Effects of split-thickness and full-thickness skin grafts on secondary graft contraction in horses.

Full-thickness, circular (4-cm diameter) cutaneous wounds were created on the metacarpi and metatarsi of 6 horses. Immediately after wounding, 1 wound on each horse received a meshed, split-thickness skin graft (0.64 mm) obtained from the ventrolateral aspect of the horse's thorax by use of a pneumatic dermatome, whereas a second wound received a meshed, full-thickness skin graft obtained from the pectoral area. In addition, sections of split-thickness and full-thickness grafts were refrigerated in a solution of McCoy's 5A medium, to which equine serum (10%) and gentamicin sulfate solution (16 mg/dl) were added. Ten days after wounding, 1 granulating wound on each horse was grafted with a stored, meshed, split-thickness graft, and 1 granulating wound on each horse was grafted with a stored, meshed, full-thickness graft. Areas of wounds were calculated from photographs taken of wounds on days 1, 5, 10, 15, 20, 25, and 30 after wounding. Time course of contraction was determined by use of a first-order mathematic model of changes in area through time. Rate constants of contraction for fresh or granulating wounds receiving full-thickness grafts did not differ significantly from those for fresh or granulating wounds receiving split-thickness grafts. Rate constants of contraction for grafted fresh wounds, however, were significantly less than those of grafted granulating wounds, regardless of whether a split-thickness or full-thickness graft was applied.     

Full‐Thickness Skin Grafting to Cover Equine Wounds Caused by Laceration or Tumor Resection

Objective: To describe and evaluate full‐thickness skin grafting of equine wounds. Study Design: Case series. Animals: Adult horses (n=6). Methods: A full‐thickness graft was harvested from the pectoral region with the horse anesthetized or standing and sedated after local anesthetic infiltration. Grafts were attached to the cutaneous margin of the wound with staples and/or sutures if the horse was anesthetized or if the recipient site was desensitized. Cyanoacrylate glue was used to attach the grafts to the cutaneous margin of the wound of 3 horses. Medical records were reviewed for history, physical examination findings, grafting technique, postoperative complications, and outcome. Results: Three horses had full‐thickness skin grafting to cover a fresh defect created by excision of a cutaneous neoplasm, and 3 horses had full‐thickness skin grafting to cover a fresh or granulating laceration. Grafts were completely accepted in 5 horses. The superficial layers of all grafts sloughed, but the final cosmetic appearance of accepted grafts was good. Conclusions: Full‐thickness skin grafting can be performed in standing sedated horses with good cosmesis, especially when the meshed graft is expanded minimally. Clinical Relevance: Good acceptance of a full‐thickness graft can be expected, regardless of whether the graft is applied to a fresh or granulating wound.     

Effects of topical application of antimicrobials and bandaging on healing and granulation tissue formation in wounds of the distal aspect of the limbs in horses

OBJECTIVE: To determine whether povidone iodine ointment or 2 forms of silver sulfadiazine applied topically to wounds of the distal aspect of the limbs in horses affect the rate of second intention healing and to evaluate the additional influence of bandaging with these antimicrobials on granulation tissue formation. ANIMALS: 6 healthy adult horses. PROCEDURE: Six standardized 2.5-cm2 skin wounds/horse were distributed between the dorsomedial surfaces of the metacarpi and metatarsi. One of the following 6 treatments was applied to each wound: 1% silver sulfadiazine cream with bandage, 1% silver sulfadiazine slow-release matrix with bandage, 1% silver sulfadiazine slow-release matrix without bandage, povidone-iodine ointment with bandage, untreated control with bandage, and untreated control without bandage. Wound area, granulation tissue area, and perimeter were measured by use of planimetry software applied to digital images. Exuberant granulation tissue was excised when present. Days until healing, rate of healing parameter, rate of contraction, and epithelialization were compared among wound treatment groups. RESULTS: Healing parameters and mean days to healing did not differ significantly among any of the wound treatment groups. Percentage wound contraction and rate of epithelialization were similar among wound treatments. All bandaged wounds produced exuberant granulation tissue, which was surgically excised; none of the unbandaged wounds produced exuberant granulation tissue. CONCLUSIONS AND CLINICAL RELEVANCE: When exuberant granulation tissue is removed, rates of epithelialization and wound contraction were not different among wound treatment groups, whether bandaged or unbandaged. Topical application of 1% silver sulfadiazine slow-release matrix on unbandaged wounds induced the same result as medications applied beneath bandages, but without exuberant granulation tissue formation.     

Effects of hyperbaric oxygen on full-thickness meshed sheet skin grafts applied to fresh and granulating wounds in horses

OBJECTIVE: To determine the effects of hyperbaric oxygen therapy (HBOT) on full-thickness skin grafts applied to fresh and granulating wounds of horses. ANIMALS: 6 horses. PROCEDURES: On day 0, two 4-cm-diameter circular sections of full-thickness skin were removed from each of 2 randomly selected limbs of each horse, and two 4-cm-diameter circular skin grafts were harvested from the pectoral region. A skin graft was applied to 1 randomly selected wound on each limb, leaving the 2 nongrafted wounds to heal by second intention. On day 7, 2 grafts were harvested from the pectoral region and applied to the granulating wounds, and wounds grafted on day 0 were biopsied. On day 14, 1 wound was created on each of the 2 unwounded limbs, and the wounds that were grafted on day 7 were biopsied. All 4 ungrafted wounds (ie, 2 fresh wounds and 2 wounds with 1-week-old granulation beds) were grafted. The horses then received HBOT for 1 hour daily at 23 PSI for 7 days. On day 21, the grafts applied on day 14 were biopsied. RESULTS: Histologic examination of biopsy specimens revealed that grafts treated with HBOT developed less granulation tissue, edema, and neovascularization, but more inflammation. The superficial portion of the graft was also less viable than the superficial portion of those not treated with HBOT. CONCLUSIONS AND CLINICAL RELEVANCE: The use of HBOT after full-thickness skin grafting of uncompromised fresh and granulating wounds of horses is not indicated.     

Kinetics of healing of grafted and nongrafted wounds on the distal portion of the forelimbs of horses.

Full-thickness, circular, cutaneous wounds (5 cm in diameter) were created on the distal portion of the forelimbs of 6 horses. One wound on each horse was treated with 6 full-thickness punch grafts that were obtained from the horse's neck with a 6-mm skin biopsy punch and inserted in the graft sites on day 14 after wounding. The wound on the contralateral limb was not grafted. A combination of ticarcillin disodium and clavulanate potassium was applied to the wounds when bandages were changed to control bacterial infection. Areas of each wound were measured on days 1, 7, 9, 11, 13 through 15, 17 through 22, 24, 26, 29, and 32 after wounding. Three distinguishable phases of healing were observed (expansion, contraction, and epithelialization), and the time course of each phase was evaluated, using formulas of first-order processes. Rate constants of each phase were not significantly (P less than 0.05) affected by punch grafts.     

Preliminary observations on expression of transforming growth factors beta1 and beta3 in equine full-thickness skin wounds healing normally or with exuberant granulation tissue

OBJECTIVE: To determine whether transforming growth factor (TGF)-beta1 and -beta3 expression differs between equine limb wounds healing normally and those healing with experimentally induced exuberant granulation tissue (EGT). STUDY DESIGN: Six wounds were created on the lateral aspect of both metacarpi of each horse; one forelimb was untreated, and the other was bandaged to stimulate the development of EGT. Sequential wound biopsies allowed comparison of growth factor expression between the two types of wound. ANIMALS: Four horses (2 to 4 years of age; 350 to 420 kg). METHODS: Wounds were assessed grossly, histologically, and by enzyme-linked immunosorbent assay (ELISA) for TGF-beta1 and -beta3 expression at 12 and 24 hours and 2, 5, 10, and 14 days postoperatively. RESULTS: Bandaged wounds developed EGT. In all wounds, TGF-beta1 peaked early and remained elevated at 14 days. Peak TGF-beta1 concentration was higher in wounds with EGT, but not significantly so. Expression of TGF-beta3 differed from TGF-beta1, with peak TGF-beta3 concentrations being delayed. Concentrations of TGF-beta3 were higher in wounds healing normally, but this difference was not significant. CONCLUSIONS: During both normal and exuberant wound repair, the expression of TGF-beta1 occurred earlier than TGF-beta3 expression. Wounds healing with EGT tended to have higher concentrations of fibrogenic TGF-beta1 and lower concentrations of antifibrotic TGF-beta3 than wounds healing normally, although these differences were not statistically significant. CLINICAL RELEVANCE: This study suggests that the production of EGT in bandaged wounds may be related to increased expression of fibrogenic TGF-beta1 and decreased expression of antifibrotic TGF-beta3. Further investigation of the roles of TGF-beta1 and -beta3 may be important in understanding the molecular control of EGT in horses.     

Expression of transforming growth factor beta(1), beta(3), and basic fibroblast growth factor in full-thickness skin wounds of equine limbs and thorax

OBJECTIVE--To map the expression of transforming growth factor (TGF)-beta(1), TGF-beta(3), and basic fibroblast growth factor (bFGF) in full-thickness skin wounds of the horse. To determine whether their expression differs between limbs and thorax, to understand the pathogenesis of exuberant granulation tissue. STUDY DESIGN--Six wounds were created on one lateral metacarpal area and one midthoracic area of each horse. Sequential wound biopsies allowed comparison of the temporal expression of growth factors between limb and thoracic wounds. ANIMALS--Four 2- to 4-year-old horses. METHODS--Wounds were assessed grossly and histologically at 12 and 24 hours, and 2, 5, 10, and 14 days postoperatively. ELISAs were used to measure the growth factor concentrations of homogenates of wound biopsies taken at the same timepoints. RESULTS--TGF-beta(1) peaked at 24 hours in both locations and returned to baseline in thoracic wounds by 14 days but remained elevated in limb wounds for the duration of the study. Expression kinetics of TGF-beta(3) differed from those of TGF-beta(1). TGF-beta(3) concentrations gradually increased over time, showing a trend toward an earlier and higher peak in thoracic compared with limb wounds. bFGF expression kinetics resembled those of TGF-beta(1), but no statistically significant differences existed between limb and thoracic wounds. CONCLUSIONS--Growth factor expression is up-regulated during normal equine wound repair. TGF-beta(1) and TGF-beta(3) show a reciprocal temporal regulation. Statistically significant differences exist between limb and thoracic wounds with respect to TGF-beta(1) expression. CLINICAL RELEVANCE--The persistence of TGF-beta(1) expression in leg wounds may be related to the development of exuberant granulation tissue in this location, because TGF-beta(1) is profibrotic.     

Effect of autologous platelet-rich plasma application on cutaneous wound healing in dogs

This study was conducted to identify the effectiveness of platelet-rich plasma (PRP) and efficacy of intralesional injection as a method of application to acute cutaneous wounds in dogs. Healthy adult beagles (n = 3) were used in this study. Autologous PRP was separated from anticoagulant treated whole blood in three dogs. Cutaneous wounds were created and then treated by intralesional injection of PRP in the experimental group, while they were treated with saline in the control group on days 0, 2 and 4. The healing process was evaluated by gross examination throughout the experimental period and histologic examination on day 7, 14 and 21. In PRP treated wounds, the mean diameter was smaller and the wound closure rate was higher than in the control. Histological study revealed that PRP treated wounds showed more granulation formation and angiogenesis on day 7, and faster epithelialization, more granulation formation and collagen deposition were observed on day 14 than in control wounds. On day 21, collagen deposition and epithelialization were enhanced in PRP treated groups. Overall, PRP application showed beneficial effects in wound healing, and intralesional injection was useful for application of PRP and could be a good therapeutic option for wound management in dogs.     

Comparison of fibrin glue and suture in the healing of teat incisions in lactating goats

The aims of this study were to investigate whether fibrin glue can be used to close experimentally induced incisions of the teat (mammary papillae) in lactating goats and to compare the healing of the glued with the sutured incisions. Four clinically healthy lactating dairy goats, namely 8 mammary papillae were used. After surgical preparation of the papillae, a 3.5 cm long incision of each papilla was made through skin, muscular layer and mucosa into the papillary sinus. The wounds in the right papillae in all goats were closed with U-shaped uninterrupted 00 chromic catgut sutures. The wounds in the left papillae in all goats were closed, using fibrin glue. One incision was seen to be dehisced and fistulous one day after in fibrin glued teats. The animals were slaughtered 8 days after surgical manipulation. The mammary papillae were removed and examined in the viewpoint on gross and microscopic findings. The healing of wounds was slower and feeble in glued mammary papillary incisions, however faster and stronger in sutured incisions on day 8 after operations. But, available outcomes like less tissue thickness and positive cosmetic results could be obtained byfibrin glue used on mammary papillary incisions, which are very important for teats to be milked by hand and milking machine. Results suggest that it is advisable to use only one or two simple interrupted sutures in teat incisions glued with fibrin to prevent the dehiscence but with a more reliable healing than the sutured incisions.     

The effectiveness of the haemodialysate Solcoseryl for second-intention wound healing in horses and ponies

Second-intention healing of limb wounds in horses is often problematic. Solcoseryl is a protein-free, standardized dialysate/ultrafiltrate (HD) derived from calf blood, which has been shown to improve healing in both animals and humans. The efficacy of HD in the healing of deep wounds in horses and ponies was investigated. Deep wounds of 20 by 35 mm were created on both metatarsi (skin, subcutis, periosteum) and on both femoral biceps muscles (skin, subcutis, muscle) of five horses and five ponies. The wounds on one side were treated with HD, four times a week during the period that the wounds were bandaged and once daily thereafter. The wounds on the other side were left untreated. In the first 4 weeks of the healing period HD stimulated healing but inhibited healing thereafter. This pattern was significant for all wound groups (P < 0.001). Because of this change in effect, the overall effect on wound healing over the entire period was not significant (P = 0.77). HD stimulated healing initially by provoking a greater initial inflammatory response, faster contraction and faster formation of granulation tissue. Subsequently, HD inhibited healing because it significantly delayed epithelialization and caused protracted inflammation. The effects of HD were most pronounced in the horses. Because this study distinguished between contraction and epithelialization, it could be shown that HD stimulated contraction but inhibited epithelialization. Therefore, HD is useful in horses for the treatment of deep wounds during the initial phase of healing by second intention, i.e. during the first weeks when wound contraction can be expected. Treatment should be ceased when epithelialization becomes predominant.     

Cutaneous wound healing in the cat: a macroscopic description and comparison with cutaneous wound healing in the dog

OBJECTIVE: To describe the macroscopic features of first and second intention cutaneous wound healing in the cat and compare with the dog. STUDY DESIGN: Experimental study. ANIMALS: Domestic shorthaired cats (6) and beagle dogs (6). METHODS: Square, open cutaneous wounds created on the dorsal aspect of the thorax were evaluated for 21 days for temporal and spatial development of granulation tissue, wound contraction, epithelialization, and total healing. To evaluate first intention healing, breaking strength of sutured linear cutaneous wounds was measured at 7 days post-wounding. Laser-Doppler perfusion imaging was used to measure cutaneous perfusion. RESULTS: First intention healing: sutured wounds in cats were only half as strong as those in dogs at day 7 (0.406 versus 0.818 kg breaking strength). Second intention healing: cats produced significantly less granulation tissue than dogs, with a peripheral, rather than central distribution. Wound epithelialization and total wound healing (total reduction in open wound area from contraction and epithelialization) were greater for dogs than for cats over 21 days. Wound contraction on day 7 was greater for dogs, but not on day 14 or 21. Cutaneous perfusion was initially greater for dogs than for cats, but no differences were detected after day 7. CONCLUSIONS: Significant, previously unreported differences in cutaneous wound healing exist between cats and dogs. In general, cutaneous wounds in cats are slower to heal. Cats and dogs also appear to use different mechanisms of second intention healing. In cats wounds close mainly by contraction of the wound edges, whereas in dogs wounds close more from central pull, and epithelialization. CLINICAL RELEVANCE: Surgeons should view the cat as a unique species, which presents its own special challenges in wound healing, and should take this into account when planning treatment of feline wounds, either by primary closure, or by second intention healing.     

Effects of 25% propylene glycol hydrogel (Solugel) on second intention wound healing in horses

OBJECTIVE: To evaluate the effect of a commercially available 25% propylene glycol hydrogel preparation (Solugel; Johnson and Johnson Medical, North Ryde, Australia) on healing of full-thickness skin wounds on the distal aspect of the limb in horses. STUDY DESIGN: Experimental. ANIMALS: Eight Standardbred horses. METHODS: Standardized (2.5 x 2.5 cm) full-thickness skin wounds were created over the mid-dorsomedial aspect of both metacarpi in 8 horses. One wound in each horse was dressed with saline solution (0.9% NaCl) soaked gauze, and one was treated with Solugel under dry regular gauze; wounds were then bandaged with gauze-coated cotton wool and elastic adhesive bandages. Wounds were videorecorded and rebandaged twice weekly until healed. Wound healing variables were measured from the videorecordings using a computer software package and analyzed as a randomized complete block design with repeated measures. Where necessary variables were made positive for analysis; significance was set at P <.05. RESULTS: The area of the wound at the first bandage change did not vary between treated and untreated wounds. Treatment had no effect on the total rate of healing, rate of healing during the retraction phase of healing, rate of healing after the retraction phase was complete, or the amount the wounds retracted. CONCLUSIONS: Using this model of wound healing, Solugel had no effect on second intention healing of distal limb wounds in horses. CLINICAL RELEVANCE: Solugel does not appear to have any beneficial effect on healing of small full-thickness skin wounds to the distal limb of horses.     

Temporal localization of immunoreactive transforming growth factor beta1 in normal equine skin and in full-thickness dermal wounds

OBJECTIVE: To describe the localization of immunoreactive transforming growth factor (TGF)-beta1 in both normal skin and full-thickness dermal wounds of the limb and the thorax of the horse. STUDY DESIGN: Six full-thickness excisional wounds were created on the lateral aspect of one metacarpal region and on the midthoracic area of each horse. Sequentially collected tissue specimens from wound margins were assessed for TGF-beta1 expression by immunohistochemistry. ANIMALS: Four horses (2 to 4 years of age). METHODS: A neutralizing monoclonal anti-human TGF-beta1 antibody was used to detect the spatial expression of TGF-beta1 protein by immunohistochemical localization in biopsies obtained before wounding and at 12 and 24 hours, and 5, 10, and 14 days. RESULTS: No differences in localization of immunoreactive TGF-beta1 were detected between limb and thorax, for either intact skin or wounds. Unwounded epidermis stained moderately for TGF-beta1 protein throughout all layers, whereas the dermis was relatively devoid of immunoreactivity. During the acute stage of repair, migrating epithelium lost its stain, whereas cells of epidermal appendages remained strongly immunoreactive. The epithelium recovered its TGF-beta1 immunoreactivity during wound remodeling, although cells of the stratum corneum remained negative. Macrophages of the inflammatory exudate had positive cytoplasmic staining that diminished with time. Immunoreactivity of granulation tissue fibroblasts was evident early on and increased throughout the repair process. CONCLUSIONS: TGF-beta1 is constitutively expressed in normal, unwounded equine epithelium. Its expression is upregulated within the skin on injury and is associated with the cells involved in wound repair. CLINICAL RELEVANCE: A more precise understanding of the temporal and spatial expression of TGF-beta1 during wound repair in horses should provide the groundwork for possible future manipulations of both normal and aberrant tissue repair.     

Effects of a proprietary topical medication on wound healing and collagen deposition in horses

Full-thickness skin wounds were created on the dorsum of both metacarpi in 8 horses. Three topical treatment regimens were studied. All wounds were bandaged with a nonadherent dressing, which was held in place with a snug elastic wrap. Group-A wounds were treated with a proprietary topical wound medication that consisted of a spray and an ointment. Group-B wounds were treated with the same regimen, except the putative active ingredients in the ointment were omitted. Group-C wounds were treated with a dry nonadherent bandage only. Wound dressings were changed every day and the limbs were photographed every other day until the wounds were healed. Specimens of normal skin and biopsy specimens of healed wounds were examined histologically and were assayed for hydroxyproline content. Wound healing measurements quantitated for each wound were number of days to healing, maximal wound size attained, day wound contraction commenced, day epithelium first noticed, rate of wound contraction, final wound size, and fraction of the wound that healed by contraction. The cosmetic appearance of the healed wounds was also graded. Significant differences were not noticed in hydroxyproline content, histologic appearance, or any of the wound healing measurements between treatment groups. The cosmetic appearance of healed group-A and -B wounds was significantly better than the appearance of group-C wounds. The topical treatment regimens studied neither enhanced nor inhibited wound healing in this study.     

FC-62 Pale sulphonated shale oil exhibits antimicrobial and tissue repairing effects in wound healing

Oleaster ( Elaeagnus angustifolia ) is a small tree that grows throughout Iran. Using smashed tree leaves combined with olive oil is proposed in one ancient Iranian text as a good remedy for wound healing. Our objective was to evaluate this remedy experimentally. The study was carried out in two female 10-month-old Holstein calves. An area of 10 × 10 cm on each side of the thorax was surgically prepared and infiltrated with local anaesthetic. Eight uniform skin wounds were created in two rows with an 8-mm biopsy punch on each prepared area. Each side of an animal was used to evaluate one treatment (Groups 1–4). To make the mixture, fresh oleaster leaves (50 gm) were smashed with a pestle and mixed with olive oil (25 gm). The wounds were treated for 7 days. The wounds of Groups 1–3 were rinsed daily with normal saline, after which the mixture of oleaster and olive oil (Group 1) or only the olive oil (Group 2) was applied. In Group 4, no treatment was applied. All wounds were left open. On day 8, skin biopsies were taken from the wounds for histopathologic study. Group 1 wounds all showed mild granulation tissue, scab formation and complete re-epithelialization. In Group 2, there was mild granulation tissue, massive scab formation and minimal re-epithelialization. In Groups 3 and 4, mild granulation tissue, severe scab formation and very limited re-epithelialization were observed. We conclude that a fresh oleaster leaf preparation can be an effective remedy for wound healing.
Funding: Self-funded.     

Treatment of degloving injuries with autogenous full thickness mesh scrotal free grafts

In this report, we evaluated the effectiveness of scrotal tissue as an autogenous free skin graft to treat cutaneous degloving injuries of the distal limb in dogs. Surgery was performed on two male intact dogs with distal extremity degloving wounds. Dog #1 had a tarsal degloving wound with exposure of the distal tibial and tarsal bones. Dog #2 had a degloving injury over the metacarpals. Wounds were treated with daily wet-to-dry bandages in order to develop a healthy bed of granulation tissue at the graft recipient site. Scrotal ablation castration was performed once the recipient site had been prepared. Subcutaneous and adipose tissue were excised from the scrotal graft and mesh slits were created. The graft was applied to the recipient site with monofilament absorbable simple interrupted sutures. Bandaging was performed postoperatively, and bandage changes occurred four, seven, nine and 11 days postoperatively. Follow-up was performed at 30 days. In dog #1, the tarsal degloving injury graft had first intention healing with 100% graft take on day 11. In dog #2, the metacarpal degloving injury graft had 90% graft take on day nine, with second intention healing adjacent to the fifth digit pad. The scrotum is often discarded at the time of scrotal ablation castration. Distal extremity wounds can be successfully treated with free skin grafts. In male dogs, the scrotum is a viable option as a full thickness mesh free graft for distal extremity reconstructive surgery.     

Effect of wound location and the use of topical collagen gel on exuberant granulation tissue formation and wound healing in the horse and pony

Preformed collagen gel was topically applied to cutaneous wounds of the equine dorsal fetlock (thoracic limb) and metatarsal regions to evaluate the effect on exuberant granulation tissue production and wound healing. In 6 horses and 3 ponies (less than 140 cm high at the withers and less than 365 kg), 36 standardized cutaneous limb wounds were surgically induced (4 wounds/animal); 18 wounds were treated topically with collagen gel, and 18 wounds were not treated (controls). Collagen gel was initially applied to the wound at 0, 2, or 7 days after wound formation (groups 1, 2, and 3, respectively). Four measurements were regularly made: amount of wound contraction and the size of the granulation bed, epithelial covering, and total wound. Sequential skin and wound biopsies were evaluated histologically to assess wound healing. Using a computer, data were analyzed for differences in the 4 measurements between treated and control wounds, between fetlock wounds and metatarsal wounds, and among groups 1, 2, and 3. Analyses were performed on days 15 and 45 of wound healing and on the final day of healing. A significant difference (P greater than 0.05) in the production of exuberant granulation tissue, rate of epithelialization, or degree of wound contraction was not detected between the collagen-treated and control wounds. Total healing time and final scar size were similar. Wound healing patterns were significantly different (P less than 0.05) in the fetlock wounds and metatarsal wounds. All wounds enlarged up to day 15 with fetlock wounds enlarging significantly more than did the metatarsal wounds.(ABSTRACT TRUNCATED AT 250 WORDS)     

Spatial and temporal expression of types I and II receptors for transforming growth factor beta in normal equine skin and dermal wounds

OBJECTIVE : To describe immunolocalization of TGF-beta receptors (RI and RII) in normal equine skin and in thoracic or limb wounds, healing normally or with exuberant granulation tissue (EGT). STUDY DESIGN : Group A: six wounds on one metacarpus and one midthoracic area. Group B: six wounds on both metacarpi, one of which was bandaged to stimulate EGT. Immunohistochemistry was used to detect RI and RII expression in wound margins. ANIMALS : Eight horses, randomly assigned to one of two study groups. METHODS : Neutralizing polyclonal anti-rabbit RI and RII antibodies were used to detect spatial expression of RI and RII in biopsies obtained before wounding, at 12 and 24 hours, and 5, 10 and 14 days after wounding. RESULTS : RI and RII were co-localized in both unwounded and wounded skin. There were no differences in cell types staining positively between tissues obtained from the limb and the thorax, or from normally healing limb wounds and limb wounds with EGT, at any time. Because of increased cellularity within EGT, staining intensity of limb wounds with 'proud flesh' was greater than limb wounds healing normally, and thoracic wounds, during the proliferative phase of repair. CONCLUSIONS : Strong expression of RI and RII, particularly in limb wounds with EGT, suggested that signalling for stimulation of matrix proteins is in place to contribute to scarring. CLINICAL RELEVANCE : This information may help determine the appropriate time for using receptor antagonists to prevent scarring of limb wounds of horses.     

FC‐60 The role of a fresh oleaster leaf preparation in healing of experimental wounds in calves: a histopathologic study

Oleaster (Elaeagnus angustifolia) is a small tree that grows throughout Iran. Using smashed tree leaves combined with olive oil is proposed in one ancient Iranian text as a good remedy for wound healing. Our objective was to evaluate this remedy experimentally. The study was carried out in two female 10‐month‐old Holstein calves. An area of 10 × 10 cm on each side of the thorax was surgically prepared and infiltrated with local anaesthetic. Eight uniform skin wounds were created in two rows with an 8‐mm biopsy punch on each prepared area. Each side of an animal was used to evaluate one treatment (Groups 1–4). To make the mixture, fresh oleaster leaves (50 gm) were smashed with a pestle and mixed with olive oil (25 gm). The wounds were treated for 7 days. The wounds of Groups 1–3 were rinsed daily with normal saline, after which the mixture of oleaster and olive oil (Group 1) or only the olive oil (Group 2) was applied. In Group 4, no treatment was applied. All wounds were left open. On day 8, skin biopsies were taken from the wounds for histopathologic study. Group 1 wounds all showed mild granulation tissue, scab formation and complete re‐epithelialization. In Group 2, there was mild granulation tissue, massive scab formation and minimal re‐epithelialization. In Groups 3 and 4, mild granulation tissue, severe scab formation and very limited re‐epithelialization were observed. We conclude that a fresh oleaster leaf preparation can be an effective remedy for wound healing. Funding: Self‐funded.     

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 cm × 2 cm 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.