CBD and Epilepsy in Dogs: What Veterinary Research Is Finding
Few things are more frightening for a pet parent than watching a dog experience a seizure.
For families living with canine epilepsy, the goal is usually simple:
reduce seizure frequency, improve quality of life, and keep their dog as stable and comfortable as possible.
Conventional anti-seizure medications remain the foundation of treatment for canine epilepsy.
But over the past several years, veterinary researchers have been investigating another question:
Could CBD have a role as an adjunct to traditional seizure medication?
This has become one of the more closely studied areas of canine CBD research.
The results so far are encouraging.
Here is what pet parents should know.
What Is Canine Epilepsy?
Epilepsy is a neurological disorder characterized by recurrent seizures.
A seizure occurs when there is abnormal electrical activity in the brain.
Dogs may experience different types of seizures, including:
- Generalized tonic-clonic seizures
- Focal seizures
- Cluster seizures
- Episodes involving loss of consciousness
- Abnormal movements or behaviors
Cornell University notes that generalized seizures can involve falling over, limb paddling, muscle spasms, drooling, loss of bladder or bowel control, and loss of consciousness. (vet.cornell.edu)
Epilepsy can have several causes.
In some dogs, seizures are related to:
- Brain disease
- Toxins
- Metabolic problems
- Trauma
- Other medical conditions
In other dogs, no structural cause is identified.
This is often referred to as idiopathic epilepsy.
What Does “Drug-Resistant” Epilepsy Mean?
Many dogs respond well to anti-seizure medications.
But some continue to have seizures despite appropriate treatment.
These dogs may be described as having:
drug-resistant, refractory, or intractable epilepsy.
These are the dogs most commonly included in CBD studies.
That distinction is important.
Researchers have generally not studied CBD as the first treatment given to a newly diagnosed dog.
Instead, CBD has usually been added to an existing seizure-management plan when conventional medications have not completely controlled the seizures.
Why Are Researchers Interested in CBD?
CBD, or cannabidiol, is a non-intoxicating cannabinoid found in hemp.
Researchers have studied CBD's effects on multiple signaling systems in the brain, including pathways involved in neuronal excitability and seizure activity.
CBD does not act exactly like traditional anti-seizure drugs, and its mechanisms are still being studied.
Veterinary researchers became especially interested in CBD after human clinical research showed anticonvulsant effects in certain severe epilepsy syndromes.
That led to an important question:
Could similar effects occur in dogs?
Over the past several years, multiple controlled canine studies have tried to answer that question.
The 2019 Colorado State University Study
One of the landmark canine CBD epilepsy studies was published in 2019.
Researchers at Colorado State University enrolled 26 client-owned dogs with intractable idiopathic epilepsy.
The dogs continued taking their existing anti-seizure medications.
They were then randomly assigned to receive either:
- CBD
- Placebo
The CBD group received approximately:
2.5 mg of CBD per kilogram of body weight twice daily
for 12 weeks.
The results were encouraging.
Dogs receiving CBD experienced a median 33% reduction in seizure frequency compared with placebo. (pubmed.ncbi.nlm.nih.gov)
Researchers also found something especially interesting:
Higher blood concentrations of CBD were associated with greater reductions in seizure frequency.
That suggests absorption may be important.
Two dogs in the CBD group developed ataxia, or loss of coordination, and were withdrawn from the study.
The trial was relatively small, and not every dog responded.
But it provided one of the first controlled indications that CBD could potentially influence seizure frequency in dogs when added to conventional treatment.
The 2022 CBD + CBDA Study
A second important study was published in 2022.
Researchers evaluated a hemp extract containing both:
CBD and CBDA
in dogs with refractory epilepsy.
Fourteen dogs participated in a randomized crossover study.
The dogs continued taking their regular anti-seizure medications and received either:
- Placebo
- CBD/CBDA-rich hemp extract
The cannabinoid treatment was given at approximately:
2 mg/kg every 12 hours.
During placebo treatment, the dogs averaged approximately:
8 seizures
over the study period.
During CBD/CBDA treatment, that average declined to approximately:
5 seizures.
Researchers also reported that:
6 of 14 dogs experienced at least a 50% reduction in seizure activity during cannabinoid treatment, while none achieved that level of reduction during placebo treatment. (pubmed.ncbi.nlm.nih.gov)
That was a meaningful finding.
The study also measured blood concentrations of common anti-seizure medications.
Researchers did not observe significant changes in concentrations of:
- Phenobarbital
- Zonisamide
- Bromide
during the cannabinoid treatment period.
However, mild increases in alkaline phosphatase, or ALP, were observed.
Some dogs also experienced:
- Sleepiness
- Temporary increases in ataxia
The study authors concluded that the CBD/CBDA product appeared reasonably well tolerated when used alongside conventional anti-seizure medications.
The 2023 Double-Blind Crossover Study
A larger study published in 2023 included 51 dogs with drug-resistant idiopathic epilepsy.
Dogs were already receiving at least one anti-seizure drug.
Researchers compared CBD with placebo using a double-blind crossover design.
An initial CBD dose of:
5 mg/kg per day
did not meet the study's effectiveness criteria.
Researchers then evaluated:
9 mg/kg per day
in additional dogs.
At the higher dose, dogs receiving CBD experienced a significant reduction in total seizure frequency compared with placebo.
Researchers also found a reduction in the number of seizure days. (pubmed.ncbi.nlm.nih.gov)
This study strengthened the evidence that dose and blood exposure may matter.
It also reinforced a central theme in CBD research:
Not every dose produces the same result.
A 2025 Pilot Study Added More Data
In 2025, researchers published a small exploratory study involving 13 dogs with refractory epilepsy.
These dogs were already taking multiple anti-seizure medications.
CBD was introduced gradually and titrated upward.
The median seizure frequency declined from approximately:
11 seizures before treatment
to:
5 seizures after CBD was added.
Researchers reported that about 61.5% of the dogs achieved at least a 50% reduction in seizure frequency. (pubmed.ncbi.nlm.nih.gov)
They also observed a reduction in seizure clusters and owner-reported improvements in quality of life.
However, this was:
- A small study
- Not placebo-controlled
- Conducted in dogs taking multiple concurrent medications
So the findings should be considered promising rather than definitive.
Researchers also observed a significant increase in ALP, reinforcing the importance of veterinary monitoring.
What Does the Research Mean Overall?
Taken together, canine epilepsy is now one of the more promising areas of veterinary CBD research.
Multiple studies have reported reductions in seizure frequency in at least some dogs.
But there are important limitations.
Studies have involved:
- Small sample sizes
- Different CBD formulations
- Different doses
- Different combinations of conventional medications
- Different definitions of treatment response
A 2022 veterinary review concluded that CBD appears promising but that larger randomized controlled trials are still needed before clear treatment recommendations can be made. (pubmed.ncbi.nlm.nih.gov)
Cornell University similarly notes that hemp-derived cannabinoid products have shown promise in canine seizure research, while emphasizing the importance of product quality and veterinary supervision. (vet.cornell.edu)
The Most Important Word: Adjunct
This is probably the most important takeaway from the entire article.
In the major canine epilepsy studies, CBD was used:
alongside conventional anti-seizure medication
not instead of it.
Dogs continued taking medications such as:
- Phenobarbital
- Zonisamide
- Potassium bromide
- Levetiracetam
- Other prescribed anti-seizure drugs
CBD was added to the treatment plan.
That means research does not support telling pet parents to replace anti-seizure medication with CBD.
Never discontinue, reduce or change a seizure medication without veterinary supervision.
Abruptly changing some anti-seizure drugs can itself increase seizure risk.
CBD and Anti-Seizure Medications
CBD can influence enzymes involved in drug metabolism.
Cornell notes that CBD can affect liver enzymes such as cytochrome P450 enzymes, which are involved in processing many medications. (vet.cornell.edu)
That creates the potential for drug interactions.
It does not mean CBD and conventional anti-seizure medications cannot be used together.
In fact, most canine epilepsy research has done exactly that.
But it does mean your veterinarian should know:
- Which CBD product you're using
- How much your dog receives
- How often it is given
- Which other medications your dog takes
Your veterinarian may recommend periodic bloodwork or medication-level monitoring.
Why ALP Keeps Appearing in CBD Research
Several canine CBD studies have reported increases in:
alkaline phosphatase, or ALP.
ALP is an enzyme measured during routine blood chemistry testing.
An elevated ALP does not automatically mean liver injury.
But repeated ALP elevations across CBD studies make it something veterinarians should pay attention to, particularly in dogs receiving CBD long-term or alongside medications processed by the liver.
That is especially relevant for dogs with epilepsy because medications such as phenobarbital can also affect liver enzymes.
Why CBD Blood Levels May Matter
One particularly interesting finding from the 2019 Colorado State study was the relationship between:
higher blood CBD concentrations
and:
greater seizure reduction.
That helps explain why two dogs given the same labeled dose may not experience the same effect.
CBD absorption can vary based on:
- Formulation
- Carrier oil
- Food intake
- Individual metabolism
- Cannabinoid composition
- Product concentration
This is another reason researchers cannot simply say:
“Every dog with epilepsy should receive X milligrams.”
We do not yet have enough evidence for a universal canine epilepsy CBD dose.
What About CBD + CBDA?
The 2022 study is particularly interesting because it did not use CBD alone.
It used a hemp extract rich in:
CBD and CBDA.
CBDA, or cannabidiolic acid, is a naturally occurring precursor to CBD found in hemp.
Researchers are increasingly interested in combinations of cannabinoids rather than CBD alone.
However, current evidence does not prove that CBD/CBDA combinations or full-spectrum products are universally better than CBD alone.
More head-to-head research is needed.
Is CBD Safe for Dogs With Epilepsy?
The existing studies suggest that CBD and CBD/CBDA products can be reasonably well tolerated in dogs when used under study conditions.
Reported adverse effects have included:
- Sleepiness
- Sedation
- Ataxia
- Digestive changes
- Changes in appetite
- Increased ALP
The safety picture becomes more complicated when dogs take multiple medications.
That is why veterinary involvement is so important.
Product Quality Matters Even More in Epilepsy
For a dog with a seizure disorder, product consistency matters.
A pet parent should be able to verify:
- CBD concentration
- THC concentration
- Other cannabinoids
- Batch number
- Independent laboratory testing
A product should also be screened for:
- Heavy metals
- Pesticides
- Residual solvents
- Microbial contaminants
Cornell emphasizes that commercial CBD products can vary substantially in cannabinoid concentration and quality. (vet.cornell.edu)
If a dog is receiving CBD consistently as part of a wellness or veterinary plan, the amount in one bottle should not be dramatically different from the next.
What About THC?
Dogs are especially sensitive to THC.
A dog with epilepsy should never be given:
- Marijuana
- Recreational cannabis
- High-THC products
- Human THC gummies
- Cannabis edibles
THC intoxication can cause neurological symptoms that may complicate an already serious seizure disorder.
If you're using a hemp-derived CBD product, verify THC levels through an independent Certificate of Analysis.
A Real-World Cannafyl Pet Story
One of our Cannafyl Pet Parents shared this experience with us:
“My Australian Shepherd was diagnosed with epilepsy at 8 years old. Her vet referred me to Cannafyl to add Pet CBD to her existing wellness routine alongside her medications. She loves the taste, and CBD has continued to be part of her routine as she has gotten older.
Ed & Kim are all about customer experience! When I mentioned how nice it would be to have a 1,000mg Pet CBD so I could give her less, they custom made one for me and then added it to their products!
I love that they are local and their backstory for starting Cannafyl.”
We love hearing stories like this.
But individual experiences are not the same thing as clinical research.
What makes this story especially meaningful to us is that her veterinarian recommended CBD alongside her existing medications, which closely mirrors the way CBD has been studied in controlled canine epilepsy research.
Where Does Cannafyl PET Fit?
At Cannafyl, we do not position Pet CBD as a replacement for veterinary epilepsy treatment.
We believe in:
- Quality
- Transparency
- Consistent formulation
- Third-party laboratory testing
- Respect for veterinary care
- Following the science as it develops
Cannafyl PET is made with full-spectrum hemp extract for pet parents who choose to include CBD as part of their dog's overall wellness routine.
Questions to Ask Your Veterinarian
If your dog has epilepsy and you're considering CBD, ask your veterinarian:
- Could CBD interact with my dog's medications?
- Should medication blood levels be monitored?
- Should liver enzymes be checked?
- What signs of sedation or ataxia should I watch for?
- Could my dog's current medications affect CBD metabolism?
- What product information should I bring with me?
- How often should my dog be reevaluated?
Bring the CBD bottle and Certificate of Analysis if possible.
The Bottom Line
CBD and canine epilepsy is one of the more scientifically interesting areas of veterinary cannabinoid research.
Controlled studies have reported:
- Reductions in seizure frequency
- Fewer seizure days
- Meaningful responses in some dogs with drug-resistant epilepsy
But not every dog responds.
The studies remain relatively small.
And researchers are still trying to determine:
- Optimal dosing
- Therapeutic blood concentrations
- Which formulations work best
- Which dogs are most likely to respond
- How CBD interacts with conventional medications
- Long-term safety
So the responsible conclusion is not:
“CBD treats epilepsy.”
It is:
CBD is being studied as an adjunct to conventional anti-seizure medication, and several canine clinical trials have reported meaningful reductions in seizure frequency in some dogs.
That's encouraging.
And it gives researchers a very good reason to keep studying it.
This article is intended for educational purposes only and is not veterinary medical advice. Cannafyl PET is not intended to diagnose, treat, cure or prevent epilepsy or any other disease. Never discontinue or modify prescribed anti-seizure medication without veterinary supervision. Consult your veterinarian before introducing CBD to a dog with epilepsy, particularly if your dog takes prescription medications.
