Pulmonary and hepatic lesions caused by the dehydropyrrolizidine alkaloid-producing plants Crotalaria juncea and Crotalaria retusa in donkeys.

This study investigates the effects of toxins from Crotalaria juncea and Crotalaria retusa plants on donkeys. It finds that liver and lung damage can occur after consuming these plants, with the severity of the damage varied based on the type and amount of toxin consumed.

Research Methodology

• Rigorous experimental methods were employed by the researchers. They administered different doses of contaminated seeds from Crotalaria juncea and Crotalaria retusa plants to a group of donkeys for a period of 365 days.
• The Crotalaria juncea seeds had dehydropyrrolizidine alkaloids (DHPAs) in them at diverse percentages. Three groups of donkeys, each with a different dose, consumed these infected seeds daily.
• Similarly, three other donkeys were given Crotalaria retusa seeds which contained a different alkaloid toxin, monocrotaline, at varying doses.
• Throughout the study period, the researchers conducted liver and lung biopsies on the animals, observing for any clinical signs or lesions which might have developed.

Research Findings

• Most donkeys did not show any clinical signs. However, mild liver damage, or megalocytosis, was observed in those ingesting higher doses (0.6 and 1 g/kg) of Crotalaria juncea seeds.
• Donkeys that were administered the highest doses (3 and 5 g/kg) showed severe respiratory symptoms around 70 and 40 days respectively and had to be euthanized. Severe lung damage was reported in these donkeys.
• For the group consuming Crotalaria retusa seeds, again no clinical signs were observed. However, moderate liver damage was detected in all donkeys.
• In extremely high doses, the Crotalaria retusa seeds caused severe liver necrosis and death in the donkeys. The dosage that showed such severe reactions included a single dose of 5 g/kg and a daily dose of 1 g/kg for 7 days.

Conclusions drawn

• The study concludes the damaging impact of DHPAs on animals is consistent with previous reports: they cause severe liver and lung damage.
• The severity of the damage is related both to the type of DHPAs and the dose ingested.
• It also concluded that similar to horses, some DHPAs are metabolized in the liver causing liver disease, whereas others are metabolized in the lung by Clara cells in donkeys, causing lung diseases.