DISTRIBUTION:
These plants grow in the arid to semi-arid areas of southern Africa; in open plains, seasonally dry watercourses and on hills.
BOTANICAL DESCRIPTION:
General: These small, woody perennial shrubs (up to 1,5 m) are in fact semi-root parasites.
Leaves: The many thin, woody upright stems and branches of T. namaquense are green to yellow-green and virtually leafless except to the expert eye. Those of T. lineatum are grey-green or blue-green.
Flowers: The flowers are inconspicuous, pale yellowish in colour and borne at the end of the branches or in the axils of the minute leaves. Early winter - spring.
Fruit: Very small, spherical, with longitudinal ridges.
TOXIC PRINCIPLE:
Bufadienolide, a cardiac glycoside.
SYNDROME:
Non-cumulative bufadienolides.
SYSTEMS AFFECTED:
Cardiovascular system.
CLINICAL SIGNS:
• A period of laboured, shallow panting
• Diarrhoea
• Loss of muscular control
• In some cases death may be quite sudden.
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).
