A dog may be man's best friend. But for 2 million Americans with epilepsy, that canine companion could also be a lifesaver.
That's what a new study suggests, after documenting incidents in which the pets anticipated children's epileptic fits up to five hours before the seizure occurs. The research, published this week in the journal Neurology, found dogs demonstrated protective behaviors such as face licking, whining to alert others, and moving a child away from harm when suffering seizures near stair landings or furniture.
No research has yet been able determine exactly how dogs anticipate a seizure, and Dr. Adam Kirton, an author of the findings, stresses the "preliminary" aspect of the study.
But the research, conducted at Alberta Children's Hospital at the University of Calgary, Canada, sought to find anecdotal evidence to support the canine claim, and it appears it did. The research, for instance, found 42 percent of the 48 families with an untrained dog noticed their pets anticipating and reacting to their child's seizures from two minutes to five hours before the seizure occurred.
A similar study was conducted with adults in 2002 by Deborah Dalziel of the Department of Neuroscience at the University of Florida's College of Medicine in Gainesville.
While she is unable to account for the dogs' knowledge, she notes: "Dogs primarily communicate with behavior and facial expressions, so they are more aware than most people. It's certainly possible that they would hear [the seizure], see it, or even smell it."
About one in 100 people have epilepsy, a brain disorder which sometimes disrupts the passage of information through the brain and changes its chemistry, which might be what the dogs are perceiving. Also, most people with the disorder will manifest some physical change before their seizure and pets might notice that.
Finally, as Dalziel explains: "There is some evidence to suggest that our body odors change before we have a seizure. … An in-tune dog will be aware of that and make the connection between those events and a seizure."
A dog's sense of smell is more than 300 times a human's, which may account for the innate difference.
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Karie Harrison, of Ypsilanti, Mich., began to notice her 4-year-old Pembroke Welsh Corgi "Owen" would respond to her seizures when he was just a year-old: "I started to notice that he would detect it at times, sometimes even before I can."
Harrison hadn't purchased her pet with the idea of needing an aide, but she explains Owen seems to have a natural inclination to respond to her seizures.
Owen would often slightly change his behavior before Harrison noticed a warning signal of a seizure: "A lot of times, we'll be walking, and he'll just stop and sit there, and then I'll realize that I'm having a warning sign," she recounts. "So I'll sit down and Owen will just sit there, laying right by me, protecting me as I have my seizure, and often licking my face."
Neurologists whose patients have experienced seizure-alerts with their pets report similar incidents. Dr. Basim Uthman, a neurologist at the Department of Neuroscience at the University of Florida's College of Medicine in Gainesville, explains: "The natural inclination is to protect the patient. If the person falls during the seizure, they could hurt themselves, so the dogs learn to protect the patient from falling."
But many doctors are still uncertain about the "seizure-alert" responses of pet dogs.