Which of the following is an indication that a horse might be suffering from colic?

Laying down and rolling is a significant indication that a horse might be suffering from colic. Colic refers to abdominal pain in horses, which can manifest in various behaviors. When a horse is uncomfortable or in pain, it may exhibit signs such as repeated lying down, rolling, or attempting to get up, which all serve as distress signals indicating something is wrong.

This behavior is particularly worrisome because rolling can lead to further complications, such as twisting of the intestines, which can be life-threatening if not addressed promptly. Monitoring for such signs is critical for the timely diagnosis and treatment of colic, making awareness of these behaviors crucial for anyone handling or caring for horses.

The other options do not specifically indicate colic; excessive sneezing may be related to respiratory issues, increased thirst could be due to various factors including heat exhaustion or dehydration, and fatigue might suggest other health problems or simply tiredness after exertion.