Fibrosis in horses refers to the formation of excess fibrous connective tissue as a reparative or reactive process following injury or inflammation. This condition can affect various organs and tissues, including the lungs, liver, and skin, leading to impaired function and structural changes. Fibrosis is characterized by the excessive deposition of extracellular matrix components, such as collagen, which can result in tissue stiffness and scarring. In equine medicine, fibrosis can be associated with chronic conditions such as equine asthma or hepatic disease. This page compiles peer-reviewed research studies and scholarly articles that investigate the mechanisms, diagnosis, and management of fibrosis in horses, offering insights into its impact on equine health and potential therapeutic approaches.
Gelatt KN.Traumatic iridocyclitis and hyphema in the horse usually follow blunt blows to the orbit and eye. The condition is characterized by miosis, ocular hypotony, ciliary flush, swelling of the iris, and hemorrhage with excessive fibrin in the anterior chamber which permits from 2 to 6 weeks. Vigorous treatment with mydriatics, topical and systemic corticosteroids is recommended. Possible complications include anterior and posterior synechiae, cataracts, and fibropupillary membranes.
Baker JR, Leyland A.In a histological survey of 244 tumerous growths from 155 horses, the tumours commonly found were fibromas, squamous cell carcinomas, sarcoids and papillomas, most frequently affecting the skin, external genitalia, eye and orbit. The histological features that differentiate fibroblastic citaneous growths are detailed so that the clinical behaviour of these distinct neoplasms can be studied.
Platt H.A series of 10 haemorrhagic polyps of the equine nasal cavity is described. The lesions show haematoma formation, abundant haemosiderin in macrophages and giant cells, and organising fibrous tissue. In one case, angiomatoid lesions were observed in the mucous membrane of the paranasal sinuses and it is suggested that some haemorrhagic nasal polyps may originate from pre-existing haemangiomatous areas in the respiratory mucosa.
Duncan JL, Pirie HM.The clinical signs, pathology and clinical pathology associated with single experimental infections of Strongylus vulgaris in worm-free pony foals are described. The major clinical signs which became apparent in the infected foals during the first three weeks were pyrexia, anorexia, dullness and abdominal pain. Within the first two weeks of infection lesions were confined to the intestine and terminal branches of the intestinal arteries and consisted of mucosal, submucosal and serosal haemorrhage together with arteritis of submucosal and serosal arteries and also a marked inflammatory reaction...
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...
Andrade AC, Fonseca SMC, Silva Filho GB, Melo ET, Santos JRP, Frota MLSL, Duarte JMBS, Evêncio-Neto J, Brito LB, Lima TS, Wicpolt NS, Riet-Correa F....We report an outbreak of Crotalaria juncea intoxication in horses exhibiting progressive weight loss and respiratory distress in northeastern Brazil. Necropsy revealed firm, non-collapsed lungs with extensive interstitial fibrosis, bronchiolar epithelial hyperplasia with club cells proliferation, and marked pulmonary arterial remodeling. Hepatic lesions consisted primarily of centrilobular necrosis, probably resulting from hypoxic injury related to anemia and prolonged agonic death. Pasture inspection identified significant invasion by shrubs of C. juncea in various phenological stages.
Sadowska A, Wójtowicz A, Molcan T, Drzewiecka EM, Kaczmarek MM, Słyszewska M, Ferreira-Dias G, Szóstek-Mioduchowska A.Equine endometrosis is a chronic degenerative condition with fibrosis being one of the most significant characteristics. A growing body of evidence indicates the critical role of interleukin (IL)-17 in fibrotic disorders. However, its exact role during equine endometrosis remains to be discovered and explained. The main aim of the current study was to establish the expression of IL-17A signaling components in equine endometria with and without endometrosis as well as the effects of IL-17A on the transcriptomic signature, cellular functional characteristics, expression of extracellular matrix (...
Muderspach ND, Daucke R, Nielsen MW, Scoggin KE, Fedorka CE, Miller LMJ, May MG, Troedsson MHT, Ferreira-Dias G, Agerholm JS, Schoof EM....Endometrial fibrosis leads to subfertility when periglandular fibrosis impairs endometrial gland function. Identifying distinct protein expressions in mares suffering from this condition is essential for understanding the pathogenesis and developing treatments to delay fibrotic progression. To gain a better understanding of protein dynamics underlying this condition, Data-Independent Acquisition Mass Spectrometry was utilized to comprehensively characterize and compare the equine endometrial and plasma proteome from mares with different severities of endometrial fibrosis. Mares in diestrus wer...
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). ...
Boado A, Pollard D, Dyson S.There are no studies that have investigated factors influencing the outcome of dressage horses with suspensory ligament (SL) branch injuries. The aim was to determine if age, breed, work level, injury severity, anatomical localisation of injury, number of injured branches, periligamentous fibrosis, persistence of power Doppler signal or coexistent osteoarthritis of a metacarpophalangeal (MCP) or metatarsophalangeal (MTP) joint influenced the prognosis of 70 dressage horses. Outcome was defined as good (return to pre-injury level of work or higher), poor (return to a lower level of work) or ret...
Zamith Cunha R, Gobbo F, Morini M, Salamanca G, Zanoni A, Bernardini C, Gramenzi A, Chiocchetti R.Evidence suggests that the endocannabinoid system (ECS) is crucial for regulating inflammation, cell proliferation and pain. The ECS is composed of cannabinoid receptors such as type 1 (CBR1), type 2 (CBR2) and GPR55, endocannabinoids and enzymes. Proteins of ECS have previously been localized in the epidermal cells of the horse hooves. Given the physio-pathological role and cellular distribution of the ECS across species, the authors hypothesized that cannabinoid receptors are expressed within the inflammatory cells, fibroblasts and endothelial cells of the equine hoof laminae, going beyond t...
Sidwell A, Shanklin A, Miller H, Cahoon M, Hole SL, Bianco C, Pereira R.A 3-year-old Connemara X filly was referred to a UK equine hospital for further investigation of unilateral nasal discharge and facial swelling. Diagnostic imaging documented the presence of a heterogenous, soft tissue opacity with areas of focal mineralisation within the right paranasal sinuses, completely obliterating the nasal cavity, in addition to endodontic disease and significant periapical pathology associated with the right permanent fourth premolar (Triadan 108). Subsequent histopathologic examination confirmed the mass as a fibro-inflammatory polyp.
Wójtowicz A, Sadowska A, Myszczyński K, Molcan T, Kaczmarek MM, Szóstek-Mioduchowska A.Fibrosis remains incompletely understood, particularly in terms of how immune mediators shape stromal programs. We used a spontaneous large‑animal model-endometrosis (equine endometrial fibrosis) to define how interleukin‑4 (IL‑4) reprograms fibroblasts from healthy and fibrotic endometrium. Primary fibroblasts were exposed to IL‑4 (10 ng/mL) for 48 or 96 h. At 48 h, bulk transcriptomes revealed 1307 differentially expressed genes (DEGs; 648 up, 659 down) and 1271 DEGs (645 up, 626 down) in fibroblasts derived from endometria without or with endometrosis, respectively. Enrichment an...
Sadowska A, Molcan T, Słyszewska M, Skarzynski DJ, Ferreira-Dias G, Szóstek-Mioduchowska A.Equine endometrosis is a chronic degenerative condition of the endometrium. A hallmark feature of endometrosis is endometrial fibrosis accompanied by degenerative changes in the adjacent tissue structure. Tumor necrosis factor α (TNFα), a pleiotropic cytokine produced by various immune cells, plays a dual role in coordinating immune responses and regulating cell/tissue homeostasis, making it an important regulator of fibrotic-related disorders. However, the exact role of TNFα in the development of equine endometrial fibrosis remains to be discovered and explained. Therefore, the main aim of...
Profaska M, Zarzycka M, Dubniewicz K, Witkowski M, Wieczorek J, Gil D, Wafula S, Lanh DK, Kotula-Balak M.Mare endometrosis remains a poorly understood pathological process. Objective: Mare endometrial tissue with endometrosis was used to determine the effects of relaxin (RLX). Healthy tissues that were left untreated (H), or treated with vehicle (Hveh), and tissues with endometrosis that were left untreated (E), treated with vehicle (Eveh), and treated with RLX (10, 25, 50 nM; ER) were used for an ex vivo system for 72 h. Methods: Tissue histological examination, and immunoenzymatic measurement of the concentrations of transforming growth factor β (TGF-β), interleukins (IL-6 and IL-8), and pr...
Wójtowicz A, Sadowska A, Molcan T, Słyszewska M, Drzewiecka EM, Tobolski D, Ferreira-Dias G, Szóstek-Mioduchowska A.Mare endometrosis is a chronic degenerative condition of the endometrium, primarily characterized by fibrosis, involving interactions among fibroblasts, immune cells, and epithelial cells regulated by cytokines and growth factors. T helper (Th)1 and Th2 cells seem to play a pivotal role in fibrosis. However, their roles in equine endometrial fibrosis remain unknown. This study explores Th1 and Th2 cell distribution across different stages of endometrium histopathological Kenney and Doig categories; and evaluated their secretome effects on non-fibrotic endometrium derived fibroblast functional ...
Sugimoto K, Nakamura J, Deng D, Hirano E.Indoxyl sulfate (IS) is a dietary metabolite of tryptophan that is produced in the liver. It is a uremic toxin that facilitates the progression of chronic kidney disease (CKD). We previously observed that equine placental extract (ePE) inhibited IS synthesis in an inhibition assay using the liver S9 fraction. Unassigned: This study was designed to investigate the effects of ePE on adenine-induced renal failure in mice at the histological and molecular levels to understand the mechanism of action of ePE. Unassigned: We assessed this effect through biochemical and histological analyses using a...
