Not all seizures are epilepsy -- the diagnostic workup matters

Seizures in dogs can result from systemic diseases that mimic epilepsy: hypoglycemia (low blood sugar, especially in toy breeds and diabetic dogs), hepatic encephalopathy (liver disease causing toxin accumulation), electrolyte imbalances, toxin ingestion, brain tumors, inflammatory brain disease (encephalitis), and structural brain abnormalities. A first seizure should trigger a complete diagnostic workup: CBC, comprehensive metabolic panel, urinalysis, fasting and post-prandial bile acids (to screen for liver shunts), blood pressure measurement, and ideally MRI (to rule out structural lesions) plus CSF tap. Treatment with antiepileptic drugs (AEDs) without this workup risks missing a treatable underlying disease while masking its progression.

Phenobarbital remains the first-line drug for most dogs

Phenobarbital is inexpensive, effective (controls seizures adequately in approximately 60-80% of dogs when used as sole agent), and has 60+ years of safety data in dogs. Starting dose: 2-3 mg/kg twice daily. Target serum phenobarbital level: 20-40 ug/mL, measured 14 days after starting or adjusting dose. Dose adjustments are made based on therapeutic drug monitoring, not based on continued seizure activity alone. Side effects: sedation and ataxia in the first 2-3 weeks (usually resolves), polyphagia (increased appetite), polydipsia/polyuria. Long-term concern: phenobarbital is hepatotoxic at supratherapeutic levels. Liver enzyme monitoring (ALT, ALP) every 6 months and bile acids annually are required for all dogs on chronic phenobarbital. A dog with phenobarbital toxicity shows profound sedation, ataxia, and elevated liver enzymes -- reduce dose and recheck levels.

Cluster seizures and status epilepticus require emergency intervention

Cluster seizures (two or more seizures within 24 hours with full recovery between events) and status epilepticus (seizure lasting more than 5 minutes, or two seizures without regaining consciousness between them) are medical emergencies associated with significant risk of brain injury, hyperthermia, and death. Treatment: IV diazepam (0.5 mg/kg, repeated up to 3 times) or intranasal/rectal diazepam (0.5-1 mg/kg) if IV access is not immediately available. Maintain normal body temperature (hyperthermia is common during prolonged seizures -- active cooling if rectal temperature exceeds 104 degrees Fahrenheit). Transport immediately to an emergency vet. For epileptic dogs with a history of cluster seizures, most neurologists recommend prescribing intranasal or rectal diazepam for home use to administer at seizure onset before cluster patterns develop.

Diet and lifestyle modifications supplement (but do not replace) medication

A 2020 randomized controlled trial published in BMC Veterinary Research found that a medium-chain triglyceride (MCT)-enriched diet reduced seizure frequency in epileptic dogs by approximately 41% compared to a control diet, with 48% of dogs on the MCT diet achieving greater than 50% seizure reduction. MCT diets are now commercially available (Royal Canin Veterinary Diet Neurology, Purina Pro Plan Veterinary Diets NC NeuroCare). They are used as adjunctive therapy, not as a replacement for AEDs in dogs with significant seizure burden. Regular sleep schedules, reduced stress, and maintaining stable body condition also reduce seizure frequency as ancillary measures. Exercise is not contraindicated for epileptic dogs -- moderate regular exercise is appropriate and beneficial.