Effects of two occlusive, hydrocolloid dressings on healing of full-thickness skin wounds in cats.

OBJECTIVES: To determine the effects of two occlusive, hydrocolloid dressings on second intention wound healing in cats. METHODS: Three 2×2 cm full-thickness skin wounds were created on each side of the trunk of 10 cats. Two bilateral wounds were bandaged using different hydrocolloid dressings, namely Hydrocoll and DuoDerm while a semi-occlusive pad (Melolin) was applied to the third bilateral wound (control group). Wound planimetry, subjective evaluation of wound healing, and qualitative bacterial cultures were performed on the right-sided wounds, whereas left-sided wounds were subjected to histological examination. RESULTS: Subjective evaluation revealed accelerated (p <0.01) granulation tissue formation in hydrocolloid-treated wounds. The amount of wound exudate was initially greater (p <0.01) in these wounds. Seventeen out of 120 evaluated wounds (14.2%) produced purulent exudate, 11 of which showed Staphylococcus aureus growth. Fewer control wounds (3/17) emitted purulent exudate, but all of them yielded moderate bacterial growth as compared to hydrocolloid-treated wounds (8/17) which had a low incidence of bacterial growth. The only significant difference in histological variables was increased cellular infiltration noted on day 7 in Hydrocoll-treated wounds compared to controls. No significant differences in planimetry variables were found between groups. CLINICAL SIGNIFICANCE: Despite the initially increased amount of wound exudate and the low growth of Staphylococcus aureus, hydrocolloid dressings accelerate granulation tissue formation and can hence be suggested for second intention wound healing in cats.

Expressão gênica do colágeno em ferida cutânea de equinos tratada com plasma rico em plaquetas / Collagen gene expression in skin wound of horses treated with platelet-rich plasma

[...]The objective of this study was to evaluate type I and III collagen gene expression during different phases of the healing process of PRP-treated skin. Eight healthy crossbred geldings, aged 16 and 17 years (16.37±0.52) were used. Three quadrangular-shaped lesions (6.25cm²) were surgically induced in the right and left gluteal regions of all the animals. Twelve hours after induction of the lesions, 0.5mL of PRP was administered in each of the four edges of the wounds (T=treated group) in one of the gluteal regions, randomly chosen. The contralateral region was used as control (NT=non-treated group). The wounds were submitted to daily cleaning with Milli-Q water, and the samples were obtained with a 6mm diameter biopsy Punch. Six skin biopsies were obtained, with the first being performed on the day the lesions were induced (T0), and the others 1 (T1), 2 (T2), 7 (T3), and 14 (T4) days, after the wound was induced. The sixth biopsy (T5) was performed after fully healed of the skin. Evaluation of type I and III collagen gene expression was carried out by the qRT-PCR technique. The data were analyzed by the Bonferroni test, Student t-test, paired t-test, and regression analysis (p<0,05). Difference (p<0.05) between groups were observed for both collagen gene expressions from T1 to T4, being higher in the animals of group T. The peak for type I and III collagen gene expressions occurred in T5 for both groups, but the highest expression was different (p<0.05) from zero time, starting in T3. In the animals of treated group, collagen expression started to establish at T5, while in the horses of NT group, the values remained increased. Local administration of a single PRP dose in cutaneous wound of the gluteal region of horses results in a higher local gene expression of type I and III collagens. However, this expression does not alter the maximum time of macroscopic healing of the wound.

[...] Objetivou-se avaliar a expressão dos genes dos colágenos tipos I e III durante diferentes fases do processo de cicatrização da pele tratada com PRP. Foram utilizados oito equinos machos castrados, mestiços, hígidos, com idade entre 16 e 17 (16,37±0,52) anos. Três feridas em formato quadrangular (6,25cm²) foram confeccionadas nas regiões glúteas direita e esquerda de todos os animais. Doze horas após indução das lesões, 0,5mL do PRP foi administrado em cada uma das quatro extremidades das feridas (T=grupo tratado), de uma das regiões glúteas, escolhida aleatoriamente. A região contralateral foi utilizada como controle (NT=grupo não tratado). As feridas foram submetidas à limpeza diária com água Milli Q, e amostras foram obtidas com biópsias utilizando-se Punch de 6mm de diâmetro. Seis biópsias de pele foram obtidas a primeira no dia de indução das lesões (T0), e as demais com 1 (T1) 2 (T2) 7 (T3) e 14 (T4) dias após a realização das feridas. A sexta biópsia (T5) foi realizada após o completo fechamento da pele. A avaliação da expressão dos genes dos colágenos tipos I e III foi realizada pela técnica qRT-PCR e os dados analisados pelo teste de Bonferroni, t de Student, t pareado e análise de regressão (p<0,05). Diferenças (p<0,05), entre grupos, foram observadas para a expressão de ambos os colágenos nos T1 a T4, sendo maior nos animais do grupo T. O pico de expressão dos colágenos tipos I e III ocorreu no T5 para ambos os grupos, mas a maior expressão foi diferente (p<0,05) do tempo zero a partir do T3. Nos animais do grupo tratado a expressão dos colágenos começou a estabilizar no T5, enquanto que nos equinos do NT os valores permaneceram elevados. A administração local de uma única dose do PRP em ferida cutânea na região glútea de equinos, resulta em maior expressão gênica local dos colágenos tipos I e III. Entretanto, essa expressão não altera o tempo máximo de fechamento macroscópico da ferida.

Repair of horn and frontal bone avulsion in a forest buffalo (Syncerus caffer nanus) with a polymethylmethacrylate dressing.

A 2-yr-old female forest buffalo (Syncerus caffer nanus) presented with acute trauma to the right horn following a fight with a conspecific resulting in fracture and avulsion of the frontal bone, cornual process, horn, and juxtaposed skin. The animal was sedated for wound care and debridement followed by placement of an antibacterial-impregnated polymethylmethacrylate (PMMA) dressing. The dressing was noted to be intact on examination at day 7 post-injury, but had become dislodged and had to be replaced at day 11 postinjury. The replacement dressing ultimately fell off 68 days post-injury, revealing a healed circular scar. The use of PMMA in this case provided optimal wound care. In the 6 yr since the injury, the animal has grown a nearly normal-appearing horn, suggesting that the noncornual skin and associated skull structures may retain the ability to differentiate into a near-normal appearing horn because the entire horn apparatus in this case was avulsed.

Vacuum-assisted closure for treatment of a deep shell abscess and osteomyelitis in a tortoise.

CASE DESCRIPTION: A female Aldabra tortoise (Geochelone gigantea) was evaluated because of focal necrosis of the carapace. CLINICAL FINDINGS: Debridement revealed a 14.5 x 11.5-cm area of shell necrosis, deep abscess formation, and osteomyelitis involving bacterial (Klebsiella pneumoniae, Staphylococcus aureus, and Pseudomonas spp) and fungal pathogens. TREATMENT AND OUTCOME: Following extensive debridement, vacuum-assisted closure incorporating silver-impregnated bandaging materials was used. The wound was considered healed after 55 days, at which time a layer of epidermal tissue with progressing keratinization was present, with smooth underlying ossification. Keratinization with normal pigmentation continued over the next 67 days. CLINICAL RELEVANCE: Findings suggested that vacuum-assisted closure with silver-impregnated bandaging materials may provide advantages over traditional methods in the treatment of shell lesions in chelonians, including faster wound healing, improved cosmetic appearance of the healed wound, superior control of microbial contamination, and lower overall treatment costs.

The use of vacuum-assisted closure therapy for the treatment of distal extremity wounds in 15 dogs.

OBJECTIVE: To evaluate clinical outcome after vacuum-assisted closure (VAC) therapy in dogs with traumatic wounds located in the distal extremities and report our early experience with VAC. STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n=15) with traumatic distal extremity wounds. METHODS: Medical records (1999-2003) of dogs with traumatic injuries to the distal extremities managed by VAC were evaluated. Data included signalment, location of wound, time until surgical intervention, wound reconstruction methods, orthopedic procedures, outcome, complications associated with VAC, and length of hospitalization. RESULTS: The mean number of days until reconstruction was 4.6 days (range, 2-7 days). Reconstructive surgery was successful in all cases. Mean hospitalization was 9.7 days (range, 6-16 days). Complications included dermatitis at the wound margin and loss of vacuum causing wound desiccation. CONCLUSION: VAC therapy can be used to achieve adequate management of traumatic distal extremity wounds. VAC provides an effective method of securing skin grafts over the wound bed. CLINICAL RELEVANCE: VAC therapy can be used as an ancillary treatment for distal extremity wounds in dogs before surgical repair as well as a method for securing skin grafts to the wound bed.

Use of a novel abdominal wrap for protection of indwelling catheter exit sites in sheep.

Implantation of indwelling catheters in sheep presents numerous problems, including exit-site inflammation and infection and lacerated catheters from chewing. In order to address these issues, we designed a new abdominal wrap for a chronic drug study. These wraps provided protection of the catheters and exit sites, with no chewed catheters or visible signs of exit-site inflammation or infection for up to 22 weeks postoperatively.

Ischemic bandage injuries: a case series and review of the literature.

OBJECTIVE: To determine the prognosis and distribution of ischemic injuries caused by inappropriate bandaging of the lower limb in dogs and cats. STUDY DESIGN: Retrospective clinical study. ANIMAL POPULATION: Eleven client-owned animals, including 9 dogs and 2 cats with a history of injuries consistent with incorrect application of a bandage. METHODS: Medical records for dogs and cats referred to the Queen's Veterinary School Hospital with limb wounds between 1995 and 1999 were reviewed for clinical history and referring veterinary surgeons' reports, indicating that the injury was directly related to the application of a bandage to the limb. RESULTS: The indications for bandage application included 2 postoperative cruciate ligament ruptures, 2 lacerations, 3 internal fixations, an onychectomy, a shoulder dislocation, a dog bite, and a tendon strain. None of the patients had other body systems involved or underlying or concurrent diseases. Five different types of bandage were described (support, Robert Jones, pressure, splint, and Velpeau), and no particular age or breed was overrepresented. Of the 11 animals, 5 required full-thickness skin grafts, 3 had to have digits amputated, and 2 required limb amputations. Nine animals survived, but only 4 became fully functional on the affected limb. CONCLUSIONS: Bandage-related injuries are potentially serious sequelae to a routine procedure. A guarded prognosis should be given when there is loss of deeper structures. CLINICAL RELEVANCE: A review of bandaging principles is presented. Method of application, choice of materials, and close monitoring of the bandage are important factors in preventing iatrogenic injury.

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.

Contração de feridas após cobertura com substitutos temporários de pele / Contraction of wound after cover with temporaly skin substitutes

Feridas experimentais foram recobertas com substitutos temporários de pele produzidos com poliuretano, hidrocolóide, hemicelulose e vaselina e com gaze, para avaliaçäo do cálculo da área e percentual de contraçäo ao 7§, 14§ e 28§ dias de evoluçäo. O curativo hidrocolóide proporcionou uma reduçäo da área inicial ao sétimo dia, näo se observando diferenças significativas entre os tratamentos nos períodos seguintes.

An overview of the topical management of wounds.

Wounds in animals are a common and frequent reason for seeking veterinary attention. The way in which wounds are managed affect the rate of healing, the time to return to normal function, the final cosmetic appearance, and hence the satisfaction of customers. The management of wounds depends on the stage of wound healing and can include irrigation, mechanical and chemical debridement, the use of antiseptics and antimicrobials, adherent and nonadherent dressings, and miscellaneous topical applications such as aloe vera, honey and live yeast cell derivative. The advantages, disadvantages and indications for initial wound management, topical applicants and dressings are discussed.

Effects of three occlusive dressing materials on healing of full-thickness skin wounds in dogs.

The effects of 3 occlusive dressing materials and a standard, nonadherent dressing material on healing of full-thickness skin defects were evaluated in dogs. Two wounds measuring 2 x 2 cm were created bilaterally (4 wounds/dog) on the dorsolateral aspect of the trunk of 12 Beagles. Wound treatments were evenly distributed between 4 sites, using a Latin square design. Treatments evaluated were: equine amnion (group A), biosynthetic hydrogel dressing (group B), transparent polyethylene sheeting (group T), and a semi-occlusive rayon/polyethylene, nonadherent dressing (group C). Rates of contraction and epithelialization of group-A wounds were significantly greater than those of wounds of groups C, B, and T. On days 14, 21, and 28, mean percentage of wound contraction and mean percentage of total wound healed in group A exceeded those wounds in groups C, B, and T. On day 28, wounds in group A were significantly smaller than wounds in groups B and T, but were not significantly smaller than wounds in group C. All wounds in group A achieved 100% healing during the 28-day study period. Mean time for complete healing of group-A wounds was 21 days. The percentages of wounds completely healed by day 28 for groups B, C, and T were 25, 67, and 25%, respectively. Results indicate that use of equine amnion as an occlusive biological dressing on full-thickness wounds in dogs increases rate of healing.

The effect of occlusive and semi-occlusive dressings on the healing of acute full-thickness skin wounds on the forelimbs of dogs.

This project compared the effects of hydrocolloid (HC) and hydrogel (HG) occlusive dressings and a polyethylene (PE) semi-occlusive dressing on the healing of acute full-thickness skin wounds on the forelimbs of 10 dogs. All treatments resulted in a similar degree of healing at postoperative days 4 and 7. No significant differences existed in the number of wounds that were more than 90% healed at postoperative day 28 between the group treated with the HG dressing and the group treated with the PE dressing. There were significantly fewer wounds more than 90% healed at postoperative day 28 in the group treated with the HC dressing. Wounds under the HG dressing had the largest mean percentage of contraction at postoperative days 21 and 28. Wounds under the HG dressing also had the largest contraction/re-epithelialization ratio (postoperative days 21 and 28) compared with wounds under the PE and HC dressings. Wounds under the PE dressing had a significantly higher mean percentage of re-epithelialization than wounds under both occlusive dressings on postoperative days 14, 21, and 28. Wounds under the two occlusive dressings had exuberant granulation tissue present more often than wounds under the PE dressing. The two occlusive dressings had significantly higher bacterial counts on wounds compared with wounds under the PE dressing; analysis of variance (ANOVA), P = .0008. Wounds under the HC dressing showed the poorest healing in all parameters.

Evaluation of occlusive dressings for management of full-thickness excisional wounds on the distal portion of the limbs of horses.

Two 2.5-cm2 full-thickness skin wounds were created surgically over the lateral aspect of the cannon bone of each limb of 6 horses (n = 48 wounds). Dressings evaluated were a nonadherent gauze pad (group 1); a synthetic semiocclusive dressing, (group 2); equine amnion (group 3); and a synthetic fully occlusive dressing (group 4). Wounds were assessed subjectively at each dressing change, and total wound area, area of granulation tissue, and area of epithelium in each wound were determined by computerized digital analysis of photographs of the wounds. Complete healing time (wound covered by epithelium) also was determined for each wound. Statistical comparisons were made, using Kruskal-Wallis analysis and a Mann-Whitney U test. Median time to complete healing was: group 1, 53 days; group 2, 71 days; group 3, 63 days; and group 4, 113 days. Time to complete healing was significantly longer for wounds of group-4 horses than all other groups, and wounds of group-1 horses healed faster than did those of group-2 horses (P < 0.05). Wounds in group-4 horses required significantly (P < or = 0.05) more excisions of granulation tissue (median, 11.5 times) than did those in group-1 (median, 3.5), group-2 (median, 5.5) or group-3 (median, 2.5) horses. Epithelial tissue was detected later in wounds of group-4 horses (median, 27 days) than in wounds of horses in groups 1, 2 or 3 (median, 17 days); however, this difference was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of certain topical medications on healing of cutaneous wounds in the common garter snake (Thamnophis sirtalis).

The effects of four topical medications on the rate and character of healing of cutaneous wounds were studied in six common garter snakes (Thamnophis sirtalis) held at an ambient temperature of 30 degrees C. Two sets of five 6 to 8 mm round excisional wounds, four test and one control site in each set, were created on the dorsolateral body wall of each snake. Wounds were examined daily and treated for ten days, then the snakes were killed and sections of all wounds were examined by light microscopy. Composite scores, derived by ranking each treatment group in relation to the control group (control score = 0) for each of 22 characteristics associated with wound healing, were used to compare the overall effects of each treatment. Statistical comparisons were made between groups for 20 characteristics. Wounds treated with a polyurethane film merited a score of +12 and had significantly more advanced healing than untreated controls for three characteristics. Wounds treated with an ointment containing scarlet red scored +6 but healing was not significantly greater than controls. Wounds treated with an antibacterial spray powder and an antibacterial ointment healed more slowly than controls and had scores of -6 and -12 respectively.