A disposable, canister-free negative-pressure wound therapy device proves feasible, but of inferior efficacy to conventional therapies for treating cutaneous wounds in dogs.

Objective: To assess the feasibility of a canister-free negative-pressure wound therapy (NPWT) device (PICO™ 1.6, Smith & Nephew Medical Ltd) and evaluate its effect on early phases of wound healing in canine experimental cutaneous wounds.

Animals: 5 adult spayed female research Beagles.

The Horse as a Model for the Study of Cutaneous Wound Healing.

Cutaneous wounds are a major problem in both human and equine medicine. The economic cost of treating skin wounds and related complications in humans and horses is high, and in both species, particular types of chronic wounds do not respond well to current therapies, leading to suffering and morbidity. Conventional methods for the treatment of cutaneous wounds are generic and have not changed significantly in decades.

Anti-fibrotic Actions of Equine Interleukin-10 on Transforming Growth Factor-Beta1-Stimulated Dermal Fibroblasts Isolated From Limbs of Horses.

Fibroproliferative disorders occur in both humans and horses following skin injury. In horses, wound healing on the limb is often complicated by the formation of fibroproliferative exuberant granulation tissue, characterized by persistent expression of pro-fibrotic transforming growth factor-beta1 (TGF-β1) and deficient expression of anti-inflammatory interleukin-10 (IL-10). IL-10 has been shown to directly modulate fibrotic gene expression in human fibroblasts, so we hypothesized that equine IL-10 (eIL-10) may exert similar anti-fibrotic effects on equine dermal fibroblasts.

Treatment of limb wounds of horses with orf virus IL-10 and VEGF-E accelerates resolution of exuberant granulation tissue, but does not prevent its development.

Bandaging of limb wounds in horses leads to formation of exuberant granulation tissue (EGT) that retards healing due to protracted inflammation, aberrant vascularisation and delayed epithelialisation. EGT is not observed if wounds are left undressed or when wounds are on the body. A previous study showed that short-term administration of proteins derived from orf virus dampened inflammation and promoted epithelialisation of open wounds in horses.

Orf virus interleukin-10 and vascular endothelial growth factor-E modulate gene expression in cultured equine dermal fibroblasts.

Background: Wounds in horses often exhibit sustained inflammation and inefficient vascularization, leading to excessive fibrosis and clinical complications such as "proud flesh". Orf virus-derived proteins, vascular endothelial growth factor (VEGF)-E and interleukin (ovIL)-10, enhance angiogenesis and control inflammation and fibrosis in skin wounds of laboratory animals.

Hypothesis/objectives: The study aimed to determine if equine dermal cells respond to VEGF-E and ovIL-10.

Equine exuberant granulation tissue and human keloids: a comparative histopathologic study.

Objective: To compare histopathologic features of a fibroproliferative disorder in horses (exuberant granulation tissue-EGT) and people (keloid).

Sample Population: Archival tissue samples of EGT (n = 8) and keloid (12).

Methods: After automated hematoxylin and eosin, histochemical (Gomori trichrome, Verhoeff-van Gieson elastin) and immunohistochemical (vimentin, α-smooth muscle actin, CD34, CD68, CD117) stainings, tissue sections were evaluated using a semi-quantitative grading scale for presence or absence of ulceration, keloidal collagen, myofibroblasts, and elastic fibers as well as degree of inflammation, fibrosis, vascularity, and orientation of collagen fibers.

Aberrant wound healing in the horse: naturally occurring conditions reminiscent of those observed in man.

Impaired wound healing represents an enormous clinical and financial problem for companion animals and humans alike. Unfortunately, most models used to study healing rely on rodents, which have significant differences in the healing and scarring process and rarely develop complications. In order to better simulate impaired healing, the model should strive to reproduce the natural processes of healing and delayed healing.

Skin temperature during cutaneous wound healing in an equine model of cutaneous fibroproliferative disorder: kinetics and anatomic-site differences.

Objective: To map skin temperature kinetics, and by extension skin blood flow throughout normal or abnormal repair of full-thickness cutaneous wounds created on the horse body and limb, using infrared thermography.

Study Design: Experimental.

Animals: Standardbreds (n = 6), aged 3-4 years.

Hypoxia regulates the expression of extracellular matrix associated proteins in equine dermal fibroblasts via HIF1.

Background: Exuberant granulation tissue (EGT), a fibrotic healing disorder resembling the human keloid, occurs almost exclusively in limb wounds of horses and may be caused in part by a relative state of hypoxia within the wound.

Objective: The objectives of this study were therefore to (1) assess the effects of hypoxia on equine dermal fibroblast (EDF) proliferation and apoptosis, (2) study the effects of hypoxia on the expression of key extracellular matrix (ECM) associated proteins and determine if such effects are dependent on hypoxia-inducible factor (HIF), and (3) determine if EDFs from the body or limb respond differently to hypoxia.

Methods: EDFs were isolated and cultured from skin from body or limb under normoxic or hypoxic conditions for up to 7days.

Constitutive expression of hypoxia-inducible factor-1 α in keratinocytes during the repair of skin wounds in horses.

As a transient hypoxic state exists within skin wounds in horses and may be important for the healing process, this study sought to identify a molecular hypoxia response occurring in horse limb and body wounds healing by second intention. Hypoxia-inducible factor 1α (HIF1α) protein expression was studied throughout repair by Western blotting and immunofluorescence. Paradoxically, HIF1α was strongly expressed in intact skin and its expression decreased dramatically following wounding (p<0.

Regional differences in wound oxygenation during normal healing in an equine model of cutaneous fibroproliferative disorder.

Wound repair in horse limbs is often complicated by the development of exuberant granulation tissue (EGT) and excessive scarring while body wounds tend to repair uneventfully. EGT resembles the human keloid. While the events leading to keloid formation are not fully elucidated, tissue hypoxia has been proposed as a major contributing factor.

Correlation of signal attenuation-based quantitative magnetic resonance imaging with quantitative computed tomographic measurements of subchondral bone mineral density in metacarpophalangeal joints of horses.

Objective: To evaluate the ability of signal attenuation-based quantitative magnetic resonance imaging (QMRI) to estimate subchondral bone mineral density (BMD) as assessed via quantitative computed tomography (QCT) in osteoarthritic joints of horses.

Sample Population: 20 metacarpophalangeal joints from 10 horse cadavers.

Procedures: Magnetic resonance (MR) images (dorsal and transverse T1-weighted gradient recalled echo [GRE] and dorsal T2*-weighted GRE fast imaging employing steady-state acquisition [T2*-FIESTA]) and transverse single-slice computed tomographic (CT) images of the joints were acquired.

Equine thrombospondin II and secreted protein acidic and cysteine-rich in a model of normal and pathological wound repair.

Wound healing in horses is complicated, particularly when wounds are on the limb. The objectives of this study were to clone equine thrombospondin II (THBS2) and secreted protein acidic and cysteine-rich (SPARC) cDNAs and to compare the spatiotemporal expression of mRNAs and proteins during repair of body and limb wounds. These molecules were targeted in view of their potential biological contribution to angiogenesis, which is exacerbated during the repair of limb wounds in horses.

Equine lumican (LUM) cDNA sequence and spatio-temporal expression in an experimental model of normal and pathological wound healing.

The development of exuberant granulation tissue, a situation that in some ways resembles the human keloid, compromises both the aesthetic and functional outcomes of wound repair in horses. To help elucidate the underlying molecular mechanisms the spatio-temporal expression of lumican (LUM) mRNA and protein for their potential contributions to tissue remodelling of body and limb wounds, was examined in an established experimental model. Expression was studied in intact skin and in samples of 1-, 2-, 3-, 4- and 6-week-old wounds of the body and forelimb.

Effects of platelet-rich plasma on the repair of wounds on the distal aspect of the forelimb in horses.

Objective: To evaluate the effect of platelet-rich plasma on wounds on the distal aspect of the forelimb in horses.

Animals: 6 mixed-breed 10- to 15-year-old mares.

Procedures: 3 wounds were created on metacarpal regions in each of 6 horses (n = 36 wounds total).

Laminin receptor 1 is differentially expressed in thoracic and limb wounds in the horse.

Healing of wounds located on the distal limbs of horses is often complicated by retarded epithelialization and the development of exuberant granulation tissue (proud flesh). Treatments that definitively resolve this pathological process are still unavailable. Molecular studies of the repair mechanism might contribute to the development of new therapeutic strategies.

Nucleotide structure and expression of equine pigment epithelium-derived factor during repair of experimentally induced wounds in horses.

Objective: To clone full-length equine pigment epithelium-derived factor (PEDF) complementary DNA (cDNA) and to evaluate its temporal expression during repair of wounds in horses.

Animals: 4 clinically normal 2-to 3-year-old Standardbred mares.

Procedures: Full-length equine PEDF cDNA was cloned by screening size-selected cDNA libraries derived from biopsy specimens obtained from the wound edge 7 days after experimental creation of a 6.

Histological and biomechanical effects of palatal sclerotherapy in the horse using sodium tetradecyl sulfate.

Palatal sclerotherapy using sodium tetradecyl sulfate has been suggested as a treatment for dorsal displacement of the soft palate in young Standardbred horses. The present study evaluated histological and biomechanical changes in the equine soft palate following trans-endoscopic treatment with a low dose of this compound. Two horses were euthanased and examined at 2 weeks and at 1, 2, 4 and 6 months post-sclerotherapy, while two further horses served as untreated controls.

Equine ANXA2 and MMP1 expression analyses in an experimental model of normal and pathological wound repair.

Background: Wounds on horse limbs can develop exuberant granulation tissue which resembles the human keloid. Clues gained from the study of over-scarring in horses might help control fibro-proliferative disorders.

Objectives: The aim of the present study was to clone full-length equine ANXA2 cDNA then to study spatio-temporal expression of ANXA2 and MMP1 mRNA and protein, potential contributors to remodeling, during repair of body (normal) and limb (fibro-proliferative) wounds in an established horse wound model.

Equine CTNNB1 and PECAM1 nucleotide structure and expression analyses in an experimental model of normal and pathological wound repair.

Background: Wound healing in horses is fraught with complications. Specifically, wounds on horse limbs often develop exuberant granulation tissue which behaves clinically like a benign tumor and resembles the human keloid in that the evolving scar is trapped in the proliferative phase of repair, leading to fibrosis. Clues gained from the study of over-scarring in horses should eventually lead to new insights into how to prevent unwanted scar formation in humans.

Why dissection videos should not replace cadaver prosections in the gross veterinary anatomy curriculum: results from a comparative study.

The goal of our study was to evaluate the impact of a tool intended to eliminate large-animal cadavers from the anatomy laboratory, in view of their prohibitive cost and the logistic difficulties they pose. We sought to determine whether a commented video of the bovine abdominal cavity could effectively replace a prosection of this region. The hypothesis was that students receiving video instruction would achieve lower scores on a post-instructional exam than those benefiting from a commented cadaver prosection.

Endothelial cell hypertrophy is associated with microvascular occlusion in horse wounds.

Wound repair in horse limbs is often complicated by excessive fibroplasia and scarring. Occlusion of the microvessels populating the granulation tissue appears to be involved in the excessive accumulation of extracellular matrix during the repair of limb wounds. This study aimed to determine whether endothelial cell hypertrophy or hyperplasia, or both, contribute to microvascular occlusion and whether the pericyte is involved in this anomaly.

Short- and long-term skin graft survival in cattle clones with different mitochondrial haplotypes.

In contrast to nuclear DNA, cytoplasmic genes may differ among cloned animals due to the presence of polymorphic mitochondrial DNA haplotypes in the host oocytes, raising doubts about histocompatibility among clones. Three bovine clones were generated by nuclear transfer; dermal fibroblasts from a fetus were used as donor cells, whereas oocytes from abbatoir-derived ovaries were used as recipient cells. The mitochondrial DNA (sequencing of coding and non-coding regions) and nuclear DNA (13 microsatellite markers) of cloned and control animals were characterized to identify potential polymorphisms.

Comparative study on microvascular occlusion and apoptosis in body and limb wounds in the horse.

Wound repair in horse limbs is often complicated by exuberant granulation tissue, a condition characterized by excessive fibroplasia and scarring and that resembles hypertrophic scars and keloids in man. The aim of this study was to compare microvascular occlusion and apoptosis in wounds of the limb with those of the body, which heal normally. Five 6.

Effect of a silicone-containing dressing on exuberant granulation tissue formation and wound repair in horses.

Objective: To determine the effect of a silicone dressing on the rate and quality of repair of limb wounds and compare microvascular occlusion and apoptosis in wounds treated with the silicone dressing and those treated with a conventional dressing in horses.

Animals: 5 horses.

Procedure: Horses received two 6.