Grazing Mares on Pasture with Sycamore Maples: A Potential Threat to Suckling Foals and Food Safety through Milk Contamination.
Authors: Renaud Benoît, François Anne-Christine, Boemer François, Kruse Caroline, Stern David, Piot Amandine, Petitjean Thierry, Gustin Pascal, Votion Dominique-Marie
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Equine atypical myopathy (AM), a seasonal toxicological condition triggered by ingestion of sycamore maple (*Acer pseudoplatanus*) seeds and seedlings, has long been recognised in adult horses and gravid mares, but the mechanisms of disease transmission to nursing foals remained unexplained. Researchers investigated whether hypoglycin A (HGA)—the primary toxin in sycamore seeds—could pass into milk from grazing mares with confirmed blood contamination, using four mare-foal pairs on pasture with sycamore trees as their study population. HGA and its toxic metabolite were detected in milk samples from three of the four mares tested, marking the first documented evidence of toxin transfer via lactation in equine cases. These findings provide a plausible pathway for AM development in unweaned foals independent of direct seed ingestion or transplacental transfer, whilst also raising broader food safety concerns regarding raw milk and dairy product contamination in other species exposed to Sapindaceae trees.
Read the full abstract on PubMed
Practical Takeaways
- •Remove or restrict grazing access to sycamore maple trees during autumn when seeds and seedlings are present, as nursing foals may consume toxins through contaminated milk
- •Monitor unweaned foals grazing near Acer pseudoplatanus for signs of atypical myopathy (muscle weakness, sweating, dark urine) and consult veterinarians immediately if suspected
- •Consider the potential for transplacental toxin transfer in pregnant mares as well as lactational transfer when managing horses on pastures with sycamore maples
Key Findings
- •HGA and its metabolite were detectable in milk samples from 3 of 4 mares (75%) grazing near sycamore maple trees
- •This is the first documented evidence of HGA transfer into equine milk from mares exposed to sycamore maple toxins
- •Milk contamination with HGA may partially explain cases of atypical myopathy in unweaned foals
- •Sapindaceae family tree toxins in milk may pose food safety risks for raw milk and dairy products from other species