Research conducted by Nestlé Purina PetCare Co. has confirmed that dogs, like people, become flush with happiness and excitement. The findings, according to Purina behavior scientist Ragen T.S. McGowan, Ph.D., illustrate how the human-animal bond works both ways, lighting up the lives of both people and pets. “Scientists have known for years how to evaluate negative states such as stress and anxiety in animals,” McGowan said. “Less is known about how to measure positive states such as happiness or excitement.” McGowan and her team used thermal, or infrared, cameras to examine how external stimuli can generate joyful emotions in dogs, the company reported today. The cameras measured temperature fluctuations in dogs’ eyes, ears and paw pads as blood flowed to those areas. “Thermal imaging has been widely used in animal welfare studies to assess inflammation in racehorses, for example, or to see how certain conditions affect livestock’s stress levels,” McGowan said. “This is one of the first times it is being used to measure positive responses in pets.” Part of the study involved having people with no connection to a group of shelter dogs sit with and pet them for 15 minutes, the company stated. The dogs showed heightened positive emotions as measured by the thermal imaging. “Animals don’t always portray physically what is going on internally,” McGowan said. “You could put a guide dog alone in an empty room and he might lie still looking calm and relaxed because he has been trained to do so, but actually he may be really stressed because he isn’t with his owner. “On the other hand,” she added, “you could put a pet dog alone in the same room and he might run around looking more agitated, but in fact he might just be enjoying himself and exploring. “By identifying the internal indicators of what’s happening emotionally in dogs, we aim to enhance our knowledge of the most beneficial ways to interact with them.” The findings may be published early next year, according to Purina.