyrethroids are veteran pesticides developed in the 1970s-1980s 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 topical administration to livestock or other animals, synthetic pyrethroids 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 synthetic pyrethroids 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. But this is why they are considered rather safe for mammals, both humans and livestock (cats are an exception: pyrethroids are toxic to them!) and why they leave rather low residues.

For best results it is very important to ensure a complete coverage of the animals' hair coat (depending on the woll length adult sheep may need up to 5 liters product for complete wetting). This is best achieved after dipping the animals. To learn more about correctly dipping livestock read the corresponding article on dipping in this site.

It is useful to know that the active ingredients of many synthetic pyrethroids consist in a mixture of various optical isomers, typically those called "cis", and those called "trans". Cypermethrin has 8 isomers, 4 cis and 4 trans. Manufacturers of active ingredients usually supply the raw material in standard qualities, for cypermethrin typically e.g. in a 40:60, 50:50 or 80:20 cis:trans ratio. This particular product contains so-called high-cis cypermethrin (80:20). It happens that the efficacy against parasites and the mammalian toxicity of these isomers are significantly different. Typically cis isomers are more effective insecticides but also more toxic to mammals. Obviously a cis/trans 80:20 mixture is more potent than a cis/trans 40:60 mixture. Qualities with higher cis content are usually also more expensive. And the higher the percentage of the most active isomer, the lower the rate that is required for achieving the same efficacy.


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.