DOCTOR Dolittle may have been able to talk to the animals. But now scientists are claiming that an increasing body of research will help us all to assess the emotional inner life of animals from live stock to pets and help us look after their welfare better.

New studies, due to be presented at the 50th International Congress of the International Society for Applied Ethology in Edinburgh next week, will highlight how we can judge what animals are thinking and feeling using facial cues and sounds to indicate a wide range of complex emotions.

Papers due to be presented at the event, organised by the SRUC - Scotland's Rural College – will reveal that rats ears go pinker when they are happier, while horses level of emotional contentment can be read by the wrinkles around their eyes. Chickens and pigs use sounds to express how they are feeling, while those with mobile ears will use those to send out signals of distress or contentment, it is claimed.

Other studies to be revealed over the course of the five-day conference include a hard look at whether pet owners are always doing the best for their beloved animals, with research showing that indoor cats fare worse on scales of emotional contentment than those allowed to roam free, while stray dogs are happier than those left at home alone.

New findings on "emotional contagion" will also show goats express concern and emotional distress when shown pictures of other goats who are stressed, whereas rats who are tickled – and vocalise a noise compared to human laughter – are likely to make their fellow rats nearby feel more playful. Other researchers claim animals can have an optimistic or pessimistic nature.

Organisers claim that by better understanding how animals are really feeling humans will be better able to care for them.

Professor Cathy Dwyer team leader of Animal Behaviour and Welfare at the SRUC, and conference organiser, said: "We accept that animals are sentient so this is really all about understanding what think, feel and experience. That's not easy. A lot of people who have pets know when their dog is happy or sad because they know the animal well but we are interested in developing more objective measures that can be used to look at animal emotions in general, and help improve welfare standards."

She claimed that while earlier research had focused on evidencing behaviours displayed when animals were distressed, such as repetitive pacing and feather pecking, much of the newer work looks at what makes them happy, with cues read from vocalisations, postures and facial expressions.

An increasing amount of work was on the welfare of pets, she added. "Sometimes, though we think we are doing our best for our pets, it is not what they might choose. People who have indoor cats, for example, may feel that they are keeping them safe from the risk of being run over but there is a trade off between over-managing their lives and keeping them safe from harm.

"And although you might expect the welfare of stray dogs to be poor, the research shows that they have greater wellbeing than a pet dog who is left alone at home. They are pack animals.

"This is a relatively new science but it has contributed hugely to improving animal welfare. We no longer have sows in confined stalls where they can't move and increasingly we have chickens who are not in tiny cages, or can roam free. But we still have a very long way to go. The more we understand about what animals think and feel the more we can provide for them better."

Mike Mendl, professor of Animal Behaviour and Welfare at the University of Bristol, who will be speaking at the conference, said there was an increasing interest the science around animal emotions. "If we are to adequately measure the impact of the way we manage animals on their welfare, we should be trying to develop ways of scientifically assessing their emotional states," he said.

"Animal emotion research has the potential to reveal new information about, and more accurately assess, the mental experiences that animals have, and thus to improve our knowledge about their welfare. This may also extend to pets."

British Veterinary Association President Sean Wensley said new scientific understanding was helping society re-evaluate how it treats animals. He added: "The now thriving field of animal welfare science is providing an objective basis for understanding how animals experience the world, their pleasures and pains, and what they need and want from their perspectives."