Get into Your Pets' Minds

Researchers have discovered that certain electroencephalogram (EEG) waves can signal depression, anxiety, and even contentedness in humans. Meanwhile, EEG studies in rodents, farm animals, and pets have revealed how they react to being touched by a human or undergoing anesthesia. But so far, no one had found a way to record brain waves in animals while they move around.

A free-moving horse wears an electroencephalogram headband for capturing brain wave patterns

Recently, researchers from the University of Rennes have gone around that problem and devised a new, mobile headband that detects brain waves in horses, which could eventually be used with your own pets. Check out this report for learning more of their experiments. 
https://www.sciencemag.org/news/2021/03/how-horse-feeling-new-mobile-brain-wave-reader-could-tell