Horse cues

Each horse is different, but some basic behavior observations should be monitored. "Look at the horse—they usually give you a clue as to how they're feeling," Houpt says. Kicking is primarily defensive. "A fearful horse is more likely to kick you than an offensively aggressive horse. If they're in pain, they're more likely to be fearful."

Looking at a horse's hindquarters will tell you a lot because if the horse tucks its tail, it is probably frightened, which makes it more likely to kick. "But there is also the horse that is lashing its tail, displaying offensive aggression, and that horse may kick too," Houpt cautions. "If you're lucky, they'll make a kick threat. They may pick up their foot, but they won't aim at you."

Pinning ears is an obvious sign of aggression, but that happens later in the aggression progression. "By then you've missed all the subtle signs, and they may be really frustrated or in a lot of pain and ready to let fly," Williams says.

Looking at their eyes is also important. "Seeing the whites of the eyes is a good sign that the horse is fearful," Houpt says.

"When it comes to the whites of their eyes, some breeds tend to naturally show more white," Williams says. If the owner is assisting you, he or she will know what is normal for that animal.

So what does an overly tense horse look like? "Besides the more obvious signs of ear pinning and cocking of a hoof, there are the more subtle signs. Some veterinarians don't realize that a horse might be cocking a hoof because they're resting, or that particular leg is sore," Williams says. "The practitioner has to look for overall body tension, so that he or she realizes that the cocked hoof indicates that he's not just resting anymore, but thinking about whether to kick you. Look at the mouth and eyes. Tension around the mouth tells you that they're getting frustrated and hurting and are nearing the end of their rope as far as what they're going to tolerate."

Williams worked with a neglected horse that was just frustrated with people. "I noticed that his lips and face were just tight. Later in the day, he nipped at someone who was trying to handle him. He was gritting his teeth, and his mouth was clamped shut. He just looked frustrated. When I approached him earlier, I backed off realizing he needed a little space. Later in the day, another person didn't back off, and the horse bit him. He just clamped his lips together and showed a very tense look in his face," Williams says.

"One of the things that seems to be very obvious to a behaviorist but not necessarily to even the best or most experienced equine clinician is that most often when people get hurt, the horse is afraid," says Sue McDonnell, PhD, University of Pennsylvania's School of Veterinary Medicine. "Fear in horses goes unrecognized because the signs are subtle. Horses are an open-plains, grazing species, and they have evolved to hide their fear, signs of pain and discomfort in response to predators. If they displayed conspicuous behavioral signs of pain and fear, they would not only draw attention to themselves but to the whole herd."

Clinicians and handlers who get hurt often say that it just came out of nowhere. "That's the way horse behavior is designed," McDonnell says. "Most people don't see the subtle signs of fear as such but as misbehavior, so the tendency is to just increase the aggression, the restraint and all the things that push the horse over the edge, instead of relaxing, trying to be more soothing and reducing the amount of pressure on the fearful horse."