The modified Meek technique as a novel method for skin grafting in horses: evaluation of acceptance, wound contraction and closure in chronic wounds

REASONS FOR PERFORMING STUDY: The acceptance of skin grafts in horses is unpredictable and the final cosmetic result can be disappointing. Besides movement and infection, graft failure is often caused by chronic inflammation, inherently present during second intention healing of limb wounds in horses. In human burns affected by infection and inflammation, the acceptance of the island skin grafts of the modified Meek technique appeared to be better than meshed sheet skin grafts. HYPOTHESIS: The percentage take of Meek micrografts is higher than of other techniques; and rates of both wound contraction and epithelialisation are increased. METHODS: Large traumatic limb wounds of 13 horses healing by second intention were grafted using the modified Meek technique. Photographs of the wounds were taken at set intervals. Wound areas, and areas of acceptance and rejection were determined using a digital image post processor (Scion Image). The percentages of take, wound contraction and epithelialisation were calculated. RESULTS: The initial mean wound area was 7500 mm2. Graft acceptance was mean +/- s.d. 93.7 +/- 5.9%. Wound closure was due to contraction (55.2 +/- 11.1%) and epithelialisation (44.8 +/- 11.1%) and resulted in a 96.7 +/- 3.6% reduction of the initial wound area 29.1 +/- 6 days after grafting. All wounds showed functional and cosmetic healing. CONCLUSIONS: The method for skin grafting in horses achieved higher percentages of take than reported previously and consistent cosmetic and functional results. The grafts increased not only the rate of epithelialisation but also had a strong positive effect on wound contraction, resulting in rapid closure and smaller scars. POTENTIAL RELEVANCE: The modified Meek technique proved to be a novel technique for skin grafting equine wounds in clinical practice, which can be performed easily. The molecular background of the increase of wound contraction by the grafts may provide a clue in the search for medicinal stimulation of wound contraction during second intention healing.     

Low energy laser irradiation treatment for second intention wound healing in horses

Low energy helium-neon laser irradiation was administered to full thickness skin wounds (3 cm × 3 cm) on the dorsal surface of the metacarpophalangeal/metatarsophalangeal joints and cranial surface of the tarsocrural joints of eight horses. The effects on wound healing were analyzed statistically. There were no differences (p > 0.55) observed in the rate of wound healing between the low energy laser irradiated wounds and the control wounds. There was a significant difference (p < 0.006) observed in the rate of healing between the anatomical sites. Tarsal wounds healed more rapidly than fetlock wounds.     

半导体激光照射对犬创伤愈合的影响

用本地杂种犬１２只分为两组，在背部两侧定边长２ｃｍ的正方形皮肤全层缺损创，对照组左侧作为划体对照，每天对创面愈合情况进行观察记录。结果表明：砷化镓激光照射可促进犬全层皮肤缺损创的愈合，但差异不显著，而对激光照射７天内的愈合速度有显著的促进作用。     

Effect of topical rh-TGF-beta 1 on second intention wound healing in horses

OBJECTIVE: To investigate the effects on wound healing of transforming growth factor-beta 1 as a topical treatment to full-thickness, excisional wounds of the distal limb of horses. DESIGN: A randomised block study using four horses, each with wounds assigned to four treatment groups. ANIMALS: Four adult Standardbred geldings. PROCEDURE: Four, 4 cm2, full-thickness wounds were created on the dorsomedial and dorsolateral aspect of the metacarpus or metatarsus of each limb of four horses, giving a total of 64 wounds. For each limb, wounds were randomly assigned to four treatment groups: no treatment (control), carrier (Methyl Cellulose gel), 50 ng/wound rhTGF-beta 1 in carrier, and 500 ng/wound rhTGF-beta 1 in carrier. Wounds were treated on day 0 and day 8. Effects of treatment were evaluated on the basis of the presence of exuberant granulation tissue requiring excision, number of times excision was required, total wound area, area of epithelialisation, area of granulation, and histological evaluation of biopsy samples of wounds on day 8 and excised wounds on day 21. RESULTS: Topical application of TGF-beta 1 at the two concentrations studied had no significant effect on the total area of wounds (P = 0.7), the area of granulation tissue (P = 0.78), the area of epithelialisation (P = 0.92), histological assessment or subjective clinical assessment of wounds. CONCLUSION: TGF-beta 1 had no beneficial effects on wound healing. Additional trials are needed to test if it has value for wound treatment in horses.     

The effect of equine recombinant growth hormone on second intention wound healing in horses

OBJECTIVE: To evaluate the effect of intramuscular administration of recombinant equine growth hormone on healing of full thickness skin wounds on equine limbs. STUDY DESIGN: Experimental. ANIMALS: Nine Standardbred horses. METHODS: In study 1, standardized full thickness skin wounds (2.5 x 2.5 cm) were made over the dorsomedial aspect of the mid-cannon bone of 1 forelimb and 1 hindlimb in 9 horses. Wounds were bandaged without treatment (control subjects) and videorecorded twice weekly until healed. Then, in study 2, similar wounds were created on the opposite limbs; 6 horses were administered intramuscular recombinant equine growth hormone (10 microg/kg daily for 7 days, then 20 microg/kg daily for 49 days), and 3 horses (control subjects) were administered equivalent volumes of sterile water. Wounds were videorecorded 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 factorial analysis of variance; significance was set at P <.05. RESULTS: No differences in the measured variables were detected between wounds in study 1 and the control wounds in study 2. In recombinant equine growth hormone-treated horses, wounds retracted more during treatment and contracted faster after treatment stopped when compared with wounds from untreated horses. No other treatment effects were detected. CONCLUSIONS: Recombinant equine growth hormone seemingly increases wound retraction. After treatment ceases, wound contraction increases. CLINICAL RELEVANCE: Intramuscular administration of recombinant equine growth hormone (10 microg/kg daily for 7 days, then 20 microg/kg daily for 49 days) does not appear to have any beneficial clinical effect on healing of equine limb wounds.     

Effects of Chlorhexidine Diacetate and Povidone-lodine on Wound Healing in Dogs

To correlate the results of an in vitro study with clinical response, the effects of 0.005 and 0.05% chlorhexidine diacetate and 0.1 and 1.0% povidone-iodine concentrations on wound healing were evaluated in five beagle dogs. Full-thickness skin wounds (2 X 2 cm) were irrigated once daily for 14 days with the antiseptic solutions or physiologic-buffered saline. Chlorhexidine diacetate 0.05% had significantly more bactericidal activity than povidone-iodine and saline, and both chlorhexidine diacetate concentrations had residual effects 6 hours after irrigation. Neither povidone-iodine nor saline had significant bactericidal activity. The percentages of unhealed wound area and wound contraction were calculated 7, 14, and 21 days after wounding. Healed wound area and contraction were similar in wounds treated with chlorhexidine diacetate and povidone-iodine. However, wounds treated with chlorhexidine diacetate had more healed wound area on days 7 and 14 and more contraction on days 7, 14, and 21 than saline-treated wounds. At the concentrations tested, chlorhexidine diacetate irrigations provided bactericidal activity and were more beneficial to wound healing than irrigations with saline alone. These results suggest that concentrations of chlorhexidine diacetate which are cytotoxic to tissue culture fibroblasts in vitro do not interfere with wound healing in vivo.     

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)     

The effects of topical tripeptide copper complex and helium-neon laser on wound healing in rabbits

The aim of this study was to compare the clinical and histopathological effects of tripeptide copper complex (TCC) and two different doses of laser application (helium-neon laser, 1 and 3 J cm(-2)) on wound healing with untreated control wounds. Experimental wounds were created on a total of 24 New Zealand white rabbits and topical TCC or laser was applied for 28 days. The wounds were observed daily, and planimetry was performed on days 7, 14, 21 and 28 to measure the unhealed wound area and percentage of total wound healing. Biopsies were taken weekly to evaluate the inflammatory response and the level of neovascularization. The median time for the first observable granulation tissue was shorter (P < 0.05) in the low and high dose laser groups than in the control group (3 and 2.66 vs. 4.5 days), but was not different between the TCC and control groups (4.16 vs. 4.5 days). Filling of the open wound to skin level with granulation tissue was faster (P < 0.05) in the TCC and high dose laser groups than in the control group (14 and 16 vs. 25 days), but was not different between the low dose laser and control groups (23 vs. 25 days). The average time for healing was shorter (P < 0.05) in the TCC and high dose laser groups (29.8 and 30.2 vs. 34.6 days), but was not different between the low dose laser and control groups (33.8 vs. 34.6 days). Histopathologically, wound healing was characterized by a decrease in the neutrophil counts and an increase in neovascularization. The TCC and high dose laser groups had greater neutrophil and vessel counts than in the control group, suggesting a more beneficial effect for wound healing.     

Effect of bandaging on second intention healing of wounds of the distal limb in horses

Objective   To evaluate the effect of a non-occlusive dressing incorporated in a 3-layer bandage on second intention healing of wounds of the distal portion of the limb.
Study Design   Untreated wounds in 33 adult horses used in four studies using the same wound-healing model conducted over 5 years.
Methods   Standardised, full-thickness wounds were made in the skin overlying the dorsomedial aspect of the mid-metacarpus; 17 horses were bandaged with a non-occlusive dressing covered by gauze-coated cotton wool that was compressed with adhesive tape; 16 horses were left unbandaged. Wounds were photographed weekly for 9 weeks and the images were analysed electronically.
Results   There were significant effects associated with bandage (P < 0.0001), week (P < 0.001), and bandage by week interaction (P < 0.0001). There was no difference in wound area at the first time-point after wound creation (P = 0.38). After week 1, there was a difference between bandaged and unbandaged wounds in wound area at each measurement until the end of the study. Bandaged wounds showed greater and more prolonged retraction. Unbandaged wounds retracted for 2 weeks before beginning to contract, whereas bandaged wounds continued to retract for 3 weeks. In bandaged wounds excess granulation tissue required regular trimming, but not in unbandaged wounds. There was no difference between groups in the total days to healing or the overall rate of healing.
Conclusions   These results should be treated with caution until validated with contemporaneous, controlled studies. Covering a wound with a non-occlusive dressing in a 3-layer bandage led to greater wound retraction, modulated the rate of wound contraction and promoted excessive granulation tissue. If excessive granulation tissue is excised regularly, bandaging has no effect on total time to healing.     

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.     

Effects of 3 biologic dressings on healing of cutaneous wounds on the limbs of horses

Three biologic dressings [split-thickness allogeneic skin (STS)], allogeneic peritoneum (P), and xenogenic porcine small intestinal submucosa (PSIS)] were studied to determine their effects on bacterial proliferation, inflammatory reaction, vascularization, and overall healing and to compare the effects of these dressings with the effects of a nonbiologic dressing, a nonadherent synthetic pad (NASP). A medial wound (3 cm in diameter) and 2 lateral wounds (2 cm in diameter) were created at the junction of the proximal and middle thirds of each metacarpus and metatarsus in 5 horses. Each medial wound and the proximolateral wound received an STS, P, PSIS, or NASP dressing on day 8 after wounding. The other lateral wound received an NASP dressing. Bacterial proliferation, inflammatory reaction (histologic changes), and drhessing vascularization were evaluated 6 d after application of the dressing. Percentages of contraction and epithelialization, as well as healing time, were determined when the wounds had completely epithelialized. The practical applicability of the different dressings to equine wound management was also assessed. No significant difference was detected in the parameters evaluated among the treated wounds or between the treated and control wounds. The biologic dressings had no effect on infection, inflammatory response, or healing time. Vascularization was not identified in any of the biologic dressings. The PSIS and P dressings required numerous applications over the study period. The STS dressings are more practical than PSIS and P dressings owing to ease of application and stability. Thus, these biologic dressings offer no apparent advantage over a nonbiologic dressing for treatment of small granulating wounds.     

Effect of Porcine Small Intestinal Submucosa on Acute Full-Thickness Wounds in Dogs

Objective— To evaluate the effects of porcine small intestinal submucosa (PSIS) on the healing of full-thickness wounds in dogs, specifically the appearance of granulation tissue, percent epithelialization and contraction, histologic variables of inflammation and repair, and aerobic culture results.
Study Design— Prospective, controlled, experimental study.
Animals— Purpose-bred, female dogs (n=10).
Methods— Wounds were created bilaterally on the trunk; 1 side as a control and 1 treated with PSIS. First appearance of granulation tissue was recorded. Total wound area, open wound area, and epithelialized area were measured at 21 time points—wound contraction and percent epithelialization were calculated. Aerobic cultures were taken at 4 time points and wound biopsies at 8. Histologic features were graded into an Acute Inflammation Score and Repair Score.
Results— There was no difference in first appearance of granulation tissue between PSIS-treated and control wounds. Wound contraction was significantly faster in control wounds as was percent epithelialization after day 21. Histologic Acute Inflammation Scores were significantly higher in PSIS-treated wounds compared with control wounds on days 2 and 6. There were no differences in Histologic Repair Scores between PSIS-treated and control wounds or in aerobic culture results.
Conclusion— Wounds treated with PSIS contract more slowly, epithelialize less, and have more pronounced acute inflammation after implantation than control wounds.
Clinical Relevance— Acute, full-thickness wounds in dogs do not benefit from treatment with PSIS.     

Do magnetic fields influence soft tissue wound healing?--A preliminary communication

Magnetic fields have been considered for treating many ailments over man's history. There have been many anecdotal unsupported claims for successful treatment of soft tissue injury although reports have been more substantive in the orthopaedic field. The widespread clinical and veterinary use of a light self-adhesive magnetic foil in Europe prompted this trial of experimental wound healing. One hundred and sixty Sprague-Dawley rats had a linear 2.5 cm incision or a circular 1 cm skin defect made over the mid-dorsal spine. Equal numbers were randomised to receive either a magnetic foil or a dummy (control) dressing. At three, seven, 10 or 14 days linear wounds were distracted using a tensiometer; open defects were measured, excised and assayed for collagen content; 14-day wounds were examined histologically. Although wound tensile strengths increased and open wounds decreased in size with increase of hydroxyproline, there were no statistically significant differences between treated or control animals. Although easy to apply the alternate magnetic foil (giving 400 Gauss at 7 mm) conferred no statistically significant effect on soft tissue healing.     

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.     

Application of Exogenous Esterified Hyaluronan to Equine Distal Limb Wounds

The objective of this study was to evaluate the efficacy of topical application of a hyaluronan (HA) derivative in wound healing with respect to the rate of epithelialization, fibroplasia, angiogenesis and contraction, magnitude of the local inflammatory response, local expression of transforming growth factor-β 1 and 3 (TGF-β 1 and 3), tumor necrosis factor-α (TNF-α), and collagen type III deposition. In six healthy adult horses, six full-thickness skin wounds were created on the dorsal aspect of both metacarpi using a sterile template. Sites were sampled at 0, 1, 2, 5, 14, 21, and 35 days following wounding. Wounds on one limb were dressed with commercially available esterified HA fleece under a nonadherent dressing. The opposite limb was covered with the nonadherent dressing alone (control). Images of the most proximal wounds were used to determine the area of total healing and the relative contributions of epithelialization and contraction to healing. At each sample time, a control and treatment biopsy were taken for histological evaluation and special stains. All samples were evaluated for degree of inflammation, fibroplasia and angiogenesis; in situ hybridization for type III collagen, TGFβ1 and 3, and immunohistochemistry for TNF-α. Mean percentages of total wound healing, epithelialization, and wound contraction were not significantly different between control and treatment groups. In treated horses, initial wound expansion was significantly decreased during the first 2 weeks. Mononuclear cell numbers, counted in the granulation tissue, increased in both control and treated limbs over the entire course of the study. However at day 35 the macrophage numbers counted in the treated horses were significantly increased compared with the control limbs (P < .05). Although not statistically significant, relative staining for type III collagen in the treated wounds was less than that of control wounds. Results of the present study do not support a benefit of an exogenous HA-derivative in the healing of distal limb wounds in horses. The shortcomings of the study design are discussed.     

The effect of a porcine-derived small intestinal submucosa product on wounds with exposed bone in dogs

OBJECTIVE: To determine the effect of a porcine-derived small intestinal submucosa product (PSIS) on healing time, epithelialization, angiogenesis, contraction, and inflammation of wounds with exposed bone on the distal aspect of the limbs of dogs. STUDY DESIGN: Prospective, controlled, experimental study. ANIMAL POPULATION: 10 young adult, purpose-bred, male Beagles. METHODS: Small wounds with exposed bone were created on the lateral aspect of metatarsal V and the medial aspect of metatarsal II on both hindlimbs. Three sheets of PSIS were sutured into the wounds of the treated limb, and the other limb served as a control. On day 10, punch biopsies of the medial metatarsal wounds were collected and were evaluated microscopically after routine hematoxylin and eosin and phosphotungstic acid hematoxylin (PTAH) staining. The lateral metatarsal wounds were evaluated by planimetry and laser Doppler perfusion imaging on days 7, 14, and 21. Time until complete wound healing was also recorded. The level of significance was set at P < or =.05 for all statistical analyses. RESULTS: Laser Doppler perfusion measurements were significantly higher in control wounds on day 7, but no differences were noted on days 14 and 21. No significant differences in planimetric values, histopathologic appearance, or time until complete wound healing were noted among treated and control groups. CONCLUSIONS: No objective differences in healing were noted between control wounds and wounds treated with PSIS. CLINICAL RELEVANCE: There appears to be no contraindication to the use of PSIS on clean wounds with exposed bone on the distal limbs of dogs. However, our objective data provides no evidence that this product affects epithelialization, contraction, or time to complete healing in wounds with exposed bone.     

The effects of omega-3 fatty acid diet enrichment on wound healing

Omega-3 fatty acids were evaluated to determine how their anti-inflammatory properties affect wound healing. Twelve Beagle dogs were divided into two groups of six. Group I was fed an n-3 fatty acid enriched diet (n-3 FAED) with an n-6 to n-3 fatty acid ratio of 0.3, and group II was fed a control diet (CD) with a ratio of 7.7. Open and sutured cutaneous wounds were created on the trunk of the dog, and evaluated by laser Doppler perfusion imaging, tensiometry, planimetry, histopathology, and eicosanoid content. At 5 days, the n-3 FAED-fed dogs had significantly less epithelialization of the open wounds ( P  = 0.0343) and significantly less oedema in sutured wounds ( P  = 0.015). There were also tendencies of less tissue perfusion ( P  = 0.086), lower PGE₂ levels ( P  = 0.0756) and negative wound contraction in open wounds at 5 days. The n-3 FAED used in this study did not appear to have any outstanding long-term negative effect on wound healing.     

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.     

Influence of wound shape on wound contraction in horses.

Three sets of paired circular and square full-thickness skin wounds were made on the dorsum of the metacarpus (n = 48) of 8 horses. Each wound was 6.25 cm2 in area. The wounds were treated topically with an ointment, nonadherent dressing, and bandaged with a snug elastic wrap. Wounds were photographed every other day until healing was complete. Wound areas were measured and exponential and linear wound healing models were applied to the wound healing data generated. Wound healing variables measured for each wound were: number of days to healing, maximal size attained, rate of wound contraction (calculated by use of first-order and linear models), final wound size, and percentage of wound that healed by contraction. The exponential model fit the data significantly better than the linear model. The maximal size attained by circular wounds was significantly smaller than the maximal size attained by square wounds. Wound shape did not influence the rate of wound healing. On the basis of our findings, conversion of circular defects to square defects would not speed wound healing.     

Evaluation of the effectiveness of an ointment based on Alkannins/Shikonins on second intention wound healing in the dog

The enantiomeric naphthoquinones alkannins and shikonins (A/S) have been established as potent wound healing agents. The purpose of this study was to evaluate the effectiveness of an A/S based ointment for humans on second intention wound healing in the dog, as compared to wound flushing with Lactated Ringer's solution (LRS). Ten mixed breed dogs, aged 2 to 5 y, were used. One 2.5 × 2.5 cm full-thickness skin defect was created on the lateral aspect of each arm for subjective evaluation, laser-Doppler flowmetry (LDF), and planimetry. Additionally, 3 matching 2 × 2 cm wounds were created on opposite sides of the dorsal midline for histologic evaluation. Wounds were treated once daily with the A/S based ointment on the right side and by flushing with LRS on the left until healed (about 20 d). During the healing process, tissue perfusion (mean LDF value) was found to be significantly higher on the side treated with the A/S based ointment compared with the LRS-treated side. Histologically, angiogenesis (on days 4 and 11), collagen production score (on days 4, 11, and 20), and epithelial thickness score (on day 11) were significantly higher in the wounds treated with the A/S based ointment. Wound size, as evaluated by planimetry, decreased significantly from day 0 to day 20 on both sides, but no significant differences were found between the A/S based ointment and LRS-treated wounds.