Autologous Skin Transplants in the Treatment of Wounds on the Distal Parts of the Limb in Cattle.
Autologous free full-thickness and pinch skin grafts have been used in man, horse and the dog in the repair of both fresh and granulating skin wounds. The literature available contained little information on skin grafting as a technique of wound repair in cattle. The technique of full-thickness skin grafting in cattle has, however, been described. It has been reported that dehorning wounds in cattle healed faster when treated with full-thickness skin grafts than when treated conventionally. It was found desirable to investigate the effect of autologous free full-thickness and pinch skin grafts on fresh and granulating lower limb wounds in cattle. The parameters studied were: the ease of take of the autologous free-full-thickness and pinch skin grafts in fresh and granulating wounds; the acceptance of the full-thickness and pinch grafts in fresh compared to granulating wounds, and the effects of the full-thickness and pinch skin grafts on the healing time. Wound contraction and hair growth were also studied as well as the density of hair follicles, sebacious glands and sweat glands in the histological sections of grafted healed wounds. A total of thirty six full-thickness skin wounds measuring 60 mm x 60 mm were surgically created in the metatarsal and metacarpal regions in bovine calves. Eight of these wounds were grafted with autologous free full-thickness skin grafts while the other eight fresh wounds were grafted with autologous pinch skin. Four wounds were treated without grafting and studied as the controls while the remaining sixteen wounds were let to granulate for fourteen days before being subjected to further treatment. Eight of the granulating wounds were then treated with autologous free full-thickness skin grafts and the other eight granulating wounds treated with autologous pinch skin grafts. The healing times hair growth and appearance of the wounds after healing were evaluated. Wound contraction was determined by measuring the wound sizes using calipers. Graft acceptance and the density of hair follicles, sebacious and sweat glands was also evaluated in a histological section from the healed wounds. Autologous full-thickness skin grafting in fresh wounds had a shorter healing time compared to the granulating wounds and the control wounds. The healing time of pinch skin grafted fresh and granulating wounds was similar and less than that of the control wounds. Better acceptance of full-thickness skin grafts was observed in fresh wounds compared to the granulating wounds. The acceptance of pinch skin grafts in fresh and granulating wounds was good and similar. Wound contraction occurred in both the ungrafted control wounds and the grafted wounds. The best hair growth, appearance and regeneration of structures associated with the skin was observed in healed wounds that had been grafted with full-thickness skin while fresh. Sparse hair growth and poor regeneration of the structures associated with the skin was found in the pinchskin grafted wounds. No hair growth and no regeneration of skin appendages was observed in the healed control wounds and granulating full-thickness skin grafted wounds. The healed wounds in these cases were covered by a thin friable epithelial scar. The use of autologous free full-thickness and pinch skin grafting in the treatment of large fresh full-thickness skin wounds in the lower limbs of cattle were found to enhance the healing of the wounds. Pinch skin grafting was also found to be useful in the treatment of similar granulating wounds in this species. Granulating wounds did not accept full-thickness grafts.