DISTRIBUTION:
T. laxa is mainly found in grassveld areas, while T. divaricata grows in the sandy soil and dunes of the south-western areas of the Cape Province.
BOTANICAL DESCRIPTION:
General: These are perennial plants with underground rhizomes.
Leaves: Numerous soft succulent leaves arranged in rosettes
Flowers: Large, branched upright inflorescences with small white flowers.
T. laxa is a tumbleweed.
TOXIC PRINICIPLE:
•Unknown
•The plants are palatable early in the growing season and outbreaks occur in the overgrazed areas during the dry months.
• The incidence of the disease ceases soon after the onset of good rains and improvement of pastures.
SYSTEMS AFFECTED:
Central nervous system.
CLINICAL SIGNS:
•Initially the animals move with difficulty, show over-knuckling, hypersensitivity and tremor.
•Progressive ascending paresis and paralysis follow and animals remain in sternal recumbency.
•Affected animals starve or die of exposure 1 - 3 months later.
•In horses, the signs may disappear after light exercise, though the animals tire easily and show dyspnoea.
NECROPSY:
•Usually no macroscopical changes present
•Microscopically a khakhi-brown pigment is visible in the cytoplasm of the larger neurones of the brain, spinal cord and ganglia.
TREATMENT MANAGEMENT:
With proper feeding or with improved grazing, complete recovery from the early signs may occur after six months, but in some cases only partial recovery occurs and the animal retains a paretic limb.
