Evaluation of Dual-Near-Infrared-Wavelength Photobiomodulation Therapy for the Treatment of Canine Otitis Externa: A Prospective Multicenter Pilot Study.

This is the first prospective multicenter study investigating photobiomodulation (PBM) in canine OE. Inclusion criteria required an Otitis Index Score 3 (OTIS-3; scale 0-3) ≥1 for erythema and discharge and a Budach cytological score ≥1+ (scale 0-4+) for Malassezia spp. and/or bacteria associated with keratinocytes/corneocytes. Twenty-two dogs with OE (38 ears) were enrolled and underwent five PBM sessions. When the discharge score was ≥2, a ceruminolytic ear cleanser was applied before treatment. OTIS-3, Budach cytological scores, and microbiological cultures were evaluated at T0, T2, T4, and T5. Pruritus was assessed using a 10 cm visual analogue scale, and malodour was recorded as present or absent. Early improvement in pruritus and malodour was observed at T2. Median pruritus scores decreased from 5.5 cm (IQR, 4-6) to 2 cm (IQR, 0-4.75), while malodour prevalence declined from 94% to 54%. Cytological evaluation revealed reductions in yeast and keratinocyte scores, whereas microbiological culture results did not significantly change over time. No adverse events were reported. MLS-based PBM was safe and associated with improvement in clinical signs of canine OE.