Amaranthus retroflexus (Scientific name)

General poisoning notes:

Redroot pigweed (Amaranthus retroflexus) is a naturalized herb that is found across much of Canada. This plant can cause a variety of toxic problems, including perirenal edema in pigs. However, the nature of the toxic compound is not known. This plant can also accumulate oxalates to as much as 30% of dry weight. Redroot pigweed is capable of accumulating toxic concentrations of nitrates (Osweiler et al. 1985).

References:

  • Crawford, R. F., Kennedy, W. K., Davison, K. L. 1966. Factors influencing the toxicity of forages that contain nitrate when fed to cattle. Cornell Vet., 56: 3-17.
  • Duckworth, R. H. 1975. Poisoning of cattle by Amaranthus. N. Z. Vet. J., 23: 154-155.
  • Hibbs, C. M., Stencel, E. L., Hill, R. M. 1978. Nitrate toxicosis in cattle. Vet. Hum. Toxicol., 20: 1-2.
  • Osweiler, G. D., Buck, W. B., Bicknell, E. J. 1969. Production of perirenal edema in swine with Amaranthus retroflexus. Am. J. Vet. Res., 30: 557-566.
  • Osweiler, G. D., Carson, T. L., Buck, W. B., Van Gelder, G. A. 1985. Clinical and diagnostic veterinary toxicology. Third edition. Kendall/Hunt Publishing Co., Dubuque, Iowa, 494 pp.
  • Scimeca, J. M., Oehme, F. W. 1985. Postmortem guide to common poisonous plants of livestock. Vet. Hum. Toxicol., 27: 189-199.
  • Stuart, B. P., Nicholson, S. S., Smith, J. B. 1975. Perirenal edema and toxic nephrosis in cattle, associated with ingestion of pigweed. J. Am. Vet. Med. Assoc., 167: 949-950.

Nomenclature:

Scientific Name:
Amaranthus retroflexus L.
Vernacular name(s):
redroot pigweed
Scientific family name:
Amaranthaceae
Vernacular family name:
amaranth

Go to ITIS*ca for more taxonomic information on: Amaranthus retroflexus

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, , Canada. 132 pp.
  • Bailey, L. H., Bailey, E. Z. 1976. Hortus third. Revised. MacMillan, New York, N.Y., 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
  • Manitoba
  • New Brunswick
  • Northwest Territories
  • Nova Scotia
  • Ontario
  • Prince Edward Island
  • Quebec
  • Saskatchewan

References:

  • Bailey, L. H., Bailey, E. Z. 1976. Hortus third. Revised. MacMillan, New York, N.Y., 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: Amaranthus retroflexus - Google Search

Toxic parts:

  • leaves
  • stems

References:

  • Osweiler, G. D., Buck, W. B., Bicknell, E. J. 1969. Production of perirenal edema in swine with Amaranthus retroflexus. Am. J. Vet. Res., 30: 557-566.
  • Stuart, B. P., Nicholson, S. S., Smith, J. B. 1975. Perirenal edema and toxic nephrosis in cattle, associated with ingestion of pigweed. J. Am. Vet. Med. Assoc., 167: 949-950.

Notes on Toxic plant chemicals:

Nitrates have the following LD-50 values (Crawford et al. 1966):

  • LD-50 1.0 g/kg body weight in cattle
  • LD-50 0.5 g/kg body weight in other ruminants.

Acute poisoning occurs when forage nitrates exceed 1.0% nitrate (dry weight) or 1500 ppm in water (Osweiler et al. 1985). All Amaranthus spp. mentioned in this information system can accumulate toxic quantities of nitrates.

Toxic plant chemicals:

  • nitrate

References:

  • Crawford, R. F., Kennedy, W. K., Davison, K. L. 1966. Factors influencing the toxicity of forages that contain nitrate when fed to cattle. Cornell Vet., 56: 3-17.

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:

  • Crawford, R. F., Kennedy, W. K., Davison, K. L. 1966. Factors influencing the toxicity of forages that contain nitrate when fed to cattle. Cornell Vet., 56: 3-17.
  • Duckworth, R. H. 1975. Poisoning of cattle by Amaranthus. N. Z. Vet. J., 23: 154-155.
  • Hibbs, C. M., Stencel, E. L., Hill, R. M. 1978. Nitrate toxicosis in cattle. Vet. Hum. Toxicol., 20: 1-2.
  • Stuart, B. P., Nicholson, S. S., Smith, J. B. 1975. Perirenal edema and toxic nephrosis in cattle, associated with ingestion of pigweed. J. Am. Vet. Med. Assoc., 167: 949-950.

Swine

General symptoms of poisoning:

References:

  • Osweiler, G. D., Buck, W. B., Bicknell, E. J. 1969. Production of perirenal edema in swine with Amaranthus retroflexus. Am. J. Vet. Res., 30: 557-566.
  • Scimeca, J. M., Oehme, F. W. 1985. Postmortem guide to common poisonous plants of livestock. Vet. Hum. Toxicol., 27: 189-199.

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