Topic:Skin
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.
[Differential diagnosis of non-healing ‘fungal’patches in horses]. Dermatophytosis is the most common equine skin disease. Mycotic-like lesions that do not disappear are suspected of being sarcoids. The clinical symptoms and therapeutic interventions for both affections are discussed. A short review of the differential diagnoses is presented.
[Eumycotic mycetomas in horses caused by Curvularia verruculosa]. The fungus Curvularia verruculosa, which produces eumycotic mycetomas, was isolated from skin of horses with granulomatous lesions on the legs. The isolation was made in Sabouraud dextrose agar medium. The horses came from Comandante Fontana suburb, Formosa-Argentina. This finding would be the first report of Curvularia in horses in Argentina.
Marked Acantholysis Associated with Dermatophytosis due to Trichophyton equinum in Two Horses. Resumen- Dos caballos adultos manifestaron un cuadro prurítico y de dolor asociado con una dermatitis generalizada de evolución rápida y consistente en la presencia de pápulas, pústulas y costras. El examen microscópico de extensiones citológicas a partir del exudado purulento reveló la presencia de numerosos queratinocitos acantoliticos, neutrófilos no degenerados y ausencia de microorganismos, lo que sugirió un diagnóstico de pénfigo foliáceo. Las biopsias de piel mostraron dermatofitosis, marcada acantolisis y crecióTrichophyton equinum en cultivos fúngicos. Las lesiones en a...
Heterogeneity of pericyte populations in equine skeletal muscle and dermal microvessels: a quantitative study. The objective of this ultrastructural investigation was to determine if populations of pericytes in equine dermal and skeletal muscle capillaries increase in a head-to-foot direction, as has been reported in human skeletal muscles. Samples of equine microvessels were obtained from the longissimus dorsi skeletal muscle 150 cm. from the ground, from the dermis above this muscle, from the extensor carpi radiali muscle at 55 cm. from the ground, from the dermis adjacent to that muscle, and from dermis 15 cm. from the ground, just above the hoof wall. Tissues were processed for transmission electro...
[Morphologic and molecular biologic studies of the etiology of equine sarcoid]. From 932 equine skin lesions 421 were diagnosed as sarcoids (about 45%). The most common locations were the ventral body regions, head, neck and sites of thin skin. Most often the fibroblastic type, less frequently the mixed type and most infrequent the verrucous type of sarcoid were diagnosed. Detection of BPV-DNA was performed by polymerase chain reaction (PCR) using an oligonucleotide primer pair located in the E5-open reading frame. DNA of BPV 1 and BPV 2 could be differentiated by digestion with restriction endonucleases. In 97 out of 108 sarcoids BPV-DNA was detected by PCR. Most samples...
[Pemphigus foliaceus in a foal. A case history]. The clinical history, clinical, pathological and immunohistological findings of a four-month-old foal with generalised pemphigus foliaceus are presented. The typical lesions of this autoimmune skin disease are described and discussed.
Structure of equine type I and type II collagens. Collagen type I was purified from equine skin and flexor tendon, and type II collagen was purified from equine articular cartilage. The proteoglycans in these tissues were extracted, using guanidine HCl; the collagens were solubilized, using pepsin digestion, then were selectively precipitated with NaCl. Gel electrophoresis indicated that the precipitates contained only type I or type II collagen. Amino acid analysis indicated that collagen constituted > 97% of the total protein in the precipitates. Hydroxylation of proline was 42.0 +/- 0.6% (mean +/- SEM) in alpha 1(I) and alpha 2(I), and was...
Trimethoprim/sulfonamide combinations in the horse: a review. The indications for use, side-effects, and pharmacokinetic parameters of trimethoprim, sulfonamides and their combinations in the horse are reviewed. Trimethoprim/sulfonamide (TMPS) combinations are used for the treatment of various diseases caused by gram-positive and gram-negative bacteria, including infections of the respiratory tract, urogenital tract, alimentary tract, skin joints and wounds. TMPS combinations can be administered orally, since absorption from the gastrointestinal tract is relatively good. However, peak serum concentrations can vary significantly between individual horses....
Granulomatous enteritis and cutaneous arteritis in a horse. A 5-year-old Quarter Horse mare was examined because of weight loss of 2 months' duration. The horse was anemic and in poor body condition, and had several areas of cutaneous ulceration, including areas on the muzzle and distal portion of the limbs. Histologic examination of a rectal mucosa biopsy specimen revealed a lymphoplasmacytic infiltrate in the lamina propria mucosa. Results of a glucose absorption test were suggestive of malabsorption. Histologic examination of a biopsy specimen from the cutaneous lesions revealed pronounced arteritis, and weak, patchy immunofluorescent staining for i...
Comparison of IgE-binding antigens in horse dander and a mixture of horse hair and skin scrapings. Extracts of horse dander (HD) and horse hair and skin scrapings (HHSS) have been compared with respect to their content of proteins and carbohydrates. The protein content of HD is more than double that of HHSS, while the carbohydrate content is of the same order. SDS-PAGE and IEF, both combined with immunoblotting, and CIE/CRIE showed the IgE-binding ability of the proteins/glycoproteins present in the two extracts. SDS-PAGE/immunoblotting showed the presence of mainly the same IgE-binding bands in the two extracts. Nine were detected in HD, and seven in HHSS. Four of these were glycoproteins....
Hypersensitivity of horses in British Columbia to extracts of native and exotic species of Culicoides (Diptera: Ceratopogonidae). Six horses from British Columbia severely affected by Culicoides hypersensitivity, a seasonal dermatitis caused by the bites of Culicoides spp., were inoculated intradermally with extracts of six species or forms of Culicoides from British Columbia, United States, and Israel. Two native and four exotic species were thought to cause the disease in their own geographical area. The horses developed large welts within 20 min after injection of any of the six extracts, indicating an immediate (type I) reaction. The skin reactions caused by each extract peaked at or after 24 h, indicating an additio...
[Skin problems, edema and diarrhea in a yearling stallion. Symptoms of a cecum-in-colon invagination?]. A Dutch Warmblood yearling stallion was referred for skin lesions, oedema and diarrhoea. At rectal palpation a cecocolonic intussusception was diagnosed, that might have been present for at least one week. A short literature review of cecocolonic intussusception is given.
Epidermal growth factor-like activity in mares’ milk. Epidermal growth factor (EGF)-like activity was measured in mares' colostrum and milk by radioreceptor assay. Milk samples were collected from 22 mares 1 or more times during early lactation. Samples of colostrum were taken after parturition and before the foal first suckled (presuckle), within 6 hours after the foal first suckled (postsuckle), and on days 1, 2, 4, and 8 of lactation. In the 5 mares from which milk samples were obtained at each sampling time, presuckle colostral mean EGF-like activity (17.8 ng/ml) was greatest (P less than 0.05). The mean values for EGF-like activity at all ot...
Low energy laser irradiation treatment for second intention wound healing in horses. Low energy helium-neon laser irradiation was administered to full thickness skin wounds (3 cm x 3 cm) on the dorsal surface of the metacarpophalangeal/metatarsophalangeal joints and cranial surface of the tarsocrural joints of eight horses. The effects on wound healing were analyzed statistically. There were no differences (p > 0.55) observed in the rate of wound healing between the low energy laser irradiated wounds and the control wounds. There was a significant difference (p < 0.006) observed in the rate of healing between the anatomical sites. Tarsal wounds healed more rapidly than fetlock...
Kinetics of healing of grafted and nongrafted wounds on the distal portion of the forelimbs of horses. Full-thickness, circular, cutaneous wounds (5 cm in diameter) were created on the distal portion of the forelimbs of 6 horses. One wound on each horse was treated with 6 full-thickness punch grafts that were obtained from the horse's neck with a 6-mm skin biopsy punch and inserted in the graft sites on day 14 after wounding. The wound on the contralateral limb was not grafted. A combination of ticarcillin disodium and clavulanate potassium was applied to the wounds when bandages were changed to control bacterial infection. Areas of each wound were measured on days 1, 7, 9, 11, 13 through 15, 1...
Effects of split-thickness and full-thickness skin grafts on secondary graft contraction in horses. Full-thickness, circular (4-cm diameter) cutaneous wounds were created on the metacarpi and metatarsi of 6 horses. Immediately after wounding, 1 wound on each horse received a meshed, split-thickness skin graft (0.64 mm) obtained from the ventrolateral aspect of the horse's thorax by use of a pneumatic dermatome, whereas a second wound received a meshed, full-thickness skin graft obtained from the pectoral area. In addition, sections of split-thickness and full-thickness grafts were refrigerated in a solution of McCoy's 5A medium, to which equine serum (10%) and gentamicin sulfate solution (16...
[A lectin histochemical study of the epidermis off the skin and the hoof of horses]. Carbohydrate moieties of cell membranes in the epidermis of equine skin and hoof were investigated using lectin-histochemistry. The loss of desmosomes during keratinization leads to a reduced lectin affinity. Lectin binding capacity of the intercellular matrix in the stratum corneum of the epidermis is weak compared to that of the intercellular kitt of the hoof. Qualitative differences in lectin binding of the intercellular kitt of different hoof segments correlate with the quality of the horn in the respective areas.
Thermal injury by in vitro incision of equine skin with electrosurgery, radiosurgery, and a carbon dioxide laser. Freshly harvested equine skin incised with an electrosurgical unit, a radiosurgical device, or a carbon dioxide (CO2) laser was examined by light microscopy to determine the extent of thermal injury caused by each instrument. There was no significant difference between the thermal injury caused by the electrosurgical unit in the pure-cut mode and the CO2 laser in the superpulse mode, or between the electrosurgical unit and the radiosurgical device in the fully filtered cut mode. However, thermal injury caused by the CO2 laser was significantly less than that caused by the radiosurgical device....
Influence of wound shape on wound contraction in horses. Three sets of paired circular and square full-thickness skin wounds were made on the dorsum of the metacarpus (n = 48) of 8 horses. Each wound was 6.25 cm2 in area. The wounds were treated topically with an ointment, nonadherent dressing, and bandaged with a snug elastic wrap. Wounds were photographed every other day until healing was complete. Wound areas were measured and exponential and linear wound healing models were applied to the wound healing data generated. Wound healing variables measured for each wound were: number of days to healing, maximal size attained, rate of wound contraction...
Multicentric cutaneous pythiosis in a foal. A 5-month-old male Quarter Horse was examined because of multicentric, granulomatous, cutaneous lesions of the dorsum and prepuce. The cutaneous lesions were excised, and sodium iodide was administered orally for 2 weeks. Multicentric cutaneous pythiosis was diagnosed by histologic examination and immunoperoxidase staining of excised tissues. By 3 months after surgery, all lesions had healed.
Multisystemic eosinophilic epitheliotropic disease in a horse: attempted treatment with hydroxyurea and dexamethasone. Equine multisystemic eosinophilic epitheliotropic disease is rare in horses. The clinical signs vary according to the organs affected, the skin and gastrointestinal tract being most commonly involved. This paper gives the first reported description of a horse with multisystemic eosinophilic epitheliotropic disease in the United Kingdom and the attempts to treat it. The horse showed dermatological, gastrointestinal, hepatic, pulmonary and pancreatic involvement. Some improvement was seen when the horse was treated with corticosteroid and hydroxyurea.
The effect of tension on perfusion of axial and random pattern flaps in foals. Caudally based axial pattern and random pattern skin flaps, 5 cm x 10 cm, were raised on the abdomens of seven foals. Blood flow was measured 7.5 cm from the flap bases during incremental increases in applied tension. At tensions less than 1400 g, cutaneous blood flow was more than four times higher in axial pattern flaps than in random pattern flaps. Blood flow in axial pattern flaps at tensions up to 1500 g was greater than baseline flow in random pattern flaps. After removal of applied tension, perfusion in axial pattern flaps gradually increased but remained below baseline values. A short ...
Inflammatory effects of platelet activating factor (PAF) in equine skin. Intradermal administration of PAF (0.001-1 micrograms/site), but not lyso-PAF (10 micrograms/site), in the horse caused an increase in cutaneous vascular permeability which was maximal by 32 min. Responses to PAF and histamine were reduced by coadministration of the histamine 1 receptor antagonist chlorpheniramine, although only the inhibition of histamine-induced responses was dose-related and statistically significant. The cyclo-oxygenase inhibitor indomethacin was without effect on PAF-induced increases in vascular permeability. These findings suggest that the actions of PAF on equine skin ...
Langerhans’ cells in equine cutaneous papillomas and normal skin. Langerhans' cells (LC) were investigated immunohistochemically and electron microscopically in normal equine epidermis and 133 equine cutaneous papillomas experimentally induced in five 2-year-old Thoroughbred horses. Class II major histocompatibility complex antigen-positive dendritic LC were found in the normal epidermis and ultrastructurally had the characteristic Birbeck's granules. In the developing phase of the papillomas, LC were significantly decreased in number and size, indicative of a hypofunctional state. In the regressing phase of the papillomas, LC were markedly increased in numb...
Intradermal testing of horses with chronic obstructive pulmonary disease and recurrent urticaria. Six horses with chronic obstructive pulmonary disease (COPD) and 8 horses with recurrent urticaria were skin tested with 67 extracts from 58 allergens, including pollens, epidermals, cultivated farm plants, dusts, molds, and insects. Reactions were evaluated 3 times over a 24-hour period immediately after the injections. Results were compared with those obtained from 11 clinically normal horses. All horses had positive skin test reactions. Significant differences was evident between horses with COPD and clinically normal horses for only 3.0% of the possible extract reactions, and between horse...
[An outbreak of allergy to horses in children. A review of 56 recent cases]. Over the past 11 years, signs of allergy were observed in 56 children and adolescents in contact with horses. The cases consisted of 35 boys and 21 girls, 35 of them were under 10 years of age. The main clinical signs were ocular symptoms (36), asthma (30) and rhinopharyngitis (24). All the children had very positive cutaneous prick tests and specific IgE (class 3 and 4: 62%) and were polysensitized. In several children, the first manifestation occurred at the time of the first known contact with a horse or pony. No further contact was usually the only therapeutic solution. In disabled childre...
Pedicle skin flaps in ponies: viable length is related to flap width. The relationship between pedicle flap width and viable length was characterised for skin flaps of the flank in ponies. Four dorsally based, pedicle type skin flaps of 20 cm in length and 3, 6, 9 or 12 cm in width were created in a random sequence on one flank in each of 10 ponies. Flap survival length was assessed by skin texture and appearance, depilation of hair and wound healing at 14 days after surgery. There was considerable variation between animals in the viable length of flaps of the same width; however, a significant difference in the viable length of flaps of different widths was det...
Possible importance for laminitis research of recent studies on substances influencing the differentiation of cultured keratinocytes. After a survey of the state of laminitis research the authors conclude that none of the present concepts of the pathogenesis of laminitis unequivocally explains the basic clinical and morphological observations in this disease. There is therefore reason to consider the advances that have been made during the last decades in respect to the influence of various substances on the differentiation of cultured skin keratinocytes. The technique is available for studying hoof keratinocytes in a comparable way. Relevant literature on cultured skin keratinocytes is surveyed. Some of the results from exp...