Seizures

A neurological event in dogs, and a topic where hemp is not a treatment and prescribed anticonvulsants must never be changed without a veterinarian.

Calm healthy dog resting on a blanket with an owner's hand resting gently on its shoulder

Seizures in Dogs and What the Hemp Research Actually Shows

Read this part first. Hemp is not a treatment for epilepsy, and no hemp product — including ours — should ever replace or reduce a prescribed anticonvulsant. Stopping or lowering seizure medication without your veterinarian is one of the most dangerous things an owner can do.

With that said, this is a topic owners research constantly, and most of what is written about it misrepresents the science. Here is what the trials actually found.

If Your Dog Is Seizing Right Now

Keep your hands away from the mouth, move furniture away, note the time, and let it run. A seizure lasting more than about five minutes, or a cluster of seizures without full recovery between them, is an emergency — go to a veterinary hospital.

Afterwards, dogs are commonly disoriented for minutes to hours. That is normal and not itself an emergency.

The Study Everyone Quotes, Quoted Accurately

A 2019 Colorado State University trial gave 2.5 mg/kg of CBD twice daily for twelve weeks alongside existing medication in dogs with drug-resistant idiopathic epilepsy. Sixteen dogs were analysed.

The CBD group's median seizure frequency fell from 4.0 to 2.7 per month — a 33% reduction, statistically significant at P = 0.01. That figure is everywhere in hemp marketing.

What almost nobody reports is the next sentence. The proportion of dogs that responded — meaning at least a 50% reduction — did not differ from placebo: two of nine on CBD versus two of seven on placebo. The authors wrote that the proportion of responders was similar between groups. A within-group change over time is not the same as beating placebo on the endpoint that matters.

The Larger Trial

A 2023 crossover trial was bigger — 51 dogs completing. Its lower arm, roughly 5 mg/kg daily, showed no treatment effect at all. At 9 mg/kg daily, seizure days fell 24.1% on CBD against a 5.81% rise on placebo, which was significant.

And again the responder analysis was null. The liver findings were substantial: mean alkaline phosphatase rose from 278 to 1,585 IU/L at three months, with 24 of 30 dogs that started with normal ALP exceeding twice the upper reference limit. Decreased appetite and vomiting were both significantly more common on CBD. The authors concluded that liver enzymes should be monitored.

The One Trial That Found a Responder Difference

A 2022 study of a CBD:CBDA preparation in fourteen dogs did find a significant responder difference — six of fourteen against none on placebo. It is the only canine trial to show that, and it is also the smallest, with no washout between arms. Two authors were employed by the company whose product was tested, which the paper discloses. Worth knowing, in both directions.

What a Systematic Review Concluded

In 2025, researchers assessed the whole canine evidence base with formal risk-of-bias methods. Only three randomised controlled trials qualified, and all three were rated at moderate-to-high risk of bias. Their conclusion was that it is not possible to draw conclusions concerning the efficacy and potential adverse effects of CBD as a supplementary treatment for refractory idiopathic epilepsy in dogs.

That is the current honest state of the evidence. Promising enough to keep studying; nowhere near enough to act on alone.

Interactions With Seizure Medication

A controlled study of CBD alongside phenobarbital in healthy dogs found no significant pharmacokinetic interaction, and the authors did not recommend adjusting either drug on that basis. But five of nine dogs became hypoxic at the higher amounts tested, and four had markedly raised ALP.

The 2023 trial found no statistically significant change in any anticonvulsant level, but individual variation was enormous — phenobarbital ranged from −42% to +144%, and levetiracetam from −88% to well over +1,000%. The authors called for continued investigation.

The realistic concern is not a proven drug interaction. It is additive load on the liver, since both CBD and phenobarbital independently raise liver enzymes. That makes baseline and follow-up bloodwork, ordered by your vet, the sensible precaution.

What We Are and Are Not Saying

Our full-spectrum hemp products are daily wellness supplements. They are not anticonvulsants, they are not a treatment for epilepsy, and the research above does not establish that they reduce seizures.

If your dog has epilepsy, the conversation is with your veterinarian or a veterinary neurologist — including whether a supplement has any place alongside the medication your dog is already on. Bring the studies. Do not bring a marketing page.

Frequently Asked Questions

Does CBD help dogs with seizures? The evidence is genuinely unsettled. Two trials found reductions in seizure frequency measures, but neither showed a significant difference in the proportion of dogs that actually responded, and a 2025 systematic review concluded no firm conclusions can be drawn.

Can CBD replace my dog's seizure medication? No. Never stop or reduce a prescribed anticonvulsant without your veterinarian — withdrawal can trigger severe or life-threatening seizures.

Can it be given alongside phenobarbital? That is a question for your vet. Studies have not detected a significant interaction, but individual variation was very wide and both raise liver enzymes, so bloodwork monitoring is the standard advice.

What amounts were used in the research? 2.5 mg/kg twice daily in the 2019 trial, and about 9 mg/kg daily in the 2023 trial, both under veterinary supervision alongside existing medication. Those are research protocols, not serving recommendations.

Does it affect the liver? Elevated alkaline phosphatase is the most consistent finding across canine studies, and in the larger trial the majority of dogs exceeded twice the reference limit. Ask your vet about baseline and follow-up liver panels.

Can CBD cause seizures in dogs? There is no evidence it triggers seizures. The documented risks are digestive upset, drowsiness and liver enzyme elevation.

How long would it take to know? The trials ran twelve weeks. Anything shorter tells you little, especially given how much seizure frequency varies naturally.

What should I do during a seizure? Keep clear of the mouth, clear the area, time it. Over five minutes, or clusters without recovery between, means emergency care.

Is full-spectrum or isolate better here? No canine trial has compared them for this. The one study showing a responder difference used a CBD:CBDA preparation. See full-spectrum hemp extract.

Further reading: the AKC Canine Health Foundation on the CBD evidence and the AVMA on cannabis and pets.