How Do Vets Choose the Right Seizure Medication?
When Ruby had her first few seizures, I remember sitting in the vet’s office, overwhelmed and just knowing Ruby was going to start a medication. Over time, I learned that there are multiple seizure medication options and there’s no one-size-fits-all answer. Vets consider many factors when choosing a seizure drug, and the “right” one is the one that fits your dog. In this post, I’ll walk you through how vets make those decisions, and how you and I together can help them get it right.
1. Seizure Type, Frequency & Severity
When Ruby first came in, her seizures were occasional but growing. The vet considered:
How often the seizures occur (daily, weekly, monthly)
How severe they are (one-off vs clustering)
Whether there are warning signs (auras) or a pattern
If seizures are frequent or cluster together, the vet may choose a more aggressive or multi-drug regimen. For milder cases, they might start with a single medication with fewer side effects.
2. Dog’s Size, Age & Organ Function
Ruby’s weight, age, and how her liver and kidneys were functioning were big parts of the plan. Vets often:
Check liver and kidney health (because many seizure meds are metabolized or excreted via those organs)
Consider age (young dogs, seniors)
Look at body size (dosages scale)
Account for other health conditions (e.g. liver disease, other illnesses)
For dogs with compromised liver function, vets may choose meds that rely less on the liver and more on renal (kidney) clearance.
3. Drug Side Effects & Tolerability
Every seizure medication has potential downsides. Vets weigh:
Common side effects (drowsiness, appetite changes, lethargy)
More serious risks (liver toxicity, behavioral changes)
How your particular dog tolerates medications
Interactions with medications your dog is already on
They aim for the drug that gives seizure control with the fewest and mildest side effects.
4. Drug Interactions & Current Medications
Veterinarians have to check whether any anti-seizure drugs might interfere with what your dog might already be taking. Some meds boost or inhibit liver enzymes, which can change levels of other drugs. That’s why vets often start slowly or do staggered additions (adding one drug at a time).
5. Cost, Availability & Dosing Practicalities
The vet also considered:
How affordable the drug is over long term
Whether you can get it reliably (is it in stock or easy to obtain?)
How many times a day you have to give it (once vs twice vs three times)
Form (tablet, liquid, extended-release) — what is easiest for you and your dog?
A perfect drug that’s impossible to give consistently isn’t much use.
6. Monitoring & Adjustment Plans
Choosing the drug is only step one. Vets plan:
Regular blood tests (to check drug levels, liver/kidney health)
Watching for side effects or behavior changes
Adjusting dosage over time (raising, lowering, or switching) based on how your dog responds
Planning for what to do if seizures continue (adding a second drug, changing medications)
My Experience with Ruby & Medication Choices
When Ruby’s seizures increased in frequency, our vet didn’t just pick a “popular” one. She walked me through options, explaining which drugs might suit Ruby’s liver, what side effects to watch, and how easy each would be for me to administer. We started with one, as seizures increased, we adjusted, and more medication had to be added. Over time, the process felt less scary because I knew why each decision was made—and felt like a partner in Ruby’s care.
You & Your Vet—A Team in Care
The “right” seizure medication is never just the vet’s choice—it’s a decision you make together. Your observations, your dog’s history, and what you can realistically maintain are all vital parts of that equation. The more informed and communicative you are, the better the outcome will likely be for your dog.
If you’d like help understanding how to compare options, what questions to ask your vet, or how to build that decision-making confidence, my course My Dog Was Diagnosed With Epilepsy – Now What? gives you tools, checklists, and step-by-step guidance to become your dog’s best advocate.