Brand: PERMECTRIN ™ II
Company: ELANCO (BAYER)
FORMULATION: liquid concentrate for spraying animals or farm premises
ACTIVE INGREDIENT(S): Permethrin: 10% = 100 g/L
CHEMICAL CLASS of the active ingredient(s): synthetic pyrethroids
INDICATIONS: CATTLE, HORSES, SHEEP, SWINE, DOGS, POULTRY, PREMISES
PARASITES CONTROLLED (spectrum of activity)
CATTLE (Beef & Dairy) & HORSES
- Horn flies, face flies, horse flies, stable flies, mosquitoes, mites, lice, ticks including deer ticks (carrier of Lyme disease).
SWINE, SHEEP, POULTRY, DOGS
- Mosquitoes, fleas, blow flies, hog lice, poultry mites, sheep mites, ticks including deer ticks (carrier of Lyme disease).
- Houseflies, stable flies, filth & nuisance flies, fleas, lice, mites, ticks including deer ticks (carrier of Lyme disease).
- Aids in control of cockroaches, mosquitoes and spiders.
Large animals (Beef & Dairy Cattle & Horses)
- Against face flies, horn flies, horse flies:
- Backrubber: Animals self-apply. Mix 1 qt. in 20 gal.; 8 oz. in 5 gal.; 1.6 oz (48 mL) in 1 gal. of mineral oil or a non-irritating organic oil. Recharge backrubber oiler as needed. Permethrin concentration in final dilution: 1250 ppm* = mg/L.
- Against face flies, horn flies, horse Flies, stable flies, mosquitoes, lice, mites, ticks, including Deer Ticks:
- High Pressure Sprayers: Mix 1 qt. in 200 gal. or 8 oz. in 50 gal. of water. Spray to thoroughly cover entire animal. Apply from 1/2 to 1 gal. of spray per animal. For lice or mites, a second treatment is recommended 14-21 days later. Permethrin concentration in final dilution: 125 ppm* = mg/L.
- Hand, Garden or Low Pressure Sprayer: Mix 8 oz. in 3 gal.; 2.5 oz. (75 mL) in 1 gal. or 2/3 oz. (20 mL) in 1 qt. water. Spray each animal with up to 8 oz. of mixed spray. For lice or mites, a second treatment is recommended 14-21 days later. Permethrin concentration in final dilution: 2083 ppm* = mg/L.
- Against ear ticks, face flies, horn flies:
- Spot Application: Mix 2 oz. (60 mL) in 1 gal. of mineral oil or non-irritating organic oil or water. Apply 1/2 oz. per ear or 2-4 oz. on face or 12-16 oz. along the backline. Permethrin concentration in final dilution: 1563 ppm* = mg/L.
Swine, Sheep, Poultry & Dogs
- Against mange mites:
- Mix 1 qt. in 100 gal.; 8 oz. in 25 gal.; 1 oz. (30 mL) in 3 gal. of water. Spray or dip animals. Retreat after 14 days spraying walls and floor and replace bedding to kill late hatching, developing stages. Do not reapply product for 2 weeks. Permethrin concentration in final dilution: 250 ppm* = mg/L.
- Against blow flies, mosquitoes, hog lice, fleas, ticks, including Deer Ticks:
- Mix 1 qt. in 100 gal.; 8 oz. in 25 gal.; 1 oz. (30 mL) in 3 gal. of water. Spray, paint or dip to apply 1 pint per dog, pig or sheep, especially around ears. Do not reapply for 2 weeks. Permethrin concentration in final dilution: 250 ppm* = mg/L.
- Against poultry mites:
- Mix 1 qt. in 50 gal.; 8 oz. in 12.5 gal.; 2 oz. (60 mL) in 3 gal. of water. Spray 1/2 oz per bird or 1 gal. per 100 birds, directed toward vent area. Spray cages. Permethrin concentration in final dilution: 500 ppm* = mg/L.
- Against all pests previously mentioned:
- Spray Application: Mix 1 qt. in 25 gal.; 8 oz. in 6.25 gal.; 1-1/3 oz (40 mL) in 1 gal of water.* Spray all surfaces to run-off with diluted emulsion using 1 gal. per 750 sq. ft. Permethrin concentration in final dilution: 1000 ppm* = mg/L.
- Mist Blower: Use undiluted in mist blower. Mist at 4 oz. per 1,000 sq. ft. Permethrin concentration in final dilution: 100000 ppm* = mg/L.
- Power Fogger: Mix 1 qt. in 25 gal.; 1-1/3 oz. (40 mL) in 1 gal. of oil or water.* Fog at 4 oz. per 1,000 sq. ft. Permethrin concentration in final dilution: ~1040 ppm* = mg/L.
* ppm = parts per million
- LD50 (acute oral) in rats: for the a.i. 400 mg/kg (in oil vehicle, 40:60 cis:trans mixture) to 1350 - 4000 mg/kg (in aqueous vehicle, depending on the study)
- LD50 (acute dermal) in rats: for the a.i. 4000 mg/kg
- Estimated hazard class according to the WHO: U, unlikely to present acute hazard
Suspected poisoning? Read the article on permethrin safety in this site.
Withholding periods (=withdrawal times) in days for meat & milk (country-specific differences may apply: read the product label)
- Swine Meat: USA Do not ship swine for slaughter within 5 days of last treatment.
- Milk for human consumption: USA NIL
WARNING !!!: Never use on humans or cats. Permethrin is particularly toxic to cats!
Permethrin and all other 2nd-generation synthetic pyrethroids (e.g. cyhalothrin, cypermethrin, deltamethrin, etc.) are irritant to the eyes and the skin, both of humans and livestock. But irritation is usually worse when using pour-ons than after spraying.
Permethrin and all synthetic pyrethroids (e.g. cyhalothrin, cypermethrin, deltamethrin, etc.) are extremely toxic to fish and aquatic invertebrates. Do not apply directly to water, or to areas where surface water is present, or to intertidal areas below the mean high water mark. Do not contaminate water when cleaning equipment or disposing of equipment washwaters.
You may be interested in the following articles in this site dealing with the general safety of veterinary products:
- Safety for humans
- Safety for domestic animals
- Safety for the environment
- Hazard classifications of pesticides
Risk of resistance? YES, resistance of horn flies, houseflies, fleas, mosquitoes, poultry mites & cockroaches to synthetic pyrethroids (incl. permethrin) is widespread in the USA and worldwide, and can be very high. Cases of resistance of black flies and stable flies to synthetic pyrethroids (incl. permethrin) have also been reported, but their prevalence is usually low.
This means that if this product does not achieve the expected efficacy against the mentioned parasites, it may be due to resistance and not to incorrect use, which is usually the most frequent cause of product failure.
Alternative chemical classes/active ingredients to prevent resistance of external parasites through product rotation:
- Macrocyclic lactones (e.g. doramectin, eprinomectin, ivermectin, moxidectin, etc.) only as pour-ons. Injectables and drenches are ineffective against most external parasites.
- Organophosphates (e.g. coumaphos, diazinon, dichlorvos, phosmet). Many pests may have developed resistance to organophosphates too.
These alternative products may not be available in all countries, or may not be available for spraying, 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: USA
GENERIC BRANDS available? YES, numerous. This brand with generic permethrin is marketed by BAYER (now ELANCO) in the USA.
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 numerous liquid insecticides for spraying animals and/or premises containing synthetic pyrethroids for the control of flies, lice, ticks and other external parasites. Worldwide there are thousands of such products. Besides permethrin, numerous other synthetic pyrethroids are used worldwide in such products, e.g. cyhalothrin, cypermethrin, deltamethrin, etc. They all have a similar spectrum of activity and a comparable safety profile.
Permethrin is a veteran synthetic pyrethroid introduced in the 1970s (by several companies). It is a broad-spectrum non-systemic insecticide and acaricide massively used in pets, livestock, hygiene and agriculture worldwide. There are thousands of products with permethrin world-wide. It is effective against ticks, flies and certain lice species, but has also a certain repellent effect against mosquitoes, ticks and flies.
Insecticide concentrates for spraying and dipping such as this product often represent the cheapest option for insect control on animals. However the active ingredients used in such products are mostly rather old (introduced in the 1950s to 1970s) and many pests have developed resistance to them. More modern and more effective active ingredients for the control of external parasites are often not available as concentrates but only as ready-to-use pour-ons, injectables, or in the form of insecticide-impregnated ear-tags. They are usually 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 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 in meat and milk.
For best results it is very important to ensure a complete coverage of the animals' hair coat. This is best achieved after dipping the animals. Best alternative to dipping is high pressure spraying (depending on size and hair coat, adult cattle need 3 to up to 10 liters product for complete wetting). Efficacy after hand spraying or spot application are often poor due to the fact that using these methods some parts of the body may not be properly treated (e.g. inside the ears, below the tail, the udders, etc.), which allows a significant number of parasites to survive, reproduce and perpetuate the infestations. To learn more about spraying cattle and other livestock click here.
Backrubbers have and inherent weakness: Dosing depends on the behavior of the animals. It is unavoidable that some animals get too much product, and other animals not enough. Besides insufficient protection of some animals, this may cause excessive residues in other animals. For these reasons backrubber application is no more allowed in many countries (e.g. the EU, Australia, etc.). And it is generally accepted that underdosing of some animals favors resistance development. To learn more about backrubbers for cattle click here.
Control of susceptible (i.e. non-resistant) horn flies is usually good, because they spend a lot of time on cattle and thus are exposed to the insecticide for a long period of time. Lice are also exposed to insecticides for a long period of time because they never leave the host. Control of face flies is often not as good, due to their different behavior: they do not spend a lot of time on the animals and visit mainly body parts in the face that are humid with body fluids (eyes, nostrils, around the mouth), where the insecticide concentration is diluted by these body fluids. Stable flies, horse flies, black flies and mosquitoes may bite the treated animal anywhere in its body and remain attached and thus exposed to the insecticide only during their blood meals that last a few seconds or minutes, which is often too short to kill them. Ticks attaching to the hosts in those body parts that are poorly covered with insecticide are also likely to survive.
Most lice and mites species spend their whole life on the infected animals but are likely to survive hidden inside the ears if they are not properly treated. And their eggs remain unaffected by the insecticide: this is why it is very important to re-treat the animals after 2-3 weeks, when most of the eggs laid before the previous treatment have already hatched.
The permethrin strength that results in the final dilution for a particular use is often substantially different for the numerous similar products in the market. E.g. whereas for spraying poultry against mites one manufacturer recommends a dilution that results in a concentration of 1000 ppm (parts per million) permethrin in the spraying liquid, the recommendations of another manufacturer result in a concentration of 500 ppm in the spraying liquid. Both recommendations will provide control of the mites, but control and length of protection at 1000 ppm will be certainly better than at 500 ppm.
All synthetic pyrethroids have a certain repellent effect, mainly on mosquitoes but it lasts usually only a few days, if at all.
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". Permethrin has 4 isomers, 2 cis, and 2 trans. Manufacturers of active ingredients usually supply the raw material in standard qualities, for permethrin typically in a 25/75 or 40/60 cis/trans ratio. 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 40/60 mixture is more potent than a cis/trans 25/75 mixture. Qualities with a 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. If a manufacturer does not disclose the cis/trans ratio of the active ingredient used in its products it may be confusing because he may be selling the "same" product as another manufacturer, but the use recommendations are different.
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.