SATANSBOS, Silver-leaf nightshade – Solanum elaeagnifolium
By Mackie Hobson BSc(Agric), BVSc, MRCVS

1. Poisoning

All farmers will be familiar with ‘Satansbos’ also called ‘Silver-leaf nightshade’ or ‘bitter apple ‘. It is one of the Solanum species (Solanum elaeagnifolium).

‘Satansbos’ is common on most lands on which angora goats graze in South Africa but poisoning is very rare. Angora goats will not eat satansbos unless they are very hungry or are young kids that are unfamiliar with the plant. The other potential source of intake is the dried plant that has been milled up into feed.

What part of the Satansbos is poisonous?

Both the leaves and fruit are poisonous. The green leave and the unripe fruit are most poisonous. The dry plant remains poisonous and hence the concern of stansbos milled into ‘lucern’ pellets.

How much Satansbos does the goat need to eat to be toxic?

Cattle studies show that 0.1% of body weight intake will cause toxicity. So a goat would need to eat about a 30g of plant material.

What is the active ingredient causing the toxicity?

Tropane  alkaloids- especially solanine has similar effects to atropine on the nervous system. See Datura (stinkblaar) poisoning. https://www.angoras.co.za/article/datura-stinkblaar-poisoning-in-kids

The solanine is converted to solanidine in the intestine which is absorbed and causes the neurological, cardiovascular and respiratory signs.

What are the clinical signs of poisoning?

• Salivation
• Colic, intestinal stasis
• Diarrhoea
• Muscle tremors
• Weakness
• Laboured breathing
• Nervous signs- depression, incoordination, paralysis hq
• Coma and death
• Toxicity can cause birth defects

The impact of Ivermectin on Toxicity

The toxicity leads to the increase of brain levels of ivermectin. This results in the signs of head pressing, ataxia, salivation, depression - signs of ivermectin toxicity.

Treatment

There is no antidote to the poison

• Remove the goats from source of intake-Get out of land, stop feed if source.
• Tube activated charcoal 2g/kg body weight
• Provide supportive feed and water
• Valuable animals can be treated by your vet.

References:

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

CSU Guide to poisonous plants