My little cobbie gets hiccups sometimes, quite disturbing when it first happened, no reason for it, he came in from the field with them. Rang vets and she said not to worry, nothing you can do to stop them.
They went away overnight and pony no worse for it.
Our 14.2 gets hiccups every time we go anywhere as soon as I have hitched up the trailer, off he goes, usually only lasts 1/2 or so. I used to worry about it but have researched it and come to the conclusion that as he has done it for so long with no other symptons, it is just a nervous excitement thing. Quite amusing really. :