The horse’s brain, weighing just over a pound, contains hundreds of millions of nerve connections to control and coordinate specific functions in the body. Nerves travel directly from the brain or down the spinal cord to transmit signals back and forth to the rest of the body. The skull provides protection for this delicate organ. Problems within the brain manifest in a variety of ways depending on the region of the brain affected. Behavior changes, mental dullness, incoordination, and seizures are some common indications of brain disease.