It’s no secret: Working around horses can be dangerous. In fact, in a 2014 study researchers determined that equine veterinarians have the highest injury rate of any nonmilitary profession in the United Kingdom, even ahead of construction workers, prison guards, and fire fighters.

Many people injured in accidents involving horses report that the animal was unpredictable and that they “never saw it coming,” said Gemma Pearson, BVMS, Cert. AVP (EM), MRCVS, a senior clinical training scholar in equine practice at the University of Edinburgh’s Royal (Dick) School of Veterinary Studies, in Scotland.

However, she contends that horses aren’t necessarily mercurial. Rather, she said, we’re just not always able to read the signs they’re giving us. At the 2016 Western Veterinary Conference, held March 6-10 in Las Vegas, Pearson gave attendees tips on how to identify horses that might be problematic during veterinary exams and procedures.

The key to predicting whether a horse could become a problem patient is understanding his arousal, or alertness level, Pearson said. Increased arousal is associated with elevated heart rates and blood pressure, and horses are often hyperreactive (meaning they’re likely to overreact to normally innocuous stimuli, such as placing a stethoscope on their side, she said) in this state. In combination with high or low arousal levels, horses can be in a negative or positive emotional state, categorized by four