Calming CBD for Dogs: Research, Timing and Safety

Quick answer

CBD is a compound from hemp used in pet products intended to support normal calm. It is not FDA-approved for use in dogs, and these products are not treatments for any disease. Drowsiness can occur, and research has not established a predictable calming response in dogs, or how many hours any response lasts after a dose. Choose a THC-free pet product with a certificate of analysis, never human gummies, and ask your vet first if your dog takes medicine.

On this page

• Research
• How long CBD stays in the blood
• Dose
• Forms
• Gummies and THC
• Fireworks and storm checklist
• Car, vet, time alone
• Your vet
• Safety
• What to record
• Choosing
• FAQ

Does CBD calm dogs? What the research actually tested

A small number of controlled studies have tested CBD in dogs, the largest with 54 dogs, and they have not established a predictable calming response. The studies differ in the dogs used, the products, the dosing schedules and what was measured, which limits direct comparison; several were funded or run by companies with commercial interests.

This table describes how the studies were run and their limits; it is not a review of their findings.

Study	Dogs	CBD dose and timing	Situation	What was measured	Limits	Funding and authors
Morris 2020	16 shelter-sourced dogs that reacted to a fireworks recording at screening	CBD treats, about 1.4 mg/kg a day in two halves for 7 days, given 4 to 6 hours before the test; a prescription medicine, and CBD with that medicine, were also compared	A 6-minute test: 3 quiet minutes, then 3 minutes of recorded fireworks	Video-scored behavior, heart rate, blood cortisol	A recorded noise, not a real fireworks night; low dose; a dose-to-test gap set before dog blood-level data existed; no washout between test periods	Funded by AgTech Scientific, the hemp extract supplier, which the paper says had no role in the design, analysis or writing; university authors declared no conflicts
Hunt 2023	40 healthy research-colony dogs (Labradors, Beagles, Norfolk Terriers); 20 got CBD, 20 a placebo	One soft gel of THC-free CBD distillate, about 4 mg/kg (about 1.8 mg per lb), with breakfast, 2 hours before the test	45 minutes alone in a familiar room (21 dogs) or a 10-minute car ride (19 dogs)	Cortisol, heart rate and other stress measures; skin-surface temperature; behavior rated by observers who did not know which dogs got CBD	Colony dogs, not pets chosen for trouble in these situations; small groups; one product	Funded by Mars Petcare; all authors employees of Mars Petcare UK
Flint 2024	19 dogs from the same colony (9 CBD, 10 placebo)	About 4 mg/kg once a day with breakfast for 6 months; rides 2 hours after the dose	A short car ride at weeks 0, 8, 16 and 24	Cortisol, heart rate, whining, lip licking, yawning, blinded behavior ratings	Once-daily dosing; small groups; colony dogs	Funded by Mars Petcare; all authors employees of Mars Petcare
Flint 2025	54 colony dogs, each given every treat in turn (crossover)	One treat 2 hours before the ride: placebo, CBD 2 mg/kg, CBD 4 mg/kg, or CBD 2 mg/kg with L-tryptophan and alpha-casozepine	A 10-minute car ride	Blood CBD, cortisol, heart rate, posture, behavior ratings	Blood CBD after the same dose varied widely between dogs; the authors say the treat format may lower absorption	Funded by Mars Petcare; all four authors employed by Mars Petcare
Bradley 2022	40 healthy dogs (20 CBD, 20 placebo)	THC-free CBD capsule, 4 mg/kg once a day for 6 months, then 4 weeks off	Daily life; a tolerance study with no stress test	Bloodwork, including liver values, and general health	Healthy dogs; one product; once-daily dosing	Funded by Mars Petcare; all nine authors listed as Mars Petcare employees

The Waltham authors say their findings need confirming in pet dogs at home and warn against applying them to other products.

How long does CBD last in a dog? What blood levels show

Research has not established how many hours a calming response, if any, lasts after an oral CBD dose in dogs. Blood levels have been measured: across the dog studies summarized by the Merck Veterinary Manual, CBD peaked 1.2 to 6.2 hours after an oral dose, and its half-life, the time for the level to fall by half, ranged from 0.5 to 5.8 hours. Blood levels cannot be used to calculate how long a behavioral response lasts.

Individual studies mostly put the peak at about 1.5 to 3 hours. Two recent ones reported half-lives of about 8.5 to 10 hours, and the half-life lengthens over months of daily dosing.

What the blood numbers can and cannot tell you

Measurement	What it tells you	What it does not tell you
Time to peak	When the blood level is highest after an oral dose	When, or whether, a dog’s behavior changes
Half-life	How fast the blood level falls after the peak	How many hours any change in behavior lasts
Repeated-dose levels	Whether levels build up with daily dosing; trough levels settle after about 2 weeks	Whether any change in behavior builds, lasts or fades

Study dosing schedules varied. The Waltham studies gave their test products about 2 hours before the research procedure, while Morris and colleagues gave CBD treats about 4 to 6 hours before the recorded-fireworks test. These schedules were chosen for individual experiments and do not establish an optimal time to give CBD to other dogs or with other products. For daily use, give it at the same times each day, as the label directs.

Does food matter?

Food can change how much CBD is absorbed: in one small 2026 pilot (5 dogs, one product, one dose), peak blood levels were much higher with food than fasted (643 percent higher), a difference not to assume for other products. The main event study gave the dose with breakfast; follow your product’s label.

Does the form change it?

In the comparisons cited here, regular CBD oil did not show a statistically clear faster time to peak than the chews or treats tested. How much CBD was absorbed differed between formulations, so these numbers cannot be applied to every product.

How much to give

There is no FDA-approved canine CBD dose: use an amount your veterinarian confirms, and the bottle’s actual CBD concentration when you convert it to mL. Amounts are not always comparable, because some labels report milligrams of CBD while others report milligrams of hemp extract, which contains several cannabinoids. For example, if an extract is 45 percent CBD, 1 mg of extract carries about 0.45 mg of CBD. For amounts by weight and the mL for your bottle, use our CBD dosage calculator. The studies in the table used about 1.4 to 4 mg of CBD per kg; those were research doses, not recommendations. For the basics, see our guide to CBD for dogs.

Oil, chews or gummies?

All three can deliver CBD; they differ in how the dose is measured and what else is in them.

Form	How the dose is measured	What to check
CBD oil	In mL or drops, from your dog’s weight and the oil’s strength	mg of CBD per mL on the certificate of analysis
Pet chews or treats	A fixed amount per chew; halving is the only adjustment	mg of CBD per chew; store out of reach, since a dog may eat the whole bag
Pet gummies	A fixed amount per piece	Made for dogs, with no xylitol
Human CBD gummies	Sized for people	Never for dogs: see the next section

Human CBD gummies and THC: the danger

Never give your dog CBD gummies or other edibles made for people: they may contain THC or xylitol, both poisonous to dogs, and they are dosed for people.

If your dog ate one, call your vet, an emergency clinic or an animal poison control center right away, with the package in hand. Don’t wait for signs: FDA notes some serious effects of xylitol may not show for 12 to 24 hours.

THC poisoning: signs usually start within 1 to 2 hours (up to 4 on an empty stomach) and usually pass in 1 to 3 days. The most common are sleepiness, a wobbly walk and vomiting; dribbling urine, jumpiness to movement and sound, and trembling can also occur. THC is not a calming option: dogs have a high concentration of the CB1 receptors THC acts on in two parts of the brain, and FDA has approved no THC product for veterinary patients.

Xylitol poisoning: blood sugar can drop within 10 to 60 minutes; signs start with vomiting, then weakness, staggering, collapse or convulsions. Xylitol turns up in sugar-free gum and candy, chewable vitamins, some supplements and some peanut butters, so check the label of anything you hide a dose in.

Hemp seed oil is not CBD oil. FDA says hemp seed ingredients, the oil included, contain only trace amounts of CBD and THC.

Fireworks and storm checklist

Start weeks ahead; on the night, keep your dog indoors with a place to retreat, masking sound and someone at home.

Weeks ahead (months, if you can)

• If past fireworks or storms brought panic, book your vet now: the British Small Animal Veterinary Association advises several months ahead, Cornell at least a week before the event or storm season.
• Start sound training: recordings so quiet that your dog stays at ease, paired with treats or play, raised very slowly. A 2023 review says training with recordings has been considered the gold standard.
• Set up a hiding place in a familiar room far from the noise, with few or no windows. Use a covered crate only if your dog already treats it as a safe spot, door open.
• Practice with any pressure wrap or pheromone diffuser on quiet days; some dogs dislike a wrap’s handling or Velcro noise, and BSAVA lists pheromones as an add-on in appropriate cases.

A few days ahead

• Update ID tag and microchip details and secure your home and yard; frightened dogs may bolt and get lost.
• Plan to be home, or arrange a pet sitter your dog knows.

The day of

• Walk, play and take bathroom breaks early; if you must go out after the noise starts, use a leash, even in a fenced yard.
• Before it starts, close windows and blinds, open the hiding place and start masking sound. Riemer suggests a sound like the noise, such as a loud fan or drumbeats; Cornell suggests white noise and music.
• Have a long-lasting food toy ready, and give any prescribed event medicine early, before the noise.

During

• After each bang, toss a treat or start a game if your dog will eat or play. Refusing a favorite treat signals high stress; note it for your vet.
• Comfort your dog if it comes to you, but don’t force contact or pull it out of hiding; a panicking dog may bite even someone trying to keep it safe. Never punish.

After

• Write the night down; if it went badly, talk to your vet before the next event.

A storm with no warning

• Open the hiding place and start masking sound right away; Cornell notes that air pressure changes or wind gusts may be triggers too.

Car rides, vet visits and time alone

For car rides, practice in small steps that keep your dog feeling safe, and if your dog vomits in the car, ask your vet how to time food and any dose. Before a vet or grooming visit, tell the clinic what you gave and when, and ask about a pre-visit plan if visits are hard. For time alone, ACVB (the American College of Veterinary Behaviorists) starts with a vet check, then very short departures lengthened gradually at your dog’s pace. Do not assume a crate is the safest option: ACVB notes that crating often makes this worse, so discuss your dog’s response with your vet.

When your vet may need to help

Your vet can prescribe medicine for noise events and for dogs who struggle when left alone, usually alongside a behavior plan. Event medicine is tried on a quiet day first.

AVSAB says medication should not be a last resort for serious behavior problems, and your vet may refer you to a veterinary behaviorist. See your vet before trying any supplement if your dog’s behavior changes suddenly, if there is new growling, snapping or biting, or if your dog panics or hurts itself when left alone or during noise. An older dog who is newly restless, especially at night, should see the vet first too: this can have a medical cause. CBD does not replace veterinary care.

Is daily CBD safe? Can too much hurt?

Healthy dogs tolerated daily CBD at 4 mg/kg for 6 months and at 5 or 10 mg/kg for 36 weeks, with softer stools at 10 mg/kg and more drooling at 12 mg/kg in a 28-day study. Large overdoses mostly cause mild stomach upset; the bigger dangers are THC, xylitol and interactions with medicines.

A rise in ALP is not by itself liver damage. ALP, an enzyme made by the liver and by bone, was the change seen most often: in the 6-month study it rose for a time in just over half the dogs on CBD, other liver values did not change, and the bone form rose in step. Merck calls these rises transient and says liver monitoring might be indicated with long-term use; tell your vet before any bloodwork.

Drowsiness and wobbliness. Drowsiness is the side effect vets report most often. Marked drowsiness, trouble walking, trembling or unusual behavior after any cannabinoid product needs your vet’s advice; it does not show that the CBD dose alone was too much, since Merck links such signs in poison-center cases to THC or other contaminants, and another medicine or an illness can cause them. Stop further doses until you have advice, and have the package and its lab report ready.

Medicines. CBD shares liver enzymes (cytochrome P450) with many drugs, and in lab tests it blocked some dog enzymes that handle other drugs, which the authors say needs confirming in living dogs. In people, FDA warns that CBD with other drugs that slow brain activity raises the risk of sleepiness.

These were healthy dogs and specific products, so the studies do not show that CBD is safe for a dog with other health problems or medicines, or for a different product. FDA recommends talking with your veterinarian about your pet’s options.

More on side effects: Is CBD safe for dogs?

What to record and discuss with your veterinarian

Keep a written record and share it with your vet; notes made at the time beat memory. In placebo-controlled veterinary studies, 30 to 50 percent of owners whose animals received a placebo report improvement.

Write down the trigger and its timing; any dose, its time and whether it was with food; how long your dog took to settle; trembling, panting, pacing, drooling, hiding, digging at doors or trying to escape (signs Cornell lists); appetite and sleep; and any drowsiness or wobbliness, which is a side effect to report.

Choosing a calming product

Choose a THC-free product made for dogs, with a current certificate of analysis showing a batch number that matches your bottle, mg of CBD per mL or per chew, THC not detected, contaminant tests including heavy metals, and a recent test date. Quality varies: in a 2020 analysis of 29 dog CBD products, only 10 of the 27 that stated an amount were within 10 percent of their label for total cannabinoids, two had none, and four had heavy metals; the products were bought before February 2020, and three of the authors had ties to a CBD company. Also look for no xylitol and no disease claims. The NASC Quality Seal adds an independent audit and random testing against label claims. Our buyer’s guide walks through all seven checks.

Keep reading

CBD for Dogs

CBD for dogs: the full guide

Is CBD Safe for Dogs?

Is it safe? Side effects

How to Choose a CBD Product

Choose a quality product

Frequently asked questions

References

Sources checked November 2026. Studies are listed by author, journal and year; funding is in the study table.

1. Morris EM, et al. Frontiers in Veterinary Science, 2020.
2. Hunt ABG, et al. Frontiers in Veterinary Science, 2023.
3. Flint HE, et al. Journal of Animal Science, 2024.
4. Flint HE, et al. Frontiers in Veterinary Science, 2025.
5. Bradley S, et al. Frontiers in Veterinary Science, 2022.
6. Gamble LJ, et al. Frontiers in Veterinary Science, 2018.
7. Deabold KA, et al. Animals, 2019.
8. Wakshlag JJ, et al. Frontiers in Veterinary Science, 2020a.
9. Limsuwan S, et al. Frontiers in Veterinary Science, 2024.
10. Kamutchat P, et al. Animals, 2025.
11. Corsato Alvarenga I, et al. Frontiers in Veterinary Science, 2023.
12. Vaughn DM, et al. American Journal of Veterinary Research, 2021.
13. Schofs L, et al. Veterinary Research Communications, 2026.
14. Vaughn D, et al. Frontiers in Veterinary Science, 2020.
15. Corsato Alvarenga I, et al. Journal of Veterinary Internal Medicine, 2024.
16. Court MH, et al. Journal of Veterinary Pharmacology and Therapeutics, 2024.
17. Wakshlag JJ, et al. Veterinary Medicine: Research and Reports, 2020b.
18. Kogan L, et al. Frontiers in Veterinary Science, 2019 (vol 5, 2018).
19. Riemer S. Animals, 2023.
20. Merck Veterinary Manual. Toxicosis in Dogs and Cats From Cannabidiol (CBD), February 2026.
21. Merck Veterinary Manual. Toxicosis in Dogs and Cats From Tetrahydrocannabinol (THC), February 2026.
22. US Food and Drug Administration. Paws Off Xylitol; It’s Dangerous for Dogs, 2025.
23. US Food and Drug Administration. What You Need to Know (And What We’re Working to Find Out) About Products Containing Cannabis or Cannabis-derived Compounds, Including CBD, 2020.
24. US Food and Drug Administration. FDA Regulation of Cannabis and Cannabis-Derived Products, Including Cannabidiol (CBD), question 12, 2024.
25. British Small Animal Veterinary Association. Fireworks and thunder (position statement), October 2026.
26. Cornell University Riney Canine Health Center (Cohen A, Anderson K). Web page for dog owners on fireworks and thunderstorms, undated.
27. Cornell University College of Veterinary Medicine (Kaplan L). Press release with fireworks tips for pet owners, undated.
28. American College of Veterinary Behaviorists. Behavior Basics: My dog cannot be left home alone! (client handout).
29. American Veterinary Society of Animal Behavior. Position Statement on Humane Dog Training, 2021.
30. VCA Animal Hospitals (LifeLearn). Melatonin (client drug handout).
31. National Animal Supplement Council. NASC Quality Seal.

This guide is educational and is not a substitute for veterinary diagnosis or care. If you are worried about your pet, talk to your veterinarian.