EVALUATION OF A POROUS BOVINE COLLAGEN MEMBRANE BANDAGE FOR MANAGEMENT OF WOUNDS IN HORSES

Objective-To evaluate the effect of a porous bovine-derived collagen m embrane (PBCM) On the rates of wound healing, cellular events, presenc e of granulation tissue, and appearance at termination of the study in surgically created full-thickness cutaneous wounds of the distal port ion of the extremities of horses. Design-Treated wounds (n = 12) recei ved a PBCM dressing and control wounds were covered with a nonadherent dressing. Forelimbs and hind limbs were cross paired; the right forel imb and left hind limb always received the same dressing application, as did the left forelimb and right hind limb. Limbs pairs were then ra ndomly assigned to 1 of the 2 dressings. Animals-Six healthy male hors es (3 sexually intact. 3 geldings) ranging from 2 to 10 (mean, 6.5) ye ars and weighing between 278 and 568 (mean, 408.5) kg were studied. Pr ocedure-Full-thickness skin wounds (6.25 cm(2)) were created on the do rsal metatarsi and metacarpi of the experimental animals. A preformed PBCM dressing was evaluated in half the wounds (n = 12). Control wound s (n = 12) were dressed with a nonadherent gauze dressing. At each ban dage change, wounds were subjectively assessed and were photographed, and measurements of horizontal and vertical wound dimensions were docu mented. Wound biopsy specimens obtained on days 2, 5, 7, 10, 21, and 3 1 were evaluated for presence of collagen, fibrin, inflammation, epith elium, and cellular elements of healing. Planar morphometry was used t o determine total wound area and granulation area from the wound photo graphs. Percentage of contraction and epithelialization were calculate d from these values. Linear regression analysis of the square root of the total wound area and the granulation area was performed. Wound are a measurements were analyzed, using ANOVA for repeated measures. Regre ssions were compared, using covariance analysis and ANOVA. Significanc e was considered at P < 0.05. Results-Fibrin score, neutrophil score, and degree of inflammation were significantly greater in the PBCM-trea ted wounds. No significant differences in the total wound, epitheliali zed, or contraction areas were detected between the PBCM-treated and c ontrol (nonadherent-treated) wounds. Rates of wound healing were not s tatistically different between the 2 treatment groups, though they wer e significantly slower in the hind limbs, compared with the forelimbs. Scabs were formed more frequently in the PBCM-treated wounds. Conclus ions-Application of a porous collagen bandage was not detrimental to f ull-thickness cutaneous wound healing in horses.