Idiopathic Epilepsy
Epilepsy is a chronic neurological disorder characterised by a spontaneous, abnormal burst of activity within the brain causing either localised muscle twitches or generalised, whole-body convulsions (seizures). It is a different disorder to Idiopathic Head Bobbing/Head Tremors however some people may initially think their dog is having an epileptic seizure - dogs exhibiting Idiopathic Head Bobbing can usually be distracted away from the behaviour and are alert to their surroundings whereas this is not the case with IE.
Sometimes epilepsy can be developed through injury or disease, however in the idiopathic form there is no apparent cause. It has been identified as a common hereditary disease within Border Collies and affected dogs typically begin to show symptoms between the ages of 1 and 4 years of age however some can be as young as 6 months or as old as 6 years. In between seizures, affected dogs generally behave normally. Seizures often occur when the animal is resting or relaxed which is a major factor that sets symptoms apart from Border Collie Collapse (which often occurs after a period of exertion and excitement). As such, many seizures occur at night and can last from a few seconds to a few minutes. In some cases, the period between seizures is relatively predictable whilst in others it is quite irregular with clusters of seizures occurring within a short time followed by long intervals of no seizure activity. Idiopathic Epilepsy is treatable; however it is incurable and affected dogs will require lifelong medication. Allowing the condition to progress untreated can result in medical emergency situations such as cluster seizures (multiple seizures within 24 hours) and status epilepticus (a prolonged seizure lasting longer than 5 minutes or repeated seizures without recovery in between), or death. Approximately half of dogs with idiopathic epilepsy have cluster seizures, which is associated with a higher risk of death or injury in comparison with isolated seizures, as well as a decrease in the quality of life for both the dog and their owner.
Sometimes epilepsy can be developed through injury or disease, however in the idiopathic form there is no apparent cause. It has been identified as a common hereditary disease within Border Collies and affected dogs typically begin to show symptoms between the ages of 1 and 4 years of age however some can be as young as 6 months or as old as 6 years. In between seizures, affected dogs generally behave normally. Seizures often occur when the animal is resting or relaxed which is a major factor that sets symptoms apart from Border Collie Collapse (which often occurs after a period of exertion and excitement). As such, many seizures occur at night and can last from a few seconds to a few minutes. In some cases, the period between seizures is relatively predictable whilst in others it is quite irregular with clusters of seizures occurring within a short time followed by long intervals of no seizure activity. Idiopathic Epilepsy is treatable; however it is incurable and affected dogs will require lifelong medication. Allowing the condition to progress untreated can result in medical emergency situations such as cluster seizures (multiple seizures within 24 hours) and status epilepticus (a prolonged seizure lasting longer than 5 minutes or repeated seizures without recovery in between), or death. Approximately half of dogs with idiopathic epilepsy have cluster seizures, which is associated with a higher risk of death or injury in comparison with isolated seizures, as well as a decrease in the quality of life for both the dog and their owner.
There is not yet a DNA test available to identify the genetic markers of Idiopathic Epilepsy in Border Collies and avoid the condition when breeding, so management within breeding programs is limited to discontinuing a line after the condition has presented - making it important for buyers to inform their breeders at all times when IE is diagnosed. Some researchers have raised the probability that IE is a polygenic disorder (more than one gene is involved).
Diagnosis is by elimination of the other possible causes of seizures. Diagnostic tests in this process may include blood and urine tests, cerebrospinal fluid analysis, ultrasound scans, CT and MRI scans. EEG recording of the electrical activity of the brain between seizures may also be helpful in detecting IE.
Diagnosis is by elimination of the other possible causes of seizures. Diagnostic tests in this process may include blood and urine tests, cerebrospinal fluid analysis, ultrasound scans, CT and MRI scans. EEG recording of the electrical activity of the brain between seizures may also be helpful in detecting IE.
Symptoms
There are often considered to be four phases to a seizure:
Treatment for Idiopathic Epilepsy consists of anti-seizure medication which is usually required on a strict schedule. Failure to adhere to the schedule can increase seizure frequency and severity, as can stopping the medication. Well controlled epilepsy can usually give an epileptic dog the same life expectancy as other dogs, and the majority of dogs respond well to medication, however some never achieve a satisfactory response, or stop responding to treatment. Quality of life is an important consideration at all times during the diagnosis, treatment and lifetime of the dog and their family.
There are often considered to be four phases to a seizure:
- Pre-Ictal Phase: The time before the seizure, where dogs are sometimes noted to be behaving abnormally. They may hide, show signs of anxiety or seek out their owner. This phase can last up to several days and some owners have been able to predict when a seizure is coming by recognising this change in behaviour.
- Aura Phase: Usually only lasts for a few seconds and is an intensification of the previous phase.
- Ictal Phase: This is the phase where the seizure is actively occurring. Normally lasts from a few seconds to a few minutes, however this can seem longer to owners watching their dogs go through it! The actual seizure can be partial or general. General seizures known as tonic/clonic or grand mal are the most common in animals, and they will fall over and become unconscious with rigid, extended legs and their head, neck and back will potentially arch for approximately 10-30 seconds before their legs start running-like movements, they may start chewing/biting (keep their legs and your hands away from their mouth), and they may urinate or defaecate. Their pupils may dilate and they may also salivate and vocalise. It was previously thought that IE only caused general seizures however there is evidence that partial (focal) seizures may also occur, which only involve one side of the brain, do not involve loss of consciousness and can present a number of signs such as abnormal movements or tremors of the face or one limb, staring, salivation, vomiting or diarrhoea. Some general seizures may begin with a partial seizure.
- Post-Ictal Phase: The time following the seizure, lasting from minutes to hours. The dog may seem confused and lethargic - some dogs may seem blind. Behavioural changes during this phase can vary from subtle to extremely obvious, with hyper-activity and disorientated pacing, or being particularly hungry, thirsty, aggressive or affectionate.
Treatment for Idiopathic Epilepsy consists of anti-seizure medication which is usually required on a strict schedule. Failure to adhere to the schedule can increase seizure frequency and severity, as can stopping the medication. Well controlled epilepsy can usually give an epileptic dog the same life expectancy as other dogs, and the majority of dogs respond well to medication, however some never achieve a satisfactory response, or stop responding to treatment. Quality of life is an important consideration at all times during the diagnosis, treatment and lifetime of the dog and their family.