Concentration of galegine in Verbesina encelioides and Galega oficinalis and the toxic and pathologic effects induced by the plants.

Verbesina encelioides administered to sheep by gavage induced clinical signs of toxicity and pathologic lesions identical to those induced by Galega officinalis. Sheep had compromised respiratory function with shallow, rapid respiration and frothy exudate from the nares. Affected animals necropsied at time of death presented with hydrothorax with as much as 2 to 3 L of straw-colored thoracic fluid with fibrin tags and congestion and edema of the lungs. The trachea and lung airways contained frothy material with fibrin strands. In some cases, subendocardial hemorrhage of the left ventricle was present. Galegine, a guanidine compound believed to be responsible for these effects, was found at an average concentration of about 0.46% in Galega and at 0.08% in the Verbesina collection that induced toxicosis. While G. officinalis is a known poisonous plant, its very limited distribution in the U.S. causes it to be of minor importance. V. encelioides, however, is widely distributed in the U.S. and presents a potential hazard for grazing livestock. Verbesina may have been responsible for past livestock deaths in the U.S., and thus should be classified as a poisonous plant.