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, USA. 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, 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
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., 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

redroot pigweed:

Images: images.google.com

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:

abortion
bloat
blood brownish
breathing, rapid
death
dyspnea
kidney, edema of
mucous membrane, brown
nephrosis, severe
nervousness
recumbency
recumbency, ventral
regurgitation
weakness, posterior

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:

ataxia
death
gait, crouching
kidney, edema of
nephrosis, severe
recumbency, ventral
trembling
weakness

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.