Onion-Allium cepa L.-Poisonous plant

Onion

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).

Nomenclature:

Scientific Name: Allium cepa L.

Vernacular name(s): onion

Scientific family name: Liliaceae

Vernacular family name: lily

Geographic Information

Plant or plant parts used in or around the home.

Toxic parts:

Bulbs, leaves.

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)

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:

Death, Heinz bodies.

Horses

General symptoms of poisoning:

Anemia, breath, onion odor of, breathing, rapid, death, icterus, weight loss.

Sheep

General symptoms of poisoning:

Anemia