Effects of periodontal dressings on fibroblasts and gingival wound healing in dogs

In the present study the effects of different commercially available periodontal dressings (Peripac, Barricaid, Fittydent, Reso-Pack and Myzotect-tincture) on fibroblast (V-79-379A) proliferation and survival were tested in vitro. Barricaid, Fittydent and Reso-Pack periodontal dressings have only small inhibitory effects on cell proliferation (83.3 +/- 9%, 71.6 +/- 8.7% and 87.3 +/- 4.5% of control after 48 h, respectively) in comparison with the great inhibitory effect of Myzotect-tincture (2.9 +/- 0.1%) and Peripac (33.7 +/- 11.4%) (p < 0.001). Barricaid was the only dressing where 41% of cells survived after exposure, while the other four dressings killed all the cells in 6 days. In addition, the healing of artificially created gingival wounds covered by Barricaid and Reso-Pack was followed for 7 days in 12 Beagle dogs. Histological evaluation of gingival tissue demonstrated that wounds covered by Reso-Pack showed the best epithelisation and vascularity and the least inflammatory reaction in first 4 days. Later the observed parameters were similar with those of wounds covered by Barricaid or without pack. The present results indicate that Peripac periodontal dressing and Myzotect-tincture showed the highest cytotoxicity to fibroblasts in vitro. From the histological observations in Beagle dogs Reso-Pack has been found to be the most suitable dressing, followed by Barricaid.     

The effects of topical oxygen therapy on equine distal limb dermal wound healing

Topical oxygen therapy (TOT) has been used in human medicine to promote healing in chronic wounds. To test the efficacy and safety of TOT in horses, an experimental wound model was created by making 1 standardized dermal wound on each limb of 4 healthy horses (n = 16). Each wound was fitted with an oxygen delivery cannula and covered with a bandage. One limb of each front and hind pair was randomly assigned to the treatment group (fitted with an oxygen concentrator device), with the contralateral limb assigned to the control group (no device). Wound area, epithelial area, and contraction were measured every 3 to 4 d. Biopsy samples and culture swabs were taken on days 16 and 32 to evaluate angiogenesis, fibroplasia, epithelial hyperplasia, inflammation and bacterial growth. Mean healing time in treated wounds (45 d, range: 38 to 52 d) was not significantly different from that in the paired control wounds (50 d, range: 38 to 62 d). Topical oxygen therapy had little effect on dermal wound healing in this experimental wound model in healthy horses.     

Effects of nonadherent dressing materials on the healing of open wounds in dogs

Four types of nonadherent dressing materials (rayon/polyethylene dressing, cotton nonadherent film dressings, fine mesh gauze petrolatum dressings, and commercial petrolatum emulsion dressings) were applied on small full-thickness skin defects on the backs of 12 Beagles. At 7 days, the wounds treated with the petrolatum-containing dressings had more contraction than wounds dressed with cotton nonadherent film dressings and wounds dressed with rayon/polyethylene dressings. However, by days 14 and 21, there was little difference in the amount of contraction of any of the wounds. At 7, 14, and 21 days, the wounds dressed with petrolatum-containing dressings had less epithelialization than wounds dressed with cotton nonadherent film dressings and rayon/polyethylene dressings. The uniform open mesh of the commercial petrolatum emulsion dressings allowed the best absorption of exudate and bacteria into the secondary overlying bandage.     

Effects of low-intensity pulsed ultrasound on wound healing in corneas of dogs following keratoplasty

The effects of low-intensity pulsed ultrasound on wound healing were evaluated at the graft-cornea transition in dogs following lamellar keratoplasty using tunica vaginalis preserved in 98% glycerin. Twenty-one dogs were subdivided into three groups of seven animals. The first group (W/US) received daily treatment of low-intensity pulsed ultrasound (20 mW/cm2) for 15 min for the first 10 days post surgery. The second group (N/US) was submitted to the same procedure but with the ultrasound apparatus turned off. The third group, the control (CO), underwent the surgical procedure only. The animals were clinically evaluated during the initial (1-15 days), intermediate (16-30 days) and late (31-120 days) postoperative period. The corneas were evaluated by light microscopy at 1, 3, 7, 15, 30, 60 and 120 days after surgery. Clinically, there were no differences which would promote an advantage to any of the treatments. Light microscopy, however, revealed more extensive vascularization and more advanced wound healing in the W/US group, as well as a tendency towards early graft incorporation. Based on the present results, low-intensity pulsed ultrasound shows advantages, especially in situations where trophic support is a mandatory condition, facilitating better graft incorporation and rapid recovery of stromal organization.     

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.     

Rationale for hyperbaric oxygen therapy in traumatic injury and wound care in small animal veterinary practice

Hyperbaric oxygen therapy is in wide use in human medicine around the world. Although hyperbaric oxygen therapy is available for veterinary use, it is still significantly underutilised. The physical principles, gas laws and physiologic mechanisms by which hyperbaric oxygen therapy is therapeutic, especially in traumatic injuries and complicated wound care, are discussed. Then, considerations are offered for the implementation of hyperbaric oxygen therapy in veterinary practices. Finally, a review of clinical indications for veterinary practices, including a presentation of select literature, is provided. Applying hyperbaric oxygen therapy in an earlier and more consistent manner could improve short- and long-term outcomes in complicated wounds. The authors also hope this information may stimulate interest in the design of future, prospective studies for the various clinical situations described.     

Differences in cutaneous wound healing between dogs and cats.

Regardless of the species involved, wound healing follows a predictable course of overlapping phases. In spite of these commonalities, significant species differences in cutaneous wound healing have been uncovered in the Equidae and, more recently, between the dog and cat. It has also recently been shown that the subcutaneous tissues play an important supporting role in cutaneous wound healing, which may help to ex-plain healing differences between cats and dogs. These discoveries may improve veterinarians' understanding of problem wound healing in the cat and, hopefully, lead to better strategies for wound management in this sometimes troublesome species.     

Ferrets: wound healing and therapy.

In all species of mammals, the stages of wound healing are the same, and both host factors and wound characteristics affect how wounds heal. The basic principles of wound care in ferrets, such as lavage, bandaging, and surgical closure, are similar to those in other species; however, knowledge of ferrets' anatomy and pathophysiology, as well as skin conditions commonly seen in ferrets, will help ensure proper wound healing.     

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.     

Effects of chitin and chitosan on collagen synthesis in wound healing

Collagen synthesis was evaluated by measuring prolyl hydroxylase (PHL) activity induced within rat granulation tissue by a polyester non-woven fabric (NWF, 1 x 1 cm, 0.6 mm in thickness) impregnated with a chitin or chitosan suspension ranging in concentration from 0.1 to 10 mg/ml. In addition, PHL activity induced in rat granulation tissue by a NWF impregnated with a phosphate buffer solution was examined as a control. The PHL activity in each group remained low until 4 days post-implantation (Day 4). However, in the 10 mg chitin group, the PHL activity increased rapidly without scatter of the data at Day 7 and remained at a plateau until Day 14. In other groups, PHL activity increased linearly until Day 14. The data varied widely at Day 7. Compared to chitosan, chitin at the higher concentration was found to induce stable collagen synthesis in the early wound healing process.     

Ultrasonographic and radiographic assessment of uncomplicated secondary fracture healing of long bones in dogs and cats

OBJECTIVES: To evaluate the use of ultrasonography (US) to detect bone healing in uncomplicated diaphyseal fractures of dogs and cats, and to compare these observations with detection of healing by radiography (RG). STUDY DESIGN: Clinical study. ANIMALS: Dogs (33) and cats (11). METHODS: RG and brightness mode US were used to follow uncomplicated secondary fracture healing. Fractures were examined at admission and then every 2-4 weeks until healed or implant removal. Temporal differences in definitive detection of healed fracture by imaging technique were examined by species, patient age, bone, and fracture type. RESULTS: US images obtained during uncomplicated secondary fracture healing were consistent with images of fracture healing described in humans. Mean time to US diagnosis of a healed fracture (mean 46 days) was significantly shorter than by RG (mean 66 days). Mean time until diagnosis of a healed fracture (US and RG) did not differ significantly between open and closed treatment. Patients 36 months (n=11), but there was no significant difference between the latter 2 groups. Diagnosis of a healed simple fracture by US was significantly quicker than for a comminuted fracture (P<.05), but no difference was noted when using RG. CONCLUSIONS: US can be used to evaluate secondary fracture healing in biologically treated fractures in dogs and cats. US permits detection of a healed fracture earlier than RG. CLINICAL RELEVANCE: Earlier diagnosis of a healed fracture by US can prevent unnecessarily long limb immobilization and allow earlier dynamization.     

Effects of pico-tesla electromagnetic field treatment on wound healing in rats

OBJECTIVE: To evaluate the effects of a pico-tesla electromagnetic field (PTEF) on healing of sutured and open skin wounds and clinicopathologic variables in rats. ANIMALS: 64 male Fischer-344 rats. PROCEDURE: An incision made in the dorsal aspect of the neck was sutured (n = 32) or left open to heal (32). In each group, 16 rats were not PTEF-treated (controls). Wound treatment consisted of exposure to a PTEF once daily. Rats in each group were euthanatized at days 2, 4, 7, and 14. Wounds were evaluated via tensiometry (sutured wounds), digital planimetry (open wounds), laser Doppler perfusion imaging, bacteriologic culture, and histologic examination. Blood samples were collected from all rats for analysis. RESULTS: At day 14, sutured wounds in PTEF-treated rats were stronger (ultimate stress) and tougher (strain energy) than were sutured wounds in control rats. Open wounds in PTEF-treated rats contracted more quickly at days 2 and 4 than did those in control rats. Compared with control wounds, histologic changes (indicative of improved healing) in sutured and open wounds in PTEF-treated rats were detected as early as day 4. Laser Doppler perfusion measurements, results of CBCs, serum biochemical analyses, and bacteriologic cultures were not different between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Exposure to the PTEF caused no adverse effects on clinicopathologic, histologic, or bacteriologic variables tested in this study. It appears that PTEF is a safe form of adjuvant treatment for wounds and improves strength of sutured wounds and speeds contraction of open wounds.     

The influences of hyperbaric oxygen therapy with a lower pressure and oxygen concentration than previous methods on physiological mechanisms in dogs

Recently, hyperbaric oxygen therapy with a lower pressure and oxygen concentration (L-HBOT) than previous methods has been used for dogs in Japan; however, the influences of L-HBOT on dogs have not been clarified. To verify the influences of L-HBOT on physiological mechanism in dogs, we investigated blood gas parameters, glutathione peroxidase (GPx) activity, heart rate variability, stress-related hormones and skin conductance (SC) in 4 clinically normal beagle dogs with catheters in their carotid arteries and jugular veins when they were quiet, after running, after receiving L-HBOT (30% oxygen concentration, 1.3 atmospheres absolute, 30 min) or after not receiving L-HBOT. The results showed there were no changes in blood gas parameters, heart rate variability and catecholamine levels after L-HBOT. GPx activity was significantly higher, and the SC and cortisol level were lower in dogs that received L-HBOT than those when they were quiet. These results suggested that L-HBOT may have a small influence on oxygenation dynamics, activate antioxidant enzymes such as GPx, restrain autonomic nervous activity and control the balance between oxidation and antioxidation inside the body.     

Positive effects of hyperbaric oxygen therapy in a cat with cutaneous nocardiosis

Hyperbaric oxygen therapy (HBOT) has been beneficial in treating people with nocardiosis. This report describes Nocardia spp. affecting a cat, with lesions confined to the skin. To the best of the authors’ knowledge, this is the first report of HBOT, combined with amikacin, used to successfully treat feline cutaneous nocardiosis.     

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.