In spring, ripe syringa berries that lie thickly under the trees are often eaten by sheep and goats, pigs, and horses.
The bitter, wrinkled, yellow berries are usually consumed before the rains come, when the grass has been grazed to the roots, and the animals are not receiving any hay supplement.
Although common in South Africa, the tall syringa tree (Melia azedarach) with its scented lilac flowers and dark green leaves, is not indigenous. It was originally imported here from India as an ornamental plant.
The ripe berries are toxic to children as well as livestock, rabbits, guinea pigs and dogs.
Although deaths have been described in chickens, syringa berries do not seem to affect wild birds, and some species spread the seeds to new areas.
Signs of poisoning
Children and dogs that consume enough of these berries will salivate and vomit. They will also suffer from diarrhoea and severe abdominal pain, followed by poor coordination, convulsions, coma and death.
Horses may show dilated pupils, pale mucous membranes and signs of colic. Pigs vomit out syringa berry seeds, while sheep and goats regurgitate them when ruminating.
Sheep, goats and pigs show dilated pupils and poor coordination, then become paralysed in the hindquarters. Within a day or two, they are unable to rise, and over time their breathing becomes laboured and their gums turn blueish. Death comes in two to three days.
A post-mortem will reveal signs of severe gastric irritation and respiratory failure. Syringa seeds are often found in the ruminal or intestinal contents.
No specific treatment exists for syringa poisoning. A dose of one teaspoon (5g) activated charcoal per kilogram of body weight in half a cup of water can be given by mouth.
Children and dogs can be hospitalised and given supportive treatment, such as intravenous fluids and sedatives to prevent convulsions.
The best prevention is to cut down all syringa trees in the area; the wood is similar to mahogany and can be made into planks or used as firewood.
Sweep up the berries and burn them; composting them assists in distributing the seeds to new areas.
Usually, sheep and goats eat the berries only when forage is scarce before the rains come, so provide hay to guard against possible deaths.