Mad horse disease (Eufez)

Mad horse disease is a colloquial name for a disease expressed among significant portions of Cornelian horse herds.

The horses suffering from this disease have been studied, as their behaviour is similar to those experienced by people who have eaten psiloleaves. Since these horses so often graze in fields where these plants are common, it has been speculated that constant consumption has resulted in some genetic deformities among offspring. This has essentially led to an offshoot of Cornelian horses which bear these mad traits. In humans, psiloleaves are often associated with psychedelic experiences.