A new study published in Frontiers in Allergy found that dogs with chronic allergic skin disease experienced reduced itching while receiving cannabis oil alongside conventional medication, with improvements maintained even after the medication dosage was cut in half.
The study, published October 14, was conducted by researchers from the Federal University of Santa Maria and Federal University of Santa Catarina in Brazil. It examined whether cannabis oil could help manage canine atopic dermatitis, a chronic inflammatory skin condition that causes persistent itching, irritation and skin damage.
Researchers enrolled 16 dogs whose symptoms had not been adequately controlled with oclacitinib, a prescription allergy medication commonly sold under the brand name Apoquel. Fourteen completed the full 90-day study.
The dogs initially received their usual medication alongside a placebo oil for 30 days. During the following month, the placebo was replaced with full-spectrum cannabis oil containing primarily cannabidiol (CBD), administered twice daily at 2 milligrams of CBD per kilogram of body weight. For the final 30 days, researchers continued the cannabis treatment while reducing each dog’s oclacitinib dosage by 50%.
Owner-reported itching scores declined from an estimated average of 3.44 at baseline to 2.31 after 30 days of cannabis treatment, measured on a five-point scale. Scores remained relatively stable at 2.42 after the conventional medication dosage was halved.
The reductions in itching compared with baseline were statistically significant, although the direct comparison between the placebo and cannabis treatment periods did not reach statistical significance. Researchers also found no statistically significant changes in skin lesion severity across the treatment periods.
An additional observation emerged after the treatment period ended. When cannabis oil was discontinued while the reduced medication dosage was maintained, nine dogs began scratching again within seven days. Four resumed scratching within two days, while five remained stable throughout the follow-up period.
The cannabis formulation contained CBD alongside smaller amounts of THC, cannabigerol (CBG), cannabichromene (CBC) and other cannabinoids. Researchers said these compounds may influence inflammatory pathways through the body’s endocannabinoid system, which helps regulate immune activity and skin function.
Reported side effects included temporary drowsiness, vomiting and soft stools. Similar symptoms were also reported during the placebo treatment period, and all documented adverse events were described as mild and self-limiting.
The researchers said their findings suggest cannabis oil warrants further investigation as a supplemental treatment for canine atopic dermatitis, particularly for dogs requiring long-term medication.
They also highlighted the potential significance of maintaining symptom control while reducing conventional medication use, which could eventually offer additional treatment flexibility for veterinarians managing chronic allergic skin conditions.
The study’s small sample size and fixed treatment sequence limit how conclusively the improvements can be attributed to cannabis oil, but the researchers said the results provide preliminary evidence supporting larger controlled clinical trials.
