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Medicinal Plants for Livestock

Chenopodium ambrosioides

[Introduction] [Description] [Common Names] [Chemical Compounds] [Toxicity] [Uses and Efficacy] [References] [Return to medicinal plants list]


Chenopodium ambrosioides (Family Chenopodiaceas) originated in Central America, though it has been distributed to much of the world. It has been used as an anthelmintic (medicine for controlling internal parasites) for many years. In the early 1900s it was one of the major anthelmintics used to treat ascarids and hookworms in humans, cats, dogs, horses, and pigs. Usually, oil of chenopodium was used. It was sometimes referred to as Baltimore Oil, because of the large production facility in Baltimore that specialized in extracting the oil from the plant. Chenopodium was replaced with other, more effective and less toxic anthelmintics in the 1940s.

Chenopodium is still used to treat worm infections in humans in many countries. In Honduras, as well as other Latin American countries, the whole plant or the leaves are ground and added to water. This mixture is then consumed. In a few areas in Latin America, the plant also is used to treat worm infections in livestock.


Chenopodium ambrosioides is an herb that grows to a height of 40cm. The leaves are oval (up to 4cm long and 1cm wide) and toothed. The flowers are small and green, and the seeds are very small and green when fresh and black when dry. The plant has a very strong odor. Seeds can be purchased through seed catalogues.

Common Names

  • American Wormseed -- U.S.
  • Apazote, Epazote, Ipazote -- Latin America
  • Paico -- Peru
  • Wurmsaamen Gansefuss -- Germany
  • L'anserine vermifuge -- France
  • Erva de Santa Maria -- Brazil

Chemical Compounds

There are many compounds in Chenopodium. The compound considered to be the active ingredient is ascaridole, a monoterpene. The major components of oil of chenopodium are: ascaridole (60-80%), isoascaridole, p-cymene, limonene, and x-terpinene. The level of the different compounds varies depending on the part of the plant, age of the plant, and whether it is dried or fresh plant material.

The quantity of ascaridole (or other compounds) in chenopodium can be determined using gas chromatography and mass spectrometry (GC/MS). The major compounds in chenopodium can be extracted with methanol or hexanes and then sent through the GC/MS.

Some of the Compounds in Chenopodium ambrosioides (for a more complete list see USDA Phytochemical and Ethnobotanical Databases.):

  • Alpha-pinene -- plant 440-4800 ppm
  • Ascaridole -- leaves 185-18000 ppm
  • D-camphor -- plant
  • Essential oil -- fruit 1830-25000 ppm, leaves 2000-3000 ppm
  • L-pinocarvone -- plant 1040-11400 ppm
  • Limonene -- plant
  • P-cymene -- leaves 365-4400 ppm
  • P-cymol -- plant 730-8000 ppm
  • Saponins -- roots 25000 ppm
  • Terpinene -- plant
  • Terpinyl-acetate -- plant 75 ppm
  • Terpinyl-salicylate -- plant 75 ppm


Oil made from Chenopodium ambrosioides is very toxic. However, little is known about the toxicity of fresh and dried plant material, how the oil and plant are metabolized, and why toxic reactions occur. The reaction that animals have to chenopodium seem to vary. For example, one goat can shows signs of mild toxicity, while another goat, from the same herd, may not show any adverse effects. Therefore, using this treatment can be risky. Signs of toxicity include: salivation, increased heart rate and respiration, changes in blood chemistry, decreased rumen motility, decreased contractions in the intestines, and convulsions. Oil of chenopodium can cause skin reactions, and it is dangerous to inhale.

Oil of chenopodium has caused death or adverse reactions at doses of:

  • Goats -- 0.2ml/kg body weight (BW)
  • Sheep -- 0.1ml/kg BW
  • Cats -- 0.2ml/kg BW
  • Dogs -- 0.2ml/kg BW (vomiting)
  • Rabbits -- 0.5ml

The dose that causes adverse effects is very close to the dose that is supposed to be efficacious. Therefore, extreme caution should be used when treating an animal with this plant or the oil made from the plant. Other than treating the symptoms, there is no known cure to an overdose from this plant and the oil.

Uses and Efficacy

Oil of Chenopodium and paste from fresh plant are primarily used to treat internal parasites in humans and non-ruminant animals. However, good data on efficacy is not available. Trials done in the early 1900s usually did not have control animals to which the treated animals could be compared.

In vitro studies with oil of chenopodium and chenopodium extracts have shown that it inhibits egg development of parasites and inhibits maturation of larva. However, these results have not been confirmed in in vivo studies.

Current research is being done on the potential of using chenopodium to treat ruminants at Cornell University. Results of the completed trials show that oil of chenopodium does decrease fecal egg counts. However, the decrease is not very large and does not compare to the control that can be achieved with other anthelmintics. Also, the effective dose does cause some adverse reactions in the animals. Oil of chenopodium has been shown (in vitro) to decrease egg hatching of Haemonchus contortus, a common parasite of small ruminants. Further research is needed to determine the efficacy, dose, and practical applications for oil and fresh plant material of Chenopodium ambrosioides.

When oil of chenopodium was in common use, it was administered via gel capsules and followed up with castor or linseed oil. Often, the person or animal taking the drug fasted first. Recommended doses were:

  • Dogs -- 0.03-0.1ml/kg BW followed by 30ml castor oil, fast for 24h before treatment
  • Horses -- 16-18 ml and 1L of linseed oil, fast for 36h before treatment
  • Swine -- 0.5-1ml/11.5kg BW, followed by 60ml castor oil
  • Cats -- 0.03-0.05ml/kg BW, followed by 30ml castor oil
  • Chickens -- 0.3ml in 3ml castor oil

Doses being tested are:

  • Goats -- 0.2ml/kg BW
  • Sheep -- 0.1ml/kg BW

Doses with fresh plant material are harder to determine, since the quantity of compounds in the plants varies so much. The only information on fresh plant doses are for humans. One book recommends two cups of a plant/water mixture (8 leaves with water) per day for adults and 3-4 tablespoons of the mixture per day for children over five. The book warns against giving the treatment to children under 5 and pregnant women.

Some Other Uses (in humans):

  • Amebicide -- Trinidad
  • Analgesic -- China
  • Anemia -- Colombia
  • Arthritis -- China
  • Asthma -- Dominican Republic, Panama, Trinidad, and Turkey
  • Bite(Bug) -- China
  • Dysentery -- Panama and Trinidad
  • Fungicide -- Trinidad
  • Narcotic -- U.S.
  • Nerves -- Mexico, Turkey, and U.S.
  • Stimulant -- Trinidad and Turkey
  • Stomach (ache) and/or colic -- Brazil, Chile, China, Dominican Republic, Haiti, Honduras, Mexico, Turkey, and Venezuela
  • Vermifuge -- Bahamas, Brazil, China, Dominican Republic, Guatemala, Haiti, Mexico, Panama, Spain, Trinidad, Turkey, U.S., and Venezuela


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  • Beckstrom-Sternberg, Stephen M., and James A. Duke. "The Phytochemical Database." (ACEDB version 4.3 - data version July 1994).
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  • Salant, W. and C.W. Mitchell. 1916. The influence of oil of chenopodium on intestinal contractility. Amer. J. Of Phy., 39: 37-52.
  • Salant, W. 1917. The pharmacology of the oil of chenopodium. JAMA, 69 (24): 2016-2017.
  • Taylor, E.L. 1930. The use of drugs in the treatment of diseases caused by nematode and trematode worms. 11th Int. Vet. Congress, London. John Bale, Sons & Danielsson, Ltd: London.
  • Wynn, S.G. 1996. Anthelmintic therapy in holistic veterinary practice. J. of the Amer. Holistic Vet. Med. Assoc., 15 (1): 15-19.