Drimia species

Abstract

DISTRIBUTION: Widely distributed in southern Africa and grows in a variety of soils. Invasive in overgrazed areas.

BOTANICAL DESCRIPTION: Urginia sanguinea General: A perennial bulbous plant with annual aerial parts. The bulb is pear-shaped, reddish-brown and enclosed in black or purple papery scales. Leaves: The leaves are grey-green, up to 30 cm long and sometimes have revolute margins. Flowers: The inflorescence is ±30 cm high and bears numerous white flowers with green or brownish stripes on the backs of the petals. September - October. Fruit: The fruit is clearly 3-chambered, splitting open to release the black, flat, winged seeds.

Urginia altissima General: The bulb grows half exposed above the ground. It is large with tough overlapping fleshy scales. Leaves: The leaves are grey-green, tough and erect, up to 30 cm long. Produced after the flowers. Flowers: The inflorescence is up to 60cm high and bears numerous white flowers with a central green stripe, born on horizontal stalks. They usually open early and close by 13h00. September - October.

TOXIC PRINCIPLE: The active principle of U. sanguinea is a cardiac glycoside, named transvaalin.

SYNDROME: Non-cumulative bufadienolides.

SYSTEMS AFFECTED: Cardiovascular system.

CLINICAL SIGNS: • Diarrhoea. • Colic. • Tremors. • Staggering. • The animal hangs its head and shows signs of muscular weakness. • Paralysis and death from heart failure may follow.

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: • Lignocaine. • ß-blocking agents. • ACP: Tranquillizer (multipotent blocker). • Atropine (if AV-block is present).