thanks everyone - my last coloured horse had various horseware rugs which fitted him fine - and did fit Arnie when he first arrived - but as he is growing they are just too tight for him!
I have a clydesdale cross horse, who definately takes after the clydesdale in him. He has quite a large neck - what rugs have quite large neck openings as I am finding a lots of rugs are too tight at the front for him?