Physiological reactivity to spontaneously occurring seizure activity in dogs with epilepsy and their carers

R.M.A Packer,H.A Volk,R.C Fowkes

doi:10.1016/j.physbeh.2017.04.008

Abstract

There is a complex bidirectional relationship between stress and epilepsy. Stressful stimuli and subsequent cortisol release act as a trigger for seizure activity in some individuals with epilepsy, and seizure activity itself may act as a stressor to the affected individual. Epilepsy is the most common chronic neurological condition in domestic dogs and requires chronic management by their human carers, impacting upon the quality of life of both dog and carer. Seizures occur unpredictably and may be stressful for carers to witness and manage. In the present study we investigated the role of seizure activity as a stressor, measuring the effect of spontaneously occurring seizure activity in dogs with epilepsy upon their own cortisol levels and that of their carers. Furthermore, we tested whether individual differences in HPA reactivity were associated with owner personality characteristics and the quality of the dog–carer relationship. Saliva samples were obtained from sixteen dog-carer dyads in the home setting 20 and 40minute post-seizure, and at time-matched points on the following (non-seizure) day. Significant differences in cortisol levels were found in dogs at 40minute post-seizure (265.1% increase), and at 20minute post-seizure in their carers (40.5% increase). No associations were found between cortisol reactivity and the strength of the dog-carer bond. Carers with higher neuroticism scores exhibited higher cortisol levels at both post-seizure sampling points. As there was a gender bias in the carer sample (15/16 were female), and there are known sex differences in cortisol reactivity in response to psychological stress, the conclusions of this study may be limited to female carers. These findings are the first to objectively demonstrate the acutely stressful effects of seizures in dogs with epilepsy and their carers.

Highlights

Epilepsy is a disease of the brain characterised by an enduring predisposition to generate epileptic seizures, practically applied as having ≥two unprovoked epileptic seizures >24 h apart [1]
All dogs met tier I certainty of the International Veterinary Epilepsy Taskforce’s criteria for the diagnosis of idiopathic epilepsy [7], and all dogs were being treated with anti-epileptic drugs (AEDs)
There is a complex relationship between stress and epilepsy, with stress and subsequent cortisol release potentially acting as a trigger for seizures [39, 40], and seizures themselves acting as a stressor upon the body

Summary

Introduction

Epilepsy is a disease of the brain characterised by an enduring predisposition to generate epileptic seizures, practically applied as having ≥two unprovoked epileptic seizures >24 h apart [1]. Management of dogs with IE often requires a long-term commitment by caregivers, including medicating their dog several times per day (which is associated with an ongoing financial burden) and continually monitoring their pets for side-effects of these medications, in addition to acute events such as seizures resulting in emergency vet visits at unpredictable times [10,11,12,13]. Seizures can be unpredictable and appear uncontrollable, and may be stressful for carers to witness and manage. Parents of children with epilepsy are at an increased chance of developing post-traumatic stress disorder, anxiety and depression compared to parents of children with other chronic illnesses or non-caregivers, due to unpredictability of seizures and the restrictions imposed upon their lives by epilepsy [15,16,17]

Methods

Results

Discussion

Conclusion