I gelded my colt last year when he was about 7 months old- no problems. So did the neighbors geld the ones that were ready and dropped. I have also heard that gelding earlier *may* make them grow a tiny bit taller, but do you ever prove that?!! In regards to gelding them young, they will never develope the stallion tendancies and attitude- and many seem to avoid getting that 'thickness' that some stallions develope also- the neck, jaws, etc....