Elevated thromboxane levels are associated with a number of disease states, including dermal pressure ulcers. When dazmegrel was orally administered to greyhound dogs wearing leg casts, it resulted in a sparring effect on the skin areas of potential pressure ulcer development. The objective of this research was to determine if bioelastic matrices could provide controlled release of thromboxane A2 synthetase inhibitor (dazmegrel) at tissue concentrations sufficient for inhibition of thromboxane synthesis. The animal used for these studies was the greyhound, which has thin skin, angular conformation, limited body fat and is predisposed to pressure ulcers similar to those occurring in humans. In vivo skin penetration studies showed that epidermal exposure to bioelastic thromboxane synthetase inhibitor (TSI) matrix resulted in local tissue concentrations of TSI sufficient for thromboxane synthetase inhibition. There were no significant differences between dazmegrel in the skin layers (epidermis, dermis and subcutaneous layers) on 1, 7 and 14-day exposures.

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.

Human fibrin sealant (HFS) and bovine fibrin sealant (BFS) were delivered as preformulated fibrinogen-thrombin mixtures that are light activated. These formulations were evaluated in the healing of incised cutaneous wounds in beagle dogs. Four groups were differentiated by sealant type and study duration with group: BFS for 10 days, HFS for 10 days, BFS for 30 days, and HFS for 30 days. Healing was evaluated by noting incidences of open wounds, laser Doppler perfusion imaging (LDPI), planimetry, breaking strength, and histopathology. In the absence of tension, both sealants tended to hold wound edges together; however, HFS tended to be better than its controls and BFS. Both sealants augmented suture closure, necessitating fewer sutures for wound closure. At 5 and 30 days BFS wounds had more perfusion than HFS wounds, indicating more inflammation. At 10 and 30 days BFS wounds had larger scar areas than their controls, while scar areas of HFS wounds were smaller than either BFS wounds or controls. Breaking strengths indicated that HFS wounds were stronger than their controls and BFS wounds. Histologically, mild to moderate chronic-active inflammation was observed in wounds receiving either sealant, and this persisted longer in BFS wounds. Overall, HFS had positive qualities, thus showing potential for functional and cosmetic wound closure.

OBJECTIVE:To evaluate effects of treatment with a pulsed electromagnetic field (PEMF) on healing of open and sutured wounds, clinicopathologic variables, and CNS activity of dogs.ANIMALS:12 adult female Beagles.PROCEDURE:Open and sutured wounds were created in the skin of the trunk of the dogs. Dogs were divided into 2 groups. One group received PEMF treatment and 1 group served as untreated (control) dogs. The PEMF-treated dogs received treatment twice a day starting the day before surgery and lasting through day 21 after surgery. Wounds were evaluated by use of tensiometry, planimetry, laser Doppler perfusion imaging, and histologic examination. Clinicopathologic variables and electroencephalographic tracings were also evaluated.RESULTS:Use of PEMF treatment resulted in significantly enhanced epithelialization of open wounds 10 and 15 days after surgery. Five days after surgery, wounds of control dogs had a negative value for wound contraction, whereas PEMF-treated wounds had a positive value. The PEMF treatment did not cause significant changes in short-term planimetric, perfusion, tensiometric, histologic, clinicopathologic, or electroencephalographic results.CONCLUSIONS:The PEMF treatment enhanced wound epithelialization in open cutaneous wounds and provided indications of early contraction without significant short-term changes in other variables.

Objectives-To ascertain the effects of dietary omega-3 (n-3) fatty acids on biochemical and histopathologic components of the inflammatory stage of wound healing.Animals-30 purpose-bred Beagles.Procedure-Dogs were allotted to 5 groups of 6. Each group was fed a unique dietary fatty acid ratio of omega-6 to n-3-diet A, 5.3:1; diet B, 10.4:1; diet C, 24.1:1; diet D, 51.6:1; and diet E, 95.8:1. Dogs were fed once daily for 12 weeks, then biopsy specimens were taken from 4-day-old wounds of each dog and analyzed by gas chromatography-mass spectrometry for. prostaglandin E-2 (PGE(2)) metabolites, and ratios of omega-6 to n-3 fatty acids, arachidonic acid (AA) to eicosapentaenoic acid (EPA), adrenic acid to docosahexaenoic acid, and PGE(2) to prostaglandin E-3 (PGE(3)) metabolites.Results-Qualitative analysis was carried out on AA, EPA, adrenic acid, docosahexaenoic acid, and the major metabolite from the PGE(2) and PGE(3) pathway. These molecules were further quantified with respect to diet to determine significant differences. By analysis of the AA-to-EPA ratio, diet A was different from diets D and E and diets B and C were different from diet E (P < 0.05). By analysis of the PGE(2)-to-PGE(3) metabolite ratio, diet A was different from diet E (P < 0.05). Though biochemical analysis indicated dietary dependence, histopathologic data indicated no significant difference with respect to diet groups.Conclusion-The biochemical component of the inflammatory stage of wound healing can be manipulated by diet.Clinical Relevance-Omega-3 fatty acid-enriched diets can be used to control inflammation associated with dermatologic conditions.

OBJECTIVE:To ascertain the effects of locally injected immunostimulant and tripeptide-copper complex (TCC) on improving healing of pad wounds.DESIGN:Wounds in pads of large dogs were injected with either medication or physiologic saline solution (controls). Healing was evaluated.ANIMALS:12 mature English Pointers.PROCEDURE:Full-thickness 6 x 8-mm wounds in metatarsal and third and fourth digital pads were injected with immunostimulant or TCC at 0, 3, and 6 days after wounding. Wounds on control dogs were injected with physiologic saline solution. Using planimetric measurements at 0, 3, 6, 14, and 21 days, rates of healing were evaluated. Biopsy of the digital pad wounds at 3, 6, and 14 days was used to evaluate collagen content by hydroxyproline analysis. Biopsy specimens were also evaluated for type-I and type-III collagen, using Sirius red differential staining.RESULTS:Effect on healing rate and hydroxyproline content was best during the first week for immunostimulant. Immunostimulant- and TCC-injected wounds had more type-I collagen than did controls at 6 days; TCC-injected wounds had the most type-I collagen. At 14 days, the amount of type-I collagen in TCC-injected wounds was significantly greater than that in other wounds.CONCLUSIONS:Tested medications had positive effects on healing of pad wounds.CLINICAL RELEVANCE:Intralesional injection of medications helps ensure their presence for enhancement of wound healing. The benefit could be lost with topical use in a bandage if the bandage is lost or becomes wet.

Short limb, coaptation, walking casts with one layer of stockinette as lining were applied to one pelvic limb of 10 mature greyhound dogs. One group of five dogs received a thromboxane synthetase inhibitor (TSI) per os at 10mg/kg, t.i.d. while the casts were in place. The second group of five dogs received a placebo t.i.d. After 14 days, the casts were removed. The skin over the calcaneal tuberosity and medial malleolus was observed for physical abnormalities. Skin biopsies were taken from these areas for thromboxane B2 analysis and histopathologic evaluation. Based on all three parameters evaluated, the TSI had a sparing effect on skin subjected to pressure.

Twenty adult laboratory beagles were participants in a 21-day study evaluating the effects of a tripeptide- and tetrapeptide-copper complex on open wound healing of dogs as compared to vehicle/placebo-treated and untreated control wounds. Initially, the wounds treated with either of the multipeptide-copper complex medications produced a greater than normal amount of exudative material, however, they developed granulation tissue sooner than the control or vehicle/placebo-treated wounds. The wounds also had a significantly greater percentage of contraction and total wound healing at seven days compared to vehicle/placebo-treated and control wounds. The granulation tissue formed after treatment with both multipeptide-copper complexes tended to be exuberant, which in some cases appeared to interfere with epithelialization of the wounds at 21 days.