Effect of fluorescence biomodulation as an adjunct to standard wound management in open wounds in dogs and cats: a prospective, randomised, within-wound controlled clinical trial.

BACKGROUND: Open wounds are a common clinical problem in small animal practice and are associated with delayed healing, infection, and increased treatment burden. Fluorescence biomodulation (FB), a form of photobiomodulation therapy (PBMT), has shown benefits in several dermatological conditions; however, its efficacy in veterinary open wounds remains unclear. OBJECTIVES: To evaluate the effect of FB as an adjunct to standardised wound management on healing progression in open wounds in dogs and cats using a prospective, randomised, within-wound controlled clinical trial. METHODS: Fifteen client-owned dogs and cats with open wounds of various aetiologies were enrolled. Each wound was divided into two portions: one treated weekly with FB and one untreated control, both receiving standardised wound care based on the TIME framework. Quantitative wound area reduction was assessed by serial planimetric measurements. Qualitative healing parameters were scored weekly by two blinded observers, and semiquantitative histological and immunohistochemical evaluation was performed in surgically treated cases. Paired statistical analyses were used. A time-integrated analysis based on the area under the curve (AUC) of normalised wound area was performed to assess healing kinetics. RESULTS: No statistically significant differences were observed between treated and control portions for percentage wound area reduction, qualitative healing scores, or semiquantitative histological and immunohistochemical outcomes. Quantitative planimetry showed a heterogeneous response, with seven wounds favouring the treated portion, six favouring the control portion, and two showing equivalent outcomes. Exploratory post hoc time-integrated analyses suggested a trend toward earlier wound area reduction in some cases, particularly when treatment was initiated early; however, these findings were not statistically significant. Complete wound closure during follow-up did not differ significantly between portions. Histological analysis showed only small numerical differences between portions, with no statistically significant differences in collagen deposition, angiogenesis, inflammatory response, fibroblast proliferation, or CD31 and Ki67 expression. CONCLUSION: Under the conditions tested, FB did not demonstrate a consistent measurable advantage over standardised wound management in open wounds in dogs and cats. Any potential clinical benefit appeared modest and possibly limited to selected wound presentations. Further prospectively stratified studies focused on healing speed and readiness for closure are warranted.