Evaluation of a porous bovine collagen membrane bandage for management of wounds in horses.

Abstract: To evaluate the effect of a porous bovine-derived collagen membrane (PBCM) on the rates of wound healing, cellular events, presence of granulation tissue, and appearance at termination of the study in surgically created full-thickness cutaneous wounds of the distal portion of the extremities of horses. Methods: Treated wounds (n = 12) received a PBCM dressing and control wounds were covered with a nonadherent dressing. Forelimbs and hind limbs were cross paired; the right forelimb and left hind limb always received the same dressing application, as did the left forelimb and right hind limb. Limbs pairs were then randomly assigned to 1 of the 2 dressings. Methods: Six healthy male horses (3 sexually intact, 3 geldings) ranging from 2 to 10 (mean, 6.5) years and weighing between 278 and 568 (mean, 408.5) kg were studied. Methods: Full-thickness skin wounds (6.25 cm2) were created on the dorsal metatarsi and metacarpi of the experimental animals. A preformed PBCM dressing was evaluated in half the wounds (n = 12). Control wounds (n = 12) were dressed with a nonadherent gauze dressing. At each bandage change, wounds were subjectively assessed and were photographed, and measurements of horizontal and vertical wound dimensions were documented. Wound biopsy specimens obtained on days 2, 5, 7, 10, 21, and 31 were evaluated for presence of collagen, fibrin, inflammation, epithelium, and cellular elements of healing. Planar morphometry was used to determine total wound area and granulation area from the wound photographs. Percentage of contraction and epithelialization were calculated from these values. Linear regression analysis of the square root of the total wound area and the granulation area was performed. Wound area measurements were analyzed, using ANOVA for repeated measures. Regressions were compared, using covariance analysis and ANOVA. Significance was considered at P < 0.05. Results: Fibrin score, neutrophil score, and degree of inflammation were significantly greater in the PBCM-treated wounds. No significant differences in the total wound, epithelialized, or contraction areas were detected between the PBCM-treated and control (nonadherent-treated) wounds. Rates of wound healing were not statistically different between the 2 treatment groups, though they were significantly slower in the hind limbs, compared with the forelimbs. Scabs were formed more frequently in the PBCM-treated wounds. Conclusions: Application of a porous collagen bandage was not detrimental to full-thickness cutaneous wound healing in horses.