Effects of a cross-linked hyaluronic acid based gel on the healing of open wounds in dogs.

OBJECTIVE: To compare effects of a cross-linked hyaluronic acid (HA) based gel (CMHA-S) to a standard wound management protocol on the healing of acute, full-thickness wounds in dogs. STUDY DESIGN: A prospective, controlled, experimental study. ANIMALS: Purpose-bred, adult, female beagles (n = 10). METHODS: Two 2 × 2 cm wounds were surgically created bilaterally on the trunk of each dog and each side randomized to treatment (CMHA-S) or control (CON) groups. Total and open wound areas were measured with digital image planimetry at 15 time points. From these data, percent contraction and percent epithelialization were calculated. Tissue biopsies were obtained at 6 time points and histologic features were scored. RESULTS: Total wound area was significantly larger and percent contraction was significantly less in CMHA-S compared to CON wounds at all data points between days 9 and 18. At day 25, and for the remainder of the study, CMHA-S wounds were smaller and contracted more than CON wounds, reaching significance at day 32. Percent epithelialization was significantly less in CMHA-S compared to CON wounds at all data points after day 11. Histologically, fibroblastic cellular infiltration was significantly higher in CMHA-S wounds at day 21. CONCLUSIONS: CMHA-S wounds healed more slowly than CON wounds. This HA-based gel is not indicated in acute, full-thickness skin wounds in dogs as administered in this study. However, treatment may be beneficial in the mid-to-late repair stage of healing, or if scar minimization is desired. Further studies to evaluate the effects of the CMHA-S gel on canine wounds are indicated.

Effects of negative pressure wound therapy on healing of open wounds in dogs.

OBJECTIVE: To compare the effect of negative pressure wound therapy (NPWT) with standard-of-care management on healing of acute open wounds in dogs. STUDY DESIGN: Prospective, controlled, experimental study. ANIMALS: Adult dogs (n=10). METHODS: Full-thickness 4 m × 2 m wounds were surgically created on each antebrachium and in each dog were randomized to receive either NPWT or standard wound dressings (CON) for 21 days. Dressing changes and wound evaluations were made at 8 time points. First appearance of granulation tissue, smoothness of granulation tissue, exuberance, percent epithelialization, and percent contraction were compared. Biopsies for histopathology were taken, and histologic scores determined, at 5 time points, and aerobic bacterial wound cultures performed at 2 time points. RESULTS: Granulation tissue appeared significantly earlier, and was smoother and less exuberant in NPWT wounds compared with CON wounds. Percent contraction in NPWT wounds was less than CON wounds after Day 7. Percent epithelialization in NPWT wounds was less than CON wounds on Days 11, 16, 18, and 21. Histologic scores for acute inflammation were higher in NPWT on Day 3, and lower on Day 7, than CON wounds. Bacterial load was higher in NPWT on Day 7. CONCLUSION: NPWT accelerated appearance of smooth, nonexuberant granulation tissue; however, prolonged use of NPWT impaired wound contraction and epithelialization.