Pet Costs

Dog Seizure Medication Cost: Phenobarbital, Keppra, and What Epilepsy Costs Over a Year

By PetPawCalc Team · November 12, 2026 · 9 min read · How we write

Seizures are one of the most frightening things an owner can see, and one of the most common reasons dogs are referred to a veterinary neurologist. When no underlying cause is found, the diagnosis is usually idiopathic epilepsy, and the treatment is daily medication — often for life.

That makes epilepsy a long-term budget item. The medication is usually affordable, but the total depends on which drug your dog takes, how big your dog is, how often blood tests are needed, and whether the seizures are well controlled.

What the Medications Cost

A reference table from the Illinois State Veterinary Medical Association gives monthly drug costs for a 25 lb (11 kg) dog:

Drug Monthly cost (25 lb dog) How often given Blood level checks
Phenobarbital About $10–$20 Twice a day Yes, regularly
Potassium bromide Varies by compounding pharmacy, usually low Once a day Yes, after about 3 months
Zonisamide About $12–$70 Twice a day Optional
Levetiracetam (Keppra) About $10–$250 Three times a day Not routinely
Levetiracetam extended-release About $75–$90 Twice a day Not routinely

Retail examples from GoodRx: about $16–$26 for 60 phenobarbital tablets, and about $13–$25 for 30 levetiracetam 250 mg tablets. Larger dogs need more, so costs rise with weight.

What owners actually spend: in a survey of 225 owners of epileptic dogs by researchers at North Carolina State University (Nettifee et al., 2017, Journal of the American Animal Hospital Association), the median monthly medication cost was $51–$75, and about 10% spent more than $200 a month.

Monitoring: The Part People Forget to Budget

Phenobarbital and bromide need blood tests to keep the dose effective and safe:

The lab test itself is inexpensive — Texas A&M’s diagnostic lab charges $36.75 for a phenobarbital level — but clinics add exam and collection fees, so each check typically costs more than that. Basic bloodwork at a general practice usually runs about $80–$300.

One cost trap: phenobarbital lowers thyroid test results. A dog on phenobarbital can look hypothyroid on a T4 test without having thyroid disease. If your vet suggests thyroid medication for a dog on phenobarbital, ask whether a full thyroid panel has been done — see Dog Hypothyroidism Treatment Cost.

Phenobarbital vs Keppra

Phenobarbital is the long-established first choice. A consensus update from the American College of Veterinary Internal Medicine and the International Veterinary Epilepsy Task Force summarised eight studies of 311 dogs on phenobarbital alone: 82% had seizures reduced by more than half, and 31% became seizure-free. It’s cheap and given twice daily. The trade-off is side effects — increased thirst, urination and appetite, weight gain, and sedation early on — and the need for regular blood tests.

Levetiracetam (Keppra) has the fewest side effects of the common options, is barely processed by the liver, and doesn’t need routine level checks. The standard tablets are given every 8 hours, which is hard for many households; the extended-release form is twice daily but can’t be split or crushed, which can make it awkward and more expensive for small dogs. Some dogs need higher doses over time.

Side effects are common across all the drugs: in the NC State survey, 81% of owners reported side effects, most often lethargy, increased appetite or thirst, and changes in behavior or alertness.

When Daily Medication Starts

Not every seizure means lifelong medication. The ACVIM and IVETF consensus guidance recommends starting long-term treatment when a dog has:

The goal is fewer and milder seizures with as few side effects as possible. Complete seizure freedom is a bonus, not the usual result. Clinician’s Brief notes that dogs with well-controlled seizures and minimal side effects typically have a normal lifespan and good quality of life.

Diagnosis and Emergencies: The Big One-Time Costs

Item Typical cost
Exam and basic workup (bloodwork, urine) About $160–$490
Neurology consultation About $200–$300
Neurologic workup with MRI and spinal fluid tap About $3,000–$3,500
ICU care for a seizing dog, with bloodwork and medication About $1,000–$1,800

The specialist figures are from the University of Wisconsin’s neurology service (2021 pricing), so current prices are likely to be at least that much. An MRI is used to look for a structural cause in the brain, such as a tumor or inflammation. Ask your vet whether it would change the treatment plan for your dog.

Cluster seizures and seizures lasting over five minutes are emergencies. Ask your vet what to do if one happens, and whether a rescue medication to give at home is appropriate for your dog.

Ways to Keep the Cost Down

A Note on Insurance

Accident-and-illness policies often cover epilepsy diagnosis, medication and monitoring if seizures didn’t happen before coverage began. A single seizure in your dog’s records before enrollment can lead to an exclusion, so insuring young dogs early matters. Our Pet Insurance Cost Estimator gives a rough idea of premiums.

Frequently Asked Questions

How much does seizure medication cost for a dog? For a 25 lb dog, an Illinois State Veterinary Medical Association reference table puts phenobarbital at about $10–$20 a month, zonisamide at $12–$70, and levetiracetam (Keppra) anywhere from $10 to $250, or $75–$90 for the extended-release form. In a survey of 225 owners of epileptic dogs, the median monthly medication spend was $51–$75, and about 10% spent more than $200.

Is phenobarbital or Keppra cheaper for dogs? Phenobarbital is usually cheaper per month and is given twice a day, but it needs regular blood tests to check the drug level and liver health. Levetiracetam (Keppra) has few side effects and doesn’t need routine level checks, but the standard form is given three times a day and can cost more, especially for large dogs. Which works out cheaper overall depends on your dog’s size and how its seizures respond.

When does a dog with seizures need daily medication? Veterinary consensus guidance recommends starting long-term treatment when a dog has two or more seizures within six months, a seizure lasting more than five minutes or three or more in 24 hours, unusually long or severe recovery periods after seizures, seizures that are becoming more frequent or severe, or a known brain lesion or injury. A single seizure often doesn’t need daily medication.

How often does a dog on phenobarbital need blood tests? The drug level is usually checked about 2 weeks and 6 weeks after starting, then about every 6 months, and 2 weeks after any dose change or if seizures increase. Blood counts and liver tests are also checked, typically every 6–12 months once stable. The lab fee for a phenobarbital level is modest — one university lab charges $36.75 — but clinics add exam and collection fees.

How well does phenobarbital work for dogs? Across eight studies of 311 dogs given phenobarbital alone, 82% had their seizures reduced by more than half and 31% became seizure-free, while about 15% didn’t improve. Dogs that don’t respond well usually have a second drug added.

How much does an MRI for dog seizures cost? Usually a few thousand dollars. One university neurology service quoted $3,000–$3,500 for a typical neurologic workup including MRI and a spinal fluid tap, plus about $200–$300 for the initial consultation. It’s worth asking your vet whether an MRI would change the treatment plan before booking one.