DISTRIBUTION:
• Originally a native of Brazil.
• It is usually found in the moister eastern parts of the country where it grows as an under-storey or at the margins of forests.
• Also cultivated as a hedge or windbreak.
• Inland it usually grows near rivers or watercourses.
BOTANICAL DESCRIPTION:
General: Usually an evergreen, multi-branched shrub of 1 - 2 m, but could grow to a tree of up to 15 m high at the coast.
Leaves: The twigs and dark green alternate leaves have an unpleasant smell when crushed.
Flowers: A tubular flower with creamy-yellow lobes in small groups in the axils of the uppermost leaves. Closing at night.
Fruit: A succulent purple black berry, 1 cm in diameter, which normally contains 6 seeds.
TOXIC PRINCIPLE:
The toxic principle is a carboxyatractyloside similar to the poisonous principle of Xanthium strumarium.
SYNDROMES:
Chase valley disease – Hepatoxic syndrome without photosensitization.
SYSTEMS AFFECTED:
Liver.
CLINICAL SIGNS:
• Mainly a cattle problem - liver damage as well as nervous signs.
• Green berries and young sprouts most poisonous.
• Also garden refuse problem.
• High dosage - peracute deaths.
Acute/Subacute poisoning:
Gastrointestinal Tract: Salivation; Ruminal stasis; Constipation.
Central Nervous System:Weakness; Ataxia; Stands with an arched back and outstretched neck; Aggressiveness - especially in KwaZulu-Natal; Struggle a lot before death.
NECROPSY:
Macroscopical findings:
• Liver degeneration as well as haemorrhages and oedema of the gall
bladder wall
• Haemorrhages - serosal and liver capsule
• Hydrothorax, hydropericardium and ascites• Ruminal stasis and constipation - faeces covered with bloody mucous.
HISTOPATHOLOGY:
• Centrilobular necrosis and haemorrhage.
• Mild bile duct proliferation.
TREATMENT:
Supportive and symptomatic. Prevention: Keep stock away from infected veld at danger periods -especially during June and July when it is most toxic.
