The skin of horses is a complex organ that serves multiple functions, including protection, thermoregulation, and sensory perception. It consists of several layers, primarily the epidermis and dermis, each contributing to the overall health and functionality of the skin. The epidermis provides a barrier against environmental factors, while the dermis supports the skin structure and houses blood vessels, nerves, and hair follicles. Equine skin is also involved in the production of sweat and sebum, which aid in temperature regulation and skin lubrication, respectively. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, and health conditions of equine skin, as well as advancements in dermatological treatments and care practices.
Jørgensen E, Lazzarini G, Pirone A, Jacobsen S, Miragliotta V.Information on microscopic anatomy of equine skin is sparse. In horses, limb wounds often become chronic and/or non-healing whereas body wounds heal normally. These dissimilarities in healing patterns might be a product of different phenotypic characteristics of body and limb skin. The objective of this study was to investigate microscopic anatomy, epidermal thickness, keratinocyte proliferation and differentiation as well as the presence of mast cells in normal equine skin of body and limb. Methods: The study involved body and limb skin biopsies from six horses. Histological characteristics o...
Tannahill VJ, Cogan T, Allen K, Acutt E, Busschers E.To determine the efficacy and dermal tolerance of a novel alcohol-based skin antiseptic (ABSA) in horses. Methods: Experimental study. Methods: Systemically healthy horses (n = 25) with no history or clinical signs of skin disease. Methods: Four clipped sites on the abdomen were randomly assigned to a skin preparation protocol: saline (negative control; NC), chlorhexidine gluconate followed by isopropyl alcohol (positive control; PC), saline followed by the ABSA (ABSA A), or a commercially available horse shampoo followed by the ABSA (ABSA B). Microbiological swabs were obtained from each ...
Szczepanik MP, Wilkołek PM, Adamek ŁR, Gołyński M, Sitkowski W, Taszkun I.The measurement of transepidermal water loss (TEWL) is one of the biophysical skin parameters used to assess skin barrier function. Assessment of transepidermal water loss, may depend on such factors as body region, age, sex or breed and the hair coat has been considered as one of the factors that may cause variation of TEWL values. The aim of our research was an examination of the influence of clipping on the amount of TEWL. The examination was performed with 12 Wielkopolska horses with Courage Khazaka Multi Probe Adapter 5 and a TEWL TM 300 probe. The TEWL values were statistically constant ...
Fettelschoss-Gabriel A, Fettelschoss V, Thoms F, Giese C, Daniel M, Olomski F, Kamarachev J, Birkmann K, Bühler M, Kummer M, Zeltins A, Marti E....Insect-bite hypersensitivity is the most common allergic dermatitis in horses. Excoriated skin lesions are typical symptoms of this seasonal and refractory chronic disease. On a cellular level, the skin lesions are characterized by massive eosinophil infiltration caused by an underlying allergic response. To target these cells and treat disease, we developed a therapeutic vaccine against equine IL-5 (eIL-5), the master regulator of eosinophils. The vaccine consisted of eIL-5 covalently linked to a virus-like particle derived from cucumber mosaic virus containing the tetanus toxoid universal T-...
Li 李靖 J, Liu B, Yu F, Liu T, Peng Y, Fu Y.Hereditary equine regional dermal asthenia (HERDA) is an autosomal recessive inheritable disorder described in the Quarter Horses and related breeds. In this case report, a 2-year-old Quarter Horse filly was diagnosed with HERDA based on clinical findings and genetic testing. The observed clinical signs were stretchy, loose and thin skin, and open wounds on the upper body. Skin biopsy results were consistent with the common findings previously described in the literature. This is the first HERDA case report in China (and in Asia). Genetic testing protocols should be implemented for breeding fa...
Hofberger SC, Gauff F, Thaller D, Morgan R, Keen JA, Licka TF.OBJECTIVE To identify signs of tissue-specific cortisol activity in samples of suspensory ligament (SL) and neck skin tissue from horses with and without pituitary pars intermedia dysfunction (PPID). SAMPLE Suspensory ligament and neck skin tissue samples obtained from 26 euthanized horses with and without PPID. PROCEDURES Tissue samples were collected from 12 horses with and 14 horses without PPID (controls). Two control horses had received treatment with dexamethasone; data from those horses were not used in statistical analyses. The other 12 control horses were classified as old horses (≥...
Lomas HR, Robinson PA.Equine insect bite hypersensitivity (IBH), commonly known as sweet itch or summer eczema, is a frustrating recurrent skin disease in the equine industry involving an immune reaction to the bites of spp. midges. To investigate the impact of IBH in the field, an exploratory pilot study was conducted with equine stakeholders in one region of central England. Nine semi-structured, face-to-face interviews were conducted with horse owners and an equine veterinarian. The aim was to gain an understanding of experiences with IBH, and to gauge opinions on the value of the various management strategies ...
Tomich LM, Pieper JB, Stern AW.Dermoscopy is a noninvasive diagnostic technique that allows visualization of structures of the superficial dermis not visible with the naked eye. Objective: To assess the usefulness and applicability of dermoscopy for evaluation of healthy equine skin. Methods: Twelve healthy horses from a research herd. Methods: Five regions (cheek, lateral neck, dorsum, flank and abdomen) were examined with contact dermoscopy using both nonpolarized and polarized light at both 17-fold and 24-fold magnification. These findings were compared to histological features of skin biopsies cut both longitudinally an...
Legnani S, Zini E, Roccabianca P, Funiciello B, Zanna G.Dermoscopy is a diagnostic tool that has been introduced into small animal dermatology for the evaluation of hair and the skin surface. To the best of the authors' knowledge, the use of this technique on horses and the dermoscopic appearance of equine hair and skin have yet to be reported. Objective: To assess the feasibility of dermoscopy, and to describe hair and skin surface features of healthy warmblood horses. Methods: Thirty four client-owned, healthy adult horses. Methods: Six body regions (head, neck, dorsal thorax, ventral thorax, croup and mane) were examined with a smartphone-attach...
Pereira RCDF, De La Côrte FD, Brass KE, da Silva Azevedo M, Gallio M, Cantarelli C, Dau SL, Cezar AS, Inkelmann MA.Wounds localized on the distal limbs in horses are difficulty healing. No studies have been conducted to evaluate homologous platelet-rich plasma (PRP) in horses. The aim of this study was to evaluate the effect upon applying autologous PRP, homologous PRP, and autologous PRP gel on the wound healing process of wounds on the distal limb of horses. To study a possible correlation between the platelet count and wound healing time, four skin wounds of 4 cm2 were surgically created on the dorsolateral aspect of the third metacarpus in eight healthy adult horses. Each skin wound was randomly treate...
Li B, He X, Zhao Y, Bai D, Shiraigo W, Zhao Q, Manglai D.Studies on the molecular genetics of horse skin pigmentation have typically focused on very few genes and proteins. In this study, we used Illumina sequencing to determine the global gene expression profiles in horses with white-colored coats and those with black-colored coats, with the goal of identifying novel genes that could regulate horse coat color. Results: Genes encoding ribosomal-associated proteins were highly expressed in horse skin. We found a total of 231 unigenes that were differentially expressed between horses with white coats and horses with black coats; 119 were down-regulate...
Veraldi S, Genovese G, Peano A.Trichophyton equinum is a zoophilic dermatophyte usually causing ringworm in horses. Cases of skin infections in humans are very rare. CASE REPORT : We describe a case of tinea corporis caused by T. equinum on a buttock of a rider who often rode bareback with short trousers. Conclusions: Although T. equinum was considered in the past as a strict zoophilic dermatophyte, our case report confirms that it can cause dermatophytoses also in humans. A review of epidemiological and clinical features of human infections caused by T. equinum is presented.
Balmer P, Bauer A, Pujar S, McGarvey KM, Welle M, Galichet A, Müller EJ, Pruitt KD, Leeb T, Jagannathan V.Keratins represent a large protein family with essential structural and functional roles in epithelial cells of skin, hair follicles, and other organs. During evolution the genes encoding keratins have undergone multiple rounds of duplication and humans have two clusters with a total of 55 functional keratin genes in their genomes. Due to the high similarity between different keratin paralogs and species-specific differences in gene content, the currently available keratin gene annotation in species with draft genome assemblies such as dog and horse is still imperfect. We compared the National...
Harman RM, Yang S, He MK, Van de Walle GR.The prevalence of chronic skin wounds in humans is high, and treatment is often complicated by the presence of pathogenic bacteria. Therefore, safe and innovative treatments to reduce the bacterial load in cutaneous wounds are needed. Mesenchymal stromal cells (MSC) are known to provide paracrine signals that act on resident skin cells to promote wound healing, but their potential antibacterial activities are not well described. The present study was designed to examine the antibacterial properties of MSC from horses, as this animal model offers a readily translatable model for MSC therapies i...
Harnacker J, Hainisch EK, Shafti-Keramat S, Kirnbauer R, Brandt S.Equine sarcoids are common therapy-resistant skin tumours induced by bovine papillomavirus type 1 or 2 (BPV1, BPV2) infection. We have previously shown that prophylactic vaccination with BPV1 L1 virus-like particles (VLPs) efficiently protects horses from experimental BPV1-induced pseudo-sarcoid development. Here, we assessed BPV1 L1 VLP vaccine-mediated long-term protection from experimental tumour formation in seven horses 5 years after immunization with three different doses of BPV1 L1 VLPs, and three unvaccinated control animals. Horses were challenged by intradermal inoculation with infec...
Harmon CCG, Hawkins JF, Li J, Connell S, Miller M, Saenger M, Freeman LJ.OBJECTIVE To determine the effects of 3 topically applied treatments (1% silver sulfadiazine cream [SSC], triple antimicrobial ointment [TAO], and hyperosmolar nanoemulsion [HNE]) on microbial counts, exuberant granulation tissue (EGT) development, and reepithelialization of contaminated wounds at the distal aspect of the limbs of horses. ANIMALS 8 healthy adult horses. PROCEDURES A 2.5 × 2.5-cm, full-thickness, cutaneous wound was created at the dorsal aspect of each metacarpus and metatarsus (1 wound/limb/horse), covered with nonadhesive dressing, and bandaged. Wounds were inoculated with b...
Semik E, Ząbek T, Gurgul A, Fornal A, Szmatoła T, Pawlina K, Wnuk M, Klukowska-Rötzler J, Koch C, Mählmann K, Bugno-Poniewierska M.In this study, for the first time we report the genome-wide DNA methylation profile of skin tumour in horses and describe differentially methylated genomic regions (DMRs) with respect to healthy skin. Methods: The comparative analysis of DNA methylation patterns detected using Reduced Representation Bisulfite Sequencing (RRBS) technique, allowed identification of 136 regions showing differential methylation between sarcoid and normal skin tissue. Results: Most of the identified DMRs were short fragments, less than 1 kb in size, located in the intergenic regions. Among identified DMRs there wer...
Szczepanik MP, Wilkołek PM, Adamek ŁR, Pluta M, Gołyński M, Sitkowski W, Kalisz G, Taszkun I, Pomorski ZJ.Non-invasive methods of skin condition assessment include, among others, the evaluation of transepidermal water loss (TEWL). The aim of the study was to examine whether TEWL values depend on horse breed. The study was conducted on four breeds: "Felin" ponies (FP) (n=16), Polish koniks (PK) (n=15), Polish cold-blooded horses (PcbH) (n=11) and Wielkopolska horses (WH) (n=12). It was found that horse breed influences TEWL values. In the neck region, statistically significant differences were found between PK and FP (p=0.006), and PK and WH (p=0.0005). In the lumbar region, there were statisticall...
Allen WR, Gower S, Wilsher S.Implantation and placentation in the mare does not commence until as late as day 40 after ovulation. The reasons for this and the growth factors and/or hormones which drive placentation when it does finally occur are of considerable academic and practical interest. Placental interface tissues recovered from 11 accurately aged and perfused-fixed horse uteri between 20 and 68 days of gestation were stained immunocytochemically for Epidermal Growth Factor (EGF), its specific receptor (EGF-R) and for the steroid hormone enzyme, aromatase. EGF was present in endometrial gland and lumenal epithelia ...
Pin D.Dermatophytoses in animals are fungal diseases of the skin caused by dermatophyte fungi of the genus Microsporum or Trichophyton. Because the infection is generally follicular, the most common clinical sign is one or many circular areas of alopecia with variable erythema, scaling and crusting, and the primary differential diagnoses are follicular infections, such as bacterial folliculitis and demodicosis. Although dermatophyte folliculitis or ringworm is the most commonly observed lesion of dermatophytoses in animals, other presentations may be observed according to the host species and the de...
Semik E, Gurgul A, Ząbek T, Ropka-Molik K, Koch C, Mählmann K, Bugno-Poniewierska M.Equine sarcoids are the most commonly detected skin tumours in Equidae. In the present research, a comparative transcriptomic analysis was performed which aimed at looking inside a tumour biology and identification of the expression profile as a potential source of cancer specific genes useful as biomarkers. We have used Horse Gene Expression Microarray data from matched equine sarcoids and tumour-distant skin samples. In total, 901 significantly differentially expressed genes (DEGs) between lesional and healthy skin samples have been identified (fold change ≥ 2; P < 0.05). The la...
Murgiano L, Waluk DP, Towers R, Wiedemar N, Dietrich J, Jagannathan V, Drögemüller M, Balmer P, Druet T, Galichet A, Penedo MC, Müller EJ....We investigated a family of horses exhibiting irregular vertical stripes in their hair coat texture along the neck, back, hindquarters, and upper legs. This phenotype is termed "brindle" by horse breeders. We propose the term "brindle 1 (BR1)" for this specific form of brindle. In some BR1 horses, the stripes were also differentially pigmented. Pedigree analyses were suggestive of a monogenic X-chromosomal semidominant mode of inheritance. Haplotype analyses identified a 5 Mb candidate region on chromosome X. Whole genome sequencing of four BR1 and 60 nonbrindle horses identified 61 private v...
Duesterdieck-Zellmer KF, Larson MK, Plant TK, Sundholm-Tepper A, Payton ME.OBJECTIVE To measure penetration efficiencies of low-level laser light energy through equine skin and to determine the fraction of laser energy absorbed by equine digital flexor tendons (superficial [SDFT] and deep [DDFT]). SAMPLE Samples of skin, SDFTs, and DDFTs from 1 metacarpal area of each of 19 equine cadavers. PROCEDURES A therapeutic laser with wavelength capabilities of 800 and 970 nm was used. The percentage of energy penetration for each wavelength was determined through skin before and after clipping and then shaving of hair, through shaved skin over SDFTs, and through shaved skin,...
Tartor YH, El Damaty HM, Mahmmod YS.Rapid and accurate identification of dermatophytes is crucial for the effective control of disease outbreaks. Current methods based on culture and microscopic characteristics may require weeks before positive identification is made. Objective: To (i) identify the most common pathogenic dermatophytes affecting Arabian horses; (ii) compare the performance of direct microscopy (DM), culture, PCR using hair samples (PCRhair ) and PCR based on culture isolates (PCRculture ) for the diagnosis of dermatophytosis. Methods: Samples of hair and crusts of skin lesions from Arabian horses were collected o...
Wise LM, Bodaan CJ, Mercer AA, Riley CB, Theoret CL.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. Objective: The study aimed to determine if equine dermal cells respond to VEGF-E and ovIL-10. Equine dermal cells are expected to express VEGF and IL-10 receptors, so viral protein treatment is likely to alter cellular gene expression an...
Frank LA, Kania SA, Weyant E.Dermatophilus congolensis causes a crusting dermatitis that affects horses. Diagnosis requires the identification of the organism with cytological evaluation of crust samples. This method can lack sensitivity in chronic cases. Objective: To develop a probe-based real time quantitative polymerase chain reaction (RT-qPCR) test to assist with the diagnosis of dermatophilosis in horses. Methods: Twenty six privately owned horses and seven horses from a research colony were used. Methods: Crust samples, collected from 14 horses with suspected dermatophilosis and 12 horses with crusting skin disease...
Goodale EC, White SD, Outerbridge CA, Everett AD, Affolter VK.Hyperaesthetic leucotrichia (HL) rarely affects horses and causes painful lesions on the dorsum that result in leucotrichia. This may be a variant of erythema multiforme (EM), but there are no studies investigating this condition. Objective: Describe the clinical and histological features of HL and compare them to the histological features of EM. Methods: A retrospective review of medical records from 1985 to 2015 identified 15 horses with HL. Thirteen biopsies of HL and five of EM were evaluated and compared. Results: Arabian horses and their crosses (χ(2) (1) = 8.56, P < 0.01) and A...
Knottenbelt DC.Few skin diseases specifically or exclusively affect older horses and donkeys. Hypertrichosis (hirsutism) associated with pituitary pars intermedia dysfunction is probably the most recognized and best understood exception and is the most common age-related skin condition in equids. Many other conditions are known to be more serious in older horses. Horses affected with immune-compromising conditions can be more severely affected by infectious diseases of the skin or heavy and pathologically significant parasitism. Neoplasia of the skin is probably more prevalent and worse in older horses, alth...
Zachar EK, Burgess HJ, Wobeser BK.Fine-needle aspiration (FNA) is commonly used to diagnose skin disease in companion animals, but its use in horses appears to be infrequent. Equine veterinarians in western Canada were surveyed to determine their opinions about FNA and 15 years of diagnostic submissions were used to compare the perceived to actual value of FNA in the diagnosis of skin disease in horses. Practitioners viewed FNA as quick, easy, economical, and minimally invasive. However, most veterinarians rarely chose to use FNA due to a perception that sample quality and diagnostic yield were poor and there was a narrow rang...
Paßlack N, van Bömmel-Wegmann S, Vahjen W, Zentek J.Zinc supplements are often used in equine nutrition to support skin and hoof quality or the immune function. However, no data on the effects of dietary zinc on the intestinal microbiota of horses and ponies are available so far. In the present study, varying dietary zinc concentrations (maintenance (4 mg/kg BW/day), 120 mg/kg dry matter (DM)/day and 240 mg/kg DM/day) were achieved by the supplementation of either zinc chloride hydroxide or zinc methionine (six treatment periods of 4 weeks each). Eight healthy adult ponies and two healthy adult horses were included, and faecal samples were coll...
Sarcoids are the mostcommon skin tumors in horses, characterized by rare regression, invasiveness and high recurrence following surgical intervention and Delta Papillomaviruses are widely recognized as the causative agents of the disease. In order to gain new insights into equine sarcoid development, we have evaluated, in 25 equine sarcoids, by immunohistochemistry and western blotting analysis, the expression levels of VEGF, Ki67 and bcl-2. Moreover, we have measured microvessel density and specific vessel parameters. Results: All sarcoid samples showed a strong and finely granular cytoplasma...
Watts AE, Fubini SL, Vernier-Singer M, Golkowski C, Shin S, Todhunter RJ.To determine the effect of nonthermal plasma on Staphylococcus aureus, fibroblasts in monolayer culture, and clean and contaminated skin explants. Methods: Normal skin from euthanized horses. Methods: S aureus organisms were plated and treated with nonthermal plasma followed by bacterial culture to assess viability. Fibroblasts in monolayer culture and the epidermal and dermal surfaces of clean and S aureus-contaminated skin explants were treated. The effects of distance and duration on the response to treatment were compared. Results: Compared with controls, treatment with nonthermal plasma r...
Maurice MN, Kazeem HM, Kwanashie CN, Maurice NA, Ngbede EO, Adamu HN, Mshelia WP, Edeh RE.This study was designed to determine the occurrence and species distribution of dermatophyte from cutaneous skin lesions of horses in Kaduna State, Nigeria. A total of 102 skin scrapings were collected from 102 horses with skin lesions. Mycological studies were carried out using conventional techniques. Dermatophytes were isolated from 18 (17.6%) of the 102 samples collected. The 18 dermatophytes were distributed into 10 different species belonging to Microsporum (n = 5) and Trichophyton (n = 5) genera. T. verrucosum (n = 4) was the most predominant species isolated followed by M. equinum (n =...
Schöniger S, Summers BA.Melanocytic tumours are important in horses, especially grey horses. Intradermal common melanocytic naevi, cellular blue naevi and combined cellular blue naevi are subgroups of human melanocytic tumours, which have not been reported in horses. In this study, we describe 20 horses with skin tumours similar to these naevi of humans. These tumours represented individual skin masses in male and female horses of different breeds. Tumours resembling human intradermal common melanocytic naevi were noted in 12 horses aged between 2 and 17 years. Seven horses aged between 4 and 15 years developed cutan...
Yuan Z, Philbey AW, Gault EA, Campo MS, Nasir L.Papillomaviruses are normally strictly species-specific and even under experimental conditions do not usually infect any other host than the natural host. The only documented reports of natural papillomavirus cross-species infection are of BPV-1/BPV-2, which can infect horses and induce equine sarcoids. BPV DNA has not been detected in non-sarcoid equine tumours or equine papillomas, but its presence has been reported in some cases of equine dermatitis. In the present study, we show that equine inflammatory skin conditions harbour episomal circular double stranded BPV-1 genomes, with copy numb...
Marais HJ, Nel P, Bertschinger HJ, Schoeman JP, Zimmerman D.There are no reports in the literature describing any tumours, and specifically sarcoids, in zebras. The equine sarcoid, a locally aggressive, fibroblastic skin tumour, is the most common dermatological neoplasm reported in horses. The Cape mountain zebra (CMZ) has been described as one of the most vulnerable mammals in South Africa with current populations existing in isolated units. All South African CMZ are descendants from no more than 30 individual animals originating from 3 populations, namely the Mountain Zebra National Park, and Kammanassie and Gamka Mountain Nature Reserves near Crado...
Halliwell RE, Fleischman JB, Mackay-Smith M, Beech J, Gunson DE.Twenty-five horses with chronic pulmonary disease were skin tested with allergenic extracts of 24 molds, 4 thermophilic actinomyces, barn dust, hay dust, soya-bean mill dust, and grain mill dust. The results were compared with those obtained on 25 normal horses. Between the 2 groups of horses, there was a highly significant difference in positive skin test results at 30 minutes and 4 hours.
Rüfenacht S, Straub R, Steinmann B, Winand N, Bidaut A, Stoffel MH, Gerber V, Wyder M, Müller E, Roosje PJ.Hereditary equine dermal asthenia (HERDA) is an autosomal recessive skin disease that affects predominantly Quarter Horses and related breeds. Typical symptoms are easy bruising and hyperextensible skin on the back. The prognosis is guarded, as affected horses cannot be ridden normally and are often euthanised. In the Quarter Horse, HERDA is associated with a mutation in cyclophilin B (PPIB), an enzyme involved in triple helix formation of collagen. Here we describe the case of a Swiss Warmblood filly with symptoms of HERDA without PPIB-mutation and in which we also could exclude Ehlers-Danlos...
Harmon CCG, Hawkins JF, Li J, Connell S, Miller M, Saenger M, Freeman LJ.OBJECTIVE To determine the effects of 3 topically applied treatments (1% silver sulfadiazine cream [SSC], triple antimicrobial ointment [TAO], and hyperosmolar nanoemulsion [HNE]) on microbial counts, exuberant granulation tissue (EGT) development, and reepithelialization of contaminated wounds at the distal aspect of the limbs of horses. ANIMALS 8 healthy adult horses. PROCEDURES A 2.5 × 2.5-cm, full-thickness, cutaneous wound was created at the dorsal aspect of each metacarpus and metatarsus (1 wound/limb/horse), covered with nonadhesive dressing, and bandaged. Wounds were inoculated with b...
Wilmink JM, Stolk PW, van Weeren PR, Barneveld A.Second-intention healing of limb wounds in horses is often problematic. Solcoseryl is a protein-free, standardized dialysate/ultrafiltrate (HD) derived from calf blood, which has been shown to improve healing in both animals and humans. The efficacy of HD in the healing of deep wounds in horses and ponies was investigated. Deep wounds of 20 by 35 mm were created on both metatarsi (skin, subcutis, periosteum) and on both femoral biceps muscles (skin, subcutis, muscle) of five horses and five ponies. The wounds on one side were treated with HD, four times a week during the period that the wounds...
Bischofberger AS, Tsang AS, Horadagoda N, Dart CM, Perkins NR, Jeffcott LB, Jackson CJ, Dart AJ.To investigate the effect of activated protein C (APC) on second intention healing of distal limb wounds in horses. Methods: In this experimental study of eight Standardbred geldings, six full-thickness skin wounds (2 × 1.5 cm) were created on one metacarpus (biopsy limb) and five similar wounds were created on the contralateral metacarpus (photographed limb). Three wounds on the biopsy limb were treated topically with 190 µg APC on days 1, 3, 6 and 9, while the remaining three wounds were untreated (control). One treated and one control wound were biopsied on days 4, 7 and 11 for hi...
Hardy MH, Fisher KR, Vrablic OE, Yager JA, Nimmo-Wilkie JS, Parker W, Keeley FW.The hyperextensible, fragile skin of two related horses was compared with the skin of eight normal horses. Skin sections were examined by light microscopy and transmission electron microscopy. The deep dermal layer of the dorsal abdomen was much thinner in the affected horses, and contained bundles of collagen fibers which were more loosely packed. Within individual fibers, the fibrils were frequently curved and nonparallel rather than straight and parallel. Both of the affected animals had a greater range of fibril diameters than a normal horse. They had some unusually thick fibrils with very...
Holder TE, Schumacher J, Donnell RL, Rohrbach BW, Adair HS.To determine the effects of hyperbaric oxygen therapy (HBOT) on full-thickness skin grafts applied to fresh and granulating wounds of horses. Methods: 6 horses. Methods: On day 0, two 4-cm-diameter circular sections of full-thickness skin were removed from each of 2 randomly selected limbs of each horse, and two 4-cm-diameter circular skin grafts were harvested from the pectoral region. A skin graft was applied to 1 randomly selected wound on each limb, leaving the 2 nongrafted wounds to heal by second intention. On day 7, 2 grafts were harvested from the pectoral region and applied to the gra...
Weber LA, Funtan A, Paschke R, Delarocque J, Kalbitz J, Meißner J, Feige K, Kietzmann M, Cavalleri JV.Equine sarcoid (ES) is the most prevalent skin tumor in equids worldwide. Additionally, aging grey horses frequently suffer from equine malignant melanoma (EMM). Current local therapies targeting these skin tumors remain challenging. Therefore, more feasible topical treatment options should be considered. In order to develop a topical therapy against ES and EMM, betulinyl-bis-sulfamate and NVX-207, derivatives of the naturally occurring betulin and betulinic acid, respectively, were evaluated for their antiproliferative (crystal violet staining assay), cytotoxic (MTS assay) and apoptotic (Anne...
Loeffler A, Herrick D, Allen S, Littlewood JD.Allergic pruritus and urticaria in the horse are challenging for veterinarians and owners; little is known about their long-term management. Objective: To summarize intradermal allergen test results (IDT), and to assess owners' perceptions of skin disease and the effects of medical treatment and management changes in their atopic horses over time. Methods: Eighty two horses with atopic dermatitis in southeastern England between 2006 and 2011. Methods: The IDT results were reviewed retrospectively. Owners completed telephone questionnaires on skin changes, medication, effect of allergen-specifi...
Harnacker J, Hainisch EK, Shafti-Keramat S, Kirnbauer R, Brandt S.Equine sarcoids are common therapy-resistant skin tumours induced by bovine papillomavirus type 1 or 2 (BPV1, BPV2) infection. We have previously shown that prophylactic vaccination with BPV1 L1 virus-like particles (VLPs) efficiently protects horses from experimental BPV1-induced pseudo-sarcoid development. Here, we assessed BPV1 L1 VLP vaccine-mediated long-term protection from experimental tumour formation in seven horses 5 years after immunization with three different doses of BPV1 L1 VLPs, and three unvaccinated control animals. Horses were challenged by intradermal inoculation with infec...
Dart AJ, Cries L, Jeffcott LB, Hodgson DR, Rose RJ.To evaluate the effect of intramuscular administration of recombinant equine growth hormone on healing of full thickness skin wounds on equine limbs. Methods: Experimental. Methods: Nine Standardbred horses. Methods: In study 1, standardized full thickness skin wounds (2.5 x 2.5 cm) were made over the dorsomedial aspect of the mid-cannon bone of 1 forelimb and 1 hindlimb in 9 horses. Wounds were bandaged without treatment (control subjects) and videorecorded twice weekly until healed. Then, in study 2, similar wounds were created on the opposite limbs; 6 horses were administered intramuscular ...
Sánchez-Casanova RE, Masri-Daba M, Alonso-Díaz MÁ, Méndez-Bernal A, Hernández-Gil M, Fernando-Martínez JA.A wide spectrum of welfare issues is encountered on working equids. The objectives of this study were: (i) to determine the prevalence of cutaneous lesions in working equids in tropical regions of the North-Central of Veracruz State, Mexico, (ii) to identify the most prevalent cutaneous pathological conditions in this population of working equids, and (iii) to identify risk factors associated to the presence of work-related skin wounds. A number of 467 working equids presented for treatment at Donkey Sanctuary Mobile Clinic Program - National Autonomous University of Mexico from seven differen...
Stahl J, Kietzmann M.The effect of physical and chemical permeation enhancers on in vitro transdermal permeation of lidocaine was investigated in the horse.Therefore, the effect of six vehicles (phosphate-buffered saline (PBS), 50% ethanol, 50% propylene glycol, 50% isopropylalcohol, 50% isopropylalcohol/isopropylmyristate and 50% dimethylsulfoxide) was examined as well as the effect of microneedle pretreatment with different needle lengths on transdermal drug delivery of lidocaine.The skin was obtained from the thorax of six Warmblood horses and was stored up to two weeks at - 20°C. Franz-type diffusion cells we...
Morgan K, Funkquist P, Nyman G.The aim of this study was to study the physiological, especially thermoregulatory, responses during intense exercise in the clipped horse compared to the horse with winter coat. Six Standardbred trotters were studied before and after clipping. They performed an inclined incremental high intensity treadmill exercise test and were monitored during recovery. The clipped horse differed significantly (ANOVA) during exercise as compare to coated: less increase in central venous blood temperature, higher skin surface temperature, greater difference skin to ambient temperature and higher rate of nonev...
Sharma R, Barakzai SZ, Taylor SE, Donadeu FX.Despite the high prevalence of skin conditions in the horse, there is a dearth of literature on the culture and biology of equine skin cells, and this is partially attributable to the lack of suitable in vitro skin models. The objective of this study was to develop a three-dimensional (3D) culture system that would support the proliferation and differentiation of equine keratinocytes, similar to that observed in natural epidermis. Cell monolayers were obtained from explants of equine skin and serially passaged as highly pure keratinocyte populations (> 95% of cells), based on their express...
da Silveira EA, Bubeck KA, Batista ER, Piat P, Laverty S, Beauchamp G, Archambault M, Elce Y.This prospective clinical study evaluates the effectiveness of an alcohol-based hand rub (Avagard™) for pre-surgical hand antisepsis in an equine hospital and compares it with traditional scrubbing technique using 4% chlorhexidine gluconate sponges and water. Prior to elective surgery, 3 board-certified surgeons were randomly assigned to hand antisepsis with either technique. Culture samples of each hand were taken at 4 times: before and after neutral soap hand wash, after scrub or rubbing technique, and after surgery. There was no significant difference in mean bacterial colony forming unit...
Borena BM, Meyer E, Chiers K, Martens A, Demeyere K, Broeckx SY, Duchateau L, Spaas JH.Mammal skin plays a pivotal role in several life preserving processes and extensive damage may therefore be life threatening. Physiological skin regeneration is achieved through ongoing somatic stem cell differentiation within the epidermis and the hair follicle. However, in severe pathological cases, such as burn wounds, chronic wounds, and ulcers, the endogenous repair mechanisms might be insufficient. For this reason, exogenous purification and multiplication of epithelial-like stem/progenitor cells (EpSCs) might be useful in the treatment of these skin diseases. However, only few reports a...
Miksík I, Deyl Z.Skin and aorta collagen specimens of Wistar rats, white mice, beagle dogs, cats, horses, and human necropsies of different ages were examined with respect to the content of glycated products. The data presented show that (a) glycation and accumulation of the chromophore(s) are comparable in collagen samples from different species of comparable age; (b) glycation and pigmented accumulation increase markedly during the first 5-10 years of age; (c) the extent of glycation is different in different tissues (in particular, glycation of aortal collagen is about twice that of skin collagen); and (d) ...
Vyas R, Keller JJ, Honda K, Cooper KD, Gerstenblith MR.Animal-type melanoma is a rare subtype of melanoma with heavily pigmented dermal epithelioid and spindled melanocytes. Its classification as a subtype of melanoma versus a borderline melanocytic tumor is debated. Objective: Our primary objective was to characterize the demographics, clinical presentation, histopathology, management, and outcomes of patients with animal-type melanoma. Methods: We performed a systematic review and meta-analysis of the English-language literature on animal-type melanoma. Results: We identified 190 cases of animal-type melanoma. They occurred equally in men and wo...
McCue ME, Davis EG, Rush BR, Cox JH, Wilkerson MJ.A 4-year-old Paint mare was examined because of respiratory tract infection, dermatitis, and weight loss of 2 months' duration. Initial examination revealed generalized pruritic dermatitis, ocular and nasal discharges, and stranguria. Laboratory abnormalities included leukopenia and hypoalbuminemia. Further examination of the respiratory tract revealed grade III of IV pharyngitis and pyogranulomatous pneumonia. Endoscopic examination of the bladder revealed a prolific mass at the junction of the bladder and urethra. Hypoproteinemia was suspected to be caused by protein-losing enteropathy. On h...
Pettersson CM, Broström H, Humblot P, Bergvall KE.Equine sarcoids are the most prevalent skin neoplasm in horses worldwide. Although several treatments are available, none are consistently effective and recurrence is common. Objective: To evaluate the efficacy and safety of topical imiquimod 5% cream and Sanguinaria canadensis + zinc chloride for treatment of equine sarcoids and investigate possible systemic effects on distant untreated sarcoids. Unassigned: Twenty-five client-owned horses with a total of 164 tumours were included in the study. Fifty-seven tumours were treated and 107 tumours were left untreated. Methods: Skin biopsy sample...
Power HT, Watrous BJ, de Lahunta A.In 6 horses, clinical signs of illness implicated a lesion involving the facial and vestibulocochlear nerves. One horse had signs of otitis externa. Five horses had radiographic changes primarily involving periosteal bony proliferation of the stylohyoid bone at its articulation with the temporal bone. Five horses improved with antibiotic therapy. Otitis media-interna was found at necropsy of one horse.
