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.
Beetson SA, Hilbert BJ, Mills JN.The effectiveness of the glutaraldehyde coagulation test (GCT) in detecting failure to acquire colostral immunoglobulin in neonatal foals was investigated. This was achieved by comparing and correlating results from the GCT with those obtained by single radial immunodiffusion (SRID) of equine IgG. The GCT was found to be a practical, inexpensive, semiquantitative test with a high specificity and sensitivity at critical IgG levels.
Ainsworth DM, Dodds WJ, Brown CM.A 16-year-old gelding was examined because of weight loss, inappetence, and intermittent fever of 2 months' duration. Preliminary laboratory findings revealed anemia, hypoproteinemia, thrombocytopenia, and prolongation of the activated partial thromboplastin time. A deficiency or inhibition of coagulation factor XI, factor XII, or high molecular weight kininogen was diagnosed. This defect was not associated with a bleeding diathesis, but should be considered as a cause of prolongation of the activated partial thromboplastin time.
Duncan SG, Meyers KM, Reed SM, Grant B.This experiment was designed to establish a model for the study of gastrointestinal disturbances as a result of prolonged endotoxin uptake in the horse. The hepatic portal vein of 7 horses was catheterized (through flank incisions) to give chronic hepatic portal infusions of lipopolysaccharide (LPS, endotoxin). Lipopolysaccharide was infused at a rate of 1 microgram/kg of body weight/hr for 24 hours. Two of the horses were infused with saline solution for 12 hours before LPS infusions were given. Lipopolysaccharide was shown to affect behavior and hematologic and coagulation values. The 1st ho...
Crawford AM, Mills JN.Venoms of the tiger snake and brown snake were procoagulant, in vitro, when tested with cat, dog, horse and wallaby plasma. In the absence of calcium and phospholipid the coagulant activity of tiger snake venom was minimal. In contrast, brown snake venom alone had marked procoagulant activity. This activity, however, was enhanced by the presence of calcium and phospholipid. Death adder venom exerted an anticoagulant effect. Apparent species' differences in susceptibility to the coagulant venoms were noted. However, the probable explanation of these differences was attributed to variation in th...
Knezevic PF, Fessl L.Thrombosis of the aorta as the cause of intermittent claudication in the horse appears to be rare. Two cases out of about 10 000 horses 1973-1984 are discussed. There are various views on its aetiology, whereby haemodynamic factors and disturbances of coagulation have been mentioned as well as parasites. For treatment surgical methods should be explored in addition to medical procedures. History, diagnosis and the attempt of an aortic thrombectomy in a 12 year old thoroughbred mare are described in this paper. A standardbred stallion was left untreated on owners wish.
Ewert KM, Fessler JF, Templeton CB, Bottoms GD, Latshaw HS, Johnson MA.To evaluate the effect of certain drugs on hematologic changes, blood chemical values, and survival in endotoxin shock, anesthetized ponies were given (IV) endotoxin (Escherichia coli O55:B5) and then treated as follows: Group A ponies--given a saline infusion at 5 minutes and at 3 hours after they were given endotoxin; group B ponies--given flunixin meglumine at 5 minutes and at 3, 6, 9, and 24 hours after they were given endotoxin; group C ponies--treated with dexamethasone; and group D ponies--treated with prednisolone at 5 minutes and at 3, 9, and 24 hours after they were given endotoxin. ...
Duncan SG, Reed SM.In horses with large bowel disease, those with circulating endotoxins but no evidence of altered hemostasis had a good prognosis for survival. Those with circulating endotoxins and evidence of altered hemostasis (fibrin degradation products) had a poor prognosis. Portal vein infusion of endotoxins over 24 hours caused hoof discomfort, evidenced by shifting of weight and standing with all 4 feet together, and a decreased hoof temperature. Clinical signs appeared within 30 minutes of initiation of infusion and subsided within 4 hours despite continued infusion. Long-term heparin therapy results ...
Stephens KA, Morcom E, Hood DM.A fluorometric assay was used to determine plasma antithrombin III (AT III) activities in 15 healthy adult horses. Nearly all plasma samples had an initial value of greater than 100% thrombin inhibited, so a 1:1 dilution of the prepared samples was performed. Following dilution, the mean value of the animals was 59.17 +/- 7.4% thrombin inhibited. Mares had significantly greater AT III activity than did geldings (P less than 0.01). The results of this study indicate the horse has more AT III activity than did other domestic species in which AT III activity has been reported.
Duncan SG, Meyers KM, Reed SM.This study was designed to test the efficacy of heparin anticoagulant therapy in the horse and its effect on the formed elements of blood. Nine clinically normal, nontraumatized adult horses were subjected to 4 different heparin maintenance regimens (dosages of 320, 240, 160, and 40 U/kg of body weight). Porcine intestinal mucosa heparin (20,000 U/ml) was injected subcutaneously every 12 hours for 96 hours (total 9 times). A loading dose of one-third the maintenance dose was given IV just before the first heparin injection. Three control horses were given an equivalent volume of 0.9% saline so...
Morris DD, Beech J.Disseminated intravascular coagulation (DIC) was diagnosed as a secondary disease in 6 horses. Four horses had localized and/or systemic sepsis, one horse had disseminated neoplasia, and one had idiopathic ulcerative enteropathy. The diagnosis of DIC was based on the finding of at least 3 of 4 abnormalities: thrombocytopenia, prolonged prothrombin time, prolonged activated partial thromboplastin time, and a high concentration of fibrinolytic degradation products. The most common clinical signs other than those attributable to the primary disease process were abnormal hemorrhage (4 hours) and v...
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...
Vrins A, Carlson G, Feldman B.Warfarin or dicoumarol prevents the production of functional clotting factors II, VII, IX and X. Navicular disease and thrombophlebitis are examples of equine thrombotic diseases in which warfarin has been used therapeutically. The initiation of anticoagulant therapy is relatively simple but attending veterinarians must be aware of the potential risks in order to minimize them. These risks include epistaxis, bleeding into the gastrointestinal tract and at the venipuncture site, and increased susceptibility to hematoma formation following local trauma. Vitamin K, especially vitamin K(1) is a sw...
Johnstone IB.Nonsteroidal anti-inflammatory drugs are commonly used in the treatment of inflammatory conditions, and have potential value in the treatment of thrombotic disease in the horse. This study compares the potency of three nonsteroidal anti-inflammatory drugs phenylbutazone, naproxen (equiproxen) and flunixin meglumine (banamine) with respect to their effects on equine platelets. Two functional responses of horse platelets were evaluated in vitro: their ability to aggregate and their ability to make available platelet factor 3 procoagulant activity. Flunixin at a concentration of 10(-6) M signific...
Frauenfelder HC, Fessler JF, Moore AB, Bottoms GD, Boon GD.The effects of dexamethasone (1 mg/kg of body weight) on hematologic, blood gas, and blood coagulation values in anesthetized ponies during endotoxin-induced shock were evaluated. Fifteen ponies were assigned to 3 groups of 5 ponies each: group 1, anesthetized nontreated and dexamethasone-treated controls; group 2, endotoxin, nontreated; group 3, endotoxin, dexamethasone treated. The hematologic changes in this endotoxin shock model included leukopenia and hemoconcentration. Significant hematologic effects were not seen in ponies after administration of dexamethasone. However, dexamethasone tr...
Brumbaugh GW, Stitzel KA, Zinkl JG, Feldman BF.Myelomonocytic myeloproliferative disease in a horse was diagnosed on the basis of hematologic, enzymatic, and histopathologic findings. It was characterized clinically by depression, weight loss splenomegaly, lymphadenopathy, coagulopathy, and bacteremia. Hematologic findings included severe refractory anemia, thrombocytopenia, monocytosis, and pleomorphic leukocytes, with a left shift of the myeloid series. The serum lysozyme concentration was 14.5 microgram/ml (normal, less than 5 microgram/ml). The bone marrow contained many immature cells of the myeloid series and had a myeloid-to-erythro...
Greene CE, Tsang VC, Prestwood AK, Meriwether EA.Optimal reaction conditions for the activated partial thromboplastin time (APTT), 1-stage prothrombin time (PT), and Russell's viper venom time were studied for pooled plasmas of horses, cattle, sheep, goats, swine, dogs, cats, and persons. Changes in CaCl2 and NaCl concentrations had significant effects on the APTT and PT reactions. The APTT was more sensitive than the PT to changes in CaCl2 concentration. The CaCl2 concentration recommended by the manufacturer for the APTT was suboptimal for some of plasmas of domesticated animals in ths study. Infusorial earth (Celite, activator) concentrat...
Hussein KS, Jones BE.Glutathione peroxidase (GSH-Px) was determined in whole blood from cows, goats and horses using cumenehydroperoxide as substrate. Heparin was found to be the most suitable anticoagulant. The highest activities of GSH-Px were found with high concentrations of heparin in the blood samples (1000 and 1250 IU/ml of blood). Sodium fluoride and especially EDTA and sodium citrate gave lower activities of the enzyme. Storage of the blood samples at room temperature (~20°C) or in a refrigerator (~5°C) for 3 days resulted in significantly lower activities of the enzyme, especially in horse blood. Gluta...
Kuiper R, Franken P.The course run by the disease is described in a horse which showed the symptom complex of colitis X following treatment with oxytetracycline. Disseminated intravascular coagulation was also observed in this horse. The possibility of disseminated intravascular coagulation being part of colitis X is discussed.
Scott EA, Byars TD, Lamar AM.The hematologic and clinical effects of anticoagulation with warfarin were documented in 4 horses. All of the animals had thrombophlebitis (external jugular vein). Measures of coagulation were monitored, with a prothrombin time of 1.5 to 2.5 x base-line value being used as the effective range of anticoagulation. Recanalization was achieved in 2 of 4 cases. Hemorrhage, both subcutaneous and through a surgical incision, was a complication. Vitamin K1, an antidote to warfarin toxicosis, was administered intravenously to reverse anticoagulation and to control hemorrhage.
Gentry PA, Woodbury FR, Black WD.The clotting times obtained with different assay procedures for routine coagulation tests were examined for horse and pony samples. The whole blood clotting time test and the activated coagulation test seemed to give similar results when both tests were done at 22 C. The results obtained for the activated partial thromboplastin time assay varied, depending on the commercial reagent used for the test. Consistent results were obtained for the one-stage prothrombin time assay with each reagent used.
DeNotta SL, Brooks MB.Horses with clinical signs of unprovoked or excessive hemorrhage should be evaluated for underlying platelet defects or coagulopathies. This article provides an overview of preliminary screening and definitive tests to assess coagulation and identify hemostatic defects in horses, as well as a review of the hemostatic disorders most frequently encountered in clinical practice.
Raisbeck MF, Garner HE, Osweiler GD.Gram negative endotoxins play a contributory role in the syndrome which results from over consumption of carbohydrates by horses and ponies. Since the antibiotic polymyxin B exerts a direct anti-endotoxin effect by chemically modifying the active lipid A moiety of endotoxin, it might be expected to protect horses after carbohydrate overload and provide a new therapeutic and experimental tool for this condition. The present study was undertaken to evaluate the effect of polymyxin B on hemostatic, hemodynamic, acid-base, and clinical aspects of the syndrome resulting from carbohydrate overload. ...
Stadler P, van Amstel SR.The results of a study conducted to determine the clinico-pathological changes in 4 experimentally-induced cases of endotoxaemia in the horse are reported on. Endotoxaemia was induced by injecting commercially available E. coli 055:B5 lipopolysaccharide intravenously at a dose of 1 microgram kg-1. The haematocrit, red cell count, total and differential white cell counts, thrombocyte count, prothrombin time, partial thromboplastin time, fibrinogen level, level of fibrin degradation products, arterial acid-base status, serum lactate and blood glucose were determined repeatedly. Changes that occu...
Henry MM, Moore JN.Whole blood re-calcification times were evaluated as a measure of endotoxin-associated coagulopathy in horses. First, the effects of endotoxin concentration and duration of in vitro incubation of citrated whole blood with endotoxin on the whole blood re-calcification time of blood collected from healthy horses were determined. Increasing concentrations or incubation times of endotoxin accelerated the whole blood re-calcification time. This effect was attributed mainly to increased monocyte thromboplastin activity. Second, whole blood re-calcification time, a clotting profile, plasma factor VII...
Jarvis GE, Evans RJ.Endotoxaemia is a leading cause of death among horses. Thrombocytopenia is a common finding in clinical and experimentally-induced cases of endotoxaemia and can lead to coagulopathies, including disseminated intravascular coagulopathy which is usually fatal. In this study it was shown that endotoxin (3 ng ml-1 to 25 micrograms ml-1) can aggregate equine platelets in heparinised whole blood in vitro. The endotoxin-induced aggregation (EIA) was shown to be dependent on the presence of leucocytes in the blood and did not occur when detoxified endotoxin was used, suggesting that lipid A was necess...
Leclere M, Chevalier Z, Dubuc V, Beauchamp G, Bédard C.The amount of thrombin generated reflects the endogenous thrombin potential (ETP), which depends on the balance of pro- and anticoagulant factors. The calibrated automated thrombogram (CAT) allows for the direct measurement of thrombin generation during the clotting process. Objective: (1) To describe the results of the CAT assay in horses, (2) to establish intra-assay and intra- and interindividual variation of thrombin generation in healthy horses, and (3) to compare in vitro low-molecular-weight heparin (LMWH) sensitivity between healthy and sick horses. The hypothesis for the last objectiv...
van den Bogaard AE, Thijssen HH, Hemker HC.The anticoagulant, warfarin, has been reported to be effective as treatment for navicular disease in horses. Since other forms of treatment for this disease are palliative, this new anticoagulant therapy has become widely employed. Despite the fact that initiation of anticoagulant therapy is relatively simple, attending veterinary practitioners should be aware that careful monitoring of this therapy is required for both safety and efficacy. Navicular disease is an example of equine thrombotic disease, and the goal of warfarin therapy is the prevention of new thrombus formation, while at the sa...
Sinn D, Wintzer HJ.The pharmacokinetics of racemic phenprocoumon were studied in 8 adult horses after the single intravenous and oral administration of 0.75 mg/kg. After i.v. administration the plasma concentration of phenprocoumon showed a biphasic decline in time. The pharmacokinetics were calculated on the two-compartment open model. The average plasma half-life (beta-phase) was 22 hours, the apparent volume of distribution was 0.61 l/kg, Cltot was 25.2 ml/kg/h (13.9-40.9 ml/kg/h). The systemic bioavailability of oral phenprocoumon was 97.6%, Tmax was found to be 4-12 hours. The effect of phenprocoumon on the...
Ainsworth DM, Dodds WJ, Brown CM.A 16-year-old gelding was examined because of weight loss, inappetence, and intermittent fever of 2 months' duration. Preliminary laboratory findings revealed anemia, hypoproteinemia, thrombocytopenia, and prolongation of the activated partial thromboplastin time. A deficiency or inhibition of coagulation factor XI, factor XII, or high molecular weight kininogen was diagnosed. This defect was not associated with a bleeding diathesis, but should be considered as a cause of prolongation of the activated partial thromboplastin time.
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),...
Belgrave RL, Hines MT, Keegan RD, Wardrop KJ, Bayly WM, Sellon DC.The development of ultrapurified hemoglobin-based oxygen carriers has eliminated many problems associated with whole-blood transfusions in other species. We hypothesized that the administration of polymerized ultrapurified bovine hemoglobin (PUBH) would result in improved hemodynamic parameters in ponies with normovolemic anemia without adverse effects on renal function or coagulation times. Normovolemic anemia was induced in 6 healthy adult ponies. Over a 3-day period, at least 45 mL/kg of whole blood was withdrawn from each pony until a target PCV of <12% was attained. Plasma was separate...
Ross J, Dallap BL, Dolente BA, Sweeney RW.To determine the pharmacokinetics and pharmacodynamics of epsilon-aminocaproic acid (EACA), including the effects of EACA on coagulation and fibrinolysis in healthy horses. Methods: 6 adult horses. Methods: Each horse received 3.5 mg of EACA/kg/min for 20 minutes, i.v. Plasma EACA concentration was measured before (time 0), during, and after infusion. Coagulation variables and plasma alpha(2)-antiplasmin activity were evaluated at time 0 and 4 hours after infusion; viscoelastic properties of clot formation were assessed at time 0 and 0.5, 1, and 4 hours after infusion. Plasma concentration ver...
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...
Olver CS, Nielsen VG.Carboxyheme and metheme states modulate hemostasis in humans and other species. Further, carbon monoxide and/or nitric oxide production increase in inflammatory disorders involving the gastrointestinal tract, with associated hypercoagulability or hypocoagulability. In particular, the horse suffers both thrombotic or coagulopathic complications during acute gastrointestinal disease. This investigation characterized the thrombelastographic response to carboxyheme (via CORM-2) or metheme (via phenylhydroxylamine, PHA) states without/with addition of tissue type plasminogen activator. Citrated pla...
Satué K, Gardon JC, Muñoz A.The process of fibrin clot formation is a series of complex and well-regulated reactions involving blood vessels, platelets, procoagulant plasma proteins, natural inhibitors, and fibrinolytic enzymes. Vasculitis can be caused by a variety of different agents as bacteria, viruses, protozoal, rickettsial organisms, toxic, drugs, medications, and neoplasms. The most common cause of vasculitis is the purpura hemorrhagica, which is associated with exposure to Streptococcus equi ssp. equi or less commonly, equine influenza. Deficiencies or defects of the hemostatic components may result in bleeding ...
Monreal L, Anglés A, Espada Y, Monasterio J, Monreal M.Changes in haemostasis in horses with colic were assessed by using specific and sensitive markers of coagulation and fibrinolysis activity. Blood samples from 41 horses with severe colic and from 30 healthy control horses were tested. Diagnosis of DIC was based on the findings of at least 3 of 6 abnormalities: thrombocytopenia, prolonged clotting times (PT and APTT), increased polyclonal FDPs, decreased fibrinogen and decreased AT-III activity. Plasma thrombin-antithrombin III complexes (TAT), monoclonal fibrin degradation products fragment D (D-dimer) and monoclonal fibrinogen degradation pro...
Cook VL, Blikslager AT.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...
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.
Bishop RC, Kemper AM, Burges JW, Jandrey KE, Wilkins PA.To evaluate a point-of-care viscoelastic coagulation monitor (VCM Vet) for use in horses by assessing variability between devices and establish reference intervals (RIs) for healthy adult horses. Methods: Prospective observational study. Methods: Two university teaching hospitals. Methods: Healthy adult horses (n = 68). Methods: None. Results: Blood collected by direct jugular venipuncture was applied directly from the syringe into 2 VCM Vet cassettes to establish coefficients of variation (CVs) and RIs for reported parameters of clotting time (CT), clot formation time (CFT), alpha angle, am...
Bentz AI, Palmer JE, Dallap BL, Wilkins PA, Boston RC.Coagulopathy is a potentially underrecognized complication of sepsis and septic shock in critically ill neonatal foals. Objective: Critically ill neonatal foals have abnormalities in coagulation that are associated with disease severity and outcome. Methods: Foals <72 hours old admitted to a neonatal intensive care unit. Methods: Prospective, observational study. Blood was collected at admission, 24, and 48 hours for platelet count, prothrombin time, activated partial thromboplastin time, antithrombin activity and concentrations of fibrin degradation products, and fibrinogen in plasma from all...
Mendez-Angulo JL, Mudge MC, Vilar-Saavedra P, Stingle N, Couto CG.To evaluate the use of citrated recalcified (nonactivated) thromboelastography (TEG) in healthy horses and horses with colitis and suspected coagulopathies. Methods: Prospective, observational study conducted between October 2007 and June 2009. Methods: Veterinary Teaching Hospital. Methods: Forty-five healthy adult horses and 12 sick adult horses with colitis and prolonged prothrombin time (PT) or activated partial thromboplastin time (aPTT). Methods: None. Results: Whole blood was collected on admission. Coagulation profile (PT, aPTT, platelet count, and fibrinogen concentration) and citrate...
Moore LA, Johnson PJ, Bailey KL.A six-day-old Missouri foxtrotter colt was examined because it had had diarrhoea since it was 24 hours old. A diagnosis of colitis, septicaemia, and disruption of the arterial blood flow to the pelvic limbs was made on the basis of clinical and laboratory findings. Despite intensive medical therapy, the foal died 13 hours after being examined. Postmortem examination revealed diffuse fibrinous enteritis with lymphoid necrosis, multifocal fibrinonecrotic typhlocolitis, disseminated intravascular coagulation, and a large occluding thrombus at the aortic termination. The results of bacteriological...
Gentry PA, Feldman BF, O'Neill SL, Madigan JE, Zinkl JG.Various haemostatic analytes were systematically evaluated for four months pre-partum and five months post partum in 14 healthy mares. The plasma fibrinogen concentration and both Factor VIII:C and von Willebrand factor activity showed gradual increases from mid-gestation and reached maximal, or near maximal activity at parturition. These increases were paralleled by an increase in plasma fibronectin concentration, the appearance of fibrinogen degradation products, and a modest rise in antithrombin III concentration. In contrast, the activity of Factor VII and Factor IX, and the one-stage prot...
Ferreira JF, Albuquerque ALH, Amorim RM, Ferreira RS, Takahira RK, Borges AS, Oliveira-Filho JP.In this retrospective study, clinical records of nine horses with a diagnosis of Bothrops envenomation were investigated. The accidents were classified as severe (5/9), moderate (2/9), or mild (2/9) according to the adapted bothropic snakebite severity score (BSSS). All snakebites were on the head region. The main clinical signs were local edema, blood coagulation disorders, and respiratory distress. The whole-blood clotting time (WBCT) was prolonged in all horses, and five horses presented with uncoagulable blood. All horses received specific snake antivenom according to the BSSS (six vials f...
Topper MJ, Prasse KW.To adapt manual human chromogenic assays for coagulation factors VII (F.VII), VIII:coagulant (F.VIII:C), IX (F.IX), and X (F.X), and C1-esterase inhibitor (C1-INH) for use with an automated analyzer, and to measure the activity of these proteins in horses. Methods: 10 healthy horses were used to determine ranges for the assays. Pooled plasma for standards was collected from an additional 20 healthy horses. Methods: A computer-assisted analyzer was programmed from the manual method for commercially available human F.VII, F.VIII:C, F.IX, F.X, and C1-INH chromogenic assay kits. Standards were pre...
Skowronek AJ, LaFranco L, Stone-Marschat MA, Burrage TG, Rebar AH, Laegreid WW.Infection of naive North American horses with 10(4) cell culture infectious doses (CCID50) of virulence variants of African horsesickness virus (AHSV), designated AHSV/4SP, AHSV/9PI, and AHSV/4PI, reproduced three classical forms of African horsesickness: acute (pulmonary), subacute (cardiac), and febrile, respectively. Distinct clinicopathologic and hemostatic abnormalities were associated with each form of disease. Hemostatic abnormalities included increased concentration of fibrin degradation products and prolongation of prothrombin, activated partial thromboplastin, and thrombin clotting t...
Estepa JC, Lopez I, Mayer-Valor R, Rodriguez M, Aguilera-Tejero E.The aim of this study was to evaluate the influence of two commonly used anticoagulants (K3EDTA and lithium heparin) on refractometric and spectrophotometric measurement of total protein (TP) concentration in equine peritoneal fluid samples. The influence of a commercial solution of K3EDTA, a solution of K3EDTA in distilled water and lithium heparin on the refractometric and spectrophotometric (biuret) quantification of TP content in peritoneal fluid samples was assessed. Total protein concentration measured by refractometry was consistently overestimated in samples with commercial K3EDTA. The...
Dos-Santos MC, Arroyo C, Solano S, Herrera M, Villalta M, Segura A, Estrada R, Gutiérrez JM, León G.Antivenoms are preparations of immunoglobulins purified from the plasma of animals immunized with snake venoms. Depending on the number of venoms used during the immunization, antivenoms can be monospecific (if venom from a single species is used) or polyspecific (if venoms from several species are used). In turn, polyspecific antivenoms can be prepared by purifying antibodies from the plasma of animals immunized with a mixture of venoms, or by mixing antibodies purified from the plasma of animals immunized separately with single venom. The suitability of these strategies to produce polyspecif...
Dolente BA, Wilkins PA, Boston RC.To detect subclinical disseminated intravascular coagulation (DIC) in horses with colitis and to determine any association between the diagnosis of subclinical DIC and outcome or occurrence of complications in horses with colitis. Methods: Prospective study. Methods: 37 horses admitted to a veterinary teaching hospital for treatment of acute colitis. Methods: Coagulation profiles were obtained on each horse 0, 24, and 48 hours after admission. Six tests were performed: platelet count, plasma fibrinogen concentration, prothrombin time, activated partial thromboplastin time, antithrombin activit...
McCann ME, Watson TD, Boudinot FD, Moore JN.We evaluated the pharmacokinetics of IV administered sodium heparin and the pharmacodynamic effect of heparin on lipoprotein lipase (LPL) activity. Horses were allotted to 3 groups. Plasma samples were obtained from each horse before and at various times for 6 hours after heparin administration for determination of heparin concentration, LPL activity, and activated partial thromboplastin time (APTT). The disposition of heparin was dose dependent. The area under the plasma heparin concentration vs time curve (AUC) increased more than proportionally with dose, indicating that heparin elimination...
