Vets see an increased incidence of impaction colic over winter. Most impaction colics are due to digestive contents becoming stuck within the colon or caecum, most frequently at the pelvic flexure. This is a narrow U-bend within the horse’s colon that acts as a ‘pinch-point’.
Why is this:
Horses are stabled more in inclement weather; reduced exercise can reduce motility in the colon and caecum. As food moves more slowly more water is absorbed making the food drier and becoming “stuck”.
Cold or frozen water may mean that horses drink less and switching from grass to hay may mean less fluid in their diet.
Less frequently neurological problems such as grass sickness may cause colic.
How to reduce the risk:
Keep your horse moving. If they are stabled make sure they get walked out try to let them hand graze
Try adding luke warm water to their feed to make sure they get an adequate daily intake.
Monitor their droppings - note how many they normally pass and the consistency. If they pass less or start passing small, hard, pebble like droppings it can be a sign they are developing an impaction so call your vet.