I'll Have Another wears them, as reported in the Washington Post:
On Saturday afternoon at New York’s Belmont Park, a 3-year-old colt named I’ll Have Another will be equipped with horseshoes, bridle and saddle as he tries to become the first Triple Crown champion in 34 years. He will, however, be without the equine Breathe Right strips that he sported while winning the Kentucky Derby and the Preakness.More details at the Washington Post.
The white adhesive strips, stretched across the horse’s nasoincisive notch a few inches above the nostrils, are intended to help the animal breathe, run better and prevent bleeding of the lungs. Within the United States, they are banned only in New York...
In 2004, a cult following of the strips grew among Olympic riders of Three-Day Eventing (dressage, cross-country, show jumping). A horse wearing a Flair strip won the 2006 Breeders’ Cup Mile. The U.S. Equestrian Federation asked Flair to provide strips for horses at the 2008 Olympics.