[Pyrrolizidine alkaloids and seneciosis in farm animals. Part 2: clinical signs, species-specific sensitivity, food residues, feed contamination, limit values].

This research investigates the various effects of chronic pyrrolizidine alkaloid (PA) poisoning in different animal species, particularly as a result of consuming hay contaminated with PA-producing plants. The study details how the severity of the poisoning varies across species, and warns of the high sensitivity in certain species, particularly humans, towards these toxins, emphasizing the need for clean animal feed.

The Effects of Pyrrolizidine Alkaloid Poisoning

• The main focus of this research is on the chronic ingestion of hay contaminated with PA, a toxin originating from certain plant species. The ingestion of these toxins can result in severe liver damage, leading to fatal liver cirrhosis or veno-occlusive disease (a condition affecting the liver and lung).
• It’s also important to note that the effects and symptoms of PA poisoning do not display uniformly across different animal species – some may even present with central nervous symptoms.
• As an example, in horses, this poisoning can lead to elevated levels of hepatogenic serum enzymes and increase the retention time for bromosulfophthalein which are seen as indicators of the fatal outcome of this intoxication. The study also states that chronic seneciosis (a condition resulting from PA poisoning) in horses is incurable.

Species-Specific Sensitivity

• The study illustrates how sensitivity to PA poisoning varies among different species. For instance, rabbits, Japanese quails, and guinea pigs appear to be resistant to PA poisoning.
• Sheep and goats are also categorized as being insensitive, unless they ingest astronomically high amounts of PA-containing plants that exceed their body weight by several folds.
• On the other hand, pigs, cattle, and horses, along with chickens and humans, are extremely sensitive to the effects of PA-containing plants. Even a very small amount of contaminated dry hay can cause the intake of PA to exceed the daily dose considered harmless by health authorities for humans, which is 1µg/kg body weight.

Food Residues, Feed Contamination and Limit Values

• This research further emphasizes the importance of ensuring animal feed is not contaminated with PA-producing plants; in this case, the study specifically mentions Senecio jacobaea plants.
• Any feed containing visible pieces of such plants is deemed unacceptable as animal fodder and the paper suggests that it should be destroyed, keeping in view the potentially fatal effects of PA poisoning.