There is no universally established at-home CBD dose for dogs with seizures. Do not start CBD or change a prescribed seizure medication without speaking with your veterinarian. The canine studies available so far tested CBD as an add-on to conventional anti-seizure medication, not as a replacement.
The studies used doses from 2 mg/kg every 12 hours to 9 mg/kg per day. These were controlled research protocols, not universal dosing instructions. A dose that was studied in one trial may not be safe or appropriate for every dog.
CBD Dosing Evidence for Dogs With Seizures
| Research protocol | CBD amount studied | Main finding |
|---|---|---|
| CBD/CBDA-rich hemp extract | 2 mg/kg every 12 hours | Seizure frequency decreased in a small study of 14 dogs. Six dogs had at least a 50% reduction in seizures. |
| CBD oil | 2.5 mg/kg every 12 hours | Median seizure frequency fell by 33% in a small trial. Two dogs developed ataxia and were withdrawn. |
| CBD oil | 9 mg/kg per day | Seizure frequency and seizure days decreased compared with placebo, but the difference in dogs achieving at least a 50% reduction was not statistically significant. |
The studies also reported increased liver enzymes. Some dogs developed reduced appetite, vomiting, sleepiness or loss of coordination.
What Dose Has the Strongest Seizure-Specific Evidence?
The largest recent canine trial tested 9 mg of CBD per kilogram of body weight per day in dogs already taking anti-seizure medication. The dogs had fewer seizures and seizure days, but CBD did not produce a clear increase in the number of dogs whose seizures fell by at least 50%. Liver enzymes increased at both tested doses, so the researchers recommended liver-function monitoring.
That finding does not make 9 mg/kg/day a suitable starting dose for your dog. The trial involved dogs with drug-resistant idiopathic epilepsy and took place under veterinary supervision.
A separate study of 14 dogs tested 2 mg/kg every 12 hours using a CBD/CBDA-rich hemp extract. It reported fewer seizures and seizure days, but the study was small and used a specific product. Results may not apply to every CBD oil sold for pets.
How to Calculate the Liquid Amount Your Veterinarian Prescribes
CBD dosing is based on milligrams of CBD, not an assumed number of drops.
CBD concentration = total CBD in bottle ÷ total bottle volume in mL
Liquid volume to give = prescribed CBD dose in mg ÷ CBD concentration in mg/mL
Example Calculation
Suppose a veterinarian prescribes 2 mg/kg every 12 hours for a 10 kg dog:
- 10 kg × 2 mg/kg = 20 mg per dose
- A bottle containing 600 mg of CBD in 30 mL contains 20 mg/mL
- 20 mg ÷ 20 mg/mL = 1 mL per dose
This is a calculation example, not a recommendation to start CBD.
Some labels list the total hemp extract rather than the actual CBD content. Confirm the amount of CBD per milliliter with your veterinarian or the manufacturer before measuring a dose.
Why Veterinary Supervision Matters
The U.S. Food and Drug Administration has not approved cannabis or CBD products for treating animals. The FDA says it cannot assure their safety or effectiveness and recommends discussing treatment options with a veterinarian.
CBD may affect the liver and can cause:
- Sleepiness or unusual lethargy
- Vomiting or reduced appetite
- Wobbliness or loss of coordination
- Increased liver enzymes
- Interactions with other medicines
A small study in healthy dogs found no significant pharmacokinetic interaction between CBD and phenobarbital. That study was limited, however, and does not show that CBD is safe with every seizure medication or for dogs with liver disease.
Your veterinarian may recommend blood tests before treatment and during follow-up, especially if your dog takes phenobarbital, potassium bromide, zonisamide, levetiracetam or another long-term anti-seizure medication.
Avoid THC-Containing Cannabis Products
Do not give a dog marijuana, THC oil or a human cannabis product. Possible signs of cannabis toxicity in pets include lethargy, depression, heavy drooling, vomiting, agitation, tremors and convulsions.
Contact an emergency veterinarian or animal poison control service if your dog may have ingested THC.
When a Dog Seizure Is an Emergency
Seek emergency veterinary care if:
- A seizure lasts more than five minutes
- Your dog has repeated seizures without fully recovering between them
- Your dog has multiple seizures close together
- This is your dog's first seizure
- Your dog may have ingested THC, medication or another toxin
A seizure lasting longer than five minutes, or repeated seizures with incomplete recovery, is classified as status epilepticus and needs urgent treatment.
Bottom Line
Published canine studies have tested approximately 2 mg/kg every 12 hours and 9 mg/kg per day, but no single CBD dose is proven safe and effective for every dog. CBD should be considered only with veterinary guidance, accurate milligram measurement and follow-up for seizure frequency, side effects and liver enzymes.