We enrolled 30 dogs with mild to moderate atopic dermatitis and 30 healthy control animals in the study. The dogs with atopic dermatitis were treated with either Apoquel® (n=17) or Cytopoint® (n=10), whereas one dog was switched from Apoquel® to Cytopoint®, one dog was treated with prednisone followed by Apoquel®, and one dog was treated with a topical shampoo.
Both Apoquel® and Cytopoint® reduced the clinical severity of the skin lesions during 8 weeks of treatment. Skin swabs and blood samples were collected from the atopic and control dogs at Day 0, and from the atopic dogs at 4 and 8 weeks after initiation of treatment. Analysis of the lipid composition of the skin and blood samples by mass spectrometry showed significant differences between atopic and control dogs. In addition, nonlesional skin of atopic dogs had a different skin lipid profile from that of control dogs.
Treatment changed the lipid composition both in the skin and the blood, however, there was marked variation in the direction and extent of the changes between individual dogs. This research suggests that atopic dermatitis is associated not only with changes in lipids in the skin but also systemic changes