Field horsetail (Common name)

General Poisoning Notes:

Field horsetail (Equisetum arvense) is a native plant growing across Canada. This plant contains thiaminase which causes thiamine deficiency in horses. Ruminants are not generally affected by problems of thiamine deficiency because it is made in the rumen. However, some cattle were reported to have symptoms. In Canada, horses have been poisoned by ingesting field horsetail (Henderson et al. 1952, Cheeke and Schull 1985).

References:

  • Cody, W. J., Wagner, V. 1981. The biology of Canadian weeds. 49. Equisetum arvense L., 61: 123-133.
  • Henderson, J. A., Evans, E. V., McIntosh, R. A. 1951. The antithiamine action to Equisetum. J. Am. Vet. Med. Assoc., 120: 375-378.

Nomenclature:

Scientific Name:
Equisetum arvense L.
Vernacular name(s):
field horsetail
Scientific family name:
Equisetaceae
Vernacular family name:
horsetail

Go to ITIS*ca for more taxonomic information on: Equisetum arvense

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

  • Alberta
  • British Columbia
  • Labrador
  • Manitoba
  • New Brunswick
  • Newfoundland
  • Northwest Territories
  • Nova Scotia
  • Ontario
  • Prince Edward Island
  • Quebec
  • Saskatchewan
  • Yukon Territory

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: Field horsetail - Google search

Notes on Poisonous Plant Parts:

The horsetails have separate fertile and sterile fronds. Field horsetail has a fertile frond that is flesh-colored and appears before the green sterile frond.

Toxic Parts:

  • leaves
  • stems

References:

  • Cheeke, P. R., Shull, L. R. 1985. Natural toxicants in feeds and poisonous plants. AVI Publishing Company, Inc., Westport, Conn., USA. 492 pp.

Notes on Toxic Plant Chemicals:

Thiaminase is an enzyme that splits thiamine, a B vitamin, making it inactive. Thiamine is involved in decarboxylation reactions in animal bodies. Deficiency of thiamine leads to accumulation of pyruvate in the blood, with a resulting impairment in energy metabolism and cellular shortage of ATP. Hay that contains horsetail at a level of 20% or more may produce symptoms of thiamine deficiency in horses in 2-5 weeks (Cheeke and Schull 1985).

Toxic Plant Chemicals:

  • thiaminase

References:

  • Cheeke, P. R., Shull, L. R. 1985. Natural toxicants in feeds and poisonous plants. AVI Publishing Company, Inc., Westport, Conn., USA. 492 pp.

Animals/Human Poisoning:

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

Cattle

Horses

Sheep

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