Crown Vetch (Coronilla varia) poisoning in a budgerigar (Melopsittacus undulatus)

A 9-month-old, male budgerigar (Melopsittacus undulatus) was presented with an acute onset of weakness and vomiting. The bird had recently ingested leaves of freshly harvested crown vetch (Coronilla varia) from a fresh cutting of the plant placed next to the bird's cage. During the following 10 hours, the bird exhibited tachypnea and showed progressive neurologic signs of weakness, incoordination, tremors, and depression. The bird was treated with supportive care and activated charcoal. Its condition stabilized in the following 8 hours, with improvement within 48 hours and complete recovery in 2 weeks. Crown vetch grows in disturbed soils, tolerates dry conditions, and is often planted to prevent soil erosion. The toxic constituent of crown vetch is the nitrotoxin, beta-nitropropionic acid, a potent neurotoxin.