Animals are just as expressive as humans. But unlike people, when they feel pain, they can't just say it.

That's why a group of veterinarians and computer scientists from UC Davis are part of a team of researchers trying to use facial recognition to identify pain in animals.

"What a lot of people don't know is that the animal structure that we see in horses, dogs, cats, a lot of that muscular structure is very similar to people," Dr. Jamie Peyton, a veterinarian at UC Davis' Veterinarian Teaching Hospital, said.

"So, what we're doing now is having a big collaborative group...all coming together to say how we do we look at facial recognition...and find these signs of pain by looking at their facial features," she added.

The technology to do this is still being developed. However, so far, computer scientists have trained the technology to recognize animal faces in photos (similar to how a computer can recognize a human's face on, say, Facebook), as well as identify the different parts of an animals' face.

"One of the signs of pain is tension around the eyes or nostrils...if you know where the eyes and nostrils are, you can zoom in on that part and detect pain," Maheen Rashid, a computer scientist at UC Davis, explained.

The next step, is to teach the technology to identify those different expressions.

Ultimately, the researchers hope that this will not only allow veterinarians to better identify and treat sick animals, but also help non-verbal people, too.

"We are one part of a very big project, where we're really trying to identify pain recognition by looking at facial features," Petyon said, "If we can recognize pain well, then we can treat it. But we have to see it first."