What organ system is impacted by Senecio in cows?

• A. Heart
• B. Kidneys
• C. Liver
• D. Lungs

Answer: (C)

Senecio plants contain pyrrolizidine alkaloids that become toxic after the compounds are metabolized in the liver. The liver’s enzymes convert these alkaloids into reactive intermediates that damage hepatocytes, especially in the central areas of the liver lobules, leading to cell death, inflammation, and eventually fibrosis. This hepatic injury impairs detoxification and bile excretion, and can cause secondary issues like photosensitization when phylloerythrin builds up. Because the toxins require liver metabolism to become harmful and the liver is the site where this injury occurs, the liver is the primary organ system affected by Senecio in cows. The other organs aren’t the main targets of this poisoning.