Summary

At the forefront of pyrrolizidine alkaloid (PA) poisoning is the chronic ingestion of contaminated hay, which causes liver damage resulting in an ongoing fatal liver cirrhosis or in the veno-occlusive disease in liver or lung, respectively. The symptomatology of PA-poisoning is not identical for all animal species, and also includes central nervous symptoms. In affected horses significantly elevated levels of hepatogenic serum enzymes and an increase of the retention time for bromosulfophthalein indicates the fatal outcome of the intoxication. Chronic seneciosis of horses is incurable. Rabbits, Japanese quails, and guinea pigs are regarded as poison-resistant species. Sheep and in particular goats are insensitive unless extremely high amounts of plants which exceed the animal’s body weight by several-fold are ingested. In contrast, pigs, cattle, and horses as well as chicken and likewise man are very sensitive to poisonings by PA-containing plants. In sensitive animal species a very small amount of contaminated dry hay is needed to exceed the daily dose of 1µg/kg body weight PA which is taken as harmless for man by health authorities. Therefore, all feed with visible pieces of Senecio jacobaea plants are not acceptable as animal fodder and should be destroyed.