Acomputer programme that can detect whether farm animals or pets are in pain has been developed by scientists at Cambridge University.
The artificially intelligent system has been designed to recognise five different facial expressions in sheep and estimate whether the animal is suffering and how severe is the discomfort.
It is hoped cameras could be mounted on water troughs to monitor animals when they approach and issue a warning to the farmer if the sheep appears distressed, so that diseases in the flock can be picked up early.
The results could also be used for others types of animals, such as rodents used in animal research, pets or horses, say the researchers.
“There’s been much more study over the years with people,” said Professor Peter Robinson, of Cambridge’s Computer Laboratory.
“But a lot of the earlier work on the faces of animals was actually done by Darwin, who argued that all humans and many animals show emotion through remarkably similar behaviours, so we thought there would likely be crossover between animals and our work in human faces.
“I do a lot of walking in the countryside, and after working on this project, I now often find myself stopping to talk to the sheep and make sure they’re happy.”
The algorithm looks for signs of pain including eyes narrowing, cheeks tightening, ears folding forwards, lips pulling down and back, and nostrils change from a U shape to a V shape.
“The interesting part is that you can see a clear analogy between these actions in the sheep’s faces and similar facial actions in humans when they are in pain – there is a similarity in terms of the muscles in their faces and in our faces,” said co-author Dr Marwa Mahmoud.
To train the model, the Cambridge researchers used around 500 photographs of sheep, which had been gathered by veterinarians in the course of providing treatment.
Severe pain in sheep is associated with conditions such as foot rot, an extremely painful and contagious condition which causes the foot to rot away; or mastitis, an inflammation of the udder in ewes caused by injury or bacterial infection.
Both conditions are common in large flocks, and it is hoped that early detection will lead to faster treatment and pain relief and early diagnosis.
The algorithm will be presented on June 1 at the 12th IEEE International Conference on Automatic Face and Gesture Recognition in Washington, DC.