Diagnosing Seizures: Why a Comprehensive Neurological Exam Is the Most Important Next Step After Normal Bloodwork

Seeing your dog have a seizure can be one of the most frightening experiences as a pet owner.

Naturally, the first step is to visit your veterinarian, who will typically start with bloodwork to rule out common causes. But what happens when those results come back… normal?

That’s where many owners feel stuck.

What Is a Seizure?

A seizure occurs when there is abnormal electrical activity in the brain.

It can look like:

• Shaking or convulsing
• Loss of consciousness
• Stiffness or collapse
• Repetitive movements or unusual behavior

Seizures can happen for different reasons, and not all of them originate in the brain itself.

What Causes Seizures in Dogs?

There are two broad categories:

1. Causes Outside the Brain (Extracranial)

These are often identified through bloodwork and can include:

• Low blood sugar
• Toxins
• Liver or kidney disease
• Metabolic imbalances

2. Causes Inside the Brain (Intracranial)

These are not detected with routine blood tests and may include:

• Inflammation (such as meningitis)
• Brain tumors
• Stroke
• Structural abnormalities

What Is the IVETF?

The International Veterinary Epilepsy Task Force (IVETF) is a group of veterinary experts who developed guidelines to help veterinarians diagnose and manage seizures in dogs.

Their goal is simple:
Provide a clear, step-by-step approach to finding the cause of seizures

What Do the IVETF Guidelines Recommend?

The IVETF outlines a logical process:

Step 1: Bloodwork

Rule out causes outside the brain.

Step 2: Neurological Exam

Evaluate how the brain and nervous system are functioning.

Step 3: Advanced Diagnostics (if needed)

MRI and, in some cases, spinal fluid analysis depending on what is detected from the scan.

Why the Neurological Exam Is So Important

When bloodwork comes back normal, the next critical question becomes:

Is this seizure coming from the brain?

A comprehensive neurological exam is the best way to answer that.

During this exam, a veterinarian evaluates:

• Balance and coordination
• Reflexes
• Cranial nerve function
• Subtle signs of brain or spinal cord disease

What the Exam Tells Us

The neurological exam helps determine:

If the exam is normal:

The IVETF advises pursuing advanced diagnostics (MRI ± CSF) if any of the following are present:

1. Age at Seizure Onset

• Less than 6 months old
• Greater than 6 years old

Why this matters:
Idiopathic epilepsy most commonly starts between 6 months and 6 years.
Outside that range, the likelihood of:

• brain tumor
• inflammation
• congenital abnormality
  goes up significantly.

2. Focal (Partial) Seizures

• Seizures affecting only one side of the body
• Twitching of a limb or face
• Abnormal behavior without full collapse

Why this matters:
Focal seizures are more commonly associated with structural brain disease.

3. Cluster Seizures or Status Epilepticus

• Multiple seizures in a short period (cluster)
• A prolonged seizure or repeated seizures without recovery

Why this matters:
These patterns are more concerning for underlying brain pathology rather than uncomplicated epilepsy.

4. Poor Response to Anti-Seizure Medication

• Seizures continue despite appropriate treatment
• Increasing frequency or severity

👉 Why this matters:
Idiopathic epilepsy typically shows at least some response to medication.
Lack of response raises suspicion for:

• inflammatory disease
• tumor
• other structural issues

5. Progressive Pattern

• Seizures becoming more frequent
• Symptoms changing or worsening over time

👉 Why this matters:
Progression suggests an active disease process, not a stable epilepsy condition.

If the exam is abnormal:

• There is a higher likelihood of underlying brain disease
• An MRI is recommended

Why This Step Matters

Without a neurological exam, decisions about treatment or imaging are often based on guesswork.

With it, you can:

• Avoid unnecessary testing
• Identify serious conditions earlier
• Move toward the right diagnosis faster

Getting the Right Answers

Seizures are complex, but the process to diagnose them doesn’t have to be.

Following a structured approach—starting with bloodwork and then moving to a neurological exam—helps ensure your dog gets the care they need as efficiently as possible.

Next Step: A Clear Plan Forward

If your dog has had a seizure and bloodwork has come back normal, a neurological exam is the most important next step.

It provides clarity, direction, and peace of mind about what to do next.

Call to discuss your dog’s case
Schedule a comprehensive neurological exam

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Clear Answers. Thoughtful Diagnosis. Better Outcomes.