Amaranthus retroflexus (red wheat). Related species: A. viridis (green amaranthus). A member of the plant family AMARANTHACEAE. Stout, erect plant with a hairy red stem, ovate leaves at its base and leafless above. Small red flowers in dense spikes, made up of many small cymes. Indehiscent, unilobular fruit.


[affected.gif] Animals most affected
Cattle, sheep, (horses, pigs, goats, rabbits).


[etiology.gif] Etiology
Direct ingestion of the plant is rare, even in times of food shortage or drought. Poisoning occurs more commonly following ingestion of forage or contaminated silage (mainly maize silage). Problems develop when ingestion has taken place over several days.


[toxic.gif] Toxicity
The plant is rich in oxalic acid (especially in the leaves). Variable content (often very high) of nitrates (0.2-1.5%).
Toxic doses not well known.

TD rabbits 600 g taken for several days (5-7)
  cattle several kg per day for several days



[clinical.gif] Clinical features
After 410 days of ingestion:


[clinical.gif] Lesions
Perirenal oedema (in pigs, sheep, goats, cattle) with subcapsular petechiae, renal degeneration and necrosis;


[treatm~1.gif] Treatment
No antidote. Prevent further ingestion of the plant (within 48 hours) to avoid fatalities.