Submitted by Fiona Dove 7th November 2013
I lost my 2-y-o gelding Yarpha Exquisite yesterday to Atypical Myopathy - my vet had never heard of a case in Scotland before but Royal Dick have apparently had several cases reported since last weekend's gales and at least 6 horses have died in England since last week's high winds. It's caused by the horse picking up sycamore seeds, which contain a toxin that disturbs glucose uptake and use in the muscles, leading to muscle breakdown. The only treatment is immediate IV fluids to try and flush the toxins through the kidneys but even then it's between 60% and 90% fatal. Death is usually due to respiratory or cardiac failure when the lung and heart muscles are affected, or to kidney failure because of the overload of protein and toxin in the blood. Any horse exposed to sycamore seeds in the grazing area is at risk but youngsters under 4 and Shetlands particularly so, since they will try out unusual foods rather than sticking to grass.
Symptoms are muscle stiffness and tremor, sweating, depression, lethargy and dark urine. Affected horses continue eating normally, unlike grass sickness. A bloodtest will confirm raised protein levels in the blood.
Horses on grazing with nearby sycamores or sycamore seeds in the grass should be removed, seeds cleared with leaf-blowers or leaf-hoovers, or additional feed should be put out to try and prevent the horses picking up the seeds. Squizzy went from healthy on Monday to put down yesterday afternoon and one owner lost a horse after only 3 hours in an affected paddock.
Given the sudden high incidence of Atypical Myopathy and the fact that most people have never heard of it, I wanted to get the warning out to as many people as possible. Please, could you post a warning on the Society's website? The peak risk comes in the autumn when seeds fall and in the spring when they germinate - it may be too late to help any more horses this autumn but if we can raise awareness amongst owners, next spring and future years might be safer.