Onion (Common name)

General Poisoning Notes:

Cultivated onion (Allium cepa) has caused hemolytic anemia in livestock including cattle, horses, and experimentally in sheep. Death can occur in severe cases. The formation of Heinz bodies in the red blood cells is a common occurrence. Heinz bodies consist of a precipitate, denatured hemoglobin caused by oxidant attack (Hutchinson 1977).

References:

  • Hutchinson, T. W. 1977. Onions as a cause of Heinz body anaemia and death in cattle. Can. Vet. J., 18: 358-360.
  • Kirk, J. H., Bulgin, M. S. 1979. Effects of feeding cull domestic onions (Allium cepa) to sheep. Am. J. Vet. Res., 40: 397-399.
  • Thorp, F., Harshfield, G. S. 1939. Onion poisoning in horses. J. Am. Vet. Med. Assoc., 94: 52-53.

Nomenclature:

Scientific Name:
Allium cepa L.
Vernacular name(s):
onion
Scientific family name:
Liliaceae
Vernacular family name:
lily

Go to ITIS*ca for more taxonomic information on: Allium cepa

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

Plant or plant parts used in or around the home.

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: Onion - Google search

Toxic Parts:

  • bulbs
  • leaves

References:

  • Hutchinson, T. W. 1977. Onions as a cause of Heinz body anaemia and death in cattle. Can. Vet. J., 18: 358-360.
  • Kirk, J. H., Bulgin, M. S. 1979. Effects of feeding cull domestic onions (Allium cepa) to sheep. Am. J. Vet. Res., 40: 397-399.
  • Thorp, F., Harshfield, G. S. 1939. Onion poisoning in horses. J. Am. Vet. Med. Assoc., 94: 52-53.

Notes on Toxic Plant Chemicals:

Onions (Allium spp.) contain various toxins that can cause problems. N-propyl disulphide, an alkaloid, has been implicated as the toxic chemical (Hutchinson 1977). More recent studies have shown that S-methyl-L-cysteine sulfoxide (SMCO) is involved in forming Heinz bodies and hemolytic anemia. This chemical is less toxic in nonruminant animals (Benevenga et al. 1989).

(Note: calcium oxalate crystals have been found in the dry outer skin or scale leaves of this plant (Sarma and Terpó 1980)). Garlic (Allium sativum) is a cultivated plant grown for its bulbs.

Toxic Plant Chemicals:

  • N-propyl disulphide
  • oxalate
  • S-methyl-L-cysteine sulfoxide (SMCO)

References:

  • Benevenga, N. J., Case, G. L., Steele, R. D. 1989. Occurrence and metabolism of s-methyl-l-cysteine and s-methyl-l-cysteine sulfoxide in plants and their toxicity and metabolism in animals. Pages 203-228 in Cheeke, P. R., ed. Toxicants of plant origin. Vol. III. Proteins and amino acids. CRC Press, Inc., Boca Raton, Fla., USA. 271 pp.
  • Hutchinson, T. W. 1977. Onions as a cause of Heinz body anaemia and death in cattle. Can. Vet. J., 18: 358-360.
  • Kirk, J. H., Bulgin, M. S. 1979. Effects of feeding cull domestic onions (Allium cepa) to sheep. Am. J. Vet. Res., 40: 397-399.
  • Sarma, S. K., Terpó, A. 1980. The occurrence of different types of calcium oxalate crystals in Allium cepa L. and Allium fistulosum L. and their importance in taxonomy. Acta Agron. Acad. Sci. Hung., 29: 25-37.

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:

  • Hutchinson, T. W. 1977. Onions as a cause of Heinz body anaemia and death in cattle. Can. Vet. J., 18: 358-360.

Horses

General Symptoms of Poisoning:

References:

  • Thorp, F., Harshfield, G. S. 1939. Onion poisoning in horses. J. Am. Vet. Med. Assoc., 94: 52-53.

Sheep

General Symptoms of Poisoning:

References:

  • Kirk, J. H., Bulgin, M. S. 1979. Effects of feeding cull domestic onions (Allium cepa) to sheep. Am. J. Vet. Res., 40: 397-399.

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