Think of your dog's nervous system as the control center for his body. The brain, spinal cord, and roadmap of nerves that travel to every inch of your dog's body tell him what his senses detect and which muscles to move. They also help him learn. The nervous system also includes the intangibles that make each dog's personality unique. So along with relatively understandable disorders, such as movement problems, behavior disorders also start here.
The brain has three main areas — the cerebrum, the cerebellum, and the brain stem. The delicate tissue of the brain is protected with a sturdy covering of tissue called the meninges as well as the bones of the skull. While those coverings form important shields, they can cause problems with brain trauma as they don't allow room for swelling. Secondary pressure is often more damaging to brain tissue than the original injury. If your dog has serious brain trauma, he may need holes drilled into the skull so these shields can be opened to allow for expansion.
Do not put your hand into the mouth of a dog having seizures! Dogs don't have the risk of swallowing their tongues like people do. If you get bitten, you'll need to take yourself to the emergency room as well as get your dog to the veterinary hospital.
The cerebrum is the part of the brain where learning takes place. It collects input from your dog's senses (such as vision and smell) and controls emotions. Epileptic seizures originate in the cerebrum; these seizures are basically a short circuit of the neurons there.
The cerebellum is the part of the brain that helps your dog with balance and movement. A problem in the cerebellum might show up as a wobbly gait or clumsiness. The brain stem controls many of the body's most basic functions. For example, directions for breathing originate here.
The spinal cord runs through the bony vertebral column down your dog's back. This is a very important pathway for nerves that travel from the brain, carrying information for individual muscles and cells. Information is also carried as feedback from muscles and cells back to the brain. For example, say your dog is running, and the footing suddenly changes from grass to rocks. The brain has been directing long, hard landing strides. Now, the feet pass back the information that the surface has changed. The brain quickly changes its message to accommodate the poor footing, and the dog shortens and lightens his stride.
An injury to the spinal cord may lead to paralysis or death. Ruptured spinal column discs that put pressure on the spinal cord often have permanent effects on the nerves involved. Discs can rupture from severe trauma, such as being hit by a car, or from repeated low-level damage due to wear and tear. Some breeds (such as the long, low-backed breeds like dachshunds and basset hounds) are predisposed to disc problems from the way their bodies are formed.
Your dog has great numbers of nerves throughout her body. These nerves continually send messages back and forth from the brain and body. Many of these functions are subconscious. Your dog doesn't have to think carefully to breathe. When nerve cells are damaged, pain reports go back to the brain. If conditions change, the news is passed on to the brain so adjustments can be made.