• Seizure: A single episode of abnormal brain electrical activity
• Epilepsy: Recurrent seizures (two or more unprovoked seizures more than 24 hours apart)
• Idiopathic Epilepsy: Epilepsy with no identifiable underlying cause (most common in dogs)
• Status Epilepticus: Continuous seizure activity lasting >5 minutes, or multiple seizures without full recovery between them—a medical emergency

Generalized Seizures

• Tonic-clonic (grand mal): Most recognizable; stiffening then jerking
• Tonic: Muscle stiffening only
• Clonic: Rhythmic jerking only
• Atonic: Sudden loss of muscle tone (drop attacks)
• Myoclonic: Brief, shock-like jerks
• Absence: Staring episodes (rare in dogs)

Focal (Partial) Seizures

• May involve one limb, one side of face, or unusual behaviors
• Can progress to generalized seizures (focal-onset to bilateral tonic-clonic)
• Behaviors: fly-biting, star-gazing, tail-chasing, limb jerking

The period before the seizure where the dog may show behavioral changes:

• Restlessness or anxiety
• Seeking owner or hiding
• Whining or vocalization
• Salivation
• Staring into space
• Duration: seconds to hours before seizure

Tonic Phase (typically 10-30 seconds):

• Dog falls to one side
• Muscles become rigid
• Head thrown back
• Legs extended stiffly
• May vocalize or cry out
• Pupils dilate

Clonic Phase (typically 30-90 seconds):

• Rhythmic jerking of limbs
• Paddling motions
• Jaw chomping
• Excessive salivation (may be bloody if tongue bitten)
• Loss of bladder/bowel control
• Dog is unconscious

Focal seizures may appear as:

• Facial twitching
• Rhythmic blinking
• Head turning
• Single limb jerking
• Snapping at invisible flies
• Unusual behaviors (rage, aggression, fear)

Recovery period after the seizure:

• Disorientation and confusion
• Temporary blindness
• Excessive hunger or thirst
• Restlessness or pacing
• Exhaustion and prolonged sleep
• May last minutes to days
• Gradual return to normal behavior

The most common cause in dogs (estimated 75% of epileptic dogs):

• Presumed genetic basis
• No identifiable structural or metabolic cause
• Typically develops between 1-5 years of age
• Some breeds highly predisposed

Breed Predispositions

• Beagles
• German Shepherds
• Golden Retrievers
• Labrador Retrievers
• Belgian Tervurens
• Border Collies
• Australian Shepherds
• Bernese Mountain Dogs
• Irish Setters
• Vizslas

Problems within the brain:

• Brain tumors (more common in older dogs)
• Meningoencephalitis (inflammatory brain disease)
• Hydrocephalus
• Stroke (cerebrovascular disease)
• Head trauma
• Brain malformations
• Infectious diseases (distemper, toxoplasmosis, fungal)

Problems outside the brain:

• Hypoglycemia: Low blood sugar (common in toy breeds, puppies)
• Hepatic encephalopathy: Liver disease (portosystemic shunt)
• Electrolyte imbalances: Low calcium, sodium abnormalities
• Toxin exposure: Lead, ethylene glycol, metaldehyde, organophosphates
• Severe kidney disease: Uremia
• Hypothyroidism: In some cases
• Severe hyperthermia: Heat stroke

Normal brain's response to:

• Toxins
• Metabolic disturbances
• Certain medications
• Systemic illness

• < 1 year: Consider developmental, infectious, toxic causes
• 1-5 years: Idiopathic epilepsy most likely
• > 5 years: Brain tumors, metabolic disease more common

Detailed history is crucial:

• Description of episodes (video very helpful)
• Age at first seizure
• Frequency and duration of seizures
• Pre-ictal and post-ictal behaviors
• Potential toxin exposure
• Vaccination and travel history
• Diet and access to garbage
• Medication history
• Family history (if known)

• Complete neurological examination between seizures
• Often normal in idiopathic epilepsy
• Abnormalities suggest structural or metabolic cause
• Evaluate for signs of systemic disease

Complete Blood Count (CBC)

• Rule out infection, anemia

Serum Chemistry

• Blood glucose level
• Liver function (bile acids, ammonia)
• Kidney values
• Electrolytes (calcium, sodium, potassium)
• Protein levels

Urinalysis

• Assess kidney function
• Screen for toxins in some cases

Thyroid Panel

• Low thyroid can contribute to seizures

Bile Acids

• Screen for portosystemic shunt

Blood Pressure

• Hypertension can cause neurological signs

Infectious Disease Testing

• Based on geographic exposure and clinical signs

MRI (Magnetic Resonance Imaging)

• Gold standard for evaluating brain
• Detects tumors, inflammation, malformations
• Recommended if:

CT Scan

• Less detailed than MRI
• May detect some structural changes
• More accessible than MRI

• Collected after MRI (never before imaging)
• Evaluates for inflammation, infection
• Important for diagnosing encephalitis

• Limited availability in veterinary medicine
• Can detect abnormal brain electrical activity
• Helpful for confirming epilepsy diagnosis

Treatment typically recommended when:

• Two or more seizures in 6 months
• Status epilepticus or cluster seizures occur
• Prolonged post-ictal phase (>24 hours)
• Underlying progressive condition identified
• Single severe seizure with significant injury

• Reduce seizure frequency (aim for >50% reduction)
• Minimize seizure severity
• Maintain quality of life
• Avoid serious side effects
• Prevent status epilepticus

Phenobarbital

• Most commonly used anticonvulsant in dogs
• Dose: 2-3 mg/kg twice daily (starting dose)
• Therapeutic level: 20-35 μg/mL
• Side effects: sedation, increased appetite/thirst, liver effects
• Requires therapeutic monitoring
• Controlled substance

Potassium Bromide (KBr)

• Often used with phenobarbital or alone
• Dose: 20-40 mg/kg once daily
• Therapeutic level: 1000-2000 μg/mL (with phenobarbital) or 2000-3000 μg/mL (alone)
• No liver metabolism
• Side effects: sedation, rear leg weakness, pancreatitis risk
• Long half-life; takes months to reach steady state
• Loading dose may be given

Levetiracetam (Keppra)

• Excellent safety profile
• Dose: 20-30 mg/kg three times daily
• Extended-release: 30 mg/kg twice daily
• Minimal drug interactions
• May need higher doses with phenobarbital
• Expensive at high doses

Zonisamide (Zonegran)

• Good adjunct medication
• Dose: 5-10 mg/kg twice daily
• Minimal drug interactions
• Side effects: sedation, inappetence
• Avoid in sulfonamide-allergic animals

Gabapentin

• May help as adjunct therapy
• Better established for pain than seizures
• Dose: 10-20 mg/kg three times daily

• Pregabalin: Similar to gabapentin
• Topiramate: Limited veterinary experience
• Imepitoin (Pexion): Available in some countries

• Therapeutic drug levels regularly
• Liver enzymes (phenobarbital)
• Seizure diary kept by owner
• Adjustments based on seizure control and levels

Status epilepticus is a life-threatening emergency defined as:

• Continuous seizure activity lasting > 5 minutes
• Multiple seizures without full recovery between them

Why It's Dangerous

• Brain damage begins after 5-30 minutes
• Hyperthermia
• Metabolic acidosis
• Muscle damage (rhabdomyolysis)
• Aspiration risk
• Can be fatal

At Home (While Transporting)

• Keep calm
• Move dog away from hazards (stairs, water, furniture)
• Do NOT put hands in mouth
• Time the seizure
• Keep dog cool
• Transport immediately to veterinary emergency

First Priority: Stop the seizure

• IV access and blood glucose check
• Diazepam (Valium): 0.5-1 mg/kg IV, can repeat x2
• Midazolam: 0.2-0.5 mg/kg IV/IM (may be faster IM)
• Levetiracetam: 30-60 mg/kg IV

If Benzodiazepines Fail

• Phenobarbital: 15-20 mg/kg IV (loading dose, given slowly)
• Propofol: CRI for refractory status epilepticus
• General anesthesia may be required

Supportive Care

• IV fluids
• Temperature monitoring and cooling
• Oxygen supplementation
• Blood work
• Correct any metabolic abnormalities

Multiple seizures within 24 hours:

• Also considered an emergency
• Higher risk of progressing to status epilepticus
• Treatment as above
• Pulse diazepam may be used at home (rectal or intranasal)

Veterinarians may prescribe:

• Diazepam rectal gel: 1-2 mg/kg rectally
• Intranasal/buccal midazolam: 0.2 mg/kg
• Levetiracetam pulse: 60 mg/kg at onset of cluster

When to Seek Emergency Care

• Seizure lasting > 2-3 minutes
• Multiple seizures in 24 hours
• Difficulty breathing
• Seizure different from typical pattern
• Injury during seizure
• First-ever seizure

• Many dogs live normal, happy lives with proper management
• Approximately 15-30% of dogs are refractory to treatment
• Quality of life often very good between seizures
• Average survival with idiopathic epilepsy similar to non-epileptic dogs with treatment

Keep detailed records of:

• Date and time of each seizure
• Duration
• Description of seizure
• Any potential triggers
• Pre-ictal and post-ictal behavior
• Medications given
• Response to treatment

• Block access to stairs during and after seizures
• Prevent access to pools or bodies of water
• Pad hard floor surfaces if possible
• Supervise outdoor time
• Consider baby gates

While seizures often occur randomly, possible triggers include:

• Stress or excitement
• Sleep deprivation
• Missing medication doses
• Hormonal changes (estrus)
• Weather changes (some dogs)
• Flashing lights (rare in dogs)

• Give medications at same times daily
• Never stop medications abruptly (can cause severe seizures)
• Keep emergency medication supply
• Notify vet before surgery or other medications

• Witnessing seizures is stressful
• Connect with support groups (Facebook, forums)
• Communicate openly with veterinary team
• Set realistic expectations
• Focus on quality of life

• Most dogs can exercise normally
• Avoid swimming unsupervised
• Avoid extreme temperatures
• Watch for seizure triggers
• Short, frequent activities may be better than exhausting play

When seizures don't respond adequately to treatment:

• Reassess diagnosis (are they true seizures?)
• Check therapeutic drug levels
• Ensure medication compliance
• Consider adding second medication
• Advanced imaging if not done
• Dietary therapy (MCT oil, ketogenic diets)
• Referral to veterinary neurologist

Emerging evidence for:

• Medium-chain triglyceride (MCT) oil: May help reduce seizure frequency
• Ketogenic diets: Being studied; may have some benefit
• Prescription diets: Purina NC (NeuroCAre) contains MCT

• Very limited availability in veterinary medicine
• May be option for focal seizures with identifiable source
• Requires specialized centers

Limited evidence but sometimes tried:

• Acupuncture
• CBD products (variable quality, not well-regulated)
• Herbal supplements

• Dogs with idiopathic epilepsy should not be bred
• Strong genetic component in many breeds
• Spaying/neutering does not affect seizure control
• Some medications have teratogenic effects

• Can occur in dogs (and humans)
• Rare but recognized
• May be related to severe seizures
• No way to predict which dogs at risk
• Good seizure control may reduce risk

Long-term management requires:

• Regular medication (lifelong)
• Periodic blood testing
• Emergency veterinary care for clusters/status
• Possible advanced imaging
• Potential specialist referrals