A horse's nervous system includes its brain, spinal cord, and the many nerves spread throughout its body (called "peripheral nerves"). Together, these components form connected pathways that let the horse sense its environment and respond to it.
One well-known type of nervous system pathway is a reflex. Reflexes are simple, “automatic” responses experienced by all animals. For example, when an eyelid is touched, it automatically closes. When a toe is pinched, the leg pulls away without conscious effort.
Many kinds of problems can affect the nervous system of horses and other animals, including birth defects, infections, inflammation, poisoning, body-chemistry (metabolic) problems, poor nutrition, injuries, aging (degenerative) diseases, and cancer. Some neurological problems are more common in certain horse breeds or sexes, or at certain ages.
