Communication between dogs and humans could be improved with wearable tech for canines.
Developed in the US, the harness is fitted with sensors that monitor both a dog's posture and its vital signs and can pass the information to an owner.
It also contains vibrating motors so owners can communicate with a dog even if it is out of sight.
The harness could help with training or refine how working dogs and their handlers cooperate.
The harness was fitted with motion detectors to help interpret a dog's body language - their primary means of communication, said Dr David Roberts, an assistant professor of computer science at the North Carolina State University, who helped develop the prototype.
"We can determine when they're sitting, standing, running, even when they're out of sight," he said in a statement.
More subtle information about a dog's wellbeing is also gathered via heart-rate and body-temperature sensors. These can alert people if a dog is stressed or excited.
"We're reliant on the physiological and behavioural sensors to give us a picture of the dog's mental and emotional state," said Sean Mealin, a PhD student at NC State, who has also worked on the project.
"This can help handlers identify and mitigate stress for the dogs," said Mr Mealin. "It's an important issue. Particularly because guide dogs are bred and trained not to display signs of stress in their behaviour."
In addition, handlers can add another layer to the way they communicate with a dog, by making motors on the harness nudge a dog to reinforce a spoken command or prompt a dog to take action if it is a long way away.
Finally, the wearable tech can be augmented with a variety of other devices, such as microphones, cameras and environmental sensors that can gather data, as from dogs being used in disaster zones.
The creators of the harness are now working on a miniaturised version and improving its sensors so they can be used in animal shelters and hospitals to monitor the wellbeing of animals in care or recovering from treatment.