White Snakeroot (Common name)

General Poisoning Notes:

White snakeroot (Eupatorium rugosum) is a native herb that grows in rich soils in eastern Canada. This plant has caused illness and death of humans and several types of livestock. Large losses of human life occurred in the 19th century from the mysterious milk sickness. Mortality ranged from 10 to 25%, and the population of entire villages left a location because they could not find the cause of the disease. It was later discovered that cattle had ingested white snakeroot and that a toxin was subsequently passed through the milk to humans and was toxic. With modern collection and combination techniques, milk sickness from commercial milk sources is no longer a problem. However, the resurgence of small-scale farming and home milk production may result in occasional cases of milk sickness (Kingsbury 1964, Stotts 1984, Cheeke and Schull 1985, Beier and Norman 1990).

Several types of herbivorous livestock have also been poisoned by ingesting white snakeroot, resulting in a disease called trembles. Cattle, goats, horses, sheep, and swine have shown toxic reactions. Suckling animals can develop milk sickness as well. Trembles was more of a problem in the past, before the increased use of herbicides and prepared feeds. Poisoning was also more frequent when animals were allowed to range through bushlots. The amount of white snakeroot that must be ingested before death is variable, ranging from 1 to 20%. Symptoms can occur within a few days or up to 3 weeks later. Daily intake rates of 0.5-1.5% of body weight generally leads to the onset of symptoms. Drying the plant material does not completely remove the danger to animals (Doyle and Walkley 1949, Kingsbury 1964, Cheeke and Schull 1985, Beier and Norman 1990).

Additional care must be taken with milk from cattle or goats that may have ingested white snakeroot. Many articles state that a lactating animal does not always show symptoms. However, milk from that animal can still cause milk sickness. Calves, humans, and cats have been poisoned in such cases. Dogs given the milk are also at risk. Experimental work has shown that trembles can occur in rabbits and guinea pigs. White snakeroot grows in rich moist open woods and along water courses. Animals should not be allowed to graze this plant.

References:

  • Beier, R. C., Norman, J. O. 1990. The toxic factor in white snakeroot: identity, analysis and prevention. Vet. Hum. Toxicol., 32: 81-88.
  • Cheeke, P. R., Shull, L. R. 1985. Natural toxicants in feeds and poisonous plants. AVI Publishing Company, Inc., Westport, Conn., USA. 492 pp.
  • Couch, J. F. 1927. The toxic constituent of richweed or white snakeroot (Eupatorium urticaefolium). J. Agric. Res., 35: 547-576.
  • Doyle, L. P., Walkey, F. L. 1949. White snakeroot (Eupatorium urticaefolium) poisoning in livestock. Purdue Univ. Agric. Exp. Stn. Bull., 270. 14 pp.
  • Kingsbury, J. M. 1964. Poisonous plants of the United States and Canada. Prentice-Hall Inc., Englewood Cliffs, N.J., USA. 626 pp.
  • Olson, C. T., Keller, W. C., Gerken, D. F., Reed, S. M. 1984. Suspected tremetol poisoning in horses. J. Am. Vet. Med. Assoc., 185: 1001-1003.
  • Stotts, R. 1984. White snakeroot toxicity in dairy cattle. Vet. Med. Small Anim. Clin., 79: 118-120.

Nomenclature:

Scientific Name:
Eupatorium rugosum Houtt.
Vernacular name(s):
white snakeroot
Scientific family name:
Compositae
Vernacular family name:
composite

Go to ITIS*ca for more taxonomic information on: Eupatorium rugosum

References:

  • Agriculture Quebec. 1975. Noms des maladies des plantes du Canada/ Names of plant diseases in Canada, Quebec City, Que., Canada. 288 pp.
  • Alex, J. F., Cayouette, R., Mulligan, G. A. 1980. Common and botanical names of weeds in Canada/Noms populaire et scientifiques des plantes nuisibles du Canada. Revised. Agric. Can. Publ., Ottawa, Ont., Canada. 132 pp.
  • Bailey, L. H., Bailey, E. Z. 1976. Hortus third. Revised. MacMillan, New York, N.Y., USA. 1290 pp.
  • Scoggan, H. J. 1978, 1979. The flora of Canada. Nat. Mus. Nat. Sci. (Ottawa) Publ. Bot. 7(1)-7(4). 1711 pp.
  • Van Wijk, H. L. 1911. A dictionary of plant names. Martinus Nijhoff, The Hague, The Netherlands. 1444 pp.
  • Victorin, M. 1964. Flore Laurentienne. 2nd ed. Univ. Montreal, Montreal, Que., Canada. 952 pp.

Geographic Information

  • New Brunswick
  • Nova Scotia
  • Ontario
  • Prince Edward Island
  • Quebec

References:

  • Bailey, L. H., Bailey, E. Z. 1976. Hortus third. Revised. MacMillan, New York, N.Y., USA. 1290 pp.
  • Boivin, B. 1966, 1967. Énumération des plantes du Canada. Provencheria 6. Nat. Can. (Que.) 93: 253-274; 371-437; 583-646; 989-1063. 94: 131-157; 471-528; 625-655.

Image or Illustration

Images: White snakeroot - Google search

Toxic Parts:

  • leaves
  • stems

References:

  • Doyle, L. P., Walkey, F. L. 1949. White snakeroot (Eupatorium urticaefolium) poisoning in livestock. Purdue Univ. Agric. Exp. Stn. Bull., 270. 14 pp.
  • Kaufmann, G. W. 1982. Seasonal variation of tremetol concentrations found in white snakeroot, Eupatorium rugosum Houtt (Compositae). Proc. Iowa Acad. Sci., 89: 151-152.
  • Olson, C. T., Keller, W. C., Gerken, D. F., Reed, S. M. 1984. Suspected tremetol poisoning in horses. J. Am. Vet. Med. Assoc., 185: 1001-1003.

Notes on Toxic Plant Chemicals:

Tremotol is a secondary aromatic alcohol with a sterol and ketone fraction. One of these ketones, tremetone, has been tested on chickens, with negative results, but was toxic to goldfish in experimental studies. In Iowa the concentration of tremotol was found to be highest during the summer (Kaufmann 1982).

Toxic Plant Chemicals:

  • tremetol

References:

  • Couch, J. F. 1927. The toxic constituent of richweed or white snakeroot (Eupatorium urticaefolium). J. Agric. Res., 35: 547-576.
  • Kaufmann, G. W. 1982. Seasonal variation of tremetol concentrations found in white snakeroot, Eupatorium rugosum Houtt (Compositae). Proc. Iowa Acad. Sci., 89: 151-152.

Animals/Human Poisoning:

Note: When an animal is listed without additional information, the literature (as of 1993) contained no detailed explanation.

Cattle

General Symptoms of Poisoning:

References:

  • Doyle, L. P., Walkey, F. L. 1949. White snakeroot (Eupatorium urticaefolium) poisoning in livestock. Purdue Univ. Agric. Exp. Stn. Bull., 270. 14 pp.
  • Stotts, R. 1984. White snakeroot toxicity in dairy cattle. Vet. Med. Small Anim. Clin., 79: 118-120.

Dogs

No details about poisoning symptoms available.

Goats

No details about poisoning symptoms available.

Horses

General Symptoms of Poisoning:

References:

  • Doyle, L. P., Walkey, F. L. 1949. White snakeroot (Eupatorium urticaefolium) poisoning in livestock. Purdue Univ. Agric. Exp. Stn. Bull., 270. 14 pp.
  • Olson, C. T., Keller, W. C., Gerken, D. F., Reed, S. M. 1984. Suspected tremetol poisoning in horses. J. Am. Vet. Med. Assoc., 185: 1001-1003.

Humans

No details about poisoning symptoms available.

Rabbits

No details about poisoning symptoms available.

Sheep

General Symptoms of Poisoning:

References:

  • Couch, J. F. 1927. The toxic constituent of richweed or white snakeroot (Eupatorium urticaefolium). J. Agric. Res., 35: 547-576.
  • Kingsbury, J. M. 1964. Poisonous plants of the United States and Canada. Prentice-Hall Inc., Englewood Cliffs, N.J., USA. 626 pp.

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