When Olivia Emenaker decided to train her Basset Hound, Dublin, to alert her before she had a seizure, it was partly because he seemed to already have a talent for it on his own.
At the time, she was living with her mother, because her seizures made it unsafe for her to live on her own, and Dublin was the family pet.
“One day when I was playing with him, I started feeling kind of weird, but at the time I didn’t think much of it. Dublin suddenly dropped the toy, looked at me, and started running back and forth, barking,” she says. “About two minutes later I ended up going into a convulsive seizure. My mom thought maybe he was trying to alert me in some way. And that’s when we realized he might have some skills to help me.”
Emenaker and Dublin trained with Medical Mutts Service Dogs, who have been training seizure-alert dogs, many of whom come from shelters, since 2013. Executive director Jennifer Cattet says it’s a three-part process. First, they pair the scent collected when a person is having a seizure with treats. “We want that smell to elicit an emotional response in the dog,” she says. “That specific smell is going to be meaningful to the dog.”
The second step is a discrimination test, where the dog learns to pick the scent out of a set of cans with other smells in them. So that they don’t learn just to pick out the scent of that particular person, one can contains scent collected when the individual is not having a seizure.
Finally, they pair the scent with an alert behavior. At Medical Mutts, they usually train the dog to give a strong poke with their nose. “We prefer a behavior that is not going to be disruptive if you’re out in public,” she says. “The poke is hard to ignore, but it can be as discreet as it needs to be.”
The alert gives the person time to sit or lie down in a safe situation so they won’t fall or otherwise endanger themselves. The dogs can also be trained to use the poke to get help from another person. Before the pandemic, Dublin went with Emenaker to her job at Lowe’s. “He was taught to go get help and I taught him to only get help from the people in the red vest,” she says. Her co-workers made a red employee vest for Dublin to wear as well.
The dogs can also learn to perform tasks during the seizure, such as lying next to or on top of the person, getting medication or a drink, or pushing a button to trigger a phone or alarm. Emenaker says Dublin started performing another task for her without training. She has seizures at night as well as during the day, and would sometimes fall out of bed and hurt herself. “Halfway through his training, he actually stared laying on top of my legs so I wouldn’t fall out of bed,” she says. She started rewarding the behavior when she could, but says, “I didn’t teach him that, Medical Mutts didn’t teach him that; he just started doing that on his own.”
Edward Maa of the University of Colorado says that while dogs have been observed to react in advance of seizures for some time, it wasn’t always obvious that scent was involved. “It was thought that maybe the dogs were cueing in on facial expressions or some kind of behavioral change of the owner.”
But recently it has been scientifically proven that there is indeed a smell that dogs are detecting. Medical Mutts teamed up with a research group from the University of Rennes in France and published a paper demonstrating this in 2019.
You might wonder exactly what they are smelling, though. Dogs have been trained to detect many diseases. But while it’s easy to imagine, say, a cancerous cell having a smell, where does the smell of a seizure come from? Maa was intrigued by research at Florida International University in collaboration with Canine Assistants, who also train seizure-alert dogs, which had identified nine volatile organic compounds (VOCs) in the smell.
One compound in particular, called menthone, seemed to be critical. At the time, he says, “there was nothing really written about it, except that it’s an intermediate step of menthol, which is the smell component of mint. So the question is, why is a plant-based product being produced in humans?”
He couldn’t find an answer to that question. “But one interesting thing that did pop up in the literature: an intermediate before menthone is used by insects as an alarm pheromone,” he says. “An insect that’s being attacked will put out this alarm pheromone to tell its buddies to run away. And some plants produce the same alarm pheromone when attacked by insects to scare the insects away.”
He was pondering this, and its possible connection to human pheromones, when his son asked him to watch the horror movie It with him. “There’s a scene where I can feel the hairs on the back of my neck rise. At the same time, the scary clown thing says, ‘I can smell your fear,’” he says. “And I thought, maybe what the dog is smelling is a human alarm pheromone that has never been described before.”
So he called his collaborator, Jennifer Arnold of Canine Assistants, and said, “You just need to show people this movie and we can collect their sweat. If the dogs can’t distinguish the two, then it’s the same thing. So that’s what we did.” The resulting paper was just published under the title “Epilepsy and the Smell of Fear.”
Their research has also shown that it’s possible to detect the scent far in advance of when dogs usually alert. The implications of this are huge, he says, and go beyond the possibility of training dogs to alert much sooner. “By having this 68-minute warning, which is what we found to be the average, we can develop devices, warning systems, wearables, or implantables that could interact with this signal to either notify emergency personnel, notify the patient, or actually deliver a treatment.”
But in the meantime, dogs like Dublin are already changing people’s lives, as Emenaker says: “He’s helped me get my freedom back, to be able to get out there and work.”
This article was reviewed/edited by board-certified veterinary behaviorist Dr. Kenneth Martin and/or veterinary technician specialist in behavior Debbie Martin, LVT.
Linda Lombardi writes about the animals that share our planet and our homes for magazines including The Bark, websites including National Geographic and Mongabay.com, and for the Associated Press. Her most recent book, co-authored with Deirdre Franklin, is The Pit Bull Life: A Dog Lover’s Companion.
Published July 19, 2021