Effects of a bioactive glass on healing of closed skin wounds in dogs.

OBJECTIVE: To determine effects of intraincisional bioactive glass on healing of sutured skin wounds in dogs. ANIMALS: 9 purpose-bred mature female Beagles. PROCEDURE: 3 small matched bilateral (treated vs control) full-thickness truncal skin incisions were made and sutured. Treated wounds received intraincisional particulate bioactive glass prior to closure. Laser Doppler perfusion imaging was used to assess percentage change in tissue perfusion 3 and 5 days after incision on 1 set of 2 matched wounds, and skin and subcutaneous tissue-cutaneous trunci breaking strength were assessed at 5 days. The other 2 sets of wounds were used for histologic evaluation at 5 and 21 days, respectively. RESULTS: Subjective signs of gross inflammatory reaction were not detected in treated or control wounds. At 5 days, median subcutaneous tissue-cutaneous trunci breaking strength was significantly higher in treated wounds than in control wounds-(188.75 vs 75.00 g). At 5 days, median scores were significantly higher for neutrophils (1 vs 0), macrophages (2 vs 1), and necrosis (1 vs 0) for treated wounds than for control wounds. At 21 days, median macrophage scores were significantly higher for treated wounds than for control wounds (2 vs 1). CONCLUSIONS AND CLINICAL RELEVANCE: Bioactive glass in soft tissues does not cause a gross inflammatory reaction but causes an increase in histologic signs of inflammation, which decreases with time. Bioactive glass has potential for increasing tissue strength. Increased subcutaneous breaking strength could be beneficial in treating wounds in which early healing strength is needed.     

马来亚豪猪中国亚种皮肤伤口无疤痕愈合能力的研究

[目的]研究马来亚豪猪中国亚种皮肤伤口无疤痕愈合方式。[方法]对马来亚豪猪中国亚种的耳部实施贯穿伤及撕裂伤,以7 d为节点拍照记录伤口愈合情况;运用石蜡切片、HE染色等方法对豪猪耳部伤口愈合进展进行组织学观察。[结果]撕裂伤口能够在63 d内以无疤痕的方式愈合,于再生区观察到新生的脂肪组织、真皮、表皮和丰富的毛囊。[结论]该研究结果有助于探明豪猪皮肤创伤无疤痕愈合的机理以及了解动物皮肤损伤修复的机制,可为治愈人的大面积皮肤创伤提供参考。     

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.     

Primary cutaneous coccidioidomycosis in a dog and a cat.

Primary cutaneous coccidioidomycosis was diagnosed in a dog and a cat examined because of lymphangitis and lymphadenitis associated with skin wounds. This benign and self-limiting form of disease was distinguished from the skin lesions associated with systemic coccidioidomycosis by means of historic, physical, and serologic criteria established in human medicine.     

Microbiology of equine wounds and evidence of bacterial biofilms

Horse wounds have a high risk of becoming infected due to their environment. Infected wounds harbour diverse populations of microorganisms, however in some cases these microorganisms can be difficult to identify and fail to respond to antibiotic treatment, resulting in chronic non-healing wounds. In human wounds this has been attributed to the ability of bacteria to survive in a biofilm phenotypic state. Biofilms are known to delay wound healing, principally due to their recalcitrance towards antimicrobial therapies and components of the innate immune response. This study describes the presence of bacterial biofilms within equine wounds. Thirteen 8-mm diameter tissue samples were collected from (n=18) chronic wounds. Following histological staining, samples were observed for evidence of biofilms. Fifty one wounds and control skin sites were sampled using sterile swabs. Control skin sites were on the uninjured side of the horse at the same anatomical location as the wound. The isolated bacteria were cultured aerobically and anaerobically. The biofilm forming potential of all the isolated bacteria was determined using a standard crystal violet microtitre plate assay. Stained tissue samples provided evidence of biofilms within 61.5% (8 out of 13) equine wounds. In total 340 bacterial isolates were identified from all the equine wound and skin samples. Pseudomonas aeruginosa and Enterococcus faecium were the most predominantly isolated bacterial species from equine wound and skin samples respectively. Staphylococcus was the most commonly isolated genus in both environments. Bacteria cultured from chronic and acute wounds showed significantly (P<0.05) higher biofilm forming potential than bacteria isolated from skin. This paper highlights preliminary evidence supporting the presence of biofilms and a high microbial diversity in equine chronic wounds. The presence of biofilms in equine wounds partly explains the reluctance of many lower limb wounds to heal. Non-healing limb wounds in horses are a well documented welfare and economic concern. This knowledge can be used to shape future treatments in order to increase the healing rate and decrease the costs and suffering associate with equine wounds.     

Presuturing as a means of reducing skin tension in excisional biopsy wounds in four horses

Excisional biopsy of a skin lesion was performed in 4 horses after stretching the surrounding skin with mattress sutures. The technique of presuturing allowed all biopsy wounds to be closed without excessive tension on the suture lines.     

Autologous, split skin transplantation on the lower limbs of horses.

The skin grafting experiments were carried out on the cannon regions of horses to throw light on four matters relating to split skin transplantation. They were: The thickness of donor split skin that would provide good wound cover and still leave adequate tissue to permit uneventful healing at the donor site; whether split skin grafts were more readily accepted on fresh than on granulating wounds; the size of wounds that would benefit from grafting; and the maximum size of graft that would be readily accepted. The findings were: Split skin grafts 0.76 mm thickness gave the best results although grafts 0.63 mm thickness were satisfactory; split skin grafts were accepted more readily on fresh wounds than on granulating tissue; wounds which exceeded 1/10th of the skin area on the cannon region justified grafting; the upper limit in size was not established as the largest grafts used were more readily accepted than smaller grafts.     

FC‐61 The role of a liquorice preparation in healing of experimental wounds in calves: a histopathologic study

Liquorice, a derivative of the root of Glycyrrhizia glabra, has been proposed as a treatment for gastric ulcers. Here, a preparation of liquorice combined with sesame oil was evaluated in experimental wound healing. 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 of the animals 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, powdered and sieved liquorice (16 g) was mixed with sesame oil (36 g) to make a suspension. The wounds were treated for 7 days. The wounds of Groups 1–3 were rinsed daily with normal saline, after which the mixture of liquorice and sesame oil (Group 1) or only the sesame oil (Group 2) was applied to the wounds. 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. In Group 1, seven wounds (87%) showed moderate granulation tissue, mild scab formation, and complete re‐epithelialization. In Group 2, there was massive scab formation with no granulation tissue 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 preparation of liquorice and sesame oil can be an effective remedy for wound healing. Funding: Self‐funded.     

Comparative Aspects of the Healing of Excisional Wounds on the Leg and Body of Horses

Standardized 20 mm diameter excisional skin wounds were made on the body and distal limbs of 6 ponies at 18,12, 4, and 2 weeks prior to biopsy. The results of comparative area analysis of leg and body wounds show that leg wounds take significantly longer to heal than body wounds. There is a longer preparatory phase and a greater amount of wound retraction in the leg wounds. At 12 weeks postwounding, the area of the epithelium covering the wound site is significantly larger in the leg wounds compared to the flank wounds. Histological examination of the wounds showed that there is less epithelialization of leg wounds at 2 and 4 week postwounding, and that the granulation tissue of these wounds extends slightly above the level of the adjacent skin. Within the granulation tissue of leg wounds, there are clefts filled with fibrin and inflammatory cells. Once epithelialization is completed, the leg wounds are covered by acanthotic epidermis with numerous large epidermal projections. In contrast, the flank wounds are covered by thin epidermis devoid of epidermal projections. One wound at 18 weeks postwounding had histological features typical of a keloid.     

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.     

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.     

The palliative efficacy of modified Mohs paste for controlling canine and feline malignant skin wounds

In veterinary medicine, the management of malignant skin wounds is highly challenging. We conducted a study on seven case animals (four dogs and three cats) which presented with malignant skin wounds. All seven animals had signs and symptoms which were controlled following treatment with a modified Mohs paste. Upon obtaining informed consent from their owners, the animals requiring management of malignant wounds were enrolled in this study. The modified Mohs paste was prepared by mixing zinc chloride, zinc oxide starch powder, glycerin, and distilled water. The modified Mohs paste was topically applied to and left to remain on the malignant wounds for one hour, under controlled conditions. Once the paste was removed, the wounds were irrigated with a solution of sterile saline. At the first examination, the wounds of each animal were observed for signs of exudate, malodor, and bleeding. In every case, visible improvement was observed immediately after the modified Mohs paste treatment. Specifically, the size of the malignant wounds, and the number of times the dressing gauze required changing, significantly decreased (p < 0.05 and p < 0.01, respectively). The open malignant skin wounds caused by mammary gland tumors disappeared in two cases. The Mohs paste has been shown to be a viable option for the palliative treatment in canine and feline malignant skin wound management.     

Comparison of equine amnion and a nonadherent wound dressing material for bandaging pinch-grafted wounds in ponies

OBJECTIVE: To evaluate healing of pinch-grafted wounds on the distal aspect of the limbs of ponies bandaged with equine amnion or a standard nonadherent wound dressing material. ANIMALS: 6 ponies. PROCEDURE: A 2.5x2.5-cm full-thickness section of skin was removed from the dorsal aspect of each limb at the midpoint of the metacarpus or metatarsus. Six days later, wounds were grafted with partial-thickness pinch grafts. Half the wounds were bandaged with amnion, and the other half were bandaged with a nonadherent dressing. Bandages were changed every 3 days until wound healing was complete. At each bandage change, numbers of grafts lost were recorded, and wounds were measured. RESULTS: Percentage of grafts lost from wounds bandaged with amnion was not significantly different from percentage lost from wounds bandaged with the nonadherent dressing. Median healing time for wounds bandaged with amnion (30 days) was significantly less than median healing time for wounds bandaged with the nonadherent dressing (39 days). All wounds were healed by day 45. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that amnion can be used for bandaging pinch-grafted wounds on the distal aspect of the limbs of ponies.     

Effect of a hydrocolloid dressing on first intention healing surgical wounds in the dog: a pilot study

OBJECTIVES: To evaluate the efficacy of a hydrocolloid dressing for the treatment of surgical wounds in dogs. METHODS: Six healthy young female dogs of medium size and different breed underwent ovariohysterectomy. Histological evaluation was performed on biopsies taken from the edges of the wounds at day 7. The dressing was applied on one half of the wound according to manufacturer's instructions; the second half served as control. Biopsy specimens were fixed in a 10% formalin buffered solution pH 7.4, paraffin embedded and stained with haematoxylin and eosin. For clinical assessment, the presence and quality of exudate, erythema of the surrounding area, swelling and correct apposition of the wound margins were evaluated. RESULTS: The hydrocolloid dressing was easy to use. The clinical quality of the treated skin wounds was superior to the non-treated ones. Comparison of histological features between treated and untreated wounds showed a more regular organisation of the granulation tissue in the treated wounds, with fibroblasts being aligned parallel to the overlying epidermis. The number of inflammatory cells and the extension of granulation tissue were less prominent and less widespread in treated compared to untreated wounds. CONCLUSION: The dressing performed very well in terms of adhesiveness and flexibility. It was useful in the management of surgical wounds to avoid contamination and ameliorate the epithelialisation rate and granulation tissue morphology of the surgical scar.     

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.     

Use of a tilapia skin xenograft for management of a large bite wound in a dog

A 13-year-old neutered male miniature dachshund suffered ~30% total skin loss following an attack by another dog. After numerous failed attempts at wound management and closure, the wound was successfully healed by epithelialization using tilapia skin grafts. At each tilapia skin graft placement, the wound bed appeared pink, clean, and healthy with excellent progression of epithelialization at all edges. With use of the tilapia grafts, epithelialization occurred at a rate of 1.76 mm/day. As a result, the wound reached complete closure by epithelialization with no evidence of wound contracture in 102 days.Key clinical message:Tilapia skin grafts were successfully used for management of a large bite wound in a dog and may promote accelerated epithelialization in full thickness skin wounds.     

Effects of a hydrolyzed collagen dressing on the healing of open wounds in dogs

OBJECTIVE: To determine the effects of a hydrolyzed bovine collagen dressing (HBCD) on healing of open wounds in healthy dogs. ANIMALS: 9 female Beagles. PROCEDURES: 2 full-thickness skin wounds were made bilaterally on the trunk of each dog. Wounds on 1 side were treated with powdered HBCD covered with a semiocclusive nonadherent bandage. Wounds on the other side (control wounds) were covered with a semiocclusive nonadherent bandage only. Wound healing was subjectively assessed, and percentage increase in tissue perfusion was assessed by use of laser Doppler perfusion imaging (LDPI). Planimetry was performed to determine the percentages of contraction, epithelialization, and total wound healing. Biopsy specimens were examined microscopically to evaluate histologic changes. RESULTS: The HBCD did not induce a strong inflammatory reaction, as reflected by results of LDPI and histologic examination. Moreover, HBCD appeared hydrophilic and provided an environment to keep wounds clean and enhance early epithelialization. After treatment for 7 days, treated wounds had a significantly greater percentage of epithelialization than control wounds (12.13 vs. 7.03%). CONCLUSION AND CLINICAL RELEVANCE: The hydrophilic property of HBCD may cleanse contaminated wounds with the body's homeostatic fluids and enhance early wound epithelialization.     

The effect of low level laser therapy (LLLT) on wound healing in horses.

Laser therapy is used in many countries, including South Africa, for the treatment of skin wounds. Low level galium aluminium arsenide (GaAlAs) laser was administered to full thickness skin wounds (3 x 3 cm) induced surgically on the dorsal aspect of the metacarpophalangeal joints of 6 crossbred horses in a randomised, blind, controlled study. Treated wounds that received a daily laser dosage of 2 J/cm2 were compared with nontreated control wounds on the opposite leg. There were no wound complications. Both groups of wounds were cleaned daily using tap water. Wound contraction and epithelialisation were evaluated using photoplanimetry. There were no significant differences in wound contraction or epithelialisation between the laser treated and the control wounds. It was therefore concluded that laser therapy had no clinically significant effect on second intention wound healing in this study.     

Use of the scrotum as a transposition flap for closure of surgical wounds in three dogs

OBJECTIVE: To describe use of the scrotum as a pedicle flap to cover defects created by tumor excision in the perineum or caudal and medial aspect of the thigh. STUDY DESIGN: Clinical study. ANIMALS: Three dogs. METHODS: After tumor excision and prescrotal castration, an incision was made around the base of the scrotum, leaving a pedicle on the side opposite the skin defect. After removal of the tunica dartos and abdominal fascia, the scrotal skin was stretched and shaped to the defect, then sutured in position with a simple interrupted pattern. Bandages that were changed every 48 hours compressed the flaps, and healing was observed until sutures were removed. RESULTS: Two dogs had first intention healing in 15 days, whereas 1 dog developed necrosis of 10% of the flap, and this area healed by second intention. CONCLUSION: In male dogs, the scrotal skin can be used as a pedicle flap for reconstructive surgery of wounds in the perineum and the proximomedial and caudal aspect of the thigh. CLINICAL RELEVANCE: The perineal region remains a surgical challenge because of the lack of the available skin for reconstruction of surgical wounds. The scrotal skin should be considered for use as a transposition flap to cover skin defects in this region.     

Electrical stimulation on skin wound healing in the horse: preliminary studies

The effect of low-level direct-current stimulation on skin wound healing in the horse was assessed. Self-sustaining electrical circuits with electrodes were implanted subcutaneously in or near the wound. Stimulation by direct current (10 or 20 microA) was used to determine the effect on equine skin healing. The efficacy of electrotherapy was evaluated by sequentially comparing the clinical appearance of the wound and measuring the size of the granulating wound bed. The histologic appearance of the healing stimulated wounds was compared with that in nonstimulated control wounds created on 9 horses. Seemingly, electrical stimulation had no discernible effect on experimentally created skin wounds. Clinical observation and histologic examination of the wounds indicated that severe tissue reaction from the implanted electrodes and concurrent local infection produced local detrimental effects to wound healing.