French researchers have found that dogs can detect the odor characteristic of an epileptic seizure, regardless of the type of epilepsy and the individual patient. To do this, scientists trained dogs to respond to the sweat and breathing of one person during an epileptic seizure, and then tested the effectiveness of training on the smells of other people. Thus, a new type of assistance dog was created – the seizure alert dog. Here are more details on Can dogs sense seizures in humans?
How is it possible?
The composition of human body fluids (urine, sweat and saliva) can change in the presence of certain diseases, due to which their smell can also change. Some diseases by smell can be recognized by dogs known for their effective sense of smell, although there are works that refute this.
Whether a dog can recognize the disease, however, depends on how well it was trained: for example, recently scientists were able to teach dogs to identify malaria-like odors from their socks. Other studies show that dogs can also be taught and predicted for certain conditions, such as a drop in blood sugar and diabetes, or even an impending migraine.
Is there any confirmation?
In a new study, scientists led by Amélie Catala from the University of Rennes, France, decided to test whether guide dogs can be trained to smell an epileptic seizure. Their experiment involved five dogs, which are trained to detect and respond to various diseases by smell. Initially, all dogs were trained to detect the smell of sweat and breath of a person in an epileptic seizure using biomaterials from one patient. During testing, however, the scientists used the smells of sweat and breath from five other patients with different types of epilepsy.
During the test, dogs were given a choice of seven canisters with the scent of each of the five patients separately: the canisters contained odors corresponding to the breath and sweat of the patients during an epileptic seizure, physical activity, and odors taken on a random day at rest. The dogs had to find the right smell and stop in front of it, after which a special bowl with treats was opened for some time.
The researchers found that dogs spent significantly more time around samples that matched the scent during an epileptic seizure. At the same time, such a reaction of dogs did not depend on the type of epilepsy of the participants, which means that all types of the disease are united by a certain specific odor.
The authors of the work concluded that the response of dogs to odors characteristic of epilepsy may be useful in the future for research that will help to identify certain markers of approaching seizure. This, in turn, will be useful for dogs that need to be monitored for sickness: so far, this experiment shows that dogs can detect the presence of a seizure only when it has already begun.
Alzheimer’s disease already knows how to detect odors that predict the presence of the disease even before characteristic lesions: five years ago, using an experiment on animals, scientists showed that odorous biomarkers of this disease are contained in urine.
Now you know that some diseases can slightly change the smell of a person, and such dogs can smell it. Now seizure alert dogs are taught and trained, and then anyone in need can buy one. Unfortunately, right now there’s not a lot of seizure alert dogs, as it is really difficult to train them.