Surely you also have read or heard somewhere already, that there are so-called seizure-alert dogs, which for example signal epileptic seizure in advance, and that these dogs actually save lives. Not so long ago we found an article on the Epilepsy Foundation page, which surprisingly refuted the statement.

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In the following it will be about, what we know at present about seizure-alert dogs on the basis of scientific examinations. It may be surprising, what can be proven, and what not.

Based on one study the number of seizures already by the dog’s mere presence also can be reduced

What are seizure-alert dogs?

Seizure-alert dogs we classify into two types: one helps the owner during and after the seizure by bringing telephone, water from the fridge, giving emotional support. So they help during and after the seizure, but not sure, that they know to signal in advance its approach. To the second type belong those dogs, which before the approach of the seizure by 5–45 minutes may signal to the owner, that something is preparing, then also give support during and after the event. This behaviour can be congenital or learned as well; some dogs even without ever having been trained for it signal with attention-calling behaviour (pawing, eye contact etc.) the deviations.

Deborah Dalziel, coordinator of the project researching seizure-alert dogs at the University of Florida Faculty of Veterinary Medicine, according to her: “There is this misconception that any seizure dog can be trained to alert, which just isn’t true. A dog can cue in on minute behavioral differences, but can't be trained to alert.” Furthermore she also draws attention to, that there are no scientific studies, which would support the numerous theories about how the dog perceives the approach of the seizure; most of them up to today are also based on assumptions and anecdotal evidence.

“What we know on how dogs can alert to a seizure before it occurs is still a mystery. From a scientific standpoint, there is still so much that remains to be determined” – says dr. Basim Uthman, associate professor of neurology and neuroscience at the University of Florida Faculty of Medicine and Brain Research Institute.

Where does science stand on the question?

In the 1998 study of Dalziel, Uthman and their colleagues 63 epileptic persons filled in qualitative questionnaire. Of them 29 had dog. Of the 29 dog owners, nine reported, that their dog reacted to their seizures. These dogs stayed near their owner, standing or lying beside them, sometimes licked the owner’s face or hand during the seizure and directly after it. Of the nine dogs about three it was also reported, that they signalled the approaching seizure in advance.

Although the case number of the research was too small for definitive conclusions, the results point to, that the alert behaviour is not breed-, age- or sex-dependent. According to the study the dog more probably signals in advance certain type of seizure, with persons prone to migraine, and those, who experience certain type of auras. In addition, the research also pointed out, that the effectiveness of the seizure-alert dog depends greatly on the owner’s ability, to recognise, and to react appropriately to the dog’s signals. This is confirmed by Megan Esherick, trainer of Canine Partners For Life: “For some people, a seizure-alert dog can really make a difference. Generally, the person needs to have the cognitive ability to notice that the dog is trying to alert them and respond accordingly. Sometimes the dog may be alerting in more subtle ways other than barking or pawing, and the person needs to be able to pick-up on that.”

Photo: welovedogz.hu

A recent, 2024 study according to it both trained, and spontaneous alert dogs can be able to recognise or forecast the epileptic seizures. The most probable mechanism is the dogs’ extraordinary sense of smell, which perceives the volatile compounds released before the seizure, supplemented with the fine changes appearing in the owner’s behaviour and physiology. The results are promising, since in several studies it was successful even under laboratory conditions to prove, that dogs reliably distinguish the pre-seizure patterns. At the same time the majority of the researches are small-sized, retrospective and often self-report based, which limits generalisability. The review emphasises, that well-designed, prospective examinations are needed for the precise determination of reliability, accuracy and ratio of false alarms. Altogether they established, that seizure-alert dogs can be useful, but still cannot be considered fully proven, standardised method.

To this same conclusion arrived an earlier, 2018 study as well, which also emphasised, that one of the main shortcomings of the scientific literature is, that few are the large-sized, randomised and controlled examinations. Most data are self-report based, on questionnaires and behaviour observation, which may distort the results. Many researches are small sample-sized, thus difficult to draw general conclusions. In addition often lacking is the objective EEG-support, which would confirm, that dogs indeed before the seizure signal. According to the authors these shortcomings hinder, that precisely measurable be the dogs’ forecasting ability and reliability.

In one examination the researchers collected sweat- and breath samples from epileptic patients before, during and after seizure, as well as in control situations. The samples were presented to trained dogs, to find out, whether they recognise the smells connected to the seizure. Several dogs were able reliably to distinguish the pre-seizure samples from the control samples. This indicates, that the chemical changes connected to the seizure are already present before the occurrence of the seizure. The results confirm, that the dogs’ sense of smell may give real basis for forecasting the seizures, but as explained above, still very many examinations would be needed, that we could understand precisely, what is happening.

Another, also in 2024 published study however revealed a very interesting aspect of the seizure-alert dog–owner relationship. According to Van Hezik-Wester and their colleagues the seizure-alert dogs not only may forecast the seizures, but may reduce their frequency as well. Many of the patients participating in the examination reported, that in the presence of the dog more rarely occurred seizure. In addition significant improvement was experienced in quality of life, for example in sense of safety, independence and social relationships. The researchers emphasised, that this intervention can be particularly useful at those, for whom the medicinal treatment is not effective enough. Despite the encouraging results they also propose further, controlled examinations for confirmation of the results.

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