Illness/syndrome similar to tying up

[mynutmeg]

There's an illness/syndrome which presents with similar symptoms to tying up but is seen in horses who wouldn't normally be associated with tying up. Normally presents in horses who aren't very fit, grass kept types.
I cannot remember what it's called - any suggestions?
Thank you

 

[texel]

Do you mean equine atypical myopathy ?

 

[mynutmeg]

hi, yes thats it. Thank you!!

 

[popularfurball]

Or Epsm?