Idiopathic Epilepsy - Seizure Diagnostics

Bloodwork is essential for evaluating causes of seizures from other parts of the body, such as liver disease, kidney disease, or low blood sugar (also called hypoglycemia). It is important to remember that the brain has a special barrier between it and the blood called the blood brain barrier, so issues within the tissue of the brain such as inflammation or tumors may not always show up in this blood work!

Common blood tests include:

The Complete Blood Count (or CBC for short): This checks for signs of infection, anemia, or inflammation.

The Serum Chemistry Panel: This evaluates the function of your dog's liver, kidneys, and some panels may include tests to evaluate the pancreas or muscle as well. It can also detect imbalances in electrolytes or blood sugar.

A Thyroid Level: This is often a basic screening test that may be performed to evaluate the function of your pet's thyroid. If this is abnormal, or if clinical signs of hypothyroid are present your veterinarian may request to send out a complete thyroid panel. There is limited evidence to suggest they hypothyroidism causes seizures, but may make them harder to control.

Bile Acids and Ammonia Tests: These tests are sometimes used to assess liver function more thoroughly, particularly if your dog's exam or chemistry panel shows any abnormalities. Depending on the hospital, they may perform one test over the other.

Note that some of these tests have to be sent to an outside lab while others might be able to be performed in the hospital. Your veterinarian can let you know when to expect test results.

If initial tests don't reveal a cause for the seizures, your veterinarian may recommend advanced imaging, such as a CT scan or MRI. While a CT or CAT scan may be able to see some causes, an MRI is superior when it comes to evaluating the brain.

MRI can help identify brain tumors, inflammation, or other structural abnormalities.

CSF analysis can provide critical information, especially if your veterinarian suspects infectious or inflammatory diseases like encephalitis or meningitis. Be aware that not all veterinarians have access to an MRI or ability to perform a CSF tap. Both of these have to be performed under general anesthesia.

Some neurologists may use a diagnostic called an electroencephalogram or EEG for short. This is most commonly done when looking for seizures that do not have outward signs of seizure activity or when trying to evaluate if episodes are seizures or other clinical conditions. An EEG measures the electrical activity in your dog's brain and is used to confirm abnormal patterns associated with epilepsy.