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Why Is My Dog Having Seizures? Causes, First Aid & When to Go to the ER

Watching your dog have a seizure is one of the most frightening experiences a pet owner can face. The convulsions, the loss of consciousness, the paddling and vocalization — it can feel like your dog is dying. In most cases, the seizure itself is not immediately fatal, but that does not mean it can be ignored. Seizures are a symptom, not a diagnosis, and understanding their underlying cause is essential to keeping your dog safe long-term.

What Happens During a Dog Seizure?

A seizure is caused by abnormal, uncontrolled electrical activity in the brain. Depending on which area of the brain is affected, seizures can look very different:

  • Grand mal (generalized tonic-clonic): The most dramatic type — the dog loses consciousness, falls, and exhibits rhythmic convulsions involving all four limbs. Salivation, urination, and defecation during the episode are common.
  • Focal seizures: Only one part of the body is affected — facial twitching, repetitive chewing motions, or rhythmic movement of one limb. The dog may remain conscious.
  • Absence seizures: Brief episodes of staring or disconnection, often missed by owners.

Most seizures are followed by a postictal period — a recovery phase that can last minutes to hours, during which the dog may appear disoriented, wobbly, temporarily blind, or unusually hungry or thirsty. This is normal and expected.

What Causes Seizures in Dogs?

The causes of seizures in dogs fall into three broad categories:

Intracranial causes (originating within the brain):

  • Idiopathic epilepsy — the most common cause in otherwise healthy dogs aged 1–5 years; a heritable condition in many breeds with no identifiable underlying disease
  • Brain tumor
  • Encephalitis (brain inflammation, infectious or immune-mediated)
  • Traumatic brain injury
  • Hydrocephalus

Extracranial causes (disease outside the brain affecting brain function):

  • Low blood sugar (hypoglycemia) — particularly in toy breeds and diabetic dogs
  • Liver disease or portosystemic shunts
  • Kidney failure
  • Severe electrolyte imbalances

Toxic causes:

  • Xylitol (sugar-free products)
  • Certain flea products applied incorrectly
  • Recreational drugs
  • Metaldehyde (slug bait)
  • Certain mushrooms

Identifying the cause requires a thorough workup including blood and urine testing. Advanced imaging — typically MRI — is needed to evaluate the brain itself. Cerebrospinal fluid (CSF) analysis may be recommended to look for infectious or inflammatory causes. Our Internal Medicine specialist, Dr. Emily Purswell, DACVIM, is available Monday through Friday to help guide complex neurological diagnostic workups.

What Should I Do If My Dog Is Seizing?

Stay as calm as possible and follow these steps:

  1. Do not put your hands near your dog’s mouth. Dogs cannot swallow their tongues — this is a myth — but they can bite reflexively and severely injure you.
  2. Clear the area. Move furniture or other objects away to prevent your dog from injuring themselves.
  3. Time the seizure. This is critical information for your veterinarian.
  4. Keep the environment quiet and dim. Stimulation can prolong or re-trigger seizures.
  5. Record a video if it is safe to do so — even a 30-second clip helps your veterinarian understand what type of seizure occurred.
  6. Do not restrain your dog forcefully. Gentle cradling to prevent falls is appropriate, but do not pin them down.

When Is a Seizure an Emergency?

Go to an emergency veterinary facility immediately if:

  • The seizure lasts more than 3–5 minutes (status epilepticus — a seizure that will not stop on its own is a neurological emergency)
  • Your dog has more than two seizures within a 24-hour period (cluster seizures)
  • Your dog does not return to a near-normal state within 30 minutes of the seizure ending
  • This is your dog’s first-ever seizure
  • Your dog is very young (under 6 months), very old, or has a known underlying medical condition
  • You suspect your dog ingested a toxin

Status epilepticus causes direct brain damage and can be fatal. Brain temperature rises rapidly during continuous seizure activity, and without intervention, irreversible neurological injury occurs within minutes.

How Are Seizures Treated?

Emergency treatment focuses on stopping the seizure and stabilizing the patient. Intravenous benzodiazepines (diazepam or midazolam) are the first line of treatment for status epilepticus. If the seizure does not respond, additional anticonvulsant medications are administered.

Long-term management depends entirely on the underlying cause. Dogs with idiopathic epilepsy typically require lifelong anticonvulsant medication — most commonly phenobarbital, potassium bromide, or levetiracetam (Keppra) — combined with regular blood monitoring to ensure therapeutic drug levels and assess for side effects.

What Is the Prognosis for a Dog With Seizures?

Prognosis varies widely by cause. Dogs with well-controlled idiopathic epilepsy can live normal lifespans with good quality of life. Dogs with brain tumors or severe encephalitis face a more guarded outlook, though many still respond well to appropriate treatment. The key is accurate diagnosis — treating epilepsy in a dog that actually has a brain tumor will fail because the root cause is never addressed.

When to Go to the Emergency Vet

If your dog is actively seizing, has had more than one seizure today, or has not returned to normal within 30 minutes of a seizure — come in immediately. Do not wait for your regular vet to open.

North Springs Veterinary Emergency & Specialty Center has emergency veterinarians on staff 24/7. Our Internal Medicine specialist Dr. Emily Purswell, DACVIM, is available Monday through Friday for complex neurological workups. Come to Come to 10520 White Diamond Pt, Colorado Springs, CO or call (719) 920-4430.

 

Sources and Further Reading

  1. Podell M, et al. “2015 ACVIM Small Animal Consensus Statement on Seizure Management in Dogs.” Journal of Veterinary Internal Medicine. 2016;30(2):477–490.
  2. Berendt M, et al. “International Veterinary Epilepsy Task Force consensus report on epilepsy definition, classification and terminology in companion animals.” BMC Veterinary Research. 2015;11:182.
  3. Chandler K. “Canine epilepsy: what can we learn from human seizure disorders?” Veterinary Journal. 2006;172(2):207–217.
  4. Bhatti SF, et al. “International Veterinary Epilepsy Task Force consensus proposal: medical treatment of canine epilepsy in Europe.” BMC Veterinary Research. 2015;11:176.
  5. American College of Veterinary Internal Medicine. “Seizure Disorders.” ACVIM.org.

This article is written for educational purposes and does not constitute veterinary medical advice. If your pet is experiencing a medical emergency, seek immediate veterinary care.