Study review: 5 published studies on the safety of CBD for dogs

Randomized, placebo-controlled, 28-day safety and pharmacokinetics evaluation of repeated oral cannabidiol administration in healthy dogs

Study Method:

  • Twenty-four young, healthy, purpose-bred research Beagles were chosen for this study. 20 of those were picked to proceed to testing.
  • Researchers gave the dogs a single dose of full spectrum CBD per day for 28 days. Doses of various strengths were tested in different dogs, up to a maximum dosage of 12 mg/kg.
  • “Outcome variables were assessed through daily health observations, veterinary examinations, CBC, and serum biochemical analysis.”
  • The CBD used in this study was made from hemp grown by Canopy Growth and extracted using CO2. That full-spectrum CBD extract was infused into an MCT carrier oil.

Study Results:

  • “CBD administration was well tolerated by dogs, with no clinically important changes in measured safety outcomes.”
  • At higher doses, researchers observed mild side effects from CBD, including “gastrointestinal adverse events (mainly hypersalivation) and significantly higher serum alkaline phosphatase activity.”
  • “Within each CBD dose group, repeated administration increased total systemic exposure.”
  • But, after around 2 weeks, the low points of CBD concentration between doses reached a “steady state.” That means a consistent amount of CBD was always detectable in the dogs.

Date: 25 July 2023
Publication: American Journal of Veterinary Research
Authors: Vaughn, Dana M., Lina J. Paulionis, and Justyna E. Kulpa
Full study:

Long-term daily feeding of cannabidiol is well-tolerated by healthy dogs

  • 40 dogs were given a daily capsule containing 4 mg/kg of CBD, for a 6-month period, with regular vet checkups and blood tests throughout the study.
  • The researchers found that around half the dogs in the study have raised levels of the liver enzyme alkaline phosphatase (ALP), but didn’t see any associated negative effects on dogs’ health or well-being.
  • There were no other side effects observed, so the study concluded that long-term CBD supplementation and the recommended dosage is safe for dogs.

Date: 21 September 2022
Publication: Frontiers in Veterinary Science
Authors: Bradley S, Young S, Bakke AM, Holcombe L, Waller D, Hunt A, Pinfold K, Watson P, Logan DW
Full study:

Preliminary investigation of the safety of escalating cannabinoid doses in healthy dogs

Researchers gave 20 beagles one of three types of cannabis oil from Tweed Inc. One type was a full-spectrum CBD oil, the second was THC oil, and the third contained a 60/40 blend of CBD and THC.

After giving the dogs different dosages of the three oils over several days and monitoring the dogs’ health, researchers found that CBD oil was as well tolerated as a placebo oil, even in huge doses as high as 62 mg/kg. At higher doses, some of the dogs began to experience mild side effects, which mainly consisted of nausea and diarrhea.

The researchers also found that cannabis oils containing above-trace amounts of THC are likely to cause adverse neurological effects. One dog taking THC oil experienced severe ataxia. Two dogs taking CBD/THC oil experienced severe ataxia and lethargy.

Date: 11 February 2020
Publication: Frontiers in Veterinary Science
Authors: Vaughn, Dana M., Lina J. Paulionis, and Justyna E. Kulpa
Full study:

Single-Dose Pharmacokinetics and Preliminary Safety Assessment with Use of CBD-Rich Hemp Nutraceutical in Healthy Dogs and Cats

Study Method:

  • 6 cats and 6 Beagles between 11 months and five years of age
  • Given 2 mg/kg of full-spectrum CBD treats twice per day for 12 weeks
  • Bloodwork was taken and analyzed every four weeks
  • CBD treats contained high amounts of CBD-A.

Study results:

“Fortunately, there were no changes in physical examination and few changes in the CBC and serum chemistry parameters suggesting the relative safety of oral supplementation over 12 weeks…CBD-rich hemp nutraceuticals appear to be safe in healthy adult dogs.”

“Cats do appear to absorb or eliminate CBD differently than dogs, showing lower serum concentrations and adverse effects of excessive licking and head-shaking during oil administration.”

Date: 19 October 2019
Publication: Animals
Authors: Deabold, Kelly A., Wayne S. Schwark, Lisa Wolf, and Joseph J. Wakshlag
Full study:

Pharmacokinetics of cannabidiol administered by 3 delivery methods at 2 different dosages to healthy dogs

Over six weeks, this study gave 30 young male beagles either 150 mg or 300 mg of CBD oil per day in two doses (which worked out to about 10 and 20 mg/kg). They tried three different CBD products from Applied Basic Science – gel capsules, oil, and a cream.

After running blood work on the dogs throughout the six weeks, the researchers also found that CBD oils are the most effective type of CBD product, being most successfully and consistently absorbed into the body. The researchers concluded that CBD cream “does not penetrate deeper skin layers.”

All dogs finished the study and no serious side effects were reported.

Date: July 2018
Publication: Canadian Journal of Veterinary Research
Authors: Bartner, L. R., McGrath, S., Rao, S., Hyatt, L. K., & Wittenburg, L. A
Full study: