Experimental poisoning by Niedenzuella stannea in cattle and corresponding detection of monofluoroacetate

ABSTRACT: In Brazil sodium monofluoroacetate (MFA) containing plants are represented by 16 species that belong to three principle genera: Palicourea ( Rubiaceae ), Amorimia ( Malpighiaceae ), and Tanaecium ( Bignoniaceae ). These plants can cause acute cardiac failure often referred to as sudden death syndrome. The objective of this paper was to determine if N. stannea contains MFA and to report the clinical signs and pathology of cattle experimentally poisoned by this plant. MFA was detected in all N. stannea plant parts except mature leaves. Niedenzuella stannea was dosed to cattle at single doses of 15-30g kg-1 bw. Clinical signs and pathology observed were similar to those reported by other MFA-containing plants. Animals showed marked tachycardia, labored breathing, muscle tremors, loss of balance, ataxia, falling, recumbence, pedaling movements, and opisthotonous leading to death in few minutes. Gross lesions included engorgement of the large veins, severe lung edema, and petechiae , ecchymosis and suffusions in the pericardium, epicardium and pleura. Histologically, hydropic vacuolar degeneration and necrosis of epithelial cells of the kidney were observed. Cattle that received daily doses of 4g kg-1 body weight for 24 days showed no clinical signs. In summary, this is the first report that N. stannea contains monofluoroacetate and causes sudden death in cattle