Many people with epilepsy and other conditions rely on seizure-response dogs. Trained as service dogs, these dogs can alert parents when a child has a seizure. They might use a call button or special phone to call for help. They can guard a person having a seizure, protecting the person from injury and even removing objects that might cause harm. They might roll the person into a position in which he or she can breathe.
Some dogs take dealing with seizures a big step further, by sensing when a seizure is about to occur and warning the person, as much as 10 or 20 minutes before the seizure. Estimates are that 10 to 15 per cent of trained dogs can sense when a seizure is about to happen. Sometimes, a dog becomes able to detect an oncoming seizure after having lived with a person as a seizure-response dog for several months.
Scientists aren't sure what the dogs sense. One theory is that a person about to have a seizure has changes in blood or other body chemistry that a dog's highly sensitive nose can smell. A dog might sense a sudden spike in temperature that precedes a stroke. Another theory is that a dog's detail-oriented vision can detect small changes in the person's movements, changes that humans – even the person about to have the seizure – does not notice.
However it works, the dog's warning can alert the person in time to get to a safe place, take medication and/or let others know that he or she might soon need help. [source: SDC]