Short in front?

[showjump]

My lad is 'short' in front. He has had afew weeks doing very little work wise, and has been in field afew times (hes not a field fan) but on tures i took him for a lesson, and trainer noticed he was short.
Trotted him up yesterday and still short. Feet arent overly warm, and can feel a very slight digital pulse.

Ideas guys?

Thanks