Sometimes it is easy to determine when horses are in pain, but sometimes, especially with chronic pain, it is difficult to know. Dr. Claudia Sonder from UC Davis indicates that like humans, horses can display involuntary facial expressions that communicate stress, fear and pain. And they can display these expressions in subtle ways as just a change in the shape of the mouth, eye or nose can tell us whether the animal is in pain.

UC Davis has a large herd of horses with chronic painful conditions such as arthritis, laminitis and navicular disease and so they had the ideal situation to study these horses in pain. The group set out to create software that would map the horse’s face and then make a program to read the faces and expressions displayed. The team used pictures of humans and then pictures of horses to map the facial expressions, while videos were used to assess stress, fear, boredom and anxiety in the animal’s faces. It is hopeful that the program can help veterinarians determine if horses are in pain when it is not obvious otherwise. More data is required but Dr. Sonder believes this will allow vets to treat animals faster by understanding that they are in pain from just their facial expressions. In one case, Dr. Sonder was able to look at a mare who appeared normal but the shape of her nostrils indicated she was in pain; further analysis revealed she had a major problem.

Eventually, it is hopeful that vets will have a computer program available in their offices to aid in determining pain in horses. It is also possible this technology could be used in cats, dogs and other animals to determine if they are in pain; it would be especially helpful if they are in the hospital and their pain medication is wearing off and another dose is needed.