Oclacitinib shows promise for reducing allergic skin disease in horses

A recent study suggests that oclacitinib, a medication traditionally used in dogs, could offer a new treatment option for allergic skin conditions in horses, potentially improving welfare and performance.

A veterinary study published in Veterinary Dermatology suggests that oclacitinib, a medicine long used in dogs, (Apoquel – Zoetis) may also ease allergic skin disease in horses. In a trial involving 16 client-owned animals, researchers found that daily treatment for 21 days cut itchiness in 15 horses and improved skin lesions in most, with hair loss also easing in several cases.

According to the authors, improvement in owner-rated pruritus was usually apparent within four days. The findings build on earlier work in horses, including a 2022 pharmacokinetic study that showed the drug is absorbed quickly and cleared within hours, supporting its potential use in equine medicine.

The condition itself is often driven by insect bites or environmental allergens such as dust, and can leave horses scratching, rubbing and injuring themselves. Ashley Fowler of Kentucky Equine Research noted that intense pruritus can undermine both welfare and performance.

The latest study was encouraging, but the authors urged caution. Small rises in liver, muscle and kidney markers were seen during treatment, although all remained within normal ranges. They recommended monitoring blood values, particularly in horses with pre-existing hepatic, renal or muscular disease.

The results suggest oclacitinib could become a useful part of management, especially where insect control is effective, but larger trials will be needed before it can be considered routine practice.

Reference: Tunhikorn, Maturawan et al. “Oclacitinib for Controlling Pruritus and Associated Skin Lesions in 16 Horses With Allergic Dermatitis.” Veterinary dermatology, 10.1111/vde.70091. 31 May. 2026, doi:10.1111/vde.70091