2025 Canadian Guide: Top 5 Veterinary Neurologic and Seizure Medications for Dogs — Evidence-Based Options for Phenobarbital, Potassium Bromide, Zonisamide, Levetiracetam, and Gabapentin (Which Is Best for Chronic Care, Emergencies and Drug Interactions?)

Phenobarbital 30mg Tablets are the long-established, best-in-class first-line maintenance anticonvulsant for canine epilepsy because of their proven efficacy, low acquisition cost, and widespread veterinary familiarity. Compared with the other medications on this list, phenobarbital delivers strong seizure reduction at lower cost but requires routine serum level and hepatic monitoring due to metabolism-related risks, making it less suitable than potassium bromide or levetiracetam for dogs with preexisting liver disease.

Potassium Bromide Oral Solution is a market-leading adjunct or alternative monotherapy for dogs when hepatic tolerance is a concern, prized for its low cost, long half-life, and renal excretion. Versus phenobarbital and newer drugs like zonisamide and levetiracetam, bromide is often cheaper and avoids hepatic metabolism, but it has a slower onset of effect and can cause polyuria, polydipsia and sedation, and is unsuitable in cats.

Zonisamide 100mg Capsules occupy a key role for refractory or adjunctive therapy in canine epilepsy as a newer sulfonamide anticonvulsant that provides effective seizure control with relatively low sedation and convenient once- or twice-daily dosing. Technically, zonisamide can be more expensive and is more hepatically metabolized than levetiracetam or potassium bromide, so it is often reserved after first-line agents like phenobarbital or as part of combination protocols.

Levetiracetam 500mg Tablets are a market leader for adjunctive and peri-ictal therapy in dogs because of their rapid onset, minimal drug–drug interactions, and low monitoring burden, making them especially valuable in patients on multiple anticonvulsants or with hepatic disease. Although generally pricier than older agents such as phenobarbital and potassium bromide and sometimes requiring more frequent dosing, levetiracetam's safety profile and predictable pharmacology give it a clear technical advantage in complex cases.