A New Trial Found CBD Was Well Tolerated in Dogs With Joint Trouble — Here's the Honest Part About What It Could and Couldn't Show

A New Trial Found CBD Was Well Tolerated in Dogs With Joint Trouble — Here's the Honest Part About What It Could and Couldn't Show

If your dog is slowing down on the stairs or taking longer to get up in the morning, you have probably wondered whether hemp-derived CBD belongs in the conversation about their comfort. A new veterinary trial out of University College Dublin gives us a useful, grown-up answer — and the most valuable thing about it is what the researchers were willing to admit.

The short version: in this small, carefully controlled study, oral CBD oil was well tolerated by dogs with confirmed joint disease. But the same study was honest enough to say it could not prove that CBD reliably reduced their pain. Both halves of that sentence matter, and most of the pet-CBD industry will only tell you the first one. We would rather tell you both.

What the researchers actually did

According to the reporting on the trial, the University College Dublin team enrolled roughly 10 dogs whose osteoarthritis had been confirmed with diagnostic imaging — not guessed from a limp. Each dog went through a randomized, double-blind, placebo-controlled crossover: a four-week stretch on oral CBD oil and a four-week stretch on a placebo oil, separated by a four-week "washout" so one period could not bleed into the next. Neither the owners nor the assessors knew which oil a dog was on at any given time.

That crossover design is the gold-standard way to run a small study, because every dog is compared against itself rather than against a different group of dogs. It removes a lot of the noise that makes weaker studies misleading.

One detail worth flagging, because we would want to know it: the CBD and placebo oils were supplied by a commercial hemp company. The researchers stated that the supplier had no role in designing the study, collecting or analyzing the data, interpreting the findings, or preparing the manuscript, and reported no competing interests. Industry-supplied product with a firewall around the science is a reasonable arrangement — but you should be told it exists, and we will always tell you.

The tolerability finding: reassuring, and clearly stated

Across the CBD period, the dogs handled the oil well. The researchers reported that oral CBD was well tolerated, with a single dog experiencing mild, temporary loose stool that resolved on its own and no other clinically relevant adverse effects. That is consistent with the broader body of canine safety research, including a separate long-term tolerability study in healthy adult dogs published in the Journal of Veterinary Internal Medicine, which found that daily CBD over months was generally well tolerated with monitoring.

Tolerability is a structure-and-function question — how a healthy or aging body handles a supplement — and it is where the evidence for CBD in dogs is genuinely strongest. That is worth saying plainly.

The pain finding: where honesty earns its keep

Here is the part a lot of brands would quietly skip. The team tracked several validated measures — the Helsinki Chronic Pain Index, the Liverpool Osteoarthritis in Dogs (LOAD) questionnaire, and the Canine Osteoarthritis Staging Tool (COAST and COASTeR). The first two rely largely on owner assessment; the COAST tools fold in clinical evaluation. Changes in the pain-related scores were generally modest, and the owner-reported measures showed more variation within individual dogs than the clinician-informed ones did. The authors' conclusion, as reported, was that the findings did not establish that CBD reliably reduced osteoarthritis pain in this group.

That is not the same as "CBD doesn't work." It is a much more specific and honest statement: a 10-dog study is too small to detect a modest effect even if one is real. The researchers underlined the point with a post-study power analysis estimating that a properly powered trial would need somewhere between 24 and 132 dogs, depending on which outcome tool is used and how large an effect you are trying to catch. In other words, the study did its job — it just did the job of a pilot, which is to tell you how to build the real trial next.

Where this sits next to HempMy Pet's own research

We think the fairest way to read any single study is to put it on a ladder alongside everything else — including our own work. So here is the honest placement:

This Dublin trial is a Level 2 design (a randomized controlled trial) but a small, preliminary one. HempMy Pet's own canine study — 30 dogs with chronic joint discomfort, run over 90 days with Dr. Robin Downing, DVM, alongside researchers at Colorado State University — sits at Level 3 (a prospective clinical study). In that study, more than 93% of the dogs showed benefit on the measures used and 94% of owners reported improved quality of life, as reported by the investigators. It had no placebo group, which is precisely why we grade it Level 3 and not Level 2. Meanwhile, the great majority of the marketing you'll see for pet CBD rests on Level 8 — anecdotes and testimonials.

None of these individual studies is a final verdict, and we won't pretend ours is either. What the field needs is more Level 1 and Level 2 evidence: bigger, longer, independently run randomized trials. The Dublin group is pointing directly at that gap, and that's a good thing. You can see how we think about evidence, and view our third-party lab results and the rest of our clinical trials, on our site.

What this means for you and your dog

If you're already using a quality hemp product to support an older dog's everyday comfort and mobility, and your dog is tolerating it well, the tolerability side of this study is quietly reassuring.

If you're weighing whether to start, the grown-up takeaway is this: the tolerability evidence is solid, the comfort evidence is promising but still maturing, and anyone selling you certainty is getting ahead of the science. Talk to your veterinarian — especially if your dog is on other medications or has liver or kidney concerns — so any supplement fits into a full comfort plan rather than replacing one.

If you want to go deeper on the joint-comfort question specifically, we keep a dedicated page on hemp and CBD for aging dogs' joint comfort, and our full range for dogs sits in the hemp for dogs collection.

Frequently asked questions

Did this study prove CBD relieves arthritis pain in dogs?
No — and the researchers said so. It found CBD was well tolerated but was too small (about 10 dogs) to reliably show a pain effect one way or the other. It's best understood as a well-designed pilot pointing toward larger trials.

Is CBD safe for dogs with joint issues?
In this trial and in other canine safety research, oral CBD has generally been well tolerated, with occasional mild, temporary digestive upset. "Well tolerated" is a safety observation, not a treatment claim. Always involve your veterinarian, particularly if your dog takes other medications.

Why do some CBD studies look more positive than others?
Study size, design, dose, and the specific measurement tools all move the results. Small studies can miss a real effect; uncontrolled ones can imply one that isn't there. This trial is a good example — the owner-reported tools varied more than the clinician-informed ones. That's why we grade every study on an evidence ladder instead of cherry-picking the flattering ones.

How is HempMy Pet's dog study different from this one?
Ours was a 30-dog, 90-day prospective clinical study run with a veterinarian and university researchers (a Level 3 design), focused on joint comfort and quality of life, without a placebo group. This new Dublin trial is a smaller randomized, placebo-controlled crossover (a Level 2 design) focused heavily on tolerability. Different tools, different strengths — together they add to the picture.

Has this study been peer reviewed?
Not yet. At the time of writing it is a preprint under consideration by the Irish Veterinary Journal, and our summary is based on published reporting of that preprint rather than a final peer-reviewed paper. We'll update this article if the peer-reviewed version changes anything material.

What should I actually do with this information?
Use it to ask better questions. Favor companies that show their testing and talk honestly about evidence, choose products formulated for the animal in front of you, and make any supplement one part of a comfort plan you build with your vet.

Source: trial reported by The Marijuana Herald (August 3, 2026), covering a University College Dublin preprint under consideration by the Irish Veterinary Journal. The primary manuscript was not publicly available at the time of writing.

This article is for educational purposes only and is not veterinary advice. HempMy Pet products are not intended to diagnose, treat, cure, or prevent any disease. Always consult your veterinarian about your pet's health.