States vet David Chamberlain is advising owners to control ragwort – a noxious weed – in fields where their horses graze.
It comes as he, the GSPCA and Guernsey Animal Aid have been made aware of a number of public concerns about horses on fields across the island containing ragwort.
Mr Chamberlain said horses were grazing animals and preferentially eat grass.
'If little grass is available then they may start to eat other plants, including noxious weeds such as ragwort.
'Ragwort contains the toxic compounds pyrrolizidine alkaloids, to which horses are particularly susceptible, although other grazing animals are also at risk.'
Ragwort plants have a bitter taste and horses do not usually consume it, Mr Chamberlain said.
However, as the plant dries, he said, its taste become less unpleasant.
