Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Coagulation
Coagulation in horses refers to the complex process by which blood forms clots, a critical function that prevents excessive bleeding following injury. This process involves a series of enzymatic reactions that lead to the transformation of liquid blood components into a stable clot. Key elements in equine coagulation include platelets, clotting factors, and fibrinogen. Abnormalities in the coagulation process can result in disorders such as excessive bleeding or thrombosis. Research in this area focuses on understanding the mechanisms of coagulation, identifying potential genetic or environmental influences, and developing diagnostic and therapeutic strategies for coagulation-related disorders in horses. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, regulation, and clinical implications of coagulation in equine health.
Response to Intravenous Allogeneic Equine Cord Blood-Derived Mesenchymal Stromal Cells Administered from Chilled or Frozen State in Serum and Protein-Free Media. Equine mesenchymal stromal cells (MSC) are commonly transported, chilled or frozen, to veterinary clinics. These MSC must remain viable and minimally affected by culture, transport, or injection processes. The safety of two carrier solutions developed for optimal viability and excipient use were evaluated in ponies, with and without allogeneic cord blood-derived (CB) MSC. We hypothesized that neither the carrier solutions nor CB-MSC would elicit measurable changes in clinical, hematological, or biochemical parameters. In nine ponies (study 1), a bolus of HypoThermosol(®) FRS (HTS-FRS), CryoSt...
Abnormal coagulation factor VIII transcript in a Tennessee Walking Horse colt with hemophilia A. Hemophilia A is an X-chromosome-linked disorder caused by a deficiency in factor VIII (FVIII). Although foals have been diagnosed with hemophilia A based on deficiency in FVIII activity, causative gene mutations have not been identified. The genomic DNA and cDNA encoding FVIII of a Tennesee Walking Horse colt affected with hemophilia A and the genomic DNA of his dam and a normal unrelated horse were analyzed with no splice site or coding sequence abnormalities identified in any of the horses. Polymerase chain reactions (PCR) were then performed on hepatic cDNA from the affected colt and an unr...
Evaluation of coagulation and fibrinolysis in horses with atrial fibrillation. To evaluate horses with atrial fibrillation for hypercoagulability; plasma D-dimer concentrations, as a marker of a procoagulant state; and a relationship between coagulation profile results and duration of atrial fibrillation or presence of structural heart disease. Methods: Case-control study. Methods: Plasma samples from 42 horses (25 with atrial fibrillation and 17 without cardiovascular or systemic disease [control group]). Methods: Results of hematologic tests (ie, plasma fibrinogen and D-dimer concentrations, prothrombin and activated partial thromboplastin times, and antithrombin activ...
Evaluation of coagulation via thromboelastography in healthy horses administered dexamethasone. Dexamethasone was administered to healthy horses daily for 7 days. Blood samples were collected at 3 time points from both treatment and non-treatment groups, and analyzed via thromboelastography (TEG). There were no significant differences in TEG parameters between treated and untreated horses, or within treatment groups over time. La dexaméthasone a été administrée à des chevaux en santé pendant 7 jours. Des échantillons de sang ont été prélevés à trois moments auprès des groupes de traitement et des groupes sans traitement et ensuite analysés par thrombo-élastographie (TEG)....
Association Between Necropsy Evidence of Disseminated Intravascular Coagulation and Hemostatic Variables Before Death in Horses With Colic. Disseminated intravascular coagulation (DIC) is frequent in horses with severe gastrointestinal disorders. Postmortem studies have found fibrin microthrombi in tissues of these horses, but studies relating these histopathological findings with antemortem hemostatic data are lacking. Objective: Antemortem classification of coagulopathy is related to the presence and severity of fibrin deposits observed postmortem in horses with severe gastrointestinal disorders. Methods: Antemortem hemostatic profile data and postmortem tissue samples (kidney, lung, liver) from 48 horses with colic. Methods: Ti...
Biological variation of thromboelastrography variables in 10 clinically healthy horses. To assess the utility of population-based reference intervals (PRIs) for interpreting thromboelastography (TEG) variables in horses using biological variation data. Methods: Prospective cohort biologic variation study conducted over a 5-week period. Methods: Veterinary teaching hospital and research facility. Methods: Ten clinically healthy horses randomly selected from a veterinary school research and teaching herd. Methods: Horse health was determined using physical examination, CBC, and biochemical and coagulation profiles prior to the start of the study. Subsequently, once weekly blood sam...
Thromboelastographic Clot Characteristics of Autologous Equine Blood Products After Activation by Autologous Thrombin, Bovine Thrombin, or Calcium Chloride. To compare clotting efficiency of platelet-rich plasma (PRP) and concentrated platelet-poor plasma (cPPP) to citrated whole blood after activation by autologous thrombin, bovine thrombin, or calcium chloride (CaCl2 ). Methods: Experimental study. Methods: Healthy adult horses (n = 6). Methods: PRP and cPPP were prepared by commercial devices. Using thromboelastography, clotting variables were compared after activation of citrated autologous blood, PRP, and cPPP by autologous thrombin, bovine thrombin, or CaCl2 , respectively. Results: PRP had the greatest clot strength and quickest clot rate, ...
Blood hypercoagulability and systemic inflammation in horses with heaves. As inflammation and coagulation are intertwined processes, the efficiency of blood coagulation of heaves-affected horses and controls were compared in an observational case-control study, using thrombelastography. In experiment 1 (Exacerbation, six heaves, five controls), horses were housed indoors and fed hay. Thrombelastography, functional fibrinogen, platelet count, hematology, and antithrombin were measured. In experiment 2 (Remission, eight heaves, 11 controls), horses were housed in a low-dust environment for at least a month when thrombelastography was performed. Heaves-affected horses ...
Evaluation of contact activation of citrated equine whole blood during storage and effects of contact activation on results of recalcification-initiated thromboelastometry. To evaluate the degree of activation of the contact pathway in citrated equine whole blood over holding times ≤ 30 minutes and assess effects of contact activation on recalcification-initiated thromboelastometry. Methods: 11 healthy adult mixed-breed horses. Methods: Blood was collected by atraumatic jugular venipuncture into prewarmed evacuated siliconized glass tubes containing citrate anticoagulant and held at 37°C for ≤ 30 minutes. Thromboelastometry was performed with an in vitro viscoelasticity (thromboelastometry) monitoring system. Factor XII and factor XI procoagulant activities ...
Differences in serum protein 2D gel electrophoresis patterns of Przewalski’s (Mongolian wild horse) and thoroughbred horses. The objective of this study was to assess differences in serum protein expression profiles of Przewalski's (Mongolian wild horse) and thoroughbred horses using proteome analysis. The serum proteins were separated by two-dimensional electrophoresis (2-DE) and five different gene products were identified. Proteins represented by the five spots were identified by matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry (MS)/MS technology. The identities of all proteins were deduced based on their similarity to proteins in the human plasma protein database. Three pr...
The use of nonsteroidal anti-inflammatory drugs in critically ill horses. To review the physiology of the cyclooxygenase (COX) enzymes with reference to the beneficial effects of nonsteroidal anti-inflammatory drugs (NSAIDs) related to their analgesic and antiendotoxic properties as well as the mechanisms responsible for adverse gastrointestinal, renal, and coagulation effects. Methods: Human and veterinary peer reviewed literature Results: NSAIDs are frequently administered to critically ill horses for their analgesic and anti-inflammatory effects. However, NSAIDs have significant side effects principally on the gastrointestinal mucosa and kidneys. These side effec...
Progression of plasma D-dimer concentration and coagulopathies during hospitalization in horses with colic. To assess the progression of plasma D-dimer concentrations and coagulation status in horses with different types of colic. Methods: Prospective clinical observational study performed between March 2004 and September 2008. Methods: Veterinary university teaching hospital. Methods: Horses admitted and treated for colic and hospitalized for >48 hours were considered. Animals were classified by diagnosis into medical obstructive conditions (MO), surgical obstructive conditions (SO), inflammatory conditions, and ischemic lesions (IS). Methods: Three blood samples were obtained from each horse (a...
Coagulopathies in horses. Although primary coagulopathies are rare in horses, changes in coagulation and fibrinolysis are commonly associated with inflammatory diseases. A clear understanding of the pathophysiology of normal and abnormal hemostasis is required to be able to choose and interpret diagnostic tests evaluating coagulation and fibrinolysis. After diagnosis, treatment of the underlying disease must occur regardless of whether clinical manifestations (excessive bleeding or thrombosis) of the coagulopathy are present or not. Specific treatment may be initiated if there are clinical signs of coagulopathy.
Hemorrhage and blood loss-induced anemia associated with an acquired coagulation factor VIII inhibitor in a Thoroughbred mare. A 23-year-old Thoroughbred mare was evaluated because of a coagulopathy causing hemoperitoneum, hematomas, and signs of blood loss-induced anemia. Results: The mare had tachycardia, pallor, hypoperfusion, and a large mass in the right flank. The mass was further characterized ultrasonographically as an extensive hematoma in the body wall with associated hemoabdomen. Coagulation testing revealed persistent, specific prolongation of the activated partial thromboplastin time (> 100 seconds; reference interval, 24 to 44 seconds) attributable to severe factor VIII deficiency (12%; reference inte...
Coagulation, oncotic and haemodilutional effects of a third-generation hydroxyethyl starch (130/0.4) solution in horses. Clinical indications for hydroxyethyl starches (HES) in horses include rapid plasma volume expansion and oncotic support during periods of hypoproteinaemia. Side effects such as coagulopathies associated with HES administration pose limitations to their use in veterinary medicine. In man, tetrastarch (130/0.4) has demonstrated less profound effects on coagulation compared with first- and second-generation HES. Objective: To evaluate the haemostatic and oncotic effects of tetrastarch (130/0.4) administered at 10, 20 and 40 ml/kg bwt in healthy horses. Methods: Randomised crossover experiment....
Systematic evaluation of evidence on veterinary viscoelastic testing part 1: System comparability. To systematically examine the evidence on system comparability between the thromboelastography and the rotational thromboelastometry viscoelastic point-of-care instruments and to identify knowledge gaps. Methods: Standardized, systematic evaluation of the literature, categorization of relevant articles according to level of evidence and quality, and development of consensus on conclusions for application of the concepts to clinical practice. Methods: Academic and referral veterinary medical centers. Results: Medline via PubMed, CAB abstracts, and Google Scholar were searched. A total of 8 rele...
Hemostatic profile during late pregnancy and early postpartum period in mares. Hemostasis is a physiological process that prevents excessive blood loss and represents a protective mechanism at the time of delivery. Peripartum hemorrhage is a recurring hazardous condition to mare's health; therefore, we aimed to study mares' hemostatic profile to investigate whether physiological adjustments occur during late pregnancy and early postpartum. Fifteen pregnant mares have been monitored from the 34th week of pregnancy until the third week after foaling. Fifteen nonpregnant mares were used as control group. Jugular blood samples were analyzed for platelet count (Plt), prothrom...
Cardiovascular, colloid osmotic pressure, and hemostatic effects of 2 formulations of hydroxyethyl starch in healthy horses. Lower molecular weight and molar substitution formulations of hydroxyethyl starch (HES) solutions might maximize cardiovascular function and colloid osmotic pressure (COP) and minimize adverse effects on coagulation. Objective: To compare effects of 1 low and 1 high molecular weight and molar substitution HES solution on cardiovascular variables, COP, and hemostasis in normal horses. Methods: Eight healthy adult horses. Methods: Randomized, crossover designed study: 10 mL/kg bolus of 6% HES (600/0.75) (hetastarch) (HS), 6% HES (130/0.4) tetrastarch (TS), and 0.9% NaCl (NS). Variables recorded ...
Training-induced changes in clotting parameters of athletic horses. The purpose of this study was to investigate the effects of training on prothrombin time, activated partial thromboplastin time, and fibrinogen (Fb) concentrations in horses to assess potential adaptive response to training. Fifteen clinically healthy horses were enrolled in the present study and equally divided into three groups. Group A completed an intense training program, group B participated in a light training program, and group C included sedentary horses. After 5 weeks, group B was subjected to the same training program completed by group A and renamed group B1. Blood samples were col...
Therapeutic plasma concentrations of epsilon aminocaproic acid and tranexamic acid in horses. Antifibrinolytic drugs such as epsilon aminocaproic acid (EACA) and tranexamic acid (TEA) are used to treat various bleeding disorders in horses. Although horses are hypofibrinolytic compared to humans, dosing schemes have been derived from pharmacokinetic studies targeting plasma concentrations in humans. Objective: We hypothesized therapeutic plasma concentrations of antifibrinolytic drugs in horses would be significantly lower than in humans. Our objective was to use thromboleastography (TEG) and an in vitro model of hyperfibrinolysis to predict therapeutic concentrations of EACA and TEA in...
Plasma D-dimer concentrations during experimental EHV-1 infection of horses. Central nervous system blood vessel thrombosis is a part of the pathogenesis of equid herpesvirus-associated myeloencephalopathy (EHM). D-dimers (DD) are stable breakdown products of cross-linked fibrin, and increased DD-plasma concentrations could reflect the degree of systemic coagulation during EHV-1 infection. Objective: We hypothesized that blood DD concentrations will be increased during periods of EHV-1 fever and viremia, reflecting an activated coagulation cascade with fibrinolysis. Methods: Twenty-eight equids were infected with EHV-1 in 3 experimental infection studies. Three (uninfe...
Comparison of components of biological variation between 3 equine thromboelastography assays. There is a paucity of information about the analytical performance of thromboelastography (TEG) in horses, specifically concerning components of variation among different analytical methods. Such data may be obtained by nested analysis of repetitive standardized sampling of healthy individuals. Objective: The objectives were (1) to assess the relative susceptibility to sources of preanalytical variation in a highly standardized setting, (2) to directly compare and evaluate the observed analytical variation, and (3) to assess the applicability of population-based reference intervals. Methods: B...
Serial viscoelastic and traditional coagulation testing in horses with gastrointestinal disease. Objectives of this study were to compare the ability of serial thromboelastography, Sonoclot, and traditional coagulation panels to detect coagulopathies associated with disease category, systemic inflammatory response syndrome (SIRS), complications, and nonsurvival in horses with gastrointestinal disease. Methods: Prospective clinical evaluation. Methods: University referral hospital. Methods: One hundred twenty-one horses admitted as emergencies for gastrointestinal disease and 28 healthy adult horses. Methods: Blood samples were collected ≤4 times from emergency horses (admission and if s...
Pharmacokinetics and thrombolytic effects of the recombinant tissue-type plasminogen activator in horses. To test the efficacy of the recombinant tissue-type plasminogen activator (rt-PA) alteplase in horses, the thrombolytic effect was tested in in vitro generated equine thrombi. The extent of lysis was determined by measuring the decrease in thrombi weight over a period of 4 hours. In vivo pharmacokinetics of alteplase were determined in 6 healthy horses. A single dose (1 mg/kg) was applied via intravenous infusion over a period of 30 minutes Coagulation-related variables, blood count and clinical parameters were taken before the treatment and until 48 h after treatment. In addition, plasma rt-P...
[Study on the reproducibility of ACTH concentrations in plasma of horses with and without equine Cushing syndrome]. The evaluation of plasma ACTH and the dexamethasone suppression test are considered the methods of choice to evaluate the course of therapy of pituitary pars intermedia dysfunction (PPID). Sampling protocols as well as vacutainers for analysis differ between the laboratories. To evaluate the reproducability of plasma ACTH measurement between four different laboratories (A, B, C, D) in Germany as well as within the laboratories themselves, ten horses with previously diagnosed PPID and four healthy horses were sampled and analyzed. Each laboratory received two differently labeled samples of each...
Changes in blood coagulation induced by exercise training in young athletic horses. Prothrombin Time (PT), Activated Partial Prothrombin Time (APTT), Fibrinogen concentration (Fbg) and Platelet number (Plt) were evaluated in 20 young athletic horses during a training program. A standardized exercise test (SET) was performed every month for three months. The V4 variations (the speed, in m/min, reached at the blood lactate concentration of 4 mmol/l) obtained for each test were calculated to assess the effect of training program on athletic performance. Blood samples were collected at 20-day intervals over a period of 80 days from the beginning of the training program. The V4 (P...
Jugular thrombophlebitis in horses: a review of fibrinolysis, thrombus formation, and clinical management. Thrombophlebitis of the jugular vein is commonly observed in horses, particularly during intensive care, and leads to local and systemic inflammatory responses as well as head and neck circulatory impairment. Thrombolytic therapy is widely used in human practice with the aim of thrombus dissolution and recanalization of the injured vessels. There are similarities between human and horse coagulation and fibrinolytic processes. This review examines the fibrinolytic system, thrombus formation, and the clinical management of jugular thrombophlebitis, including thrombolytic therapy. There is eviden...
Use of viscoelastic coagulation testing to monitor low molecular weight heparin administration to healthy horses. To evaluate the utility of thromboelastography (TEG) and Sonoclot analyses to monitor the effects of low molecular weight heparin (LMWH) administration to healthy horses. Methods: Randomized crossover study. Methods: Large animal veterinary teaching hospital. Methods: Six adult mixed breed healthy mares. Methods: LMWH (dalteparin) was administered (50 U/kg subcutaneously) either every 12 or 24 h for 3 consecutive days. Blood samples were collected before LMWH administration and then at selected time points for analysis. Thromboelastography derived R-time (R), K-time (K), angle (ANG), and maxim...
In vitro effects of three formulations of hydroxyethyl starch solutions on coagulation and platelet function in horses. To investigate the in vitro effects of 3 hydroxyethyl starch (HES) solutions on viscoelastic coagulation testing and platelet function in horses. Methods: Blood samples collected from 7 healthy adult horses. Methods: Blood samples were diluted with various crystalloid and HES solutions to approximate the dilution of blood in vivo that occurs with administration of a 10 and 20 mL/kg fluid bolus to a horse (1:8 and 1:4 dilutions, respectively). Diluted samples were analyzed through optical platelet aggregometry, platelet function analysis, thromboelastography, and dynamic viscoelastic coagulomet...
Pharmacodynamics of multi-dose low molecular weight heparin in healthy horses. To compare the pharmacodynamics of once daily and twice daily administration of low molecular weight heparin (LMWH) administration in horses. Methods: Randomized cross over study. Methods: Adult mixed breed healthy mares (n = 6). Methods: LMWH (dalteparin) was administered (50 U/kg subcutaneously) either every 12 or 24 hours for 3 consecutive days. Anti-factor Xa activity was measured before and at select time points after LMWH administration. Packed cell volume (PCV), platelet count, partial thromboplastin time (PTT), and anti-thrombin (AT) activity were monitored throughout the study. Result...
