Effectiveness of Multiwavelength Locked System laser therapy for calcinosis cutis in 3 dogs: a case series

Objective To describe the clinical effects of photobiomodulation (PBM) therapy using a dual-wavelength near-infrared laser (Multiwave Locked System; Asa Srl) as adjunctive treatment in dogs with calcinosis cutis (CC). Animals 3 client-owned dogs presented to 2 referral veterinary hospitals from 2022 through 2023 were included. Cases were identified retrospectively via medical record review. Inclusion criteria were clinical and cytological features consistent with CC and histopathological examination when available, diagnosis of hyperadrenocorticism (HAC) based on clinical signs and diagnostic workup, availability of sufficient clinical records and photographic documentation, and owner consent for PBM therapy. Photobiomodulation was applied following a standardized protocol in scanning mode with a 2-cm collimated handpiece (approx 3-cm 2 spot): 3 sessions during week 1, every 72 hours in week 2, and then weekly with 4 J/cm 2 at the first session and 2.03 J/cm 2 thereafter. Clinical Presentation Included dogs were a 5-year-old male Labrador Retriever and an 8-year-old male English Bulldog with naturally occurring HAC and a 3-year-old female German Shepherd with iatrogenic HAC. All presented with dermatologic lesions compatible with CC (erythematous-crusted plaques, erosive-ulcerative lesions, and/or papules). Results 2 dogs achieved complete lesion resolution with hair regrowth within 7 to 12 weeks; the third showed partial improvement. No adverse events occurred. Clinical Relevance Findings, although based on a limited number of cases, suggest a potential supportive role for PBM in the management of CC. Controlled studies are warranted to establish standardized treatment parameters and clarify its role in CC.