Tail wounds in military working dogs: Clinical characterization and a randomized sham-controlled trial of photobiomodulation

Background: Tail wounds in military working dogs (MWDs) are a clinically significant and challenging condition characterized by recurrent trauma and delayed healing. Photobiomodulation (PBM) has been proposed as a non-invasive therapy to enhance wound repair. Objective: To characterize the clinical presentation of tail wounds in MWDs and to evaluate the effect of PBM as an adjunctive treatment. Methods: This prospective study included an observational cohort of 21 active MWDs (age 4.1 ± 2.2 years; 95% male; predominantly Belgian Malinois [57%]) with clinically evident tail wounds and a randomized, sham-controlled interventional subset of 16 dogs (PBM n = 8, sham n = 8) that excluded dogs that were not available for the intervention due to activity duties. Dogs received daily PBM or sham treatment for 2 weeks. Wounds were assessed at baseline and 2 weeks of treatment using surface measurements, thermal imaging, and a modified canine Bates–Jensen Wound Assessment Tool (BWAT). The primary outcome was change in wound area. Results: Tail wounds were predominantly chronic (≥1 month) (76%) and recurrent (62%), with moderate-to-marked bleeding in 53% of cases. Thermal imaging demonstrated higher temperatures in the wound bed compared to surrounding tissue (Δ2.8 ± 0.7 °C, p < 0.001), indicating preserved perfusion. In the randomized cohort, wound area did not significantly change over time (PBM: 0.6 ± 0.4 to 0.7 ± 0.4 cm²; sham: 1.3 ± 1.0 to 1.1 ± 0.7 cm²). In contrast, the surrounding hairless area decreased significantly in both groups without significant between-group difference ( p = 0.077). BWAT scores showed non-significant improvement in both groups. Conclusion: PBM, as applied in this protocol, did not improve healing of tail wounds in MWDs. These findings suggest that persistent trauma may limit wound healing despite preserved repair processes.