Mesembryanthemum and Opuntia Spp (Vygies and Turksvry)
By Dr Mackie Hobson BSc(Agric),BVSc

Mesembryanthemum and Opuntia Spp (Vygies and Turksvry)

‘Vygies’ and ‘Turksvry’ grow abundantly in the karoo and semi-arid areas and can cause Oxolate poisoning.

It is associated with poisoning in goats and sheep especially during times of drought.

Oxolate can bind with calcium in the rumen and is excreted in the faeces or is otherwise absorbed and bind with calcium in the blood which causes hypocalcaemia.

The insoluble calcium oxalate can crystallise in tissue especially kidney and rumen wall.

Clinical signs:

Acute poisoning causing hypocalcaemia causes reduced mobility, head pulled back, weakness, coma occurs within hours of intake.

More chronic poisoning (few day) causes kidney damage due to blockage of renal tubules by oxalate crystals.

Treatment:

In acute cases treat hypocalcaemia with calcium borogluconate but of little help in chronic cases.

Intake levels can increase with adaptation.

Feed dicalcium phosphate as a lick with salt.

Post Mortem:

No specific lesions, some haemorrhages, ascites, hydrothorax, renal oedema, pale coloured kidneys.

Reference:

Plant Poisonings and Mycotoxicoses of livestock in Southern Africa (Kellerman, Coetzer, Naude)