Brand: SWINEGUARD ™ POUR-ON

Company: Y-TEX


FORMULATION: «pour-on» for topical administration.

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

CHEMICAL CLASS of the active ingredient(s): synthetic pyrethroids


INDICATIONS: SWINE


PARASITES CONTROLLED (spectrum of activity)

SWINE


RECOMMENDED DOSE

Apply across back of head and ears, then apply down midline of neck, over shoulders. Repeat treatment as needed, but not more often than once every 2 weeks. For optimum control, two treatments at a 14 day interval are recommended. 

Weight (lbs.) Dose rate (mL)
85 - 169 2.5
170 - 254 5
255 - 339 7.5
340 - 424 10
425 - 509 12.5
>510 15

SAFETY

  • 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.

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:


RESISTANCE PREVENTION

Risk of resistance? YES, resistance of houseflies and mosquitoes to synthetic pyrethroids (incl. permethrin) is widespread in the USA and worldwide, and can be very high. Cases of resistance of 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:

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.

So far there are no reports on resistance of mites or lice of swine to synthetic pyrethroids.

Learn more about resistance and how it develops.


MARKETING

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

  • 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? rather few pour-ons with generic permethrin for swine. This brand with generic permethrin is marketed by Y-TEX in the USA.

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

For an overview on the most used antiparasitic pour-on brands click here.


COMMENTS

This product is one of the few insecticidal ready-to-use pour-ons for lice and mite control on swine. For use on cattle and/or sheep there are hundreds if not thousands of such pour-ons. Besides permethrin, numerous other synthetic pyrethroids are used in such pour-ons, 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 also 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.

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 of the parasite (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.

All pour-ons containing contact insecticides such as synthetic pyrethroids have the same weakness: they are applied on the back of the animal and spread more or less quickly along the animal's surface to other parts of the body, but coverage is usually not homogeneous and some parts of the body are not or only poorly reached. How fast and complete the spreading is depends on a lot of factors (e.g. distance to the delivery point, rain, animal behavior such as grooming, licking, rubbing, etc.) but also on the inert ingredients in the formulation, which may or may not favor spreading. In any case, compared with the backline the concentration of the active ingredient will be significantly lower in body parts that are difficult to reach (e.g. the legs, inside the ears, etc), where parasites can survive because the concentration is not high enough to kill them. For this reason such pour-ons are mostly not effective enough against parasites such as ticks & fleas. Irregular spreading may also cause chronic exposure of some parasites to sub-lethal doses, which is known to favor development of resistance.

Since they never leave the host, control of lice is usually good because they are exposed to insecticides for a long period of time. Control of stable flies and mosquitoes is often poor, because they may bite the animals in body parts poorly covered by the insecticide 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. Trying to control populations of houseflies or other nuisance flies with on-animal topical products is usually ineffective. The simple reason is that they spend most of their time off-the animals.

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 mixtures, 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 one, but the use recommendations are different.


DISCLAIMER

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.

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