Oxytropis sericea poisoning

General poisoning notes for Oxytropis sericea

Locoweed (Oxytropis sericea) is a native herb in western Canada. This plant has caused a number of problems in cattle, horses, and sheep. Swainsonine, an indolizidine alkaloid, inhibits alpha-mannosidase in animal bodies, which can lead to disruption of cellular function. Locoism is a chronic disease that causes depression, incoordination, and nervousness under stress. Death can result. The cellular problems occur most readily in tissues of the nervous system. Pregnant animals often abort or give birth to young with congenital deformities. Congestive right heart disease occurs at high altitudes (above 2190 m) in cattle. Right ventricular hypertrophy and dilation, subcutaneous edema, and pulmonary hypertension are significant symptoms (James 1983, Cheeke and Schull 1985, James et al. 1986, Panter et al. 1988).

Oxytropis sericea

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English Common name: locoweed (Oxytropis sericea)

Botanical family name: Leguminosae

English family name: pea

French family name: pois

Notes on poisonous plant parts

The blooms and mature fruit of locoweed have higher quantities of the toxin swainsonine than do the leaves. The concentration of this toxin remains constant in leaves throughout the grazing season (Ralphs et al. 1986.)

Toxic parts: = flowers, leaves, mature fruit, seeds, stems

Notes on toxic chemicals

Swainsonine, an indolizidine alkaloid, inhibits alpha-mannosidase in the animal's body. Inhibition results in the accumulation of oligosaccharides in cells because glycosidases remove their respective sugars until a mannose residue is reached. Hydrolysis of the carbohydrate then stops. Eventually disruption of cellular function results. The effect of swainsonine on alpha-mannosidase is reversible when locoweed is no longer consumed. However, advanced clinical signs are irreversible because axon degeneration occurs. The central nervous system is most sensitive to mannose accumulation (Cheeke and Schull 1985).

Toxic chemicals

swainsonine

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