EEG for dogs and cats

What an EEG shows

Electrodes placed on the head record the electrical activity of the cerebral cortex. The recording can pick up abnormal electrical discharges, called epileptiform discharges, even between seizures.

Epilepsy is diagnosed clinically, from the history and the neurological examination. The EEG adds information about the type of seizures and the part of the brain involved, and this matters when choosing the treatment. A normal EEG does not rule out epilepsy, because the changes may be absent at the time of the recording.

When it helps

• when it is unclear whether the episodes are epileptic seizures or something else, such as fainting or a movement disorder;
• when the seizures do not respond to treatment;
• to classify the type of seizure, focal or generalised;
• with subtle seizures that are hard to spot, for example in animals with cluster seizures.

How it is done

If the animal will not stay still, the recording is made under brief sedation. Electrodes are attached to the scalp, and along with the brain activity the ECG, breathing and muscle activity are recorded.

The timing is chosen to improve the chance of catching the changes: early in the morning, during sleep or after exercise, depending on when the seizures happen.

How to prepare

• Last meal at least 12 hours before the appointment.
• Bring videos of the seizures, the medical records and the list of medicines.
• Anaesthesia is a separate procedure, often needed for an EEG. I will tell you beforehand what it involves and what it costs.

Why EEG is my field

I learnt to read EEGs while working as a technician at a human epileptology centre, and my PhD thesis (USAMV Cluj-Napoca, 2022) is on the applications of electroencephalography in diagnosing seizures in dogs. I have recorded EEGs on dogs, cats and even a lion cub with epilepsy. Research and publications