Evaluation of the effects of topical tripeptide-copper complex and zinc oxide on open-wound healing in rabbits

In this study the clinical and histopathological effects of topically applied tripeptide-copper complex (TCC) and zinc oxide on open-wound healing in rabbits was evaluated. Eighteen New Zealand rabbits were divided into three groups: TCC, zinc oxide and no treatment. One full thickness wound was created on each side of the dorsal midline in each rabbit. Wound margins were traced on days 0, 7, 14, and 21 and topical TCC and zinc oxide were applied daily for 21 days to each rabbit in the respective treatment groups. The mean unhealed wound area was significantly smaller in the TCC than in the zinc oxide group on day 7, but it was significantly smaller in the TCC group than in to the control group on days 7, 14 and 21. The mean percentage of wound contraction on day 7 was significantly higher in the TCC than in the zinc oxide group; however, it was significantly higher in the TCC group than in the control group on days 7, 14 and 21. Median time for the coverage of the wound bed with granulation tissue was significantly shorter in the TCC group than in the other groups. Filling of the open wound with granulation tissue to skin level was significantly slower in the control group than in the other two groups. Neutrophil counts decreased regardless of the group in parallel with healing, while neovascularization was best observed in the TCC group. The results suggest that TCC is a better choice in the treatment protocols of open wounds in rabbits than zinc oxide.     

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 effect of topical tripeptide-copper complex on healing of ischemic open wounds

OBJECTIVE: To evaluate the effects of topical glycyl-L-histidyl-L-lysine tripeptide-copper complex (TCC; Iamin 2% Gel; Procyte Corporation, Redmond, WA) on healing in ischemic open wounds. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Twenty-four adult male Sprague-Dawley rats. METHODS: Rats were divided into 3 groups: topical TCC, topical TCC vehicle (hydroxypropyl-methylcellulose), and no treatment (control). Six-mm-diameter, full-thickness wounds were created within an ischemic bipedicle skin flap on the dorsum of each rat. Each day, for 13 days, wound margins were traced, and the TCC and TCC vehicle groups were treated topically. Tracings were scanned, and wound perimeter and area were calculated. On days 6, 10, and 13, selected wounds were biopsied and analyzed for tumor necrosis factor alpha (TNF-alpha) and matrix metalloproteinases (MMP) 2 and 9. RESULTS: A significant decrease in wound area was seen in the TCC group, but not the vehicle group, when compared with the control group on days 3 to 5, 6 to 9, and 11 to 13 and when TCC was compared with TCC vehicle on days 3 and 9. On day 13, initial wound area had decreased by 64.5% in the TCC group, 45.6% in the vehicle group, and 28.2% in the control group. On days 6, 10, and 13, TCC-treated wounds contained significantly lower concentrations of TNF-alpha and MMP-2 and MMP-9 than control wounds. CONCLUSION: Topical TCC resulted in accelerated wound healing in ischemic open wounds. CLINICAL RELEVANCE: Topical TCC is an effective stimulant of healing of ischemic open wounds in rats and may have an application for the treatment of chronic wounds in other species. Clinical evaluation of topical TCC is warranted.     

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.     

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 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.     

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.     

Comparison of the role of the subcutaneous tissues in cutaneous wound healing in the dog and cat

Objective— To describe and compare the contribution of the subcutaneous tissues to 1st and 2nd intention cutaneous wound healing in the dog and cat.
Study Design— Experimental study.
Animals— Domestic shorthaired cats (n=6) and 6 beagle dogs.
Methods— Paired wounds were created on either side of the dorsal midline; the subcutaneous tissue was removed on 1 side and left intact on the other. Square, open wounds of the dorsal aspect of the thorax were observed for 21 days to monitor granulation tissue formation, wound contraction, epithelialization, and total healing (contraction+epithelialization). Breaking strength of sutured linear wounds was measured 7 days after wounding. Laser-Doppler perfusion imaging (LDPI) was used to measure cutaneous perfusion.
Results— First intention healing: subcutaneous tissue removal had no consistent effect on sutured wound strength at 7 days in dogs or cats. Second intention healing: removal of subcutaneous tissue reduced wound perfusion, granulation, contraction, epithelialization, and total healing. Granulation tissue formation and wound contraction were delayed to a significantly greater degree in cats than in dogs ( P <.05). Two dogs (33%) had minor wound infections.
Conclusions— The subcutaneous tissues make an important contribution to 2nd intention cutaneous healing. Dog and cat wounds had delayed 2nd intention healing when subcutaneous tissues were removed; wounds in dogs, but not cats, had largely recovered from this delay by 21 days.
Clinical Relevance— Extensive debridement of subcutaneous tissue may delay wound healing particularly in feline patients. A higher risk for wound infections may accompany extensive removal of subcutaneous tissues in dogs.     

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.     

The effect of low reactive-level laser therapy (LLLT) with helium-neon laser on operative wound healing in a rat model

The effect of low reactive-level laser therapy (LLLT) with a He-Ne laser on operative wound healing was investigated in a rat model. 10-millimeter surgical wounds were created on the backs of Sprague Dawley rats, and animals were assigned to one of eleven groups (n=5). Ten groups received either 8.5 mW or 17.0 mW irradiation of 15 seconds LLLT a day with one of five different irradiation frequencies, i.e. daily (from the 1st to 6th day following surgery), every other day (the 1st, 3rd, and 5th day), on only the 1st day, on only the 3rd day, and on only the 5th day; the 1st day was the day following the surgery. The control group received no irradiation. A skin specimen was harvested from the dorsal thoracic region on the 7th day to measure the rupture strength. The control group had the lowest rupture strength (5.01 N), and the 17.0 mW every other day irradiation group had the highest rupture strength (13.01 N). Statistical differences were demonstrated in the 8.5 mW irradiation setting between the every other day irradiation group and the control group (p<0.05); and in 17.0 mW irradiation setting between the every day irradiation, the every other day, and the 1st day only groups vs. the control group (p<0.01). Histological examination demonstrated that wound healing in the 17.0 mW every other day irradiation group was promoted most significantly such as the prevention of excessive inflammation, increased formation of collagen fibers, and recovery in continuity of tissues. The control group showed poor wound healing and the other experimental groups showed intermediate healing. Thus LLLT with a He-Ne laser was found to promote the healing of operative wounds in the present rat model, in which the most favorable application of LLLT was the 17.0 mW setting of 15 seconds a day with a frequency of every other day.     

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.     

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.     

Effects of transplanted mesenchymal stem cells isolated from Wharton’s jelly of caprine umbilical cord on cutaneous wound healing; histopathological evaluation

The aim of this study was to investigate the effects of transplanted Wharton’s jelly mesenchymal stem cells (WJMSCs) of caprine umbilical cord on cutaneous wound healing process in goat. After collection of caprine pregnant uterus of mixed breed goats from abattoir, the Wharton’s jelly (WJ) of umbilical cord was harvested. The tissues were minced in ventilated flasks and explant culture method was used for separating mesenchymal stem cells (MSCs). The isolated cells were immunostained for Actin protein, histochemically assayed for the presence of alkaline phosphatase activity, and analyzed for detection of matrix receptors (CD44) and hematopoetic lineage markers (CD34), using flow cytometery. After The isolated cells, 3 × 10⁶ MSCs were stained with BrdU and prepared for transplantation to each wound. Four 3-cm linear full thickness skin incisions were made on both sides of thoracic vertebrate of four Raeini goats (two wounds on each side). The left wounds were implanted with MSCs in 0.6 ml of Phosphate buffer saline (PBS), and the right wounds considered as control group that received 0.6 ml of PBS. The samples were taken from the wounds 7 and 12 days after the wounding, and healing process was compared histologically between the two groups. Anti-BrdU staining showed that the transplanted cells were still alive in the wound bed during the study. The histopathological study revealed that re-epithelialization was complete at days 7 in treated wounds with WJMSCs, whereas in control wound the wounds still showed incomplete epithelialization 12 days after wounding. Also, microscopic evaluation showed less inflammation, thinner granulation tissue formation with minimum scar in the treated wounds in comparison with control wounds. In conclusion, this study demonstrates the beneficial effect of caprine WJMSCs in cutaneous wound healing in goat.     

Effect of topical administration of epidermal growth factor on healing of corneal epithelial defects in horses

OBJECTIVE-To characterize healing of corneal epithelial defects in horses and to evaluate the ability of epidermal growth factor (EGF) to modulate rate of corneal epithelial healing in horses. SAMPLE POPULATION: 20 eyes in 12 adult horses. PROCEDURE: Corneal epithelial wounds were created by mechanically debriding the limbus. Corneal healing was recorded for 3 treatment groups: 50 microg of EGF/ml (n = 5 eyes), 5 microg of EGF/ml (7), and PBS solution (8). Corneal healing was recorded once daily after instillation of fluorescein stain by use of photography and calculating the area of the wound, using imaging software. RESULTS: After corneal debridement, re-epithelialization was rapid and progressed in a linear fashion for the first 5 to 7 days after surgery in all groups. After that period, rates of healing decreased. A profound increase in the degree of inflammation, neovascularization, melanosis, and scarring was observed in eyes treated with the high dose of EGF (50 microg/ml), but there was not a statistical difference in mean healing time or in mean decrease in radius during the linear phase between the control and either EGF treatment groups. However, for all 8 horses in which both eyes were debrided, the first eye healed significantly faster than the second eye, regardless of treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Beneficial effects of topical administration of a high dose of EGF for acceleration of healing of corneal defects in eyes of horses are outweighed by the intensity of the associated inflammatory response.     

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.     

Effects of topical application of taurolidine on second intention healing of experimentally induced wounds in rats

OBJECTIVE: To determine the macroscopic effects of topical application of taurolidine on second intention healing of experimentally induced wounds in rats. ANIMALS: 32 adult Sprague-Dawley female rats. PROCEDURES: In each rat, 2 skin wounds were created in the lumbar area. Groups of 7 rats were assigned to have 1 wound treated topically with hydroxycellulose gel (HDCG), 2% taurolidine in HDCG (T-HDCG), 2% taurolidine-sodium citrate solution, or bacitracin-neomycin-polymyxin B ointment; the other wound was not treated. Four control rats (8 untreated wounds) were used. Wounds were monitored for contraction, epithelialization, and complete healing at 4, 8, and 14 days after wound creation. The number of days to complete healing was also recorded for each wound. RESULTS: Compared with other treatments or untreated wounds, wounds treated with T-HDCG had decreased total healing at day 8 and decreased epithelialization and decreased total healing at day 14. Wounds treated with T-HDCG required approximately 3 days longer to completely heal than all other treated and untreated wounds. Application of bacitracinneomycin-polymyxin B ointment did not enhance wound healing. Mean time to complete healing of untreated wounds in all treatment and control groups was 10.00 to 10.14 days. CONCLUSIONS AND CLINICAL RELEVANCE: In rats, topical application of T-HDCG to wounds had a negative effect on second intention healing by delaying the epithelialization process. In mammals, generally, wounds treated topically with taurolidine may need to be treated and monitored for a longer period than other wounds treated with other common woundhealing compounds or untreated wounds.     

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 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.     

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 amnion and live yeast cell derivative on second-intention healing in horses

Equine amnion and live yeast cell derivative were evaluated as a biological dressing and as a topical wound medicament respectively, in the treatment of granulating wounds of the distal portion of the limbs of horses. Wounds measuring 2.5 x 2.5 cm were created on the dorsomedial aspect of the metacarpal and metatarsal region of all 4 limbs of 9 horses. Each wound was assigned randomly to 1 of 3 treatment groups: group C, treated with a nonadherent bandage as a control; group A, treated with amnion beneath a nonadherent bandage; and group L, treated with live yeast cell derivative beneath a nonadherent bandage. Rates of contraction and epithelialization were not significantly different among groups. Percentage of epithelialization for group A was significantly greater throughout the study than for the other groups. Number of days to complete healing was significantly less in group A and significantly greater in group L than in group C. Incidence and severity of exuberant granulation tissue were significantly less in group A than in the other 2 groups. Group L had more frequent and severe cases of exuberant granulation tissue than the other 2 groups.