Collagen is a structural protein found abundantly in the connective tissues of horses, including skin, tendons, ligaments, and cartilage. It contributes to the strength and elasticity of these tissues, playing a significant role in maintaining structural integrity. Collagen fibers are composed of amino acid chains, primarily glycine, proline, and hydroxyproline, which form a triple helix structure. In horses, collagen is involved in various physiological processes, including tissue repair and regeneration. Changes in collagen composition and structure can be associated with conditions such as joint disorders and tendon injuries. This page compiles peer-reviewed research studies and scholarly articles that explore the synthesis, function, and clinical implications of collagen in equine health.
Gunson DE.Despite being a very widespread protein, collagen is an unusual molecule possessing a great tensile strength conferred by a rope-like structure and intermolecular crosslinks. Our current knowledge of the biosynthesis of collagen is providing some insights into certain diseases of connective tissue and is also helping us to understand the healing processes of wounds and diseased tissues.
Meyers KM, Lindner C, Katz J, Grant B.Nonsteroidal anti-inflammatory drugs impair platelet aggregation and secretion in man, pigs, and rabbits and inhibit platelet thromboxane/prostaglandin synthesis. The present investigation studied the effects of phenylbutazone on platelet aggregation and bleeding times in the horse. Aggregation responses to adenosine diphosphate and collagen were markedly impaired 15 minutes and 2 hours after treatment, but 4 hours after treatment, platelet responses approximated those prior to treatment. The in vivo effect of phenylbutazone correlated with its plasma concentrations. Phenylbutazone, like aspir...
Parry DA, Craig AS, Barnes GR.A study has been made of the ultrastructural organization of the collagen fibrils and elastic fibres in tendons and ligaments from horses of ages ranging from 2 months premature to 19 years. Diameter distributions of the collagen fibrils in the common digital extensor tendon, the superficial flexor tendon and the suspensory ligament are unimodal in the foetal tissue and at birth, and at these stages of development the three collagenous tissues are virtually indistinguishable. However, at maturity, the ligament and flexor tendon have bimodal distributions similar to that found for rat-tail tend...
Schumacher HR.The normal synovial membrane as seen by electron microscopy is bordered by one to three layers of lining cells that include some with phagocytic function, others rich in endoplasmic reticulum for protein synthesis and additional cells with mixed properties. Lining cells with prominent Golgi apparatus probably produce the synovial hyaluronic acid. The synovial matrix contains collagen and mucopolysaccharide. It offers little barrier to diffusion of most materials. Superficial capillaries and venules are fenestrated and presumably allow rapid exchange of fluid and electrolytes. Deeper venules ha...
Evans JH, Barbenel JC.Tendon normally fulfills its primary role as a flexible force transmitting element very effectively and yet failure of this passive tissue leads to great disability. As a connective tissue its structure is relatively simple and the peculiar helical arrangement of collagen fibres confers highly non-linear as well as time-dependent mechanical properties. Functional significance cannot be attributed to any facet of mechanical response until the physiological pattern of loading is established. In particular the rate of deformation and the minimum force experienced by tendon in normal locomotion ha...
Saunders LZ, Bistner SI, Rubin LF.An asymptomatic, ophthalmoscopically visible proliferation affected the optic disc and nerve of two aged horses. The lesion consisted of an accumulation of foamy cells, histologically akin to fat cells, which contained an unidentified lipid-like material. The affected area and its environs were permeated by tortuous, thickened blood vessels with heavy deposits of collagen in their walls. The neuropathy is considered to be a storage disease, and although the product stored is unidentified, the lesion is similar to that of human xanthelasma. The neuropathy seems distinct from the exudative optic...
To compare ocular structures of Quarter Horses homozygous for hereditary equine regional dermal asthenia (HERDA) with those of Quarter Horses not affected by HERDA (control horses) and to determine the frequency of new corneal ulcers for horses with and without HERDA during a 4-year period. Methods: Cohort study of ocular structures and retrospective case series of horses with and without HERDA. Methods: The cohort portion of the study involved 10 Quarter Horses with HERDA and 10 Quarter Horses without HERDA; the retrospective case series involved 28 horses with HERDA and 291 horses without HE...
Unlike in Warmblood horses, aortic rupture is quite common in Friesian horses, in which a hereditary trait is suspected. The aortic connective tissue in affected Friesians shows histological changes such as medial necrosis, elastic fibre fragmentation, mucoid material accumulation and fibrosis with aberrant collagen morphology. However, ultrastructural examination of the collagen fibres of the mid-thoracic aorta has been inconclusive in further elucidating the pathogenesis of the disease. Objective: To assess several extracellular matrix (ECM) components biochemically in order to explore a pos...
Rosa MCB, Campos MEST, Albuquerque AS, Braz MS, Mapele RO, de Oliveira MCG, Toma HS, Ferraz PFP, Pereira RN, Raymundo DL.Skin wounds in horses, particularly in the distal extremities, often heal slowly due to mechanical stress, compromised perfusion, and excessive fibroplasia. This study evaluated the effects of topical Croton lechleri (CL) cream, alone or in combination with nitroglycerin, on the healing of skin wounds in the metatarsal region of horses. Six mares received six standardized wounds in each region and were treated with: saline solution, nitroglycerin (0.1 or 1 mg/mL), CL (1 or 10 µg/mL), or CL + nitroglycerin (10 µg/mL + 1 mg/mL). Wound contraction, histology, and bacterial culture were evaluate...
Samol MA, Barrett MF, Frisbie DD.Significant distal interphalangeal joint (DIPJ) pathology, particularly affecting soft tissue and articular cartilage, is often not identifiable on radiographs but can be accompanied by joint capsule enthesopathy on the middle phalanx (P2), which can be readily identified. Objective: To explore frequency and correlations between DIPJ capsule enthesopathy identified on magnetic resonance imaging (MRI) and radiographs and DIPJ articular cartilage abnormalities and other concurrent soft tissue or osseous pathology within the foot found on MRI. Methods: Retrospective descriptive case series. Metho...
Partusch L, Rutland CS, Martens A, Du Cheyne C, De Spiegelaere W, Michler JK.Exuberant granulation tissue (EGT) is a second intention wound healing disorder. It commonly occurs in the distal limb of horses. EGT causes significant increase in the duration and cost of treatment, potentially leading to the decision not to pursue treatment and euthanize the patient. The underlying pathomechanisms of this fibroproliferative disorder remain unclear, particularly in terms of collagen composition and the association between myofibroblasts and blood vessels. This study investigated the collagen composition in naturally occurring EGT following trimming in 19 horses (EGT group). ...
Kranenburg LC, Reinke KS, van den Broek J, Zaal EA, van den Boom R, van Doorn DA.Hydrolysed collagen is used as a supplement for horses with osteoarthritis, hoof horn growth problems, and gastric ulcers. To determine the oral availability of a specific hydrolysed collagen supplement and the appropriate dose, six Warmblood mares were fed two different concentrations of the supplement: 100 g HC (C), 50 g HC (C), and a control of 0 g HC (C) during one week in a randomised cross-over design. On day 7, 14 and 21, blood sampling for amino acid (AA) analysis was performed, just prior to feeding the supplement (t = 0) and every hour after feeding for 8 h (t = 1-8). Statistical ana...
Zanacchi A, Fruscione F, Grasselli S, Razzuoli E, Pastorino L, Di Lisa D.Developing advanced preclinical in vitro cancer models is essential for understanding tumor biology, improving drug discovery, and enhancing the clinical translation of new therapies. Papillomaviruses (PVs) cause diverse lesions in humans and animals; notably, bovine papillomavirus (BPV) is the main cause of equine sarcoid, the most common skin tumor in horses. Its pathogenesis involves viral infection, fibroblast transformation, and extracellular matrix (ECM) remodeling. These processes highlight the limitations of conventional two-dimensional (2D) culture systems, which fail to replicate the...
Schwarz S, Kummer S, Klang A, Walter I, Nell B, Brandt S.Squamous cell carcinoma (SCC) is the most common malignant tumor disease in horses. It predominantly affects the ocular, oronasal, and anogenital region. Equine SCC is difficult to treat, also because important aspects of SCC development and metastasis are still unclear. We previously provided evidence that equine SCC cells can adopt a stem cell-like phenotype as a hallmark of malignant progression. Here, we investigated whether equine SCCs harbor endothelial-like tumor cells that form an alternative network of pseudo-vessels better known as vasculogenic mimicry (VM). Following histopathologic...
Accorroni L, Dini F, Pilati N, Marchegiani A, Bazzano M, Spaterna A, Laus F.Wound management is a fundamental skill for veterinarians, requiring a systematic approach to wound care and a deep understanding of the biological principles underlying healing. Sucralfate, widely known as a mucoprotective agent for gastroduodenal ulcers, has recently shown promising topical effects in human skin lesions by binding and protecting growth factors from proteolytic degradation, thereby enhancing their local availability. This action promotes angiogenesis, chemotaxis and cell proliferation, while reducing oxidative stress and exerting bacteriostatic and bactericidal effects agains...
DI Stefano DA, Coccoluto L, Panina-Bordignon P, Brambilla E, Ruffini F, Murtaj V, Orlando F, Colombo M, Frigerio C, DI Bona A, Recupero D, Morroni M....Bone grafting is a surgical procedure that involves the use of bone tissue or bone substitutes to repair damaged bone. In dentistry and maxillofacial surgery, bone graft substitutes from various sources are commonly used. Given their critical role in clinical outcomes, it is essential to thoroughly investigate the biological and mechanical properties of these materials. Methods: In this in vitro study, we evaluated the biological properties of two equine-derived bone graft substitutes in comparison to β-tricalcium phosphate. The materials included one equine-derived graft containing hydrolyze...
Semevolos SA, Marchant EA.The marginal transitional zone (MTZ) is peripherally located within the diarthrodial joint, and represents the junction of synovium, fibrous joint capsule, articular cartilage, periosteum, and bone. The purpose of this study is to characterize age-related differences in protein expression of matrix and molecular regulators in the marginal transitional zone of neonatal and weanling foals. Several families of proteins with known roles in cartilage and bone development are investigated, including matrix molecules, members of the Wnt signaling family, apoptotic factors and paracrine cell signaling...
