And the answer is…..
A SYCAMORE SEED! And the condition is atypical myopathy.
This is a disease that is seen in grazing horses commonly in Autumn. Atypical myopathy has been linked to a toxin, Hypoglycin A, in the seeds of the sycamore tree. This toxin affects the horses muscles by causing degeneration of the muscle fibres causing stiffness, tremors and collapse.
Atypical myopathy is usually fatal and the signs can develop very quickly. The signs you should look out for are:
Muscle stiffness and tremors, difficulty standing, colic symptoms, dark urine, depressed state and excess sweating.
How can you prevent it?
Avoid grazing horses in fields with sycamore trees. Or fence off areas where the seeds or leaves may fall
Ensure your horse has enough to eat when grazing is poor by supplementing with hay/haylage
Avoid overstocking your fields so there is enough grazing for each horse
If you see any of the symptoms listed above – contact us immediately!
If you suspect your horse has Atypical Myopathy, keep your horse warm and dry. Do not try to move of stress them until one of our vets arrive and remove other horses from the pasture.
Clinical signs of AM to look out for are;
• Stiffness without exercise
• Abnormal urine which is brown coloured
• Muscle tremors
• Weakness, low head carriage
• High heart and respiratory rates
• Recumbence/cannot stand