DELIVERY FORM: «feed additives and medicated feeds» for oral administration.

ACTIVE INGREDIENT(S): piperazine (as monohydrochlorid) 170 g/L (=17%)

CHEMICAL CLASS of the active ingredient(s): piperazine derivative


PARASITES CONTROLLED (spectrum of activity)


  • INDIVIDUAL DOSE FOR SWINE: Give one fluid ounce (2 tablespoonfuls) for 100 lbs. body weight. 1 cupful equals approximately 8 fl. oz.
  • POULTRY DOSAGE SCHEDULE: For chickens, add 1 fl. oz. of Piperazine Water Wormer to 1 1/4 gallons of drinking water. For turkeys, add 2 fl. oz. of Piperazine Water Wormer to 1 1/4 gallons of drinking water. These dilutions are sufficient for 100 chickens under 6 weeks of age or 50 chickens over 6 weeks of age, and for 100 turkeys up to 12 weeks of age or 50 turkeys over 12 weeks of age.

Read the product label for specific detail on dosage.


  • LD50 (acute oral) in rats: >7900 mg/kg for piperazine
  • LD50 (acute dermal) in rats: n.a.

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

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

  • Meat:
    • Chicken & Turkey: 14 days.
    • Swine: 21 days
  • Eggs for human consumption: Do not use in chickens producing eggs for human consumption

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

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


Risk of resistance development? Low

There are a few old reports on resistance of pig or poultry roundworms to piperazine but it seems not to be a major issue in most places.

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, in most countries.

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

Click here for an overview on the most used antiparasitic feed additives and medicated feeds for livestock and horses.


PIG SWIG is a classic dewormer for swine & poultry from GOODWINOL-LEGEAR based on generic piperazine.

Piperazine was already used as a human medicine at the end of the 19th century. Its anthelmintic properties for animals were discovered in the 1950's. It is still used in livestock and pets, although it has been vastly replaced with more effective compounds, especially in ruminants (cattle, sheep and goats). It is also used in anthelmintics for humans, but also in antidepressants, antihistamines, antipsychotics, etc. Piperazine derivatives are also used in plastics, resins, and other industrial materials, as well as an adulterant in the psychedelic drug scene.

Piperazine is a narrow-spectrum anthelmintic, effective almost only against ascarid roundworms (e.g. Ascaris suum, Ascaridia spp, Parascaris equorum, Toxocara canis, etc). It is still moderately used in swine, poultry, horses, dogs and cats because ascarids are often the most damaging worms in these species. It is hardly used in ruminants.

Piperazine as well as pyrantel and the benzimidazoles (e.g. fenbendazole, febantel, albendazole, mebendazole, etc.) has no residual effect, i.e. it acts against the worms during a few hours after administration but is quickly metabolized and excreted. For this reason treatment must often be repeated for certain indications. This is in contrast with wormers containing macrocyclic lactones (e.g. milbemycin oxime, selamectin) that ensure efficacy against numerous roundworms during weeks after a single treatment.


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.