Horse owners warned over tree seed poisoning

Horse owners have been warned to beware of sycamore tree seed poisoning.

There has been an increase in a harmful and potentially fatal condition for horses caused by ingestion of the seeds, according to the Veterinary Ireland representative organisation.

The Equine Interest Group has asked horse owners to be vigilant about grazing environments and any possible emerging symptom of equine atypical myopathy, also known as atypical myoglobinuria.

Don Collins, chair of the Equine Interest Group said: “Horses have been known to die within 48 to 72 hours of the onset of symptoms, but survival rates can be improved by prompt treatment. Symptoms include sudden onset stiffness or muscle tremors and muscle weakness, showing as a reluctance to move and escalating to a point where the horse can no longer stand. Symptoms can also include dark coloured urine, dyspnoea, and dysphagia.”

Owners are being urged to be particularly vigilant where horses are grazing in pastures in close proximity to seed-laden sycamore trees, and to consult with their vet swiftly if they notice the potential onset of possible symptoms.

“The cause of death is a very specific metabolic block in the muscle’s ability to burn fat for fuel, triggered by ingestion of an amino acid found in seeds of sycamore trees,” Mr Collins said.

“Owners can minimise the exposure of their animals to this disease by providing plenty of good quality forage and feed if needed.

“Owners may also fence off parts of fields exposed to sycamore seeds, or alternatively move their animals to fresh pastures.”

The Department of Agriculture, meanwhile, has been alerting vets and horse owners to a number of fatal cases of equine atypical myopathy diagnosed in recent weeks, specifically in Athlone Regional Veterinary Lab.

Young horses and those new to affected pasture appear at greatest risk, especially where grass is short or scarce.

Risk is likely to be greatest when fresh seeds are on the ground, in autumn and winter. Preventive measures include:

Avoid over grazing of pastures.

Feed additional forage; for example, hay in overgrazed pasture.

Limit turnout to less than 12 hours per day during autumn and early spring.

If feasible, remove horses from pastures where sycamore or other maple trees are growing during risk period.