With their level of intelligence and a drive to please humans, dogs can be trained to do many tasks. These traits make them ideal candidates for helping those with disabilities. You've seen at least one seeing eye dog in your life, but service dogs also help the deaf and those who are paralyzed. Even people with epilepsy are able to live freer lives with the help of service dogs.
Researchers and scientists still aren't quite sure how a dog knows that his human is about to experience a seizure. It may be that a dog's acute sense of smell allows him to detect changes in his person's body chemistry right before a seizure occurs, or maybe the dog, keenly tuned into his human, is alerted by behavior that is a little "off" prior to an incident. Service dogs can be trained to recognize when a seizure is about to happen, but some dogs have a natural knack for it. Those dogs and their people usually work out a system of their own, but can get formal training as well.
Dogs who have a natural talent for sensing epileptic seizures will become agitated when they know their human is about to have one. The dogs might whine softly, lick their humans' arm or attempt to get them to sit or lie down. They're acting instinctually and they do an effective job of it. Dogs who have been trained also will give specific cues when they sense a seizure coming, like pawing at their people in a certain way and guiding their human charges to a safe place. Service dogs for epileptics can be trained to activate emergency call equipment and remind their people to take their medication at specific times.
There are service dog training schools throughout the United States that provide basic and advanced training for dogs as young as 8 months old. After learning basic skills such as obedience and proper behavior in public places, the service dogs are tested to determine how they will be trained further and eventually placed. In the 2006 book "Goldens Forever" by Todd Berger, Michael Sapp tells readers that only 10 out of 500 dogs tested were found to have the necessary qualities for seizure dog training.
Seizure dogs can be any breed or any size; in fact, many service dogs of all kinds are mixed breeds who naturally have the characteristics that make them effective service dogs. Traits like intelligence, patience, sociability, the desire to please and empathy make them exceptionally attuned to their humans' behavior and personality. Dogs as small as Chihuahuas and miniature poodles are effective seizure dogs, but so are bigger breed dogs such as golden retrievers. Retrievers are large enough that they can provide the additional aspect of protecting their people from injury during an epileptic episode.