Clinical efficacy of spray‐based heat‐treated lactobacilli in canine atopic dermatitis: a preliminary, open‐label, uncontrolled study

BACKGROUND: Canine atopic dermatitis (cAD) is a common inflammatory and pruritic skin disease, with various treatment options. The use of topical products containing natural ingredients has proven increasingly popular. OBJECTIVE: To evaluate the effects of a spray solution containing heat‐killed Lactobacillus rhamnosus and L. reuteri, on the clinical signs and cutaneous microbiota of atopic dogs. ANIMALS: Ten privately owned, mildly affected, nonseasonally atopic dogs. METHODS AND MATERIALS: The spray was applied to the ventrum every 24 h for 28 days. Clinical scores, skin barrier function and owner assessment were evaluated on day (D)0, D14, D28 and D42. The cutaneous microbiota was analysed on D0 and D28. RESULTS: A reduction in the total clinical score was seen at each time point (D14, P = 0.03; D28, P = 0.04; D42, P = 0.001). A reduction in the regional clinical scores was seen after D28 (P = 0.01) and D42 (P = 0.003). A significant reduction in the pruritus score was seen on D42 (P = 0.01). A lower hydration value was seen on D28 (P = 0.02) and D42 (P = 0.02) on the pinnae. A good‐to‐excellent response and an easy‐to‐use administration was reported by owners. There were no significant changes in the cutaneous microbiota after 28 days. CONCLUSIONS AND CLINICAL IMPORTANCE: There was a significant and rapid decrease in the clinical signs associated with cAD after use of the spray. Future larger, randomized, controlled studies are needed to confirm these results and to assess the effects on the cutaneous immunity and microflora of atopic dogs.