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For dogs and cats · May 16, 2018

CBD for dogs and cats works, but only if you get the details right

Your dog and your cat process CBD completely differently, and if you’re not accounting for that, along with dose and product quality, it probably isn’t working.

Mixed breed dog by a windowsill cannabis plant — CBD dosing for dogs requires careful species-specific calculation

By Beryl Shuttleworth, BSc Hons Biochem

Last reviewed: 2026-06-12

CBD does show real promise for dogs and cats, but what works for people won’t automatically work for your pet. Both species process CBD quite differently from us, absorbing far less of it from each dose (dogs manage around 13-19%, cats even less), and every individual animal varies. Give too little and it won’t do much; give too much and it stops working properly, CBD has that kind of sweet-spot response curve. A full-spectrum extract tends to do better than pure CBD on its own, and one simple trick: always give it with food, which roughly doubles how much your dog actually absorbs.

If a dose works for your human, the same dose scaled by weight will work for your dog or cat

I completely understand why this feels logical. If a medicine works for a 70 kg human, surely you just scale it down for a 30 kg dog? It’s how we think about most things. But with CBD, that thinking breaks down, and it’s worth understanding why, because the consequences of getting it wrong are real.

Dogs and cats process CBD through different biological pathways than we do. Without getting too deep into the chemistry, the short version is this: the way your body breaks CBD down is not the same as the way your dog’s or cat’s body does it [1]. That matters because it changes how much of the active compound actually makes it into the bloodstream and for how long it stays there.

And the absorption figures are sobering. In dogs, only about 13-19% of an oral CBD dose is actually absorbed, and in some individual dogs, researchers couldn’t detect any CBD in the blood at all after dosing [3]. Cats absorb even less than dogs from the same dose and formulation, and vary enormously from one cat to the next [4]. So a human dose, even scaled by weight, isn’t landing in the same ballpark biologically, it might deliver only a small fraction of the exposure, or in some animals, barely anything at all.

There’s another twist that catches people out: CBD doesn’t behave like most medicines where more dose equals more effect. It follows a curve, efficacy rises to a sweet spot, then drops off again if you go too high or too low [2]. That means blind scaling could easily put you above the useful range, leaving you thinking the product simply doesn’t work, when the dose was actually the problem.

Then there are the practical things that shift the picture further still. Giving a dog CBD straight after a meal doubles the amount absorbed compared to dosing on an empty stomach [13]. In cats, the raw (unheated) acidic form of CBD, CBDA, builds up in the blood at roughly twice the level of regular CBD after repeated use [5]. None of this is accounted for by a simple weight-based calculation.

The honest takeaway: species, formulation, whether your pet has just eaten, and plain individual variation all play a significant role. A weight-scaled human dose is a rough upper ceiling at best, it’s not a dosing protocol.

How CBD and cannabinoids work in dogs and cats

Here’s the honest truth about CBD (cannabidiol) in dogs: only 13-19% of an oral dose actually makes it into the bloodstream, and in some individual dogs, researchers couldn’t detect any CBD in the blood at all after dosing. That’s because dogs have a very active liver that breaks down a large chunk of the CBD before it even gets a chance to circulate. Cats absorb it even less efficiently than dogs, with blood levels peaking around 2-3 hours after dosing and a wide spread of results between individual animals.

Dogs and cats also process CBD differently to us humans at a biological level, the main breakdown product you’d see in a person barely registers in dogs and cats, which tells us their bodies are handling it through different pathways entirely. It’s one of the reasons you can’t simply scale a human dose down to a pet dose and expect the same result.

One thing I think is genuinely underappreciated: the raw, unheated forms of cannabinoids, CBDA and THCA, are absorbed and held in the blood at roughly double the levels of their better-known counterparts (CBD and THC) in cats after repeated dosing. That’s worth thinking about when you’re choosing a product.

The dose-response relationship isn’t straightforward either. CBD follows an inverted-U curve, too little and it doesn’t work, too much and the effect drops off again. This applies across anxiety, pain, and seizure control. In dogs with difficult-to-treat epilepsy, a properly conducted crossover study at 9 mg/kg/day showed a meaningful reduction in seizure frequency compared to placebo, and blood level data suggests dogs who achieved at least 50% fewer seizures tended to have CBD concentrations above 400 ng/mL.

Two practical things that really shift how much CBD a dog absorbs: the carrier oil and whether they’ve eaten. MCT (medium-chain triglyceride) oil as the base helps absorption, and giving CBD alongside food roughly doubles the amount that gets into the bloodstream compared to dosing on an empty stomach. That’s not a minor detail, it can mean the difference between hitting a useful level and not.

On the question of full-spectrum versus isolate: in animal model studies, full-spectrum extracts containing a mix of phytocannabinoids and terpenes outperformed pure CBD isolate at the same CBD concentration for both pain and seizure outcomes. In one neuropathy study, pure CBD alone did nothing, but a complex hemp extract at the same CBD dose did reduce pain responses. Terpenes like limonene, myrcene, α-pinene, and β-caryophyllene appear to be active in their own right at very low blood concentrations, with anti-inflammatory and analgesic properties that don’t rely on the same receptors as cannabinoids. That said, the entourage effect evidence is still contested, some researchers argue that certain combinations could actually work against each other rather than together, so I wouldn’t treat it as settled science just yet.

How to use CBD in dogs and cats: What the research actually tells you

Dose with food, it makes a real difference

This one’s simple but important: giving CBD to your dog alongside food doubles how much of it actually gets absorbed compared to giving it on an empty stomach. That’s not a minor detail, it’s the difference between a dose that works and one that quietly does nothing. Always give CBD with a meal. Products made with MCT (medium-chain triglyceride) oil tend to support better absorption in dogs too, though every dog is different.

More isn’t always better, the sweet spot matters

CBD doesn’t work on a straightforward “give more, get more” basis. The dose-response curve is actually bell-shaped: too little doesn’t do much, but too much can lose its effect just as quickly. This pattern has shown up across anxiety, pain, and seizure research. So if you try bumping the dose and things seem *worse* rather than better, that’s likely why, ease back rather than pushing higher.

Dogs and cats are not the same, and neither is their CBD

Dogs and cats process CBD quite differently, they use different liver pathways from each other, and from us. Cats generally absorb far less CBD from an oral dose than dogs do, with bigger differences between individual animals. Cats also take around 2-3 hours to reach their peak blood levels after dosing. A dose that works for a dog is not a safe starting point for a cat, the gap really is that significant.

Worth knowing about CBDA (the “raw” form of CBD)

CBDA is the unheated, acidic form of CBD found in raw hemp. In cats given a CBD/CBDA-rich paste, CBDA reached roughly double the blood concentration of CBD after regular dosing. If you’re worried about your cat actually absorbing enough, which is a fair concern, a full-spectrum product that keeps CBDA alongside CBD is a much better choice than a pure CBD isolate. Full-spectrum extracts have also outperformed pure CBD isolate in animal pain and seizure research, at the same CBD concentration.

What the research actually says about doses (dogs)

– In a double-blinded epilepsy trial, 9 mg/kg/day produced a meaningful reduction in seizure frequency compared to placebo.
– Safety studies show single oral doses up to 62 mg/kg caused only diarrhoea; around 4 mg/kg/day seems well tolerated in healthy dogs over shorter-term studies.
– In a noise-fear study, 1.4 mg/kg showed no calming effect at all, rodent and human research suggests the effective threshold is likely higher, but no specific anxiety dose for dogs has been confirmed in a controlled trial.

I’m not going to hand you a single “use this amount” figure for dogs or cats, because the research genuinely doesn’t support one for most conditions yet. What it does support is starting low, giving it with food, and adjusting carefully based on what you actually observe, keeping that bell-shaped curve in mind.

Keep an eye on liver enzymes

Two separate studies picked up raised levels of a liver enzyme called alkaline phosphatase (ALP) in dogs taking CBD, one at 9 mg/kg/day for epilepsy, another at 2-2.5 mg/kg twice daily after surgery. Neither study found the other main liver marker (ALT) was raised alongside it, and nobody’s quite sure what it means yet. I wouldn’t ignore it, though. If your dog is taking CBD over a longer period, a routine liver cheque with your vet is just sensible.

Cats: take it steadier

Cats in a controlled study tolerated escalating doses up to 30.5 mg/kg with only mild, passing side effects. That said, MCT oil formulations caused more tummy upset in cats, and anything containing THC brought on lethargy and wobbliness. For a cat, especially one with a sensitive stomach, a pure CBD or CBD/CBDA product in a non-MCT base is the more comfortable option.

Please do loop in your vet

This isn’t a box-ticking disclaimer. CBD genuinely affects how the liver processes other drugs, so if your animal is on any medication at all, your vet needs to know CBD is in the mix too.

What we’d recommend


Herbal Pet Calming Chews

A gentle, well-tolerated blend to help take the edge off your pet’s anxious moments.

See the product

Frequently asked questions

Can I use the same CBD dose for my dog or cat as recommended for humans?

Short answer: no, and it’s more important than most owners realise. Dogs and cats process CBD differently to us, using different liver enzymes that produce different breakdown products at different speeds. Cats absorb noticeably less CBD through the gut than dogs, even at the same dose. So scaling a human dose down by bodyweight is really just a rough starting point. Treat your pet’s dosing as a completely separate exercise, and loop in your vet.

Does giving more CBD always produce a stronger effect?

Not at all, and this trips a lot of people up. CBD follows what scientists call an inverted-U dose-response curve, which just means there’s a sweet spot: too little and it doesn’t work, too much and it stops working again. This pattern has been seen across anxiety, pain, seizure control, and depression. Getting the dose right matters far more than simply giving more.

Is full-spectrum CBD better than CBD isolate for dogs and cats?

The evidence leans toward full-spectrum. In animal studies, full-spectrum hemp extracts outperformed pure CBD at the same concentration, in one nerve-pain model, pure CBD did nothing at all, while the full-spectrum extract genuinely helped. Plant compounds called terpenes (things like myrcene, limonene, and β-caryophyllene) appear to pull their own weight here, with their own soothing and anti-inflammatory properties. That said, not everyone agrees, some researchers argue certain combinations can actually work against each other, so it’s not a settled debate.

Does CBD help with seizures in dogs?

There’s real controlled evidence that it can. A double-blinded crossover study in dogs with epilepsy found that 9 mg/kg/day of CBD cut seizure frequency significantly compared to a placebo. Dogs whose blood CBD levels climbed above 400 ng/mL were the ones most likely to see at least a 50% drop in seizures. Worth knowing: liver enzyme levels should be monitored with long-term use.

Is CBD safe for dogs and cats, what side effects should I watch for?

Generally, yes, side effects are mild and uncommon. In dogs, loose stools or vomiting turn up in somewhere between 0.45% and 3.3% of cases, and even very high single doses mainly just caused diarrhoea. The thing worth keeping an eye on is a consistent finding of raised alkaline phosphatase (a liver marker) with longer-term use, we don’t yet know how significant that is. Cats handled escalating doses well too, though MCT oil-based products caused more tummy upset, and anything containing THC could cause wobbliness and lethargy.

Does it matter whether I give CBD with food or on an empty stomach?

It matters a lot, actually. Giving CBD with food doubles how much your dog absorbs compared to dosing on an empty stomach. That’s a big deal when you consider that dogs only absorb 13-19% of oral CBD to begin with, and some individual dogs absorb barely any at all. Food and formulation aren’t minor details; they directly decide whether your dog gets a useful dose.

Should I consider CBDA rather than CBD for my pet?

It’s well worth knowing about. CBDA is the raw, unheated form of CBD found in fresh hemp, and in both dogs and cats it reaches roughly double the blood concentration of regular CBD after repeated dosing, meaning the body holds onto it more efficiently. Most commercial products are heat-processed, which converts CBDA into CBD, so if you want higher CBDA levels you need a raw or minimally processed product like a hemp paste. It’s a real, measurable difference, not just marketing.

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