SYCAMORE ALERT

Sir — On listening to a recent radio programme, I was horrified to learn about Equine Atypical Myopathy [EAM], a potentially fatal disease caused by horses eating sycamore seeds. I’m aware of the dangers of them ingesting ragwort and bracken, but wonder if EAM is as well-known?

Brian Checkland

Thingwall, Wirral H&H vet Karen Coumbe replies: “Equine Atypical Myopathy, also known as seasonal pasture myopathy, is caused by the ingestion of a toxin, hypoglycin A, which is contained in the seeds and seedlings of the sycamore tree (Acer psuedoplantus) and other similar trees. It is not a new problem, but has become more frequently reported and increasingly studied.

We now know that all parts of the sycamore tree are poisonous, but the seeds and seedlings of different trees contain variable amounts of toxin. The Royal Veterinary College can test the level of toxin in seeds, leaves and seedlings.

The onset of the disease is rapid and it is frequently fatal, so prevention is important especially at this time of year.

Suggested preventive measures include: regularly inspecting the pasture for sycamore seeds or seedlings; checking surrounding areas for the presence of sycamore trees — the “helicopter” seeds can be carried a long way on the wind; fencing off any contaminated areas of pasture; if possible, picking up seeds and removing seedlings — take the horses off the pasture while this is done; providing extra forage for the horses as some seeds will remain on the pasture and in spring, the seeds will germinate and new seedlings appear daily.