If you find yourself attracted to the idea of a magnetic blanket for your horse, you might want to consider some opposing viewpoints: Swedish researchers recently found that magnets in blankets don’t have quite the impact on blood flow that some manufacturers might claim.

“An ordinary blanket probably increases blood flow just as much as a magnetic one does,” said Anna Edner, PhD, of the Department of Clinical Sciences, Faculty of Veterinary Medicine and Animal Science in the University of Agricultural Sciences in Uppsala, Sweden.

Magnetic horse blankets have rows of magnets sewn into the filling, and some manufacturers claim these blankets increase horses' blood flow, which can help relieve sore muscles. Edner said these claims are true—the magnetic blankets do increase blood flow. But so do blankets without magnets, she said.

In their study, Edner; Anna Bergh, PhD, also of the University of Agricultural Sciences; and their team tested magnetic blankets on 10 healthy horses. Each horse wore either magnetized blankets or identical blankets fitted with deactivated magnets. Researchers analyzed the horses’ blood flow in their muscles, their skin temperature, their behavior, and their mechanical nociceptive threshold—a way to measure the horse’s sensitivity levels to pain