What is it?Epilepsy simply means a disorder characterised by recurrent seizures or fits. However, in most cases, when we use the term we are describing a particular disease, not the symptom, so this factsheet will primarily be dealing with the conditionIdiopathic Epilepsy.
Why is it important?Unfortunately, no-one knows for sure (which is what the word “idiopathic” means). However, it is likely that there are a number of different factors involved, including both genes and environmental conditions. Whatever the underlying cause, however, dogs with epilepsy have no visible defects, damage or lesions in their brains. However, their brain tissue is unusually prone to firing off random electrical bursts, resulting in a seizure. In many ways, we can think of seizures as being like electrical storms in the brain, resulting in physical symptoms.
What's the risk?The condition is most commonly diagnosed in young adults (usually 6 months to 5 years of age). Some breeds are known to be more susceptible than others (particularly Shepherd dogs, Golden Retrievers, Collies), but any dog may become epileptic.
What happens to the pet?
Recurrent seizures or fits. Seizure activity is often preceded by a “pre-ictal” phase where the dog seems distressed or anxious, before they start to fit. The fits are most often generalised (the dog falls over, paddling, often champing with their mouth and foaming; usually they lose control of bladder and bowels as well).
Afterwards, the dog usually regains consciousness rapidly, but they may take some minutes or even hours to recover fully, being confused, dazed or even blind for a while. Occasionally, dogs may suffer from partial seizures, where one group of muscles convulse but not the whole dog; or psychomotor seizures (associated with hallucinations). However, in between seizures, the dog is perfectly normal and shows no abnormal symptoms. In some cases (“Reflex Epilepsy”), a seizure may be triggered by bright lights, loud noises or excitement, but in most cases they occur more or less at random. Dogs may go weeks between seizures and then have several all together (“Cluster Seizures”) or have them regularly every couple of days or weeks. These seizures last less than 5 minutes -if a dog is fitting for more than 5 minutes, ro has two without regaining consciousness in between, this is a medical emergency called Status Epilepticus and needs emergency treatment.
How do you know what's going on?Strictly speaking, Idiopathic Epilepsy can only be diagnosed by ruling out all of the other conditions that can cause fits (salt imbalances, liver or kidney disease, poisoning, brain damage, brain tumours etc). In most cases, we will be able to make a working diagnosis by ruling out the more common conditions using blood tests and perhaps X-rays; and taking a thorough history from you. In some cases, however, we may need more advanced imaging to rule out complex brain diseases - this may require CT or MRI scans.
What can be done?
Although the condition cannot yet be cured, in most cases it can be effectively managed - and it should be, because each seizure increases the risk of another one. For emergency therapy, a drug called diazepam is used (either by injection here at the vets’, or by rectal tube at home). Longer term, the most widely used medications arePhenobarbitone(a barbiturate which is cheap and effective, but does need regular blood tests as too high a dose may be dangerous);potassium bromide(used to support phenobarb if needed); andimepitoin(a long term drug which is more expensive but does not require regular blood testing).
Some cases are termed “refractory” because they do not respond to the normal drugs; in these cases, we will often try human medications until we find the combination of drugs that is effective for that dog. In all cases, however, the medication is lifelong, and missing a dose increases the risk of another seizure.