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.
Ultrastructural aspects of equine pemphigus foliaceus-like dermatitis. Report of cases. Pemphigus foliaceus is an uncommon dermatologic disorder occurring in several species and has been reported in horses during the past decade. An ultrastructural analysis of affected skin of horses presenting to our clinics has revealed early cytopathologic features of pemphigus-like disease, some of which closely resemble pemphigus foliaceus in the human, calve, and guinea pig. Prior to complete acantholysis and bullae formation, the intercellular spaces enlarged, but intercellular bridges and desmosomes remained intact. A novel finding was presence of aggregates of electron dense granular mat...
Evidence for eumelanin and pheomelanin producing genotypes in the Arabian horse. The ultrastructural imaging of melanocytes coupled with analyses to detect sulfur-containing melanosomes by energy-dispersive X-ray spectroscopy were used to test the hypothesis that the yellowish-red and black pigments found in Arabian horses result from pheomelanogenesis and eumelanogenesis, respectively. These procedures detected pheomelanosomes in follicles at the base of hairs in chestnut horses and eumelanosomes in follicles at the base of hairs in black horses. By analyzing tissue obtained by skin biopsy, these procedures also demonstrated that skin melanocytes in a chestnut horse produ...
Intradermal challenge of Icelandic horses in Norway and Iceland with extracts of Culicoides spp. A skin test survey was carried out in Icelandic horses in Norway and Iceland using extracts of Culicoides spp. as antigen. Eleven horses with recurrent seasonal dermatitis reacted with an immediate hypersensitivity response to intradermal challenge with antigen. All except one of thirty-three clinically normal horses in Norway showed a negative response in skin tests. These findings indicate that Culicoides spp. may be the major cause of the disease in Norway. Only one of the 110 horses tested in Iceland showed any skin test reaction (weak), demonstrating that the horses were not sensitized to...
Influence of an epidermal cell extract on skin healing and scar formation. We have examined the possible regulatory role of epidermal cell extract(s) (ECE) on skin cells, namely fibroblasts and keratinocytes, both in vivo and in vitro with particular reference to modification of scar formation. In an experimental wound model in pigs, it was found that extracts of cultured human and pig keratinocytes stimulated replication of epidermal cells and their migration from wound edges and remnants of hair follicles and sebaceous glands, together with hair growth, but at the same time suppressed fibroblast proliferation in the dermis. Sections of healing skin wounds that had ...
Eumycotic mycetoma: review and report of a cutaneous lesion caused by Pseudallescheria boydii in a horse. A cutaneous mass (1.5 cm in diameter) was removed from the head of a horse and was diagnosed histologically as eumycotic mycetoma. Immunofluorescence, performed on formalin-fixed, paraffin-embedded tissue, identified Pseudallescheria boydii as the etiologic agent. Findings from earlier reports of eumycotic mycetoma were compared with those of this horse.
Chromomycosis in a horse. A 6-year-old Quarter Horse gelding was examined because it had a sharply circumscribed, firm, brown-black, roughly spherical dermal nodule at the right tuber ischii. After it was excised, the lesion did not recur. Microscopically, the dermis of the excised specimen had multiple pyogranulomas, many of which contained thick-walled, dark brown fungal elements, some with internal septation compatible with chromomycotic fungi. Chromomycosis is a rare skin disease in the horse. It may be included in the differential diagnoses of nodular and/or pigmented skin lesions that include melanoma, pyogranulo...
Preservation of skin by refrigeration for autogenous grafting in the horse. Eighteen stored split thickness meshed skin grafts were applied to surgically created lesions on the metacarpal and metatarsal regions of six horses. Donor skin was harvested from the sternal region, meshed and stored at 4 degrees C in a cell culture medium containing 10% serum. Stored grafts were applied to the wounds at 1, 2, and 3 week intervals. Acceptance of the grafts stored for 1 week was generally poor (1 of 6 grafts), whereas that of the 2 and 3 week old grafts was generally excellent (10 of 12 grafts). Poor acceptance of the 1 week old grafts was attributed to streptococcal infection...
Cutaneous vasculitis in horses: 19 cases (1978-1985). The medical records of 19 horses with cutaneous vasculitis were reviewed. Most (73.7%) affected horses were between 3 and 10 years old, and there were significantly more mares (14) than stallions or geldings (5) (P less than 0.01). Subcutaneous edema of the limbs, body, and/or head was the predominant clinical sign (18/19 horses; 94.7%). The single most prevalent laboratory abnormality was neutrophilia (greater than 7,000 neutrophils/microliter), which was detected in 10 horses (52.6%). Leukocytoclastic vasculitis was evident in skin biopsy specimens from 12 of 14 horses (85.7%). All horses we...
Skin lesions of sweet itch and the distribution of dermal mast cells in the horse. No abstract available
Congenital vascular tumours in the skin of horses. Congenital vascular tumours in the skin of the legs of two horses showed histological features at biopsy which were consistent with capillary haemangioma but, at necropsy, one tumour had invaded the superficial digital flexor tendon and was therefore classified as a haemangiosarcoma.
Immediate split-thickness autogenous skin grafts in the horse. Case reports on the treatment of equine sarcoids in 3 horses. Three horses with equine sarcoids were treated with radical surgical excision and immediate split-thickness skin grafts. Graft take ranged from 50 to 100%, and the epithelial coverage attained resulted in an early functional repair. In no instance was there a recurrence of the sarcoid.
A comparative scanning electron microscopic view of the integument of domestic mammals. Scanning electron microscopy (SEM) demonstrates efficiently species-specific differences of hairy skin (integumentum commune) of domestic mammals (pig, cat, dog, horse, cattle, sheep, goat). This technique is very helpful in characterizing the typical structural features of the epidermal layers, the arrangement of the collagen fibre bundles and the elastic fibre network in the dermis, the external and internal construction of hair follicles and hair shafts, and the functional development of skin glands. It is also possible to observe certain domestication effects, especially where the hair coa...
Myospherulosis in the subcutis of a pony. Myospherulosis was diagnosed in a mature pony. Several parent bodies containing many spherules were observed microscopically in biopsy material from an area of cellulitis. The spherules are altered red blood cells that form as the result of prolonged contact with necrotic fat or petrolatum-based ointments. These structures must be differentiated from fungal elements. The recommended treatment is surgical excision.
Molluscum contagiosum in a horse with granulomatous enteritis. Widespread cutaneous papules in a yearling Standardbred filly were attributed by light and electron microscopic examination to molluscum contagiosum. Concomitant granulomatous enteritis, suspected clinically due to protein-losing enteropathy, was verified histopathologically. An associated altered altered immune response is suggested as the reason for the widespread poxvirus infection.
[Detection of dermatomycoses in horses with the dermatophyte test medium Fungassay]. For the inoculation of the dermatophyte-test-medium Fungassay, 200 skin scrapings from horses, 13 from cattle and 13 from artificially infected guinea pigs were used. As control methods, the alkali method, the fluorescent microscope technique and the usual mycological culture were available. For the analysis of skin scrapings, the Fungassay culture mediums are clearly inferior to the usual mycological culture. Fewer dermatophytes were isolated and false positive as well as false negative results occurred. The cultivation of Trichophyton verrucosum failed on the dermatophyte-test-medium.
Lobular capillary haemangiomas in young horses. Seven cases of cutaneous haemangiomas in young horses are described, characterized by scattered, well demarcated but unencapsulated lobules, consisting of capillary sized vascular structures, separated by strands of fibrous tissue. In one case, a more cellular variant was distinguished with minor vasoformative capacity. The morphological features of these haemangiomas are compatible with bovine cutaneous angiomatosis and human granuloma pyogenicum. The lesions are considered to be vascular tumours rather than hamartomas or granulation tissue and "lobular capillary haemangioma" is suggested to ...
[Cutaneous absorption of chemicals]. Chemicals have become indispensible for the maintenance of health in animals and man. The route of administration of each medicament is decided by factors such as site of desired action, chemistry of the active ingredient, age and species of the patient, and frequency of administration (or desired duration of activity). In situations where the oral and hypodermic routes, which are used most frequently, are inadequate or unsatisfactory, dermal application can provide a valuable alternative method to achieve systemic activity. Examples of formulations currently available for dermal application c...
Parasitic skin diseases. In this discussion of parasitic skin diseases of horses, details on life cycles are given to aid the understanding and development of control strategies.
Dermatomycoses in the horse. The clinicopathological features and treatment of cases of dermatomycotic infections in horses are reported. Organisms isolated from these cases include Trichophyton mentagrophyte, T. equinum and Micosporum equinum. The Veterinary, medical and economic importance of the disease is discussed.
Dermal reactivity to histamine, serotonin and bradykinin in relation to allergic skin reactions of the horse. The reactivity of horse skin to intradermal inoculation of histamine, serotonin and bradykinin was investigated, and the resulting reactions compared with those produced in the same horses by a 1% whole-body extract of Culicoides. Both histamine and bradykinin produced large reactions, but there was no significant correlation between the dermal responsiveness to insect allergen and either histamine or bradykinin. Two anti-histamine drugs (promethazine hydrochloride and tripelennamine hydrochloride) were effective in reducing the reaction produced by the insect extract.
Immunodiagnosis of autoimmune skin disease in the dog, cat and horse. Skin biopsies from 47 dogs, 6 cats and 5 horses with suspected autoimmune skin disease were submitted for immunofluorescence from 1978 to 1985. These cases were predominantly Western Australian in origin, although a number were also referred from Queensland and Victoria. In 5 dogs, 2 cats and 2 horses immunoglobulin binding to intercellular cement substance and/or basement membrane was demonstrated by direct immunofluorescence. Antinuclear antibody was also demonstrated in several of these cases. Immunofluorescence was used in combination with histopathological examination to confirm the clini...