These "safe and effective" devices are apparently why so many horses died.
"This STRIDESafe device monitors the horse's movements 2,400 times per second throughout the race, sending 2,400 pulses of radio frequency (RF) radiation every second through the body of the horse. It also contains a GPS component that communicates with global positioning satellites. It also communicates with the RFID chip implanted in the left side of every horse's neck, ensuring that the chip also emits radiation throughout the race. And because every racehorse wears horseshoes made of aluminum, which is one of the best conductors, the frequencies that are conducted from both the STRIDESafe device and the RFID chip throughout the horse's body are absorbed and reradiated by its four shoes…."