Epilepsy is the most common chronic neurological disorder in dogs and humans, with many similarities present between the two species (Shihab et al., 2011; Winter et al., 2018). The diagnosis of epilepsy is reached by a combination of history, signalment and investigations that generally include blood tests, MRI of the brain and CSF analysis where appropriate.
In one study, half of the owners reported that knowing more about the cause of seizures helped them understand their dog’s problem better and the costs associated with this were worthwhile. Reaching a diagnosis increased both owners’ and veterinary surgeons’ confidence in case management (Chang et al., 2006).
The diagnosis of epilepsy implies an ongoing commitment and associated costs with the management by the owners, and therefore it is important to understand the impact of this disease on both dogs’ and owners’ quality of life. Owner involvement is paramount to a good outcome and consequently, owner education with regards to seizure identification and management, as well as good communication, are essential (Nettifee et al., 2017). It is accepted that dogs with epilepsy may have a shorter survival time, estimated between 2.07 and 2.3 years, where poor seizure control and high initial seizure frequency are associated with shorter survival times (Packer et al., 2018).
Measuring quality of life
Health-related quality of life (QoL) is defined by the World Health Organization as “an individual’s perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns. It is a broad ranging concept affected in a complex way by the person’s physical health, psychological state, personal beliefs, social relationships and their relationship to salient features of their environment.” This definition cannot be extrapolated to dogs and measurement of QoL in animals can be challenging.
Assessment in animals should include not only physical health but also all aspects of the pet’s life (Belshaw et al., 2015). This assessment is performed by the owners where they recognise and interpret their animal’s behaviour. As much as this may be subjective, the same occurs in humans where self-reporting is not possible (Belshaw et al., 2015; Wessman et al., 2016). In humans, evaluation of QoL is part of the assessment of the success of treatment and the same should happen in dogs.
Canine epilepsy studies have focused on the seizure presentation itself, seizure control and side effects of medications used as well as its impact on the owners. Chang and colleagues found that a good QoL, adequate seizure frequency (in this case considered one seizure every three months or less) and acceptable side effects of anti-epileptic drugs were the most important factors, and that administration of medication and monitoring and costs were not a concern.
One third of owners with work commitments and two thirds of owners without work commitments reported that caring for an epileptic dog did not interfere with their commitments, but 60 percent of them reported that it affected their free time regardless of seizure control (Chang et al., 2006). The owner’s quality of life correlates with the perceived quality of life of the pet and some owners reported panic attacks, depression and feeling isolated for looking after an epileptic pet (Wessmann et al., 2016).
Changes in behaviour and cognition
Most recently, behavioural changes and cognitive impairment have been studied. In humans, somatic and neuro-behavioural comorbidities are associated with recurrent seizure disorders and this seems to occur in pets too (Shihab et al., 2011; Winter et al., 2018; Packer et al., 2018).
In one study, questionnaires that included 80 patients were reviewed and found that in 71 percent of the dogs, their behaviour changed. Dogs on no treatment were found to be more anxious/fearful when approached by unfamiliar people or dogs, in unknown surroundings or with sudden movements. They became more aggressive in general and started barking with no reason, chasing lights or shadows, pacing and staring.
When medication was started, defensive aggressive behaviour decreased but all others increased. Non-responder dogs (with less than 50 percent decrease in seizure activity) showed significant differences in aggression, abnormal perception and behaviour compared to the responders which could lead to a behavioural marker of pharmacoresistance in dogs with epilepsy (Shihab et al., 2011).
Another important finding to consider relates to cognitive impairment. Packer et al. found four risk factors associated with canine cognitive dysfunction:
- Epilepsy diagnosis
- Older dogs
- Lighter dogs
- Training history: more training related to lower risk
However, epilepsy-related cognitive dysfunction represents a different entity from the common canine cognitive dysfunction based on nature, progress and age of onset. In canine epileptic patients, the onset of cognitive dysfunction happens earlier in life. It affects mostly memory and there is no significant progression over time. In these patients, no impairment in social interaction has been reported.
Seizure frequency has been associated with the degree of mental decline in humans and equally a history of cluster seizures and high frequency is associated with a greater degree of cognitive impairment in dogs. Interestingly, anti-epileptic drug therapy had no impact on scores of cognitive dysfunction, but this should be interpreted with caution as more information is required to confirm this finding (Packer et al., 2018).
Taking into consideration quality of life when deciding on treatment of a chronic disease is very important. It is important to evaluate the impact of the disease and the treatment, the effects they may have on the owners and how that is going to dictate compliance. Further studies are required to evaluate the effect of epilepsy in our patients but the current available literature gives good initial information to aid decision making.