21 Jul 10 Hobbes Aussie and Alfie share paddock for 1st time 19 

Following a spate of equine deaths around the UK from Atypical Myopathy in the past couple of weeks, horse owners are being warned to keep their horses away from sycamore trees.

Atypical Myopathy is an acute, often fatal rhabdomyolysis (a severe form of azoturia/tying up) that is caused by the toxin Hypoglycin-A. This is found in the seeds, and to a lesser extent the leaves, of the European sycamore (Acer pseudoplatanus).

A horse struck by this condition will suffer muscle damage, in particular damage to the heart muscle and the muscles that enable it to stand or breathe. Horses show signs typically associated with colic or tying up, including dullness, weakness, trembling, lying down, difficulty with breathing and swallowing, and dark red-brown urine.  
The recent surge of deaths from Atypical Myopathy is being blamed on the record-breaking temperatures of the 2014 summer and autumn. This is thought to have both generated an abundance of sycamore seeds, and increased the toxin levels in the seeds. 

Added to this, the recent intense winds have deposited the seeds in larger than normal quantities in paddocks, just when grass is becoming less abundant and appealing. Combined, this has increased the risk of horses eating fatal levels of the toxic seeds.

Just last weekend, St. Geroge's Vets in Wolverhampton posted a statement on Facebook that is echoed by vets around the UK. It said that it has 'seen 4 cases in the last 5 days, 2 of which have now ended in a fatality...if you suspect that your horse may have eaten any leaves/ seeds, to call us IMMEDIATELY!...We don't wish to alarm but it really does seem to be bad this year and we really want to avoid any more cases.'

RSPCA Cymru issued a similar warning after several horses died in Pembrokeshire after eating sycamore seeds while grazing.

Until winter arrives, horse owners are advised to keep horses fenced away from where sycamore seeds fall, rake up the seeds immediately, limit the time horses spend in fields with sycamores, and ensure there is sufficient alternative food to graze on.