Owners and trainers might be the best resource of information for veterinarians evaluating pain in horses because they are most likely to be familiar with the horse's normal relaxed behavior and mannerisms, according to a researcher from Colorado State University (CSU).

These individuals sometimes can pick out abnormal behaviors that might indicate the horse is in pain–such as signs of stress–better than veterinarians who are not as familiar with the horse's typical behavior, according to Ann Wagner, DVM, MS, Dipl. ACVA, ACVP, a professor of veterinary clinical sciences at CSU, who recently reviewed published content on the topic to determine the effect of stress on equine pain.

"There is no 'gold standard' for assessing pain in horses," said Wagner. She added that researchers have developed different pain scales that focus on different sources of pain (orthopedic, gastrointestinal, or laminitis, for example) to determine if a horse is in pain and to what degree.

"Many of the signs of pain mentioned in various pain scales are changes in behaviors that can be detected by owners," she said. She cited behaviors that are sometimes associated with pain in horses, such as restlessness/agitation, decreased interactive behavior (responsiveness to people and surroundings), reluctance to move, sweating, kicking at the abdomen, pawing, changes in appetite, and lameness. Many of these also can indicate that the horse is stressed, which likely has an impact on the horse's pain level, she noted