Solanum tettense

Abstract

DISTRIBUTION: It grows on flats or hill slopes, and on sandy, loamy or stony soil, especially where the soil is overgrazed or disturbed. Once S. kwebense becomes established in an area, no grass will grow in its vicinity.

BOTANICAL DESCRIPTION: General: An erect, somewhat woody, loosely branched, spiny shrub, growing up to 2 m high. Young branches are densely hairy. Leaves: The greyish-green leaves are covered with minute hairs. Flowers: Light blue flowers and orange-red to scarlet berries are borne more or less simultaneously from about October to May.

TOXIC PRINCIPLE: • Unknown neurotoxin • Causes vascuolar degeneration and necrosis of neurons especially in the cerebellum which leads to epileptiform seizures.

SYNDROME: Maldronksiekte

SYSTEMS AFFECTED: Central nervous system.

CLINICAL SIGNS: • CNS malfunction. • Stimulus needed - disturb, frighten, chase. • Experimental cases head lifted - eyes kept closed - quickly released precipitated typical symptoms. • Mildly affected animals tilt head to the side with neck extended. • Star-gazing, the eyes are rotated with white sclera visible, nystagmus. • Run sideways. • Seriously affected animals fall on their chest, muzzle or knees. • The animal struggle when attempting to stand. • Recovers very quickly, within minutes.

NECROPSY: Macroscopical findings: • Traumatic injuries. • Mild atrophy of the cerebellum. • Cerebellum is smaller when compared to normal (sometimes noticeable). Histopathology: • Vacuolar degeneration and necrosis of neurons, especially in cerebellum. • Total absence of Purkinje cells in certain parts of the cerebellar cortex. • The remaining Purkinje cells are severely affected.

TREATMENT: Management: • Veld management to prevent plants from flourishing • Recommend to the farmer to slaughter as soon as possible before animals start to lose weight or get injured.