Heparin is an anticoagulant medication used in horses to prevent and treat blood clot formation. It functions by activating antithrombin III, which inhibits thrombin and factor Xa, key components in the blood coagulation cascade. Heparin is commonly administered in equine medicine to manage conditions such as thrombophlebitis, laminitis, and disseminated intravascular coagulation. The dosage and administration of heparin must be carefully monitored to avoid complications such as hemorrhage. This page compiles peer-reviewed research studies and scholarly articles that explore the pharmacokinetics, therapeutic applications, and potential side effects of heparin in equine practice.
Parker NA, Bailey TL, Bowen JM, Ley WB, Purswell BJ, Dascanio JJ.Like the human female, the mare experiences reproductive tract pathology that may sometimes be circumvented by the use of assisted reproductive technologies (ARTs). One such technology, gamete intrafallopian transfer (GIFT), may be used in mares that exhibit ovulatory, oviductal, or uterine abnormalities that limit the use of common ARTs, such as embryo transfer. Homologous GIFT has been successfully performed in the horse; however, the logistics, costs, and associated risks of surgically transferring gametes to the oviducts of a recipient mare are considerably high. Use of a less costly speci...
Kingston JK, Sampson SN, Beard LA, Meyers KM, Sellon DC, Bayly WM.When blood is collected into sodium citrate in the proportion of 9 parts blood:1 part sodium citrate, the concentration of plasma sodium citrate in the sample will depend on the packed cell volume (PCV) of the blood sample. This difference in plasma sodium citrate concentration secondary to alterations in PCV significantly affects human platelet aggregation responses. Since horses attain a high PCV in response to high-intensity exercise we investigated the effect of differences in sample plasma sodium citrate concentration on equine platelet aggregability. In addition, low molecular weight hep...
Geelen SN, Sloet van Oldruitenborgh-Oosterbaan MM, Beynen AC.Feeding of a fat-rich diet to horses may enhance the flux of fatty acids, in the form of triacylglycerols (TAG), through the circulation into skeletal muscle. This hypothesis was tested indirectly by measuring the concentration of plasma TAG and the activity of lipoprotein lipase (LPL) in post heparin plasma. Six mature horses were fed a high-fat or a control diet according to a crossover design with feeding periods of 6 weeks. The control diet contained 1.5% fat in the dry matter and the high-fat diet 11.8%. The high-fat diet was formulated by adding soybean oil to the control diet at the exp...
Wunn D, Wardrop KJ, Meyers K, Kramer J, Ragle C.To develop methods to isolate, culture, and characterize equine hoof endothelial cells (EC) and keratinocytes. Methods: Cells harvested from the forelimbs of 8 horses. Methods: EC were obtained via catheters placed in the palmar digital arteries of the disarticulated lower portion of the forelimbs from 4 horses that had been heparinized prior to euthanasia. Phosphate-buffered saline solution was used to remove and discard RBC from blood vessels, and collagenase was used to loosen and flush EC from the vasculature. Hoof keratinocytes were obtained from 4 recently euthanatized horses by use of d...
Zientara S, Sailleau C, Moulay S, Crucière C, el-Harrak M, Laegreid WW, Hamblin C.A coupled reverse transcriptase-polymerase chain reaction assay (RT-PCR) for the detection of African horse sickness virus (AHSV) dsRNA, has been developed using genome segment 7 as the target template for primers. RNA from isolates of all nine AHSV serotypes were readily detected. The potential inhibitory effects of either ethylene diamine tetra acetic acid (EDTA) or heparin on the RT-PCR were eliminated by washing blood samples before lysis of the red blood cells and storage. There was a close agreement in the sensitivity and the specificity of the RT-PCR and an indirect sandwich ELISA. Conf...
Southwood LL, Baxter GM.Adhesions are an important complication after abdominal surgery in horses and foals, especially after small intestinal resection and anastomosis. Prevention therapies used in horses have included nonsteroidal anti-inflammatory drugs, antibiotics, heparin, dimethyl sulfoxide, carboxymethylcellulose, and meticulous surgical technique; however, the ideal surgical technique and prevention therapy has not been determined. Further, treatment of abdominal adhesions has a poor prognosis, emphasizing the need for improvements in prevention methods.
Wang YX, Kotlikoff MI.We investigated the muscarinic activation of Ca(2+)-activated Cl- currents [ICl(Ca)] in voltage-clamped equine tracheal myocytes. The threshold of cytosolic free Ca2+ concentration ([Ca2+]i) required for activation of ICl(Ca) was 202 +/- 22 nM, and full activation of the current occurred at 771 +/- 31 nM. Hexahydro-sila-difenidol (M3 antagonist) inhibited the methacholine-induced phasic [Ca2+]i increase and ICl(Ca) in a concentration-dependent manner, whereas methoctramine (M2 antagonist) only slightly attenuated the [Ca2+]i increase and ICl(Ca) (14.8 and 21.4%, respectively), consistent with ...
Sailleau C, Moulay S, Cruciere C, Laegreid WW, Zientara S.A reverse transcription-polymerase chain reaction (RT-PCR) assay followed by dot-blot hybridisation was used to detect African horse sickness virus (AHSV); the primers employed amplified the S7 gene that encodes the VP7 protein. The RT-PCR assay was compared with virus isolation for detecting AHSV in blood samples form horses experimentally infected with AHSV-4 and AHSV-9. The influence of sample storage and transportation and the effects of two anticoagulants (EDTA and heparin) were also studied. RT-PCR results were obtained within 48 hours as opposed to a minimum of 15 days for virus isolati...
Calvete JJ, Raida M, Gentzel M, Urbanke C, Sanz L, Töpfer-Petersen E.In the bovine, seminal plasma heparin-binding proteins bind to sperm lipids containing the phosphorylcholine group and mediate the capacitating effects of heparin-like glycosaminoglycans during sperm residence in the female genital tract. We report the characterization of heparin- and phosphorylcholine-binding proteins of stallion and boar seminal plasma. Horse seminal plasma proteins HSP-1 and HSP-2, and boar protein pB1, belong to the same family as the bull heparin- and phosphorylcholine-binding proteins BSP-A1/2, BSP-A3, and BSP-30K. We have determined the amino acid sequence and posttrans...
Orme CE, Harris RC.The aim of the study was to develop a model for the pre-exercise elevation of plasma free fatty acids in the horse, with a view to its future use in investigations of fat metabolism during exercise. A comparison of the lipase releasing and anticoagulative effects of heparin and a related substance pentosan polysulphate was investigated. Furthermore, the ability of heparin and pentosan polysulphate to affect an increase in plasma free fatty acid concentration, when co-administered with-a triglyceride emulsion, was quantified. Doses of 0.39 and 1.3 mg kg-1 body wt of heparin and pentosan polysul...
Sugahara Y, Matsumura T, Kono Y, Honda E, Kida H, Okazaki K.Heparin extensively inhibited infection of MDBK cells by equine herpesvirus 1 (EHV-1) strains adapted to bovine cells or hamsters, while the reagent merely reduced infectivity of strains passaged only in equine cells. The gC of two strains adapted to non-equine cells seemed to have higher affinity for heparin, although the reagent bound to both the gC and gB of all strains tested. Amino acid substitutions of the gC of the EHV-1 strains adapted to non-equine cells converged on the hydrophilic regions, amino acid residues 92 to 175, resulting in the glycoprotein becoming more cationic. These res...
Jarvis GE, Evans RJ, Heath MF.We have shown previously that endotoxin induces platelet aggregation in equine heparinised whole blood in a platelet-activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) dependent manner. ADP is an agonist of platelets and is present in platelet dense granules with ATP in high concentrations. An investigation was carried out to establish whether endotoxin-induced platelet activation was associated with release of platelet ATP and ADP. ADP-scavenging enzyme systems significantly inhibited endotoxin-induced aggregation. Plasma levels of adenine nucleotides were measured using ...
Christensen P, Whitfield CH, Parkinson TJ.The ability of the glycosaminoglycan, heparin, and the calcium ionophore, A23187, to induce acrosome reaction in equine spermatozoa was assessed using semen from 3 warmblood stallions of known high fertility. After collection of semen, the spermatozoa were washed and incubated in vitro with heparin or A23187. Incubation periods were 0, 4, 6 or 8 h with 0, 1, 10 or 100 microg/ml heparin or 0, 10, 30 or 60 min with 0, 0.01, 0.1, 1 or 10 microM A23187, respectively. Acrosome reactions were determined by staining the spermatozoa with naphthol yellow S plus erythrosin B, and sperm viability was ass...
Jarvis GE, Evans RJ.Endotoxin has previously been shown to induce platelet aggregation in equine heparinised whole blood. This study aimed to determine whether platelet-activating factor or products of cyclo-oxygenase metabolism (thromboxane A2 or prostaglandins) were important in mediating the response of platelets to endotoxin. The effects of the following drugs on endotoxin-induced aggregation were investigated: aspirin, flunixin meglumine and carprofen (non-steroidal anti-inflammatory drugs); CV-3988 and WEB2086 (platelet-activating factor receptor antagonists); quinacrine (phospholipase A2 inhibitor). The ef...
Monreal L, Villatoro AJ, Monreal M, Espada Y, Anglés AM, Ruiz-Gopegui R.Thirty healthy male horses were allotted to 3 groups and treated blindly during 4 days. Group-1 horses received unfractioned calcium heparin (100 IU/kg of body weight, SC, q 12 h). Group-2 horses received a single dose of a low-molecular-weight heparin (50 anti-Xa IU/kg, SC) every morning, and a similar volume of saline solution every evening. Group-3 horses received the vehicle (saline solution), SC, every 12 hours. Citrated and EDTA-anticoagulated blood samples were collected before starting the medication (T-0) and once daily 3 hours after each morning injection (T-3, T-27, T-51, and T-75)....
Eaton SA, Allen D, Eades SC, Schneider DA.Starling forces and hemodynamics in the digits of 5 horses were studied during early laminitis induced by oral administration of an aqueous extract of black walnut (Juglans nigra). The black walnut extract was prepared from heartwood shavings and was administered by nasogastric tube. Heart and respiratory rates, rectal temperature, central venous and arterial pressures, digital pulses, and signs of lameness were monitored. Blood samples were collected for determination of WBC count, hemoglobin concentration, and PCV and for endotoxin and tumor necrosis factor assays. Total WBC count and centra...
Calvete JJ, Reinert M, Sanz L, Töpfer-Petersen E.Boar and stallion seminal plasmas were fractionated using affinity chromatography on heparin-Sepharose. In both species, among other proteins, the heparin-binding (H+) and non-heparin-binding (H-) fractions each contained glycoforms of either porcine PSP-I or equine HSP-1 and HSP-2. However, porcine H+/PSP-I eluted as a monomeric protein, whereas H-/PSP-I formed a heterodimer with PSP-II, another major seminal plasma protein. On the other hand, the stallion proteins H+/HSP-1 and H+/HSP-2 eluted together as an aggregate of relative molecular mass (M(r)) 90,000, whereas H-/HSP-1 and H-/HSP-2 elu...
Mogg TD, Palmer JE.The medical records of 23 American Miniature Horses with hyperlipidemia, hyperlipemia, or hepatic lipidosis were reviewed. The most common clinical signs were anorexia and lethargy. The mean duration of clinical signs was 2.4 days. A primary disease was identified in 19 cases. Enterocolitis was the most common primary disease (n = 10). Intentional feed restriction, as part of treatment for colic, resulted in hyperlipemia in 2 horses and hyperlipidemia in 1. Four horses had primary hyperlipemia, 3 of which had signs of hepatoencephalopathy secondary to hepatic lipidosis. Dextrose, heparin, and ...
Calvete JJ, Mann K, Schäfer W, Sanz L, Reinert M, Nessau S, Raida M, Töpfer-Petersen E.We report the complete amino acid sequence of HSP-1, a major protein isolated from stallion seminal plasma or acid extracts of ejaculated spermatozoa. The protein consists of 121 amino acids organized in two types of homologous repeats arranged in the pattern AA'BB'. Each of the 13-15-residue A-type repeats contains two O-linked oligosaccharide chains. The B-type repeats span 44-47 amino acids each, are not glycosylated, and have the consensus pattern of the gelatin-binding fibronectin type-II module. This domain also occurs in the major bovine seminal plasma heparin-binding proteins PDC-109 (...
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...
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...
Ferrante PL, Kronfeld DS.Collection of a satisfactory blood sample requires special procedures to prevent changes in glucose and lactate content after the sample has been obtained. Changes in measured plasma glucose and blood lactate concentrations attributable to anticoagulants and storage procedures, respectively, were examined in blood samples obtained from horses at rest and after exercise. To evaluate the effect of anticoagulants on measured plasma glucose concentration, blood was preserved with either sodium fluoride/potassium oxalate or lithium heparin. Measured plasma glucose concentration in blood obtained at...
Schirmer EC, Farooqui J, Polak PE, Szuchet S.Cell-substratum adhesion plays a crucial part in the cascade of events that control growth or turn on and consummate a differentiation program. We are investigating the molecular basis of oligodendrocyte (OLG) cytodifferentiation, employing pure cultures of OLGs isolated from postmyelination brains. We have shown that such OLGs will regenerate in vitro and reenact the ontogenic development of myelin, but to do so they need a signal. Adherence to a polylysine surface in the presence of 20% horse serum generates such a signal. Among the events that are turned on upon OLG adhesion is the phosphor...
Atwal OS, McDonell W, Staempfli H, Singh B, Minhas KJ.The pulmonary intravascular macrophages (PIMs) of horse contain a unique electron-dense globular surface-coat which is arranged in a linear fashion in conformity with the contours of the cell membrane. The coat is sensitive to heparin treatment and to the digestive effect of lipolytic lipase, suggesting that the coat is predominantly composed of lipoproteins. During the present study, ultrastructural features of PIMs were analysed after exposing horses to halothane inhalation which was chosen as the model agent of lipid-soluble anaesthetic. The surface-coat showed acute sensitivity to halothan...
Laws EG, Freeman DE.Diamine oxidase (DAO), an enzyme of small intestinal origin, is released from mucosal storage sites by IV administration of heparin, to yield the plasma postheparin DAO (PHD) curve. The PHD curve is diminished when mucosal surface area is lost, and baseline (without heparin) plasma DAO activity increases when mucosal storage sites are damaged. Plasma DAO activity was measured after 2 doses of heparin were administered IV in healthy, conscious horses. In anesthetized horses, the PHD curve was studied: during sham small intestinal surgery, and during venous strangulation obstruction (VSO) of the...
Lindner A.The mean maximal lactate concentration of horses after exercise (Lamax) amounted to 4.5 +/- 2.2 mmol/l for gallop workouts of less than 11 m/s and more than 180 s (n = 35; category A), at more than 11 m/s and less than 180 s duration (n = 17; category B) to 16.3 +/- 4.8 mmol/l and at less than 11 m/s and less than 180 s duration (n = 10; category C) to 4.6 +/- 1.6 mmol/l. Lamax was always measured immediately after exercise following exercise of categories A and C. But for exercise bouts of category B Lamax was measured between the first and the tenth minute after exercise. Following exercise ...
Cohen ND, Parson EM, Seahorn TL, Carter GK.Medical records of 116 horses admitted to the Texas Veterinary Medical Center between Jan 1, 1984 and Dec 31, 1991 with duodenitis/proximal jejunitis (DPJ) were reviewed. The prevalence of laminitis was 28.4% (33/116; 95% confidence interval: 20.2 to 36.6%). The prevalence of DPJ and DPJ-associated laminitis did not appear to vary significantly by year during the study period. Anamnesis, physical examination, clinicopathologic data, and initial treatment recorded at the time of admission were reviewed to determine risk factors associated with development of laminitis associated with DPJ. A tre...
Moore BR, Hinchcliff KW.Heparin is used clinically in horses to treat hemostatic abnormalities associated with severe gastrointestinal disease, septicemia, and endotoxemia. The primary anticoagulant effect of heparin is through the suppression of thrombin-dependent amplification of the coagulation cascade, and inhibition of thrombin-mediated conversion of fibrinogen to fibrin. Heparin may be of benefit in preventing the complications associated with hypercoagulable states such as jugular vein thrombosis, laminitis, and organ failure. Heparin may also be beneficial in the prevention of intraabdominal adhesions after g...
Hinchcliff KW, Kociba GJ, Mitten LA.Thrombocytopenia in horses may be idiopathic or secondary to chronic infectious or inflammatory diseases (eg, equine infectious anemia, lymphosarcoma), drug administration, bone marrow depression, myelophthisic disease, or disseminated intravascular coagulation. This report describes EDTA-dependent pseudothrombocytopenia in a horse. Platelet counts for blood containing EDTA were consistently less than reference range, but platelet counts of blood containing heparin were within reference range. When thrombocytopenia is diagnosed in horses without clinical evidence of a bleeding tendency, EDTA-d...
Varner DD, Bowen JA, Johnson L.The onset of sperm capacitation/acrosome reaction was evaluated using heparin. Equine semen was incubated at 38 degrees C for 4.5 h in culture medium with and without 10 micrograms/mL heparin and with and without 0.1 microM of Ca2+ ionophore. Sperm acrosome reaction was detected using chlortetracycline fluorescence (CTC) and transmission electron microscopy (TEM). The CTC assay provided staining patterns that corresponded with the capacitation/acrosome reaction in other mammalian species (man, mouse, guinea pig). The percentages of incapacitated sperm (PUC), capacitated acrosome-intact sperm (...
Dart AJ, Snyder JR, Julian D, Hinds DM.The microvascular anatomic features of the small intestine was described by correlating results of microangiography, light microscopy, gross studies, and scanning electron microscopy of vascular replicas in 14 horses. After heparinization, the horses were euthanatized, a length of jejunum was transected, and blood was flushed free of the circulation, using isotonic NaCl solution. In six horses, the circulatory system was perfused with a modified radiopaque medium and evaluated radiographically. These sections were then evaluated by standard histologic methods. Sections from 8 horses were perfu...
Howard J, Graubner C.This study aimed to evaluate whether equine serum amyloid A (SAA) concentrations could be reliably measured in plasma with a turbidimetric immunoassay previously validated for equine SAA concentrations in serum. Paired serum and lithium-heparin samples obtained from 40 horses were evaluated. No difference was found in SAA concentrations between serum and plasma using a paired t test (P=0.48). The correlation between paired samples was 0.97 (Spearman's rank P<0.0001; 95% confidence interval 0.95-0.99). Passing-Bablok regression analyses revealed no differences between paired samples. Bland-A...
Srivastava SK, Barnum DA, Prescott JF.The production of M-protein antigen of Streptococcus equi was studied during in vitro growth in equine blood and in various media. Of 11 S equi strains studied, seven which had initially possessed 0.04 mg or less M-protein per 10 mg of streptococcal cell extract showed an increase in M-protein content after successive culture in heparinised horse blood. Maximum proliferation occurred in Todd-Hewitt (TH) medium with added 0.2 per cent w/v glucose when compared with TH medium alone or TH medium with 2 per cent w/v sucrose, starch, neopeptone or normal horse serum. The M-protein of these strains ...
Tennent-Brown BS, Epstein KL, Whelchel DD, Giguère S.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...
Eaton SA, Allen D, Eades SC, Schneider DA.Starling forces and hemodynamics in the digits of 5 horses were studied during early laminitis induced by oral administration of an aqueous extract of black walnut (Juglans nigra). The black walnut extract was prepared from heartwood shavings and was administered by nasogastric tube. Heart and respiratory rates, rectal temperature, central venous and arterial pressures, digital pulses, and signs of lameness were monitored. Blood samples were collected for determination of WBC count, hemoglobin concentration, and PCV and for endotoxin and tumor necrosis factor assays. Total WBC count and centra...
Gerhards H, Eberhardt C.Different doses of heparin were given to equids SC to establish 0.05 to 0.20 U of heparin/ml of plasma. Plasma heparin values and antithrombin III activities were assayed, using chromogenic substrate methods. Activated partial thromboplastin and thrombin times were determined, using conventional coagulation assays. Tests were run every hour (or every 2 hours for antithrombin III) for 12 hours from 5 groups of 5 equids each after single injection of 40, 60, 80, 100, or 125 U of calcium heparin/kg of body weight and from 11 equids after injection of 150 U of calcium heparin/kg. The smaller dose ...
Keys GJ, Berry DB, Pleasant RS, Jones JC, Freeman LE.To describe the vascular distribution pattern of contrast medium during intraosseous regional perfusion (IORP) of the distal portion of the equine forelimb. Methods: 13 cadaveric forelimbs from 12 horses without forelimb diseases. Methods: Serial lateromedial radiographic views were taken of the distal portion of 10 heparinized cadaveric forelimbs at 0, 1, 2, 6, 15, and 30 minutes during IORP of the third metacarpal bone (MCIII) by use of iodinated contrast medium and a tourniquet placed over the proximal portion of MCIII. Vascular regions of interest (ROI) were created for each radiograph. Re...
Whelchel DD, Tennent-Brown BS, Giguère S, Epstein KL.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...
Lindner A, Bauer S.The effect of storage duration at different storage temperatures on the plasma ammonia concentration of equine EDTA whole blood, EDTA plasma and heparin plasma samples was investigated. Further, the effect of jugular vein compression before and during blood sampling on the plasma ammonia values was evaluated. In EDTA whole blood kept at 4 degrees C there was no significant increase of ammonia content after 6 hours of storage, whereas the increase was already significant 3 hours after collection if the EDTA whole blood was kept at 20-22 degrees C. EDTA plasma samples stored at 20-22 degrees C, ...
Mahaffey EA, Moore JN.In vitro erythrocyte agglutination developed in 3 hospitalized horses receiving heparin treatment. The agglutination caused artifactual decreases in erythrocyte counts and increases in mean corpuscular volume (MCV) values. Treatment of cell suspensions with trypsin eliminated the agglutination and the changes in erythrocyte count and MCV. Similar abnormalities in erythrocyte counts and MCV have been reported in healthy horses treated with heparin and have been cited as evidence of hemolysis and regenerative anemia.
Gerhards H, Kietzmann M.Pharmacokinetic parameters for subcutaneous low dose heparin in horses have been determined. Four groups of five and one group of eleven mature, healthy horses of various breeds were given single subcutaneous injections of 60, 80, 100, 125, and 150 units of calcium heparin/kg of body weight (U/kg) in the pectoral region. Jugular blood samples were collected prior to, and at hourly intervals for 12 h after injection. Heparin plasma concentrations were measured using a commercially available amidolytic assay. Peak concentrations 4 h after administration were 0.021 +/- 0.016 (mean +/- SD) units o...
Southwood LL, Baxter GM.Adhesions are an important complication after abdominal surgery in horses and foals, especially after small intestinal resection and anastomosis. Prevention therapies used in horses have included nonsteroidal anti-inflammatory drugs, antibiotics, heparin, dimethyl sulfoxide, carboxymethylcellulose, and meticulous surgical technique; however, the ideal surgical technique and prevention therapy has not been determined. Further, treatment of abdominal adhesions has a poor prognosis, emphasizing the need for improvements in prevention methods.
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 ...
Meister D, Fürst A, Kaegi B, Struchen C, Kaser-Hotz B, Flückiger M.In a retrospective study the tolerance to Teflon coated catheters in long-term intravenous medication was evaluated in 80 horses. Catheters were inserted into the jugular vein and remained there for 3 to 30 days (average 8.6 days). Catheters were flushed using an heparinized solution after each medication administration. The site of catheter placement was evaluated daily for swelling, pain and venous distensibility respectively. Swelling at the site of insertion was noted in 10 horses, a small subcutaneous abscess formation was identified in one horse. Fourteen sonographic evaluations were per...
Christensen P, Whitfield CH, Parkinson TJ.The ability of the glycosaminoglycan, heparin, and the calcium ionophore, A23187, to induce acrosome reaction in equine spermatozoa was assessed using semen from 3 warmblood stallions of known high fertility. After collection of semen, the spermatozoa were washed and incubated in vitro with heparin or A23187. Incubation periods were 0, 4, 6 or 8 h with 0, 1, 10 or 100 microg/ml heparin or 0, 10, 30 or 60 min with 0, 0.01, 0.1, 1 or 10 microM A23187, respectively. Acrosome reactions were determined by staining the spermatozoa with naphthol yellow S plus erythrosin B, and sperm viability was ass...
Zizzadoro C, Belloli C, Badino P, Ormas P.A method for the separation of pure and viable lymphocytes and granulocytes from the same blood sample in horses was reported. By centrifuging equine heparinized blood at 100 xg for 10 min at room temperature (r.t.), the resulting supernatant plasma was an almost pure (97.71 +/- 0.30%; n = 15) suspension of highly viable (98.72 +/- 0.28%) lymphocytes. When sodium citrate was used as an anticoagulant, lymphocyte suspensions collected in the same manner showed lower purity (87.89 +/- 1.59%; n = 9) and higher yields (56.56 +/- 3.89%, n = 9 versus 36.11 +/- 2.23%, n = 15). Where needed, a further ...
Parker NA, Bailey TL, Bowen JM, Ley WB, Purswell BJ, Dascanio JJ.Like the human female, the mare experiences reproductive tract pathology that may sometimes be circumvented by the use of assisted reproductive technologies (ARTs). One such technology, gamete intrafallopian transfer (GIFT), may be used in mares that exhibit ovulatory, oviductal, or uterine abnormalities that limit the use of common ARTs, such as embryo transfer. Homologous GIFT has been successfully performed in the horse; however, the logistics, costs, and associated risks of surgically transferring gametes to the oviducts of a recipient mare are considerably high. Use of a less costly speci...
van den Heuvel LP, Veerkamp JH, Monnens LA, Schröder CH.1. Proteoglycans were isolated from human and equine glomeruli or tubules by guanidine extraction and anion exchange chromatography. 2. These proteoglycan preparations contained about equal amounts of heparan sulfate and chondroitin sulfates. 3. During the preparation of glomerular or tubular basement membranes the main part of proteoglycans (greater than 50%) was extracted in the salt extract. Chondroitin sulfate proteoglycan was mainly found in the water and salt extracts of glomeruli and tubules, heparan sulfate proteoglycan in the deoxycholate extracts and the basement membranes. 4. The gl...
Noël PG, Couëtil L, Constable PD.Plastic heparinised vacutainer tubes are used for blood gas analysis in horses. This collection method may not be ideal because influx of atmospheric O(2) through the permeable plastic wall of the vacutainer tube and loss of CO(2) into the gas phase above the blood sample should increase blood PO(2) and decrease PCO(2), respectively. Objective: To determine the effects of collecting blood into plastic vacutainer tubes and storage conditions on blood gas analysis values. Methods: Blood was obtained from 6 healthy horses and tonometered at 37 °C with 12% O(2) and 5% CO(2). Three ml aliquots of ...
Owens SD, Burges J, Johns JL, Carrade DD, Galuppo LD, Librach F, Borjesson DL.The therapeutic use of bone marrow-derived mononuclear cells (MNCs) and mesenchymal stem cells for the treatment of soft tissue and orthopedic injuries in equine patients is expanding. After collection, bone marrow must be reduced in volume and depleted of RBCs for immediate therapeutic use or to prepare cells for culture or cryopreservation and storage. The MarrowXpress (MXP) System is an automated, closed, sterile system designed to process human bone marrow samples. Objective: The purpose of this study was to evaluate the capacity of the MXP System to process equine bone marrow to reduce vo...
Uberti B, Pressler BM, Alkabes SB, Chang CY, Moore GE, Lescun TB, Sojka JE.To investigate the effects of heparin administration on urine protein excretion during the developmental stages of experimentally induced laminitis in horses. Methods: 13 horses. Procedures-Horses received unfractionated heparin (80 U/kg, SC, q 8 h; n=7) or no treatment (control group; 6) beginning 3 days prior to induction of laminitis. All horses were given 3 oligofructose loading doses (1 g/kg each) at 24-hour intervals and a laminitis induction dose (10 g of oligofructose/kg) 24 hours following the final loading dose (designated as 0 hours) via nasogastric tube. Serum glucose and insulin c...
Cuervo-Arango J, Claes AN, Beitsma M, Stout TAE.The in vitro production of embryos by ovum pickup (OPU) and intracytoplasmic sperm injection (ICSI) is gaining popularity among horse breeders and veterinarians. Various collection media are available for flushing follicles during OPU. The objective of this study was to determine whether the type of flushing media used to aspirate follicles and collect oocytes influences the outcome of a commercial equine OPU-ICSI program. Two commercial embryo flushing media (EFM1 and EFM2) supplemented with heparin were compared with a flushing media designed specifically for the collection of oocytes (oocy...
Bastos FZ, Barussi FCM, Santi TF, Vieira BP, Senegaglia AC, Cruz FF, Michelotto PV.There is no consensus on aspects of equine bone marrow collection and processing. The study aimed to describe the collection of large volumes of bone marrow from horses of advanced age, with emphasis on bone marrow mononuclear cells (BMMCs) recovery and viability after cryopreservation. Fourteen horses, aged 3-24 years, were divided into three experiments. E1 studied the feasibility of collecting 200 mL from the sternums of horses of advanced age; E2 examined the number of cells obtained from the first and last syringe of each puncture; and E3 investigated the influence of heparin concentrati...
Ferrante PL, Kronfeld DS.Collection of a satisfactory blood sample requires special procedures to prevent changes in glucose and lactate content after the sample has been obtained. Changes in measured plasma glucose and blood lactate concentrations attributable to anticoagulants and storage procedures, respectively, were examined in blood samples obtained from horses at rest and after exercise. To evaluate the effect of anticoagulants on measured plasma glucose concentration, blood was preserved with either sodium fluoride/potassium oxalate or lithium heparin. Measured plasma glucose concentration in blood obtained at...
Armengou L, Monreal L, Delgado MÁ, Ríos J, Cesarini C, Jose-Cunilleras E.Heparin is used in humans as prophylaxis of hypercoagulable states and disseminated intravascular coagulation (DIC). However, babies need a higher heparin dose than do adults. Septic neonate foals are at high risk of hypercoagulable state and DIC, and there is limited objective information about heparin dose for equine neonates. Objective: To assess whether neonate foals require higher dosages of low-molecular-weight heparin (LMWH) than adults. Methods: Eighteen healthy and 11 septic neonate foals. Methods: Experimental and clinical studies. Firstly, healthy foals were randomly distributed in ...
Geelen SN, Sloet van Oldruitenborgh-Oosterbaan MM, Beynen AC.Feeding of a fat-rich diet to horses may enhance the flux of fatty acids, in the form of triacylglycerols (TAG), through the circulation into skeletal muscle. This hypothesis was tested indirectly by measuring the concentration of plasma TAG and the activity of lipoprotein lipase (LPL) in post heparin plasma. Six mature horses were fed a high-fat or a control diet according to a crossover design with feeding periods of 6 weeks. The control diet contained 1.5% fat in the dry matter and the high-fat diet 11.8%. The high-fat diet was formulated by adding soybean oil to the control diet at the exp...
Schirmer EC, Farooqui J, Polak PE, Szuchet S.Cell-substratum adhesion plays a crucial part in the cascade of events that control growth or turn on and consummate a differentiation program. We are investigating the molecular basis of oligodendrocyte (OLG) cytodifferentiation, employing pure cultures of OLGs isolated from postmyelination brains. We have shown that such OLGs will regenerate in vitro and reenact the ontogenic development of myelin, but to do so they need a signal. Adherence to a polylysine surface in the presence of 20% horse serum generates such a signal. Among the events that are turned on upon OLG adhesion is the phosphor...
Young DR, Richardson DW, Markel MD.A randomised, blind prospective study was performed to evaluate effects of low dose heparin therapy on complication and survival rates in 33 horses following exploratory celiotomy. Four horses had non-strangulating lesions and seven had strangulating lesions of the small intestine, 19 had non-strangulating lesions of the large intestine, and three had duodenitis-proximal jejunitis. Eighteen required an enterotomy or intestinal resection and anastomosis. Sixteen received heparin subcutaneously (66 iu/kg every 12 h) post operatively and 17 received a saline placebo for a mean of 3.7 days. There ...
Okolo CC, Emejuo NT, Udeagbala NG, Emeto UE, Ezema AS, Omeje OV, Nweze NE.Sample processing methods and storage time affect the outcome of biochemical analysis. Objectives: We aimed to assess the effects of dipotassium-ethylenediaminetetraacetic acid (K2-EDTA) and lithium-heparin treatments and storage times on selected analytes in equine synovial fluid (SF). Conclusions: The analytes-except for TP-became unstable within a few hours postcollection. Lithium-heparin and K2-EDTA treatments significantly altered ALP, LDH, TNCCs, and pH but not the TP concentrations of equine SF. Studies establishing reference intervals for these analytes based on the anticoagulant used ...
