CBD is a possible add-on treatment for some dogs with drug-resistant epilepsy, not a proven seizure treatment or emergency medicine. A 2019 randomized trial of 26 dogs found a possible reduction in seizure frequency, but the overall evidence remains limited. The strongest studies suggest that CBD may provide a modest benefit when added to conventional treatment under veterinary supervision.
| Question | Evidence-based answer |
|---|---|
| Can CBD help some dogs with seizures? | Possibly, especially dogs with drug-resistant idiopathic epilepsy |
| Is CBD proven to work? | No. The studies are small and have methodological limitations |
| Can CBD replace phenobarbital, levetiracetam, potassium bromide or other medication? | No |
| Can CBD stop an active seizure? | There is no reliable evidence that it works as an emergency treatment |
| What are the main concerns? | Ataxia, vomiting, appetite changes, drug interactions and increased liver enzymes |
| Should owners choose a dose themselves? | No. Study doses are not DIY dosing instructions |
What Do Clinical Studies Say About CBD for Canine Seizures?
Most studies involved dogs with drug-resistant idiopathic epilepsy. This means the dogs had recurrent seizures without an identified underlying cause, and the seizures continued despite conventional anti-seizure medication.
Those findings do not automatically apply to seizures caused by toxins, low blood sugar, liver disease, brain tumors or other conditions.
2019 Randomized Trial
A 2019 randomized, blinded trial evaluated 26 dogs with difficult-to-control idiopathic epilepsy. The dogs received either CBD oil or placebo oil alongside their existing anti-seizure medication.
The CBD group had a 33% median reduction in seizure frequency. However, the percentage of dogs that achieved at least a 50% reduction was similar in the CBD and placebo groups.
Two dogs receiving CBD developed ataxia, meaning poor coordination, and left the study. Serum alkaline phosphatase, a liver-associated enzyme, also increased in the CBD group.
2023 Double-Blind Crossover Study
A larger 2023 study included 51 dogs with drug-resistant epilepsy. At the studied dose of 9 mg/kg/day, CBD reduced total seizure frequency compared with placebo.
Seizure days decreased by 24.1% during CBD treatment, compared with a 5.8% increase during the placebo phase.
CBD did not significantly increase the number of dogs that achieved at least a 50% reduction in seizures. Liver enzyme activity increased, and decreased appetite and vomiting were more common during CBD treatment.
Small CBD and CBDA Pilot Study
A separate 14-dog crossover study tested a CBD and CBDA-rich hemp extract alongside conventional medication. Average seizures fell from 8 during the placebo phase to 5 during the treatment phase.
Six of the 14 dogs achieved at least a 50% reduction in seizure activity while receiving the hemp extract. None reached that threshold during the placebo phase.
This was a small pilot study involving one specific product. It does not show that every CBD oil or hemp extract will produce the same result. Some dogs also developed sleepiness or increased ataxia.
How Strong Is the Evidence Overall?
The evidence is not strong enough to recommend CBD routinely for every dog with seizures.
A 2025 systematic review of randomized canine epilepsy trials found that the studies generally reported fewer seizures during CBD treatment. The review also found moderate to high risk of bias across the studies. It concluded that the available evidence is insufficient to determine CBD's true effectiveness, ideal dose or complete safety profile.
The evidence supports a narrower conclusion:
CBD may help some dogs with drug-resistant epilepsy when used alongside standard treatment, but veterinarians cannot yet predict which dogs will respond or how much benefit they will receive.
Can CBD Replace a Dog's Seizure Medication?
No. Do not stop or reduce a dog's prescribed anti-seizure medication without veterinary direction.
Veterinarians may use medicines such as phenobarbital, levetiracetam or potassium bromide, depending on the dog's diagnosis, seizure pattern, liver health and other factors. Stopping anti-seizure medication abruptly can worsen seizure control and may trigger severe or prolonged seizures.
If a veterinarian recommends CBD, it should be treated as a possible adjunct, meaning an addition to the current treatment plan. It should not be treated as a substitute.
Is CBD Safe for Dogs With Seizures?
CBD can cause side effects and may interact with other medicines. Reported concerns in canine epilepsy studies include:
- Ataxia or unsteady movement
- Sleepiness or lethargy
- Vomiting
- Reduced appetite
- Behavioural changes
- Increased liver enzymes
- Possible interactions with other medications
The U.S. Food and Drug Administration states that it has not approved cannabis or CBD products for use in animals. The FDA also says it cannot confirm the safety or effectiveness of products marketed for pets and warns that CBD can alter the effects of other medicines.
A veterinarian may recommend baseline and follow-up blood tests, including liver-related testing, if CBD is used alongside anti-seizure medication.
Is Human CBD Oil Safe for Dogs?
Human CBD oil should not be given to a dog unless a veterinarian specifically directs its use. Human products may contain unsuitable concentrations, added ingredients or measurable THC.
THC is different from CBD and can poison dogs. Possible signs after cannabis exposure include lethargy, depression, excessive drooling, vomiting, agitation, tremors and convulsions.
If a dog may have consumed THC or another cannabis product, contact a veterinarian, emergency animal hospital or animal poison control service immediately.
The FDA-approved CBD medicine Epidiolex is approved for specific human seizure disorders. That approval does not make Epidiolex or ordinary CBD oils approved treatments for canine epilepsy.
Can CBD Stop a Seizure That Is Happening Now?
CBD should not be used as an emergency treatment for an active seizure.
Veterinary references state that evidence for CBD in emergency seizure control is limited. There is no established evidence that CBD reliably stops status epilepticus or seizure clusters. Emergency seizure treatment uses veterinary-directed medication and monitoring.
Seek immediate veterinary care if:
- A seizure lasts more than five minutes
- Several seizures occur close together
- The dog does not recover normally between seizures
- The dog has difficulty breathing, severe overheating or prolonged unconsciousness
- The seizure may have resulted from poisoning, trauma or another emergency
A seizure lasting longer than five minutes, or multiple seizures in rapid succession, can cause permanent injury and requires urgent treatment. Do not put your fingers in the dog's mouth or try to restrain the dog during the seizure.
What Should Dog Owners Do Before Considering CBD?
Speak with the dog's veterinarian before adding CBD, particularly if the dog takes phenobarbital, potassium bromide, levetiracetam, zonisamide or another medication.
Bring or record:
- The date and time of each seizure
- The seizure's duration
- Whether the seizure was generalized or appeared focal
- How long recovery took
- Every medication, supplement and CBD product being used
- Any vomiting, appetite change, sedation or unsteady movement
Do not choose a dose based only on an online recommendation. Clinical studies used specific formulations and measured doses. Those results cannot be transferred reliably to every commercial CBD treat or oil.
Bottom Line
CBD may reduce seizures for some dogs with drug-resistant epilepsy, but the benefit is modest, unpredictable and not established well enough to replace standard treatment. Use CBD only after discussing it with a veterinarian, continue prescribed anti-seizure medication unless the veterinarian changes it, and seek urgent care for prolonged or repeated seizures.