A Dutch study shows that not all species of maple tree are dangerous to horses, despite common assumptions. Recently, scientists have shown that atypical myopathy, a muscular disease also called pasture myopathy, can result from eating the leaves, seeds or buds of maple trees that contain hypoglycin A, a toxic substance, reports Horse Talk.
Hundreds of horses in Europe die from this disease each year. Though the disease can now be diagnosed and treated much earlier, the mortality rate is still 70 percent, so prevention is key.
Researchers from Utrecht University's veterinary faculty and RIKILT Wageningen UR (an organization that specializes in detecting and identifying substances in food and animal feed and their effects) have studied equine mortality from atypical myopathy. Part of their research has involved studying maple trees to determine which species contain hypoglycin A.
Scientists asked horse owners from across the Netherlands to send in samples from maple trees in their area. The researchers received 278 samples of the three most-common types of maple trees in the Netherlands: the sycamore maple (Acer pseudoplatanus), the field maple or hedge maple (Acer campestre) and the Norway maple (Acer platanoides). The seeds, buds and leaf samples were then measured for their concentration of hypoglycin A.
The results, reported in the Journal of Veterinary Internal Medicine, found that there were no toxin levels in the field maple or the Norway maple, but every sample of the sycamore maple contained hypoglycin A. It was determined that field maples and Norway maples did not pose a threat when planted near pastures and paddocks.
Though hypoglycin A was found in the sycamore maple's leaves, seeds and buds, the toxin was present in varying levels between tree to tree and farm to farm. The presence of this toxin does not necessarily determine that the tree is unsafe. Thousands of pastures across Europe have sycamore maples in them and the horses exposed to them do not become ill. Additionally, the concentration of hypoglycin A doesn't appear to correlate with horses that fell ill, so other factors may play a role in the development of the disease.
Though the exact cause of atypical myopathy is still unclear, scientists recommended that horses in pastures surrounded by sycamore maples be given access to plenty of roughage, specifically during the fall, when the animals may be tempted to nibble on maple trees and leaves. It was also recommended that horses have restricted access to the edges of the pasture closest to these trees. If necessary, owners can use a leaf blower or rake to remove sycamore maple leaves and seeds that fall into the pasture.
It is also advised that horses be kept inside during and immediately after storms or high winds take place to give owners or caretakers time to remove any leaves, seeds and branches of the sycamore maple that may have blown down in the storm.
Read the full study here.
New to the Paulick Report? Click here to sign up for our daily email newsletter to keep up on this and other stories happening in the Thoroughbred industry.
Copyright © 2020 Paulick Report.