Fibrin is a fibrous protein that plays a significant role in the coagulation process in horses. It is formed from fibrinogen, a soluble plasma protein, through the action of the enzyme thrombin. During the coagulation cascade, fibrin strands create a mesh that stabilizes the platelet plug, forming a blood clot that helps to prevent excessive bleeding during injury. In equine medicine, the study of fibrin is important for understanding hemostatic disorders and managing conditions related to abnormal clot formation. This page compiles peer-reviewed research studies and scholarly articles that investigate the formation, function, and clinical implications of fibrin in equine health and disease.
Bohanon TC, Schneider RK, Weisbrode SE.Six normal horses received 3 intra-articular injections of sodium monoiodoacetate (MIA) in the distal intertarsal (DIT) and tarsometatarsal (TMT) joints of one hindlimb. Injections were at three week intervals, and post injection pain was controlled with routine administration of phenylbutazone for five days following each injection. All horses underwent a gradually increasing exercise programme consisting of walking and trotting beginning one week after the first injection and continuing for 24 weeks. All treated joints showed increasingly severe radiographic evidence of degenerative joint di...
Baxter GM, Parks AH, Prasse KW.Plasma and peritoneal fluid samples were collected before and after surgery from 6 horses undergoing a ventral midline exploratory laparotomy and from 6 anesthetized control horses. Coagulation/fibrinolytic components measured in the plasma and peritoneal fluid of these horses included the functional activity of antithrombin III, alpha-2 antiplasmin, plasminogen, and protein C, and the concentrations of fibrinogen and fibrin degradation products. Peritoneal fluid antithrombin III, fibrin degradation products, and plasminogen values were significantly increased after surgery (over time) in prin...
Johnstone IB, Viel L, Crane S, Whiting T.The purpose of this study was to determine whether a defect in hemostasis might be a factor in the etiology of exercise-induced pulmonary hemorrhage (EIPH). Hemostatic parameters were evaluated in 22 EIPH-positive and ten EIPH-negative racing horses while in a rested state. Nineteen EIPH-positive and ten EIPH-negative horses were further evaluated just before and immediately after a 15 min exercise period on a 260 m oval track. When EIPH-positive and EIPH-negative horses were compared at rest, there was no significant difference in any of the coagulation and fibrinolytic parameters studied. Th...
Vachon AM, McIlwraith CW, Trotter GW, Norrdin RW, Powers BE.The use of periosteal autografts to resurface osteochondral defects was investigated in 10 horses (2 to 3 years old), and the repair tissue was characterized morphologically. Middle carpal joint arthrotomies were made, and osteochondral defects were induced bilaterally on the distal articular surface of each radial carpal bone. Each defect measured approximately 1 cm2 and extended 3 mm into the subchondral bone plate. Residual subchondral bone plate of control and principal defects was perforated by drilling. A sterile fibrin adhesive was made by mixing a fibrinogen component and a thrombin co...
Prasse KW, Allen D, Moore JN, Duncan A.The balance of coagulation and fibrinolysis was studied in 15 horses during the prodromal stages of acute laminitis induced by carbohydrate overload. Progression of the disease was stopped 12 to 24 hours before the expected onset of lameness in trial 1 (8 horses) and at the onset of lameness in trial 2 (7 horses). The end points in each trial were identified by specific changes in blood pressures (trial 1) and by changes in pulse, rectal temperature, and arterial pressure (trial 2) that were anticipated on the basis of original description of the experimental model. Blood samples for hemostasi...
Winder NC, Grünig G, Hermann M, von Fellenberg R.The concentration of soluble fibrinogen derivatives (SFD) and protease and procoagulant activities were determined in cell-free supernatants of equine respiratory secretions obtained from horses with chronic pulmonary disease. The concentration of neutrophils was estimated from direct smears of the secretions. Lung specimens and smears of the secretions were evaluated for the presence of fibrin or fibrinogen by use of immunohistochemical methods. Thirty-five of 80 specimens tested contained SFD. Respiratory secretions from horses with moderate or severe chronic pulmonary disease contained SFD ...
Pause B, Nolte I, Geiss V, Mayer H, Lasch HG.A thoroughbred horse, suffering from intermittent lameness was treated with streptokinase, urokinase and warfarin. The appearing fibrinolytic changes in coagulation were exhibited in a resonance thrombogram. In attendant coagulation studies fibrinogen- and fibrin-degradation products were demonstrated. The stallion does not show any lameness since the end of the treatment and is standing in a breeding station since March 1988.
Meyers KM, Menard M, Wardrop KJ.This is a review of equine hemostasis and is divided into three sections. The initial portion describes the normal hemostatic system and includes platelet function, coagulation, fibrinolysis and control processes. The second phase is devoted to laboratory tests of hemostasis, and the last section provides information on specific alterations.
Morris CF, Robertson JL, Mann PC, Clark S, Divers TJ.A syndrome characterized clinically by oliguria, progressive severe azotemia, and edema of the abdomen and groin was seen in 2 horses. Treatment with fluids, diuretics, and corticosteroids administered intravenously was ineffective, and the horses were euthanatized. Microscopically, there was severe necrotizing angiopathy with profuse fibrin deposition in renal glomeruli and sinusoids of peripheral lymph nodes. The signs observed in the horses resembled hemolytic-uremic syndrome in human beings.
Parry BW.Clinical pathology is a valuable adjunct to physical examination of cases of colic. The present review considers evaluation of cases of colic for three main purposes: (1) making a prognosis, (2) deciding whether to operate, and (3) making a diagnosis. Blood tests noted to be useful for prognostication were hematocrit, lactate and urea nitrogen concentrations, pH, anion gap, fibrin/fibrinogen degradation products, antithrombin III activity, prothrombin time, and thrombin time. Horses with a poor prognosis often have relative polycythemia, marked lactic acidosis, high anion gap, azotemia, and co...
White NA, Tyler DE, Blackwell RB, Allen D.Records of 20 horses with small intestinal disease causing acute colic and affecting the proximal portion of the small intestine were examined retrospectively. The disease was characterized by severe to moderate pain, which was replaced by depression, fever, gastric reflux, slight distention of the affected small intestine, leukocytosis, and high concentrations of total protein in the peritoneal fluid. Grossly, the affected intestines were hemorrhagic and had yellow discoloration. Histopathologic findings included submucosal edema, neutrophilic infiltration of the submucosal and laminal propri...
Johnstone IB, Crane S.Hemostatic profiles were determined in 30 horses with clinical colic. Blood samples were obtained at the time of the animal's admission, and the following hemostatic tests were done: blood platelet count, plasma fibrinogen, plasma antithrombin, prothrombin time, partial thromboplastin time, thrombin time, protamine sulfate test for soluble fibrin monomer, and fibrin-fibrinogen degradation products. The patients were categorized in retrospect, according to the cause of the colic: group 1--colic associated with colitis and/or severe diarrhea, group 2--colic associated with torsion or obstruction...
Pablo LS, Purohit RC, Teer PA, Newton JC, Hammond LS.Total strangulation obstruction of the caudal part of the jejunum was induced in 3 groups (each of 3 ponies) for 2, 4, and 6 hours. Coagulation tests which included blood platelet counts, prothrombin time, activated partial thromboplastin time, activated coagulation time, plasma fibrinogen level, and fibrin/fibrinogen degradation products assay were performed at specified time intervals for 1 week or until death of the experimental ponies. Another 3 ponies (sham-operated) were similarly treated, except that intestinal strangulation obstruction (ISO) was not induced. Necropsy was done on ponies...
Ferguson EW, Bernier LL, Shaughness GP, Boucher JH.Fourteen horses were studied during a 157-km endurance ride. Two humans who ran the 157 km were also evaluated at the finish. Fibrin monomer samples were examined by two-dimensional gel electrophoresis and sodium dodecyl sulfate polyacrylamide gel electrophoresis. Two major species of horse Beta-chain with higher molecular weights and different isoelectric mobilities than human beta-chain were observed. Horse alpha-chains had higher molecular weights than human alpha-chains but similar alpha-chain heterogeneities. Mean euglobulin lysis time (ELT) in the horses was accelerated to similar levels...
Ferguson EW, Bernier LL, Shaughness GP, Boucher JH.Fourteen horses were studied during a 157-km endurance ride. Two humans who ran the 157 km were also evaluated at the finish. Fibrin monomer samples were examined by two-dimensional gel electrophoresis and sodium dodecyl sulfate polyacrylamide gel electrophoresis. Two major species of horse Beta-chain with higher molecular weights and different isoelectric mobilities than human beta-chain were observed. Horse alpha-chains had higher molecular weights than human alpha-chains but similar alpha-chain heterogeneities. Mean euglobulin lysis time (ELT) in the horses was accelerated to similar levels...
Jones DL, Barber SM, Jack SW, Doige CE.Gross and microscopic effects of arthroscopic partial synovectomy on synovium and articular cartilage of middle carpal joints were studied in 15 horses. A 7-mm diameter motorized synovial resector was inserted into each middle carpal joint and arthroscopic partial synovectomy and lavage or arthroscopic lavage alone was performed. Study periods were 0 (three horses), 16 (three horses), and 30 days (six horses). No gross evidence of degenerative joint disease was observed at day 16 or 30. At 30 days, resected areas lacked villi and there was deposition of fibrin on the synovial surface with vary...
Geor RJ, Weiss DJ.Pharmacologic alterations in the hematologic and rheologic properties of blood may have an important effect on transport and delivery of oxygen to working muscle during exercise. This article briefly reviews erythropoiesis, hematologic and rheologic responses to training and exercise, and the influence of these alterations on exercise performance. The hemorrheologic and performance effects of hematinics, hematopoietic stimulants, and alterations in blood rheology are discussed. The effects of exercise on blood coagulation, fibrinolysis and platelet function, and the effects of drugs that alter...
Smanik LE, Selberg KT, Mason GL, Brock M, Stewart HL, Goodrich LR, Kawcak CE.To perform a pilot study with the intent of assessing the feasibility of a modified subchondroplasty (mSCP) technique in a validated preclinical equine model of full-thickness articular cartilage loss and evaluate the short-term patient response to the injected materials. Methods: 3 adult horses. Methods: Two 15-mm-diameter full-thickness cartilage defects were created on the medial trochlear ridge of each femur. Defects were treated with microfracture and then filled by 1 of 4 techniques: (1) autologous fibrin graft (FG) via subchondral injection of fibrin glue (FG), (2) autologous fibrin gra...
Nomura M, Mizobe F, Kato T, Kuroda T, Urayama S, Muranaka M.Although severe blood coagulopathy in horses with acute colitis causes multiple organ failure, which may be fatal, few studies have focused on the correlation between the fluctuations of coagulation parameters and severity of colitis. In this study, we evaluated the fluctuations of coagulation parameters in 14 Thoroughbred racehorses with acute colitis for 5 days from the day of hospitalization and compared them between 5 survivors and 9 non-survivors. Noteworthy features in the non-survivors were that antithrombin activity and fibrin degradation products continuously decreased and increased, ...
Coyne CP, Smith JE, DeBowes RM.Several pharmaceutical compounds were evaluated for their ability to selectively inhibit activated coagulation factor-XIII-like enzyme activity (eg, XIIIa*) in pooled equine plasma. Presence of coagulation factor-XIIIa*-like enzyme activity in plasma was established by assay procedures involving incorporation of the fluorescent amine compound, monodansylcadaverine, into purified casein, which served as a protein substrate. Pharmaceuticals inhibitory to coagulation factor-XIIIa*-like enzyme activity were recognized by plasma gel formation of high spectrophotometric transmittance (transparency),...
Baxter GM, Parks AH, Prasse KW.Plasma and peritoneal fluid samples were collected before and after surgery from 6 horses undergoing a ventral midline exploratory laparotomy and from 6 anesthetized control horses. Coagulation/fibrinolytic components measured in the plasma and peritoneal fluid of these horses included the functional activity of antithrombin III, alpha-2 antiplasmin, plasminogen, and protein C, and the concentrations of fibrinogen and fibrin degradation products. Peritoneal fluid antithrombin III, fibrin degradation products, and plasminogen values were significantly increased after surgery (over time) in prin...
Easley JT, Brokken MT, Zubrod CJ, Morton AJ, Garrett KS, Holmes SP.Fourteen horses with septic arthritis underwent high-field (1.5 T) magnetic resonance imaging (MRI). Septic arthritis was diagnosed based on results from historical and clinical findings, synovial fluid analyses and culture, and radiographic, ultrasonographic, arthroscopic, and histopathologic findings. MR findings included diffuse hyperintensity within bone and extracapsular tissue on fat-suppressed images in 14/14 horses (100%), joint effusion, synovial proliferation, and capsular thickening in 13/14 horses (93%), bone sclerosis in 11/14 horses (79%), and evidence of cartilage and subchondra...
Pause B, Nolte I, Geiss V, Mayer H, Lasch HG.A thoroughbred horse, suffering from intermittent lameness was treated with streptokinase, urokinase and warfarin. The appearing fibrinolytic changes in coagulation were exhibited in a resonance thrombogram. In attendant coagulation studies fibrinogen- and fibrin-degradation products were demonstrated. The stallion does not show any lameness since the end of the treatment and is standing in a breeding station since March 1988.
Pain R, Sneddon JC, Cochrane CA.Franz diffusion cells containing uniformly dehydrated equine blood clots to simulate fibrinous eschar were used to measure the rate of debridement of fibrin by novel and traditional wound dressings, under standardised conditions of temperature, pH and humidity. Significant increases in protein breakdown occurred within 24 hours with all the dressings, but not thereafter. In general, dressings hydrated in normal saline were better as debriding agents than dressings hydrated in water. Autolytic debriding agents were 47 per cent more effective than chemical debriding agents; specifically, hydrofi...
Darien BJ, Stone WC, Dubielzig RR, Clayton MK.The morphologic changes following ascending colon volvulus result from the interaction of inflammatory and coagulation mediators. The objective of this study was to establish a quantifiable histopathologic scoring system to evaluate the serial pathomorphologic changes during ischemia and reperfusion. Such a scoring system could then be applied to subsequent studies designed to attenuate bowel lesions by regulating activity of individual mediators. Ten normal, healthy adult ponies were randomly divided into two equal groups. Following anesthesia and a 30-minute stabilization period, the colon o...
Coyne CP, Smith JE, Keeton K.A selected group of pharmaceutical compounds were evaluated for the ability to inhibit the biochemical activity of fibrinoligase (coagulation factor XIIIa*) in pooled equine plasma. Criteria for the pharmaceuticals selected were based on the mechanism of the transglutamination biochemical reaction mediated by coagulation factor XIIa*. These criteria were complemented by recognition of the molecular configuration and chemical composition of amino acid residue side chains involved in the process of covalent fibrin monomer polymerization (cross-linking, transglutamination) mediated by this enzyme...
Hosny OH, Abd-Elkareem M, Ali MM, Ahmed AF.Ulcerative keratitis is a common disease in horses which may cause blindness. To prevent secondary bacterial and fungal infections and promote quick re-growth of the epithelial layer, different treatment approaches have been employed. This study aimed to examine the effects of advanced platelet-rich fibrin (A-PRF) gel on the healing process of experimentally induced corneal ulcers in donkeys. Nine healthy adult donkeys were used for the study. The donkeys were divided into two groups: the control group, where no medication was applied to the corneal ulcer, and the A-PRF gel group, where A-PRF ...
Pereira R, Bowen M, Rapezzano G, Redpath A, Pratt S, Hallowell G.Recombinant intracameral tissue plasminogen activator (rTPA) administration can aid clearance of fibrin from the anterior chamber. In this retrospective multicentre case series, the effect of intracameral rTPA administration to treat fibrin in the anterior chamber resulting from trauma or inflammatory ocular disease was evaluated. Clinical data from 30 treatments in 29 horses were obtained from medical records from 2003 to 2022. Association between time from onset of clinical signs and time for rTPA treatment to effect was studied with regression analysis. Twenty-seven horses (93.1%) had no pr...
Gould J, Wells M, de Linde Henriksen M, Gilger BC.To determine the causes, time to resolution, effect of therapeutics, and ocular sequelae of hyphema, fibrin, and/or vitreal hemorrhage in horses. Methods: 225 horses (219 eyes) who were diagnosed with hyphema, fibrin, and/or vitreal hemorrhage. Methods: Records were retrospectively reviewed for the horses. Signalment, ophthalmic examination findings, causes, treatments, and outcomes were evaluated. Results: Common causes of intraocular fibrin or hemorrhage were equine recurrent uveitis (42/219 horses), corneal stromal abscess (32/219 horses), corneal stromal ulcer (25/219 horses), and trauma (...
Chiara M, Mariaelena C, Alessandro C, Davide B, Lavinia C, Paola MM, Barbara L, Chiara DP, Flagiello F, Pia PM.The advanced-PRF+ (A-PRF+) is a platelet concentrate, showing a higher concentration of growth factors, an increased number of cells and looser structure of the fibrin clot than leukocyte-PRF. A high variability in the size of PRF associated with patients, haematological features and centrifugation protocols was reported. The aims of this study were to evaluate the feasibility of A-PRF+ production in the field and the correlation between haematological parameters, macroscopic and microscopic features in equine A-PRF+. Samples from twenty Standardbred horses (3-7 years) were harvested with gla...
Collins E, Barr E, Zhang C, Steadman M, Gilger B, Henriksen ML.To describe the most efficient topical horizontally centrifuged platelet-rich fibrin (H-PRF) treatment protocol for equine ulcerative keratitis (EUK) that is easy to use, and to report the preliminary concentration of growth factors and cytokines in equine H-PRF. Unassigned: 5 client-owned horses diagnosed with EUK were enrolled over an 11-month period. Unassigned: 3 horses were geldings, and 2 were mares. The mean (± SD) age was 5.95 ± 5.01 years. The owners' main goal was to avoid surgery for EUK. Unassigned: H-PRF was used in 3 different protocols: solid H-PRF, sutured to the EUK area (n ...
