The untrained response of pet dogs to human epileptic seizures

Abstract

Epilepsy is a disorder of the brain and a seriously debilitating condition, which has been associated with injury, social stigmatisation and in some cases, sudden unexpected and premature death. A sense of profound isolation is felt by many individuals with epilepsy, and this community has expressed an urgent desire for an early warning system to allow them time to prepare for seizure onset. Surveys of dog owners with epilepsy have previously reported that some dogs can predict the onset of a seizure. Therefore, the current study investigated the hypothesis that if pet dogs were exposed to seizure-related odours which apparently emanated from their owners, they would respond by demonstrating attention seeking behaviours. This provides the first empirical test of this phenomenon in dogs that have not previously been trained for seizure alerting. This study, therefore, explores the propensity of pet dogs to anticipate and respond to human epileptic seizure onset in a controlled experimental investigation. Using a repeated measures design of experiment, recordings were made of the reactions of 19 untrained pet dogs to odours from sweat samples provided by three people with epilepsy and two people without epilepsy (controls). The sweat samples were from pre-ictal, ictal and post-ictal phases. Odours from the harvested sweat samples were randomly delivered to individual dogs in a test area, using two bespoke pieces of apparatus called Remote Odour Delivery Mechanisms, (RODMs). Behavioural changes by the dogs on encountering the odour samples were recorded by video for later analysis. Consistent with our hypothesis, seizure-associated odours evoked behavioural changes in the dogs, concordant with attention seeking attempts and thereby supporting the view that seizures are accompanied by a distinctive odour.

The Untrained Response of Pet Dogs to Human Epileptic Seizures

“…Dog characteristics recorded were breed, sex, age-group and years owned. Indicators of seizure odour response by the 19 untrained dogs were those which were most frequently reported in other studies of this topic; intense staring at the owner, close-proximity to the owner, and pawing or nudging the owner [ 1 , 2 , 3 , 4 , 5 , 8 , 48 , 52 , 53 , 54 , 55 , 56 , 57 , 58 ].…”

“…Each RODM consisted of a pump attached to a scent container with an outlet pipe which delivered odours a distance of 6 metres from a different room with closed door. Validation of the RODMs was completed in a separate earlier investigation using operational police drugs dogs and game flushing field trial champion dogs [ 8 ]. The results validated that all the dogs recognized their specific target substances and responded to them as they had been trained with no lack of performance [ 8 ].…”

“…Validation of the RODMs was completed in a separate earlier investigation using operational police drugs dogs and game flushing field trial champion dogs [ 8 ]. The results validated that all the dogs recognized their specific target substances and responded to them as they had been trained with no lack of performance [ 8 ]. To further reduce risk of contamination, one RODM was used to deliver experimental odours and the other for controls with no seizure-associated odour.…”

“…International surveys investigating whether untrained pet dogs can predict the onset of seizures in humans with epilepsy, have reported that they demonstrate behavioural changes which resemble attention seeking. The behaviours include intense staring; maintaining close-proximity; excessive panting; paw lifting; vocalisation; increased locomotor activity; licking; yawning and scratching [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. While some authors contend behaviours of that nature might be indicators of physiological canine stress [ 9 ], others, such as [ 10 , 11 , 12 ], conjecture that stress in dogs is more likely to be demonstrated in activities such as cringing; crouching; freezing; hiding; shaking or barking; growling; baring teeth; snapping and lunging [ 13 ].…”

“…While some authors contend behaviours of that nature might be indicators of physiological canine stress [ 9 ], others, such as [ 10 , 11 , 12 ], conjecture that stress in dogs is more likely to be demonstrated in activities such as cringing; crouching; freezing; hiding; shaking or barking; growling; baring teeth; snapping and lunging [ 13 ]. In the [ 8 ] international survey of untrained reactions of dogs to seizures, affiliative behaviours were the most commonly reported, with fearful or aggressive behaviours observed in less than 2% of dogs.…”