Clinical Efficacy of Probiotic‐Based Ear Drops Containing Lactobacilli in Canine Erythroceruminous Otitis Externa: An Open Label, Multicentre Study

Background Otitis externa (OE) represents a common clinical problem in dogs. Allergic dogs exhibit reduced diversity of the otic microbiota, and inflammation‐induced changes in the ear canal microenvironment result in a further decline in microbial biodiversity. Probiotics have demonstrated efficacy in certain dermatological conditions, including atopic dermatitis, which is, in turn, the leading primary cause of OE in dogs. Objectives To evaluate the efficacy of probiotic‐based ear drops in controlling clinical signs related to erythroceruminous non‐infected OE in dogs. Animals Thirty‐seven privately owned dogs with non‐infected OE. Materials and Methods Dogs received probiotic‐based ear drops topically every 48 h for 28 days, in accordance with the manufacturer's instructions. Assessments were performed at enrolment (Day [D]0), D14 and D28, including cytological evaluation of ear discharge, pruritus intensity (PVAS, pruritis Visual Analogue Scale), severity of otic lesions (OTIS3, 0–3 Otitis Index Score) and a quality‐of‐life survey (QoL). Results At enrolment (D0), mean OTIS3 and PVAS scores for all included animals were 5.11 ± 1.20 and 4.93 ± 1.51, respectively. Both scores decreased significantly by D28, to 1.66 ± 1.75 and 2.09 ± 2.03, respectively. Clinical improvement was evident regardless of concomitant medication use or the type of micro‐organism's overgrowth observed during the initial cytological assessment. Owner‐reported QoL improved in 80% of the dogs. Conclusion and Clinical Relevance These probiotic‐based ear drops may be a useful adjunctive therapy in cases of canine non‐infectious erythroceruminous OE.