Thevetia peruviana

Abstract

DISTRIBUTION: • An exotic ornamental shrub planted in suburban gardens • Originating in South America.

BOTANICAL DESCRIPTION: General: Evergreen shrub or small tree growing up to 10 m high. Leaves: Bright green, glossy leaves.Narrow with a prominent midrib, tapering at both ends. Flowers: Bright yellow flowers are borne singly or in few-flowered clusters towards tips of the branches. Smooth shiny lobes overlapping in one direction. Summer. Fruit: Smooth, roundish, green at first, turning black when mature, containing a hard stone with two kernels inside.

TOXIC PRINCIPLE: Thevetin (very toxic).

SYNDROME: Acute poisoning by cardenolide-containing fruit. Also refer to “Tulp Poisoning”.

SYSTEMS AFFECTED: Cardiovascular system.

CLINICAL SIGNS: • Paraysis • Breathing difficulties • Quick, but weak heartbeat.

NECROPSY: Macroscopical findings: • Not specific - rather negative • Subepi- and endocardial haemorrhages • Lung oedema, congestion, emphysema • Ruminal atony and enteritis - even haemorrhagic • Leaves present in rumen.

HISTOPATHOLOGY: In more chronic cases small foci of degeneration of cardiac musculature are seen occasionally.

TREATMENT: • Activated charcoal is very effective. • Dose 2g/kg. • Large dose is essential. • Adsorption and fixation of excess in rumen. • Even retro-diffusion back from plasma. • Minimize stress to prevent catecholamine release. Additional treatment for valuable animals: 1. Lignocaine. 2. ß-blocking agents 3. ACP: Tranquillizer (multipotent blocker) 4. Atropine (if AV-block is present).