An unprecedented number of ponies in the New Forest have died after eating enormous quantities of poisonous acorns, which were blown to the ground by the recent high winds.
The hot summer resulted in a bumper crop of the acorns, which contain pyrogallic acid and tannins.
Although they can be safely eaten by pigs, in ponies they can cause symptoms including loss of appetite, tremors, lethargy, teeth-grinding and excessive shaking of the head. Eventually, the ponies die an agonising death from internal bleeding caused by kidney or stomach damage.
According to the Daily Echo, a total of 47 ponies and 16 cattle have died after eating the acorns.
In a typical year, an average of six ponies die as a result of eating the acorns, so the death toll this year has been unusually high.
New Forest Equestrian Association chairman Tony Hockley told the Daily Mail: "Horses tend to avoid things that are poisonous but with acorns they seem to get a taste for them and hoover them up."
BBC News reports that pigs are released into the forest for 60 days each year to eat the fallen acorns. This is known as 'pannage', and the pannage season, which should have lasted from 9 September to 7 November, has now been extended until 15 December. Usually around 200 pigs are needed for the job, but this year around twice that number will be required.
Last month, it was reported that at least 12 dogs had been killed in the New Forest by a mystery illness.
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