Michelle LeBlanc, DVM, Dipl. ACT University of Florida Narcolepsy In Horses I am requesting information regarding narcolepsy. In a book I edited with Warwick Bayly, BVSc, PhD, Dipl. Clinical signs of narcolepsy vary from mild muscle weakness to complete collapse. Adult horses may drop their heads, buckle at the knees, and stumble.
Pony breeds are more likely to become recumbent.
Horses and ponies that collapse may show absent spinal reflexes and REM sleep. Episodes may last from a few seconds to 10 minutes. The prognosis for narcolepsy is variable. Some newborn Thoroughbreds and miniature horses may have severe attacks, but recover fully. In Shetland and Suffolk ponies, the disease may persist throughout life, as is true with the adult-onset form.