Unfortunately, a decrease in the temperature can mean an increased risk for colic, specifically impaction colic. Impaction colic is when feed material forms a blockage in the large colon. There are several locations in the large colon where the diameter narrows, and this is where blockages tend to form. How does cold weather play a role? In colder temperatures, horses tend to drink less water. This leads to dehydration, which can lead to impaction colic: Dehydration slows gut