Signs of Colic...
lying down more than usual
getting up and lying down repeatedly
standing stretched out
standing frequently as if to urinate
turning the head towards the flank
repeatedly curling the upper lip
pawing the ground
kicking at the abdomen
rolling
Prevention of Colic
allow as much turnout as possible
maintain a regular feeding schedule
ensure constant access to clean water
provide at least 60% of digestible energy from forage
do not feed excessive digestible energy
do not feed moldy hay or grain
feed hay and water before grain
provide access to forage for as much of the day as possible
do not over graze pastures
do not feed or water horses before they have cooled out
maintain a consistent exercise regime
make all changes in diet, exercise level and management slowly
control intestinal parasites and assess efficiency periodically.
You will know if your horse Colics... just make sure to always cool down and walk your horse... and one of the other issues is making sure you have consistant exercise.
good luck!