CBD for Dog Allergies & Itching in Canada: What 3 Dog Studies Found

Straight answer: CBD may lower how itchy an allergic dog seems, and if you want to add it to your dog's itch plan, the oil we recommend is Pure Majesty Pets Vet-Strength CBD Oil for Dogs — 30 mg CBD + 25 mg CBDA + 5 mg CBG in every mL, no intentionally added THC and a certificate of analysis on every batch. In the one placebo-controlled trial with a positive result, dogs with atopic dermatitis given a CBD + CBDA oil had lower owner-rated itch scores at 2 and 4 weeks, but their skin lesions looked the same, and a second small controlled trial found no difference at all. So CBD is an add-on to your vet's itch plan, not a replacement for it. Below: the three dog studies, Apoquel and other allergy drugs, the study dose in mL and a 4-week itch log.

If you are still choosing a product, our guide to the best CBD for dogs compares six oils sold in Canada on mg per mL, THC and cost per mg in C$. This guide answers one narrower question: is there real evidence behind CBD for dog allergies and itching, and where does it fit next to the treatments your vet already uses? The honest version is that the research is small, partly industry-funded and mixed — and the one positive trial gave CBD alongside dogs' usual allergy care.

First: The Itch CBD Cannot Fix

Most itchy dogs have a cause that needs its own treatment. Before any supplement, your veterinarian will usually want to rule out or treat:

• Fleas and mites. International guidelines say dogs with atopic dermatitis should be on effective flea control year-round (Olivry et al., 2015).
• Food allergy. The only reliable test is a strict elimination diet trial. ICADA cites 8 weeks; the 2023 AAHA allergy guidelines say 4 to 12 weeks, with a prescription diet rather than an over-the-counter one.
• Bacterial and yeast infections. Staphylococcus and Malassezia infections are common in allergic dogs and make itching worse (Merck Veterinary Manual). Recurrent ear infections can be the only sign of allergy.

See your vet promptly for red, oozing or smelly patches, open sores or scabs, hair loss, head shaking or ear odour, or itching that keeps your dog awake. If you are still working out the cause, our complete evidence-based guide to dog itching walks through it step by step.

What the Three Dog Studies Found

Only three studies have looked at oral CBD in dogs with atopic dermatitis, the most common allergic skin disease in dogs. They point in different directions.

Honest note: none of these studies used Pure Majesty Pets CBD Oil. The 2022 Cornell-led trial was funded by the company that made its oil, and that oil contained THC. The results describe those products in those dogs — not a promised result for any oil, including ours.

How Much Did Itch Scores Actually Change?

The Loewinger trial is the one most often quoted, so the numbers are worth seeing. Owners scored itch on a 10-point scale:

Three details keep this in proportion:

• The rash did not change. Vet-scored skin lesions were similar in both groups at every check. CBD seemed to change how itchy dogs behaved, not how their skin looked.
• No change in itch chemicals. Blood levels of IL-31, the most-studied itch cytokine in dogs, and four other markers did not differ from placebo.
• Other allergy drugs were allowed. Dogs could keep steroids, oclacitinib, antihistamines or ciclosporin at a stable dose, so CBD was tested on top of real-world care.

Why might CBD affect itch at all? Dog skin carries cannabinoid receptors CB1 and CB2, and both stained more strongly in the skin of atopic dogs than healthy dogs (Campora et al., 2012). That is a plausible mechanism, not proof — and a preliminary 2025 lab study found no direct anti-inflammatory effect of CBD or CBDA on immune cells from atopic dogs (Jani et al., 2025). A 2025 review summed up the field as limited placebo-controlled trials with varying doses (Bizarro et al., 2025).

CBD Is an Add-On to the Itch Plan, Not a Swap

The 2023 AAHA guidelines list oclacitinib, lokivetmab and corticosteroids for flares and long-term control, plus ciclosporin, allergen immunotherapy, essential fatty acids and antihistamines for long-term control. CBD is not in either the AAHA or the ICADA guidelines. If you want to try it, this order keeps the result readable:

1. Get the cause worked up — fleas, infections, food trial — with your vet.
2. Keep every prescribed allergy drug exactly as it is.
3. Add one new thing at a time, so you know what made the difference.
4. Score the itch weekly for 4 weeks, the length of the trial, before judging.

In Canada, cannabis products — including CBD for animals — fall under Health Canada and the Cannabis Act; talk to your veterinarian before starting.

For side effects, liver enzymes and overdose facts, read our guide to whether CBD is safe for dogs.

CBD With Apoquel, Steroids or Ciclosporin: What Is Known

This is the question owners of allergic dogs ask most, and the honest answer is that no study has measured these combinations directly in dogs. What exists:

• In the itch trials, dogs on oclacitinib, prednisolone, antihistamines or ciclosporin took CBD alongside them, but drug levels were not measured.
• In dog liver cells, CBD and CBDA did not block CYP3A12, the dog enzyme family that handles ciclosporin, but they did slow the breakdown of tramadol, and the authors called for studies in live dogs (Court et al., 2024).
• In human enzyme tests, CBD does block CYP3A4 and CYP3A5 (Yamaori et al., 2011), which is why your vet may be cautious with ciclosporin.

The practical takeaway: tell your vet about CBD before you start, especially if your dog takes ciclosporin or any other daily drug, and ask whether a baseline blood panel makes sense.

Why THC Content Matters in an Itch Oil

The positive trial's oil listed 1.2 mg of THC and 1.3 mg of THCA per mL; the Brazilian oil was full-spectrum at a 21:1 CBD to THC ratio. Itch control is usually a long-term job, and THC is the cannabinoid that causes lethargy, wobbliness and vomiting in dogs (Merck Veterinary Manual). An oil with no intentionally added THC keeps that variable out of a routine that may last months. Our guide to full spectrum vs isolate CBD for dogs explains the trade-offs.

Study Dose in mL (For the Conversation With Your Vet)

The Loewinger oil is the closest published match to our formula: roughly equal CBD and CBDA (about 30 + 31 mg/mL), dosed at about 2 mg/kg twice daily with food. Here is that study-level amount with Pure Majesty Pets CBD Oil at 60 mg of total cannabinoids per mL. Your veterinarian sets the actual amount and may start lower.

Measure with a 1 mL oral syringe and mix into a small portion of food your dog will finish — the trial gave every dose with food. Every weight is in our CBD dosage chart for dogs.

The 4-Week Itch Log to Bring to Your Vet

Allergic itch rises and falls with pollen seasons, baths and flare-ups, which is why the trial used a placebo group. At home, a simple weekly log is the closest thing to that:

Score one or two weeks before starting CBD if you can, so there is a baseline. If the itch keeps your dog restless at night, our guide to CBD for dog anxiety covers what the calm studies used.

Building Blocks for the Skin Barrier

CBD may change how itchy a dog feels; it has not been shown to rebuild the skin barrier. Fatty acids are one of the long-term options in the AAHA guidelines, and hemp seed oil is one source of them — our hemp oil vs CBD oil for dogs guide explains why they are not the same thing. For the barrier side of the plan, read how collagen supports the skin barrier in itchy dogs. Pure Majesty Pets makes liquid collagen for dogs (462 mg Type I & III collagen + 48 mg UC-II per serving, with salmon oil) and Allergy & Itchy Skin Chews with salmon, sardine, chia and borage oils, quercetin, phytoceramides and probiotics. Ask your vet before combining products with a food trial, since chews and flavoured oils add ingredients.

What It Costs With Our Oil

At C$46.00 for 60 mL, a study-level routine of 2 mg/kg twice daily costs about C$0.51 a day for a 10 kg (22 lb) dog and C$1.28 a day for a 25 kg (55 lb) dog — about C$35.78 for the full 28-day trial length for the larger dog, and one bottle covers it. To see how other oils sold in Canada compare on price and mg per mL, see our best CBD oil for dogs comparison.

Why Pure Majesty Pets CBD Oil Fits an Itchy Dog's Routine

• CBD + CBDA in a ratio close to the itch trial oil — 30 mg CBD and 25 mg CBDA per mL, plus 5 mg CBG. That trial tested another company's product; our formula has not been studied in allergic dogs.
• No intentionally added THC — the trial oil contained THC; ours is made from isolates.
• Every cannabinoid quantified, so your vet knows exactly what is being added next to Apoquel, steroids or ciclosporin.
• A certificate of analysis on every batch — cannabinoids, THC and contaminants.
• 60 mg/mL — study-level doses in small, measurable volumes, from 0.15 mL for a 4.5 kg (10 lb) dog.
• Simple ingredient list: MCT oil, sunflower lecithin, mixed tocopherols and natural bacon flavour; no added water, glycerin or xylitol.
• About C$35.78 for a 28-day trial for a 25 kg (55 lb) dog, made in North America under GMP standards, with free shipping.

Ready to discuss it with your vet? See Pure Majesty Pets CBD Oil for Dogs →

Red Flags With CBD for Itchy Dogs

• Promises to cure allergies or replace Apoquel — no CBD product is an approved veterinary medicine for allergies or itching in dogs.
• Skipping the vet for a hot, oozing or smelly patch — infections need their own treatment.
• Starting CBD in the middle of a food trial without asking your vet — flavoured oils and treats can break the diet.
• No mg per mL on the label — you cannot match the study dose or report it to your vet.
• No batch COA, or a COA with THC but no THCA result.
• Human CBD products — different strengths, and some contain xylitol.
• Vomiting, poor appetite or new drowsiness after starting — call your vet.

The Bottom Line

CBD for dog allergies and itching has early, mixed evidence: one small industry-funded trial found lower owner-rated itch with a CBD + CBDA oil, a second small trial found nothing, and neither showed healthier-looking skin. It belongs on top of a proper itch plan — fleas, food, infections and your vet's medication — never instead of it.

If your vet agrees to a 4-week trial, Pure Majesty Pets Vet-Strength CBD Oil for Dogs gives you CBD and CBDA in measured amounts close to the study oil, no intentionally added THC and a COA on every batch, for about C$1.28 a day for a 25 kg dog.