Pet dogs can tell when their owners are about to have an epileptic seizure thanks to a unique scent the canines pick up on, a study has demonstrated.
The finding — confirming various anecdotal accounts — means dogs could give warnings that have the potential to save lives if their owner falls unconscious.
Experts led from Queen’s University Belfast exposed 19 dogs to odours harvested from the sweat of people who were about to have, were having or just had a seizure.
They found that all dogs exhibited observable behavioural changes — such as by crying, barking, or making eye contact — despite having not been trained to do so.
Alongside reducing the injuries that can be associated with unexpected seizures, the finding may also allow for medical interventions before the seizure occur.
Epilepsy is a neurological condition that affects some 65 million people across the globe — of whom 20 million are unable to control their seizures with medication.
Pet dogs can tell when their owners are about to have an epileptic seizure thanks to a unique scent the canines pick up on, a study has demonstrated (stock image)
‘We hypothesized that, given the extraordinary sense of smell of dogs, a volatile organic compound exhaled by the dog’s epileptic owner may provide an early warning trigger mechanism,’ said paper author Neil Powell.
This is what dogs react to before the seizure itself occurs, the Queen’s University Belfast biologist, long-time dog lover and founder of Ireland’s Search and Rescue Dog Association explained.
‘The results have shown pet dogs to be a reliable source to detect an on-set seizure,’ he added.
In their study, Dr Powell and colleagues recruited 19 pet dogs — none of whom had any prior experience with epilepsy — and exposed them to odours that are characteristic of three different phases of seizure.
These scents were harvested from the sweat of people with epilepsy prior to, during and in the wake of a seizure. The team also took two non-seizure-related sweat samples to use as control samples for the study.
The researchers found that — when presented with the seizure-associated smells — all 19 dogs underwent noticeable behavioural changes.
‘Our findings clearly showed that all dogs reacted to the seizure-associated odour whether this was through making eye contact with their owner, touching them, crying or barking,’ explained Dr Powell.
‘There is a unique volatile smell linked to epileptic seizures, detectable by dogs who can in-turn warn their owner a seizure is likely to occur.
‘Our research was based on pet dogs with no prior training,’ he noted.
‘If we can train dogs, this has the potential to make a big difference to owners who experience unpredictable seizures and should go a long way in improving not only their safety, but also their quality of life.’
‘A reliable method of seizure prediction and detection is the holy grail for many people living with epilepsy as well as the parents of children with the condition,’ said Epilepsy Ireland CEO Peter Murphy.
‘This is especially the case where seizures involve the loss of consciousness, with a high risk of injury.
‘While recent efforts have focused on technological solutions, it is exciting and very welcome news that anecdotal reports of dogs’ ability to predict seizures have now been backed up by scientific evidence.
‘We have been immensely proud to support Dr Powell’s work and we hope that the findings will lead to new approaches alongside “man’s best friend” that promote safety and offer reassurance for people living with epilepsy.’
With his initial study complete, Dr Powell is now moving to explore how dogs might be able to detect the onset of other medical conditions — and then to create a tool to replicate this ability. Pictured: Dr Powell poses with Fern the dog
With his initial study complete, Dr Powell is now moving to explore how dogs might be able to detect the onset of other medical conditions — and then to create a tool to replicate this ability.
‘Our ultimate aim is to design an electronic device that could be sensitive to the biomarker that precedes the onset of an epileptic seizure as well as other conditions,’ he explained.
The full findings of the study were published in the journal Animals.
EPILEPSY: THE BASICS
Epilepsy is a condition that affects the brain and leaves patients at risk of seizures.
Around one in 100 people in the UK have epilepsy, Epilepsy Action statistics reveal.
And in the US, 1.2 per cent of the population have the condition, according to the Centers for Disease Control and Prevention.
Anyone can have a seizure, which does not automatically mean they have epilepsy.
Usually more than one episode is required before a diagnosis.
Seizures occur when there is a sudden burst of electrical activity in the brain, which causes a disruption to the way it works.
Some seizures cause people to remain alert and aware of their surroundings, while others make people lose consciousness.
Some also make patients experience unusual sensations, feelings or movement, or go stiff and fall to the floor where they jerk.
Epilepsy can be brought on at any age by a stroke, brain infection, head injury or problems at birth that lead to lack of oxygen.
But in more than half of cases, a cause is never found.
Anti-epileptic drugs do not cure the condition but help to stop or reduce seizures.
If these do not work, brain surgery can be effective.
Source: Epilepsy Action