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CBD Oil for Dogs and Cats: What You Need to Know

CBD (cannabidiol) oil is gaining popularity for pet pain relief, but is it safe to use? Read on to learn more about CBD oil for dogs and cats.

CBD oil for dogs
CBD oil for dogs and cats hasn’t been studied enough for veterinarians to recommend it using evidence-based science. Photo: Pixabay

Do you want to help your sick pet get better?

Of course you do.

But sometimes modern medicine doesn’t deliver the hoped-for results or is too expensive. So one of my clients may decide to try home therapy. This could be why CBD oil for pets is gaining ground as a “cure-all.”

Does CBD oil really work for dogs and cats? What’s the truth?

This article draws together what we know about CBD oil, the evidence (good and bad) for its efficacy and what every caring pet lover needs to know before giving CBD oil to their furry friend.

An Eye-Opening Story

I became interested in CBD oil for dogs because of Tracy, a Lurcher with a seizure disorder.

Tracy is 12 years old and has had serious clusters of seizures for half her life. These are severe seizures, close to life-threatening status epilepticus.

Serious Seizures

To control them, Tracy takes high doses of phenobarbitone and potassium bromide.

But these meds left her disorientated, wobbly and very thirsty — so thirsty that she wet herself, which meant taking another medication to control urinary incontinence.

Drop the dose of the meds down, and Tracy seizured …

But at a routine checkup, Tracy was brighter and more alert than normal.

It transpired that over the past few months, the client had slowly dropped the bromide down and then stopped it. The incontinence had improved so much that he’d also stopped that medication. And now he was reducing the dose of phenobarbitone.

All he’d done instead was add in CBD oil.

CBD oil may give pets the pain relief they need, but talk with your vet before giving it to your dog or cat — it may not interact well with other medications. Photo: CAPJAH

A Gamble

I was horrified. Changing Tracy’s meds risked life-threatening seizures.

But you know what? Tracy was doing better than she’d ever done before.

What’s going on?

The only change was the client had started giving CBD oil for dogs. This needed looking into.

We ran a blood test to monitor the levels of phenobarbitone in Tracy’s blood. Despite the lower dose of meds, the blood levels were a third higher than before. In fact, they were now at toxic levels.

An educated assumption would be the CBD oil was somehow “potentiating” (strengthening) the effect of the phenobarbitone. Again, this is a guess — I have no way of knowing for sure.

But we certainly needed to reduce Tracy’s phenobarbitone dose even further to get it out of the danger level.

Please Don’t Do This at Home

Please don’t misunderstand — I’m not suggesting people play around with their pets’ medication — this is potentially very dangerous indeed.

No, the moral of this story is twofold.

  1. The effects of CBD oil for dogs may be beneficial in some cases and definitely need investigating.
  2. But be careful! CBD oil may (no one knows) beef up other drugs to toxic levels.

In my limited experience of one case, CBD oil for dogs with seizures appears to have helped in this one — and I stress one — case. Drawing assumptions based on one case is dangerous and bad science.

So is there any data to back up these observations? Let’s look at what is known to date.

Does CBD Oil Really Work for Dogs?

Short answer: Maybe.

Long answer: Modern veterinary medicine is about evidence-based science. Sadly, much of the information about CBD oil for pets is anecdotal. A responsible vet does not consider anecdotal evidence a sufficient basis to recommend a product to clients.

For a long time, the laws governing marijuana and controlled drugs got in the way of research for pets. For this reason, most of the work into medicinal CBD oil has been done in the human field.1 Thus there’s a lack of information about pets.

Is it safe to assume what applies to people is the same for cats and dogs? No. (Just think Tylenol in cats or chocolate in dogs for evidence of this.)

Research needs to be done in the veterinary field. This is starting to happen, with a trial now taking place at Cornell University.2,3

But in the meantime, vets are unlikely to recommend CBD oil for dogs or cats because not enough is known about its use and, importantly, its safety.

Cannabidiol (CBD) is a naturally occurring substance found in the cannabis plant. Photo: Pixabay

What Is CBD Oil for Dogs?

But perhaps we’re getting ahead of ourselves. What is CBD oil for dogs?

CBD stands for “cannabidiol” and is a naturally occurring substance found in cannabis plants. The reason for the controversy is that cannabis contains other substances, the most notorious being THC (tetrahydrocannabidiol), which is psychoactive.

What’s important to understand is the CBD oil does not contain significant levels of THC. Therefore, while it has medicinal benefits, it doesn’t give the patient the “high” of THC.

Comfort, Not Cure

What conditions respond to CBD oil for dogs?

The current state of knowledge is that CBD oil may help ease discomfort, but it does not cure conditions.

It has anti-inflammatory and anti-anxiety properties.

CBD Oil in Dogs

  • Is CBC oil effective for dogs with seizures? This is an exciting (but unproven) avenue for further research.
  • Is CBD oil effective for dogs with anxiety? CBD oil has calming properties.
  • Does CBD oil help dogs with allergies?  It seems unlikely the anti-inflammatory effect of CBD oils is such that it might give some relief from allergies.
  • Does CBD oil help for dogs with arthritis? This is the subject of the research at Cornell University, and the results seem to say that, yes, CBD oil helps with certain types of pain.3

CBD Oil for Cats

What about our feline friends: Is CBD oil OK for cats?

Again, given the lack of hard scientific information, it seems CBD oil is safe for cats.

This is down to the lack of THCs, which are toxic.

Again, it seems inflammation, pain and anxiety are the symptoms most likely for to respond to CBD oil for cats.

The Side Effects of CBD Oil

Is CBD toxic to cats or dogs?

When given an appropriate dose (see below), the risks appear low. Some pets may get diarrhea, but stop the CBD oil, and this resolves. Other issues include:

  • Dry mouth
  • Drowsiness
  • Low blood pressure

But things may not be this simple.

For example, we don’t know what effect CBD oil for dogs has on other medications, such as epilepsy drugs — hence one of the reasons more research is needed.

CBD oil may help dogs with arthritis and anxiety. Photo: Pixabay

CBD Oil Dosage

How much CBD is safe for dogs? There are different ways of thinking about this.

Also, how much CBD oil would be toxic?

It’s the THC part that’s toxic. An average CBD oil contains a low level of THC (around 0.3%). An average CBD pet treat contains a scant 2.5–5.0 mg per treat (or 0.005 g per treat).

The toxic dose of THC is 3 g/kg. This means a 10 kg dog would need to eat around 6,000 treats to reach a toxic dose.

CBD oil contains around 90 mg (0.09 g) of THC per milliliter. Thus, a 10 kg dog would need to consume 333 mL (about the same amount as a can of fizzy drink) for a toxic effect.

However, this takes no account of how CBD oil might affect other drugs!

CBD Oil for Dogs Dosage Chart

Current data4 suggest a dose of 0.02 mg/kg to 0.1 mg/kg of CBD oil twice a day. For pain relief:

  • Dogs: 0.05 mg/kg twice a day
  • Cats: 0.025 mg/kg twice a day

Know that the Cornell Study suggests3:

  • Dogs for arthritis relief: 2 mg/kg CBD oil twice a day

Buyer Beware

CBD oil for dogs is not regulated by the FDA. This has 3 implications:

  1. You give the CBD oil at your own risk and have no legal protection against any adverse reactions.
  2. The content of the bottle isn’t regulated (i.e., the strength of active CBD oil inside varies). Indeed, in spot tests by the FDA, some CBD oils contained no CBDs!5 Buyer beware.
  3. The contents may include harsh chemicals used for processing, which are in themselves toxic.

Organic CBD Oil for Dogs

Is CBD good for dogs? Only if it doesn’t contain toxic chemical contaminants.

Some synthetic CBD oils are made using chemical distillation. The purity of these distillations can’t be guaranteed, which means you could be dosing your pet with some nasty stuff.

To avoid this, opt for the organic CBD oil that has been processed sympathetically.

Also, a big thing to be aware of: The use of medical marijuana or cannabis products is not legal in all states.6

Listen to these veterinarians discuss the benefits and risks of recommending cannabis products for pets:

YouTube player

Safe Use of CBD Oil for Dogs and Cats

If you’re serious about CBD oil, seek out a manufacturer of organic CBD oil. Then ask for a certificate of purity.

This should show lab test results that confirm the CBD and THC content. This is your guarantee that the product contains what it says on the label. There are also CBD oils that contain no THC.

Yes, this oil is more expensive, but what’s the price on peace of mind? Not only does it reduce the risk of accidental overdose, but also you’ll be able to give a consistent dose each time.

So yes, you want to help your sick pet feel better … but do so safely. If the pet is already on medication, speak to your vet first and be aware of the potential for toxic consequences.

CBD oil does appear to hold promise as a useful therapy, but sadly, at the moment, there are too many unknowns to recommend its use.


  1. Bergamaschi, Mateus M., PhD, et al. “Safety and Side Effects of Cannabidiol, a Cannabis Sativa Constituent.” Current Drug Safety 6, no. 4 (Sept. 1, 2011): 237–249.
  2. Wooten, Sarah J., DVM. “Cornell Takes the Lead in Cannabidiol Research.” DVM360. May 9, 2018.
  3. Bradford, Brady. “CHF Announces Funding for Clinical Trial to Study Cannabidiol to Treat Drug-Resistant Epilepsy in Dogs.” American Kennel Club Canine Health Foundation. Sept. 6, 2017.
  4. Petty, Michael, DVM, CVPP, CVMA, CCRT, CAAPMA. “Cannabidiol: A New Option for Pets in Pain?” DVM360. Aug. 2, 2017.
  5. “Statement by FDA Commissioner Scott Gottlieb, M.D., on the Importance of Conducting Proper Research to Prove Safe and Effective Medical Uses for the Active Chemicals in Marijuana and Its Components.” FDA. June 25, 2018. FDA report (archived).
  6. “State Medical Marijuana Laws.” National Conference of State Legislatures. Feb. 11, 2019.
vet-cross60pThis pet health content was written by a veterinarian, Dr. Pippa Elliott, BVMS, MRCVS. It was last reviewed Feb. 21, 2019.

If you have questions or concerns, call your vet, who is best equipped to ensure the health and well-being of your pet. This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. See additional information.