VPT 421: Veterinary Toxicology (2+0)

NERIUM AND THEVETIA

• Plants of importance are Nerium oleander, Nerium indicum and Thevetia neerifolia.
• All species of animals are poisoned. Usually horses and cattle do not eat this plant. But if cuttings of this plant get mixed with green fodder or hay, animals get poisoned.
• Nerium olender and Nerium inidicum are equally toxic.
• Leaves contain oleandrocide, nericide and other digitalis like glycosides.
• Poisoning is also caused by drinking the water in which the leaves are floating or by eating the leaves.

• The plant contains alkaloids, glycosides and bitter principles.
• Toxins are readily absorbed from the gastrointestinal tract and persist in the body due to enterohepatic recycling.
• Honey made from flowers, meat roasted using oleander sticks or milk from a cow poisoned with this plant, are toxic to human beings.
• The cardiotoxins interfere with the sodium potassium ATPase system resulting in a decrease in cellular potassium.
• The normal electrical conductivity on the myocardium is reduced, which results in conduction block, arrhythmias and eventually complete loss of myocardial conductivity or systole.
• Sympathetic nerves are also paralysed. Symptoms include vomiting, convulsions, diarrhoea, colic and death.
• Post mortem changes include gastroenteritis and peticheal hemorrhages.