Effect of Low-Level Laser Therapy on Bacterial Counts of Contaminated Traumatic Wounds in Dogs

Introduction: The clinical effect of low-level laser therapy (LLLT) on canine wounds is still under debate. The aim of this pilot study was to evaluate the potential influence of LLLT on the bacterial loads of wounds, using two different energy densities or doses of laser light as an adjuvant therapy for traumatic contaminated wound management. Methods: A prospective, randomized, blinded, placebo-controlled pilot clinical trial was used to evaluate the effect of two different doses of LLLT as an adjuvant treatment of contaminated traumatic wounds on the bacterial load and wound scoring in dogs. Fourteen dogs with traumatic bites or laceration wounds were randomly assigned to one of the three groups. Animals in groups A and B received a dose of LLLT of 6 and 2 J/cm² respectively. Four wavelengths were used simultaneously: 660 nm, 800 nm, 905 nm, and 970 nm. Animals in group C received placebo LLLT. Bacterial burden and clinical wound scores were evaluated. Results: A statistically significant reduction in the average count of colony forming units was observed in group B (2 J/cm²) when compared to placebo group C. Group B also showed improved wound scores. No clinically adverse effects were observed in the patients treated with LLLT. Conclusion: LLLT, with the parameters used in this pilot trial, decreased bacterial loads of contaminated wounds in dogs and improved wound scores, especially when using a dose of 2 J/ cm². This is the first time the effect of LLLT on bacterial load has been investigated in a clinical setting using traumatic wounds in canine patients.