Atypical myopathy in horses is a sneaky illness that can take their life swiftly. You might’ve heard of seasonal pasture myopathy, sycamore myopathy, or sycamore poisoning, which are all correct terms for this condition. It’s usually found in grazing equines and more popular during fall and spring. Atypical myopathy occurs when a horse ingests the hypoglycin A toxin.
This toxin is often found in sycamore seeds, seedlings, and leaves. As you may notice, these little “helicopter-like” seedlings can be hard to avoid in many areas. This toxin is not present in every seed and seedling but can be found in seeds, seedlings, and certain flowers from the genus Acer tree species. It’s important to know once your horse has ingested one of these seedlings. Then you can take the best course of action and hopefully save his life. So, here’s what you need to know about atypical myopathy in horses.
What Is Atypical Myopathy?
First, it’s important to understand what this illness actually does to a horse’s body. This disease weakens the muscles, presenting sudden stiffness, muscle tremors, collapsing, and colic-like signs. This occurs because the hypoglycin A toxin prevents energy from producing in the muscular cells. Now that you know the cause and effects of this illness, let’s look at how this might affect your horse physically.
Signs
It’s critical to notice signs of atypical myopathy to treat your horse immediately, as it typically does its damage within 24-48 hours of entering the body. Each minute counts because 70% of horses with this condition don’t survive. Contact your emergency vet as soon as you see these signs:
- Stiffness
- Shivering
- Dark Red or Brown Urine
- Weakness
- Muscle Pain
- Colic Signs
- Reluctance To Move
- Lethargy
- Low Temperature
- Difficulty Breathing
- Irregular Heart Beat
- Inability To Stand
- Muscle Tremors
- Sudden Collapse
Treatment
Once your vet confirms hypoglycin A is present, treatment begins immediately. Treatment consist of IV fluids, pain relief, and intensive care at the equine hospital. This may pose a challenge to horses who do not want to be moved, but it’s often necessary for treatment. Since this illness is quite fatal, preventative measures are the best way to keep your horse safe. Here are steps you can take to avoid this situation all together:
- Test for presence of hypoglycin A in your pasture
- Mow areas where seedlings grow and collect the cuttings
- Fence off areas with noticeable sycamore seeds and leaves
- Turn out horses for short periods
- Reduce stock density to give enough good grazing for every horse
- Provide additional hay forage, especially where the pasture is poor
- Pick up and remove all sycamore seeds when possible
- Regularly inspect your pasture for sycamore seedlings and leaves
Atypical myopathy is nothing to mess around with, but it’s certainly something to understand. The best way to keep your horses safe is by limiting their access to sycamore seedlings, which is very manageable for most horse owners. If you took the time to read about the condition, pat yourself on the back! You’re potentially saving a horse’s life just by reading this article.