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.
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 (...
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...
Ellington JE, Ball BA, Blue BJ, Wilker CE.Reliable capacitation of equine spermatozoa has been a major obstacle in the development of equine in vitro fertilization. Experiments were done to compare in vitro capacitation of equine spermatozoa by use of heparin/caffeine, calcium ionophore, uterine tube epithelial cell (UTEC)-conditioned medium, and direct culturing of spermatozoa with UTEC (coculturing). Capacitation-like changes, as determined by chlortetracycline membrane staining patterns, developed with UTEC-conditioned medium and coculturing, equivalent to that with calcium ionophore. Both of these treatments induced more (P < 0.05...
Turner TA, Brown CA, Wilson JH, Roth L, Rosenstein DS, Schweizer CM, Woodaman KA.A 14-year-old Arabian gelding was examined for colic. An exploratory celiotomy was subsequently performed and the left lobe of the liver was found to be twisted. The lobe was resected using a TA-90 surgical stapling instrument. Histologic examination of the resected liver indicated portal vein and sinusoid dilation and congestion with blood. There were focal areas of necrosis and bacterial cocci and rods throughout the section. The histologic findings were consistent with hepatic lobe torsion. After surgery, the horse was treated with broad spectrum antibiotics, anti-inflammatory drugs, hepari...
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, ...
Ledwozyw A, Jabłonka S, Tusińska E, Herbut M.The levels of endogenous heparin in the plasmas of horses, cows, sheep and pigs were determined with the use of synthetic chromogenic substrate benzoyl-isoleucyl-glutamyl-glycyl-arginyl-p-nitroanilide (S-2222). The lowest heparin concentrations were stated in cattle plasma, the highest ones in the plasma of pigs.
Dart AJ, Snyder JR, Harmon FA.The microvascular circulation of the descending colon was studied in 5 adult horses, using microangiography and light microscopy combined with gross studies and scanning electron microscopy of vascular replicas. After heparinization, horses were euthanatized, and 3 segments of the descending colon and its mesentery containing 1 vascular arcade were removed from each horse. The fecal balls were gently massaged from the lumen, and the blood was flushed free of the circulation with isotonic NaCl. In 5 segments, the vascular system was injected with a modified radiopaque medium and evaluated radio...
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...
Welch RD, Watkins JP, Taylor TS, Cohen ND, Carter GK.Disseminated intravascular coagulation (DIC) secondary to colic was diagnosed in 23 horses. Each horse was categorized retrospectively as to the cause of the colic based on surgical and/or necropsy findings: group 1 consisted of 14 horses with compromised intestine that required resection and anastomosis; group 2 consisted of 3 horses with nonstrangulating intestinal displacement and/or impactions; and group 3 consisted of 6 horses with colic associated with enteritis and/or colitis. Horses were considered to be affected with DIC if at least three of five hemostatic parameters were significant...
Provost PJ, Stick JA, Patterson JS, Hauptman JG, Robinson NE, Roth R.Large colon torsion frequently is a fatal condition in horses. The purpose of the study reported here was to determine systemic arterial pressure, plasma eicosanoid concentrations, colonic blood flow, vascular resistance, tissue pH, and morphologic features associated with large colon torsion and detorsion, and to evaluate the effects of sodium heparin (80 IU/kg of body weight, IV) treatment on these values. Values were determined in 20 anesthetized ponies that were randomly assigned into 4 equal groups: control; control/heparin; torsion; torsion/heparin. Torsions were created by a 720 degrees...
Gerhards H.Low dose calcium heparin was administered subcutaneously at 12 hourly intervals to six healthy horses at an initial dose of 150 iu of heparin/kg bodyweight (bwt) and at a maintenance dose of 120 iu/kg bwt. All injections were given at 0900 and 2100 h. Blood samples for monitoring plasma heparin concentrations were obtained prior to, at 2 hourly intervals for 84 h (treatment period), and at Hours 24, 32, 48 and 96 of the control period. Blood samples for monitoring red blood cell (RBC) mass, plasma antithrombin III activity (AT III), activated partial thromboplastin time (APTT), and thrombin ti...
Zhang JJ, Muzs LZ, Boyle MS.In vitro fertilizing ability of stallion spermatozoa was assessed using horse follicular oocytes matured in vitro. After collection, stallion spermatozoa were either: 1) washed and incubated in TALP medium with 3 mg/ml bovine serum albumin (BSA) and 10 micrograms/ml heparin for 4h, 2) washed and incubated in TALP with 3 mg/ml BSA for 3 h and cultured for a further 1 h with 1 mM caffeine and 5 mM dbcAMP, 3) washed and incubated in TALP medium with 3 mg/ml BSA at pH 7.9-8.2 for 2-4 h, or 4) diluted and incubated in TALP medium with 10 mg/ml BSA and 7.14 microM calcium ionophore A 23187 for 5-10 ...
Belknap JK, Moore JN.The records of 71 horses with small intestinal disorders requiring surgical correction were disorders requiring surgical correction were reviewed to compare the prevalence of laminitis in those horses treated prophylactically with heparin and the prevalence of horses not treated with heparin. The prevalence of laminitis was 13% (9/71), and there was no significant difference (P less than 0.05) in the prevalence of laminitis between the 2 groups. The lack of significant benefit after treatment with heparin indicates that further work needs to be done on the equine coagulation system before hepa...
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 ...
Darien BJ, Potempa J, Moore JN, Travis J.Two synthetic substrate assays (fluorometric and chromogenic) were used to measure antithrombin-III (AT-III) activity (residual thrombin activity) in non-medicated and heparin (sodium) treated horses. In 18 non-medicated horses the fluorometric substrate assay (FSA) values were similar to previous reports but they reflected inconsistent trends and larger deviations in the heparin-treated groups (Group 2: 40 and 100 U/kg IV, n = 6; Group 3: 240 U/kg IV, n = 5; Group 4: 80 U/kg IV followed by 160 U/kg SC, n = 8) when compared to the chromogenic substrate assay (CSA) values. The CSA values for th...
van Dijk S, Wensing T.1. The serum lipoprotein pattern was studied in four horses, four ponies and in three high producing lactating and three non-lactating cows. The lipoprotein pattern was estimated with a combination of the preparative ultracentrifugation and the heparin-manganese precipitation technique. 2. The lipid composition of the lipoproteins of horse, pony, lactating cow and non-lactating cow was determined. 3. In all three species more than 50% of serum total lipids was found in the HDL fraction. 4. The mean chylomicron fraction in horse and pony was 3.1%. In the cow it varied from 1.5 to 2.5%. 5. Betwe...
Boosman R, Németh F.Impairment of the microcirculation in the distal part of the foot is an important factor in the aetiology of equine laminitis. To prevent the development of chronic laminitis and the resulting complications, two new therapeutical principles were tested in the treatment of acute laminitis. Thrombosis which frequently occurs in the corium of the foot, could be controlled by administration of anticoagulants such as heparin. Alpha-receptor blocking agents such as phenoxybenzamine were used, to improve the peripheral blood flow. The use of these drugs and that of anti-inflammatory agents during the...
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...
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...
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 ...
Parker JE, Fibini SL, Car BD, Erb HN.An ischemic bowel model was used to stimulate adhesion formation in eight ponies. Heparin (40 USP u/kg) or saline was administered intravenously at surgery and was continued subcutaneously every 12 hours for 48 hours to evaluate the efficacy of heparin in preventing intraabdominal adhesions. Ponies were euthanatized after 6 weeks, and postmortem examinations were performed. A statistically significant difference was found between the heparin-treated and the control groups. Adhesions developed in three of four control ponies, and adhesions did not develop in three of four heparin-treated ponies...
Moore JN, Mahaffey EA, Zboran M.Heparin was administered subcutaneously 2 times a day for 4 days to 5 horses. An additional group of 5 horses was used as time-matched controls. Significant decreases in PCV, erythrocyte count, and hemoglobin concentration were observed during heparin therapy. The mean corpuscular volume (MCV) of the heparin-treated horses increased to a peak value of 66.1 fl on the last day of treatment. Erythrocyte creatine concentration and glucose 6-phosphate dehydrogenase activity increased moderately during the treatment. These data indicated that the rapid, profound increase in MCV during heparin therap...
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.
Lamar CH, Turek JJ, Bottoms GD, Fessler JF.Certain in vitro culture conditions were determined for equine endothelial cells obtained from the aorta and pulmonary arteries. Cells were enzymatically isolated from the vessel lumen, using clostridial collagenase (2.5 mg/ml of Hanks's balanced salt solution) incubated at 37 C for 30 minutes. Cells were cultured in alpha minimum essential medium supplemented with plasma-derived and nonplasma-derived bovine fetal sera, endothelial cell-growth supplement, heparin, and antibiotics. Smooth muscle cell growth was not inhibited with nonplasma-derived animal sera, plasma-derived equine serum, or he...
Engelking LR, Mariner JC.The effect of large-dose heparin therapy on erythrocyte mass depletion in ponies was investigated to determine whether stimulation of reticuloendothelial cell activity and catabolic function would be evidenced by enhanced catabolism of heme to bilirubin. Ponies with chronic external biliary fistula were used to examine biliary excretion of bilirubin both before and after heparin loading (107 U/kg, IV, plus 320 U/kg, subcutaneously) and at maintenance dosages of 320 U/kg given (subcutaneously) at 12 and 24 hours after initial loading with heparin. Results indicated that by 48 hours after ponies...
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 ...
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 ...
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...
Brownlow MA, Hutchins DR.Osmolality is an indication of the osmotic pressure of plasma and depends on the amount of solute and solvent (water) present. The mean (+sd) plasma osmolality of 100 clinically normal animals was 282 (+6) mOsm/kg using lithium heparin as anticoagulant. The equation, osmolality=1.86 (sodium + potassium) +glucose +blood urea nitrogen + 9, was found to predict only crudely plasma osmolality. The plasma sodium: osmolality ratio was 0.49. Water and electrolyte disorders are classified into 3 types based on the measurement of electrolytes and osmolality: (1) Hypertonic dehydration (true dehydration...
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 ...
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...
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...
Ellington JE, Ball BA, Blue BJ, Wilker CE.Reliable capacitation of equine spermatozoa has been a major obstacle in the development of equine in vitro fertilization. Experiments were done to compare in vitro capacitation of equine spermatozoa by use of heparin/caffeine, calcium ionophore, uterine tube epithelial cell (UTEC)-conditioned medium, and direct culturing of spermatozoa with UTEC (coculturing). Capacitation-like changes, as determined by chlortetracycline membrane staining patterns, developed with UTEC-conditioned medium and coculturing, equivalent to that with calcium ionophore. Both of these treatments induced more (P < 0.05...
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 ...
Müller C, Gehlen H.Venous diseases due to venous catheters have variable symptoms and clinical progress. They comprise perivenous hematoma, periphlebitis, endophlebitis, phlebothrombosis or septic thrombophlebitis. To diagnose venous disease, a clinical examination (possibillity to distend the vein, swelling, pain, increased skin temperature, and any exudation around the injection site) and an ultrasonographic examination (perivenous tissue, venous wall, venous content) of the vein are performed. Treatment of venous diseases depends on the etiology and pathogenesis and combines the use of anticoagulants (heparin...
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 ...
WEGELIUS O.The number of mast cells per area and volume have been counted in the pleura, pericardium and capsula hepatis of cattle and horse.
The capsula hepatis of cattle contains a 5—10 times larger number of mast cells than the other tissues. The pleura pulmonalis showed a content of mast cells which was only a fraction of that in the liver capsule. The high histamine content found by Riley and coworkers when analyzing ox pleura seem to indicate that histamine is liberated not only from the mast cells, but also from other elements of the tissues.
Darien BJ, Potempa J, Moore JN, Travis J.Two synthetic substrate assays (fluorometric and chromogenic) were used to measure antithrombin-III (AT-III) activity (residual thrombin activity) in non-medicated and heparin (sodium) treated horses. In 18 non-medicated horses the fluorometric substrate assay (FSA) values were similar to previous reports but they reflected inconsistent trends and larger deviations in the heparin-treated groups (Group 2: 40 and 100 U/kg IV, n = 6; Group 3: 240 U/kg IV, n = 5; Group 4: 80 U/kg IV followed by 160 U/kg SC, n = 8) when compared to the chromogenic substrate assay (CSA) values. The CSA values for th...
Trachsel D, Cohausz O, Scharf G, Wehrli Eser M.A 14-year old Swiss warmblood gelding was presented to the equine hospital of the University of Zurich because of therapy-resistant fever. An intermittent lameness suggested the presence of an intravascular aorto-iliac thrombus which was confirmed sonographically. Subsequently, treatment was initiated with Heparin s.c. and continued for 7 months with Phenprocoumon (Marcoumar). The dosage was monitored and adjusted according to the prothrombin time, which was initially measured every week, and later maximally biweekly. The lameness improved and the regression of the thrombus could be followed s...
Liberda J, Tichá M, Zralý Z, Svecová D, Vezník Z.The interaction of seminal plasma proteins, sperms and detergent-released sperm proteins of three species with different types of acidic polysaccharides was studied. Heparin-binding activity of boar, bull and stallion seminal plasma proteins, sperms and sperm proteins was compared with their ability to interact with polysaccharides differing in the presence of the sulfate groups or in their saccharide moiety (chondroitin sulfate, dextran sulfate, fucoidan, hyaluronic acid). Bull seminal plasma proteins were characterized by higher affinity to heparin, fucoidan and dextran sulfate, while signif...
Dias DP, Teixeira LG, Canola PA, Albernaz RM, Marques JA, Neto JC.The purpose of this investigation was to evaluate surgical catheter implantation in the facial artery of horses and the long-term maintenance of such arteries using heparin and ascorbic acid as filling solution. Nine horses were implanted with a polyurethane catheter. The catheters were flushed with a heparin/ascorbic acid solution every 8h and remained patent for 25 days. Arterial blood samples were collected twice a day, and one exercise test that included serial blood samples and arterial pressure recordings was performed on a treadmill. Polyurethane catheters surgically implanted in the fa...
Belknap JK, Moore JN.The records of 71 horses with small intestinal disorders requiring surgical correction were disorders requiring surgical correction were reviewed to compare the prevalence of laminitis in those horses treated prophylactically with heparin and the prevalence of horses not treated with heparin. The prevalence of laminitis was 13% (9/71), and there was no significant difference (P less than 0.05) in the prevalence of laminitis between the 2 groups. The lack of significant benefit after treatment with heparin indicates that further work needs to be done on the equine coagulation system before hepa...
Ledwozyw A, Jabłonka S, Tusińska E, Herbut M.The levels of endogenous heparin in the plasmas of horses, cows, sheep and pigs were determined with the use of synthetic chromogenic substrate benzoyl-isoleucyl-glutamyl-glycyl-arginyl-p-nitroanilide (S-2222). The lowest heparin concentrations were stated in cattle plasma, the highest ones in the plasma of pigs.
Boosman R, Németh F.Impairment of the microcirculation in the distal part of the foot is an important factor in the aetiology of equine laminitis. To prevent the development of chronic laminitis and the resulting complications, two new therapeutical principles were tested in the treatment of acute laminitis. Thrombosis which frequently occurs in the corium of the foot, could be controlled by administration of anticoagulants such as heparin. Alpha-receptor blocking agents such as phenoxybenzamine were used, to improve the peripheral blood flow. The use of these drugs and that of anti-inflammatory agents during the...
Alonso Jde M, Rodrigues KA, Yamada AL, Watanabe MJ, Alves AL, Rodrigues CA, Hussni CA.Heparin is routinely administered in postoperative abdominal surgery aiming to prevent adhesions formation; however, there is no consensus indicating its effectiveness. This study evaluated the effect of heparin on peritoneal reactivity after abdominal surgery, through the association between peritoneal fluid features and ultrasonographic and laparoscopic examination. Ten adult horses were used: control group (CG) and treated group (TG). Both groups underwent laparotomy and small colon enterotomy. TG received subcutaneous heparin at 150 IU/kg every 12 hours for 5 days. The animals underwent ...
Dart AJ, Snyder JR, Harmon FA.The microvascular circulation of the descending colon was studied in 5 adult horses, using microangiography and light microscopy combined with gross studies and scanning electron microscopy of vascular replicas. After heparinization, horses were euthanatized, and 3 segments of the descending colon and its mesentery containing 1 vascular arcade were removed from each horse. The fecal balls were gently massaged from the lumen, and the blood was flushed free of the circulation with isotonic NaCl. In 5 segments, the vascular system was injected with a modified radiopaque medium and evaluated radio...
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...
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 ...
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...
Engelking LR, Mariner JC.The effect of large-dose heparin therapy on erythrocyte mass depletion in ponies was investigated to determine whether stimulation of reticuloendothelial cell activity and catabolic function would be evidenced by enhanced catabolism of heme to bilirubin. Ponies with chronic external biliary fistula were used to examine biliary excretion of bilirubin both before and after heparin loading (107 U/kg, IV, plus 320 U/kg, subcutaneously) and at maintenance dosages of 320 U/kg given (subcutaneously) at 12 and 24 hours after initial loading with heparin. Results indicated that by 48 hours after ponies...
Yamamoto M, Tanaka Y, Sugano M.1. Changes in lipid components of lipoproteins during incubation of horse serum at 37 degrees C were investigated. In non-incubated serum, cholesterol and lecithin existed predominantly in alpha-lipoprotein or in high-density lipoprotein (HDL). Lysolecithin was mainly associated with the fraction with density above 1.21. 2. When serum was separated into alpha- and beta-lipoproteins by the heparin precipitation method after 1 hr incubation, the decrease in alpha-lipoprotein free cholesterol and lecithin was about four times that in beta-lipoprotein counterparts. 3. When serum lipoproteins were ...
Freeman KD, Barrett JG, Youngstrom DW, White NA.The 6-strand Savage (SSS) tenorrhaphy pattern is biomechanically superior to the commonly employed 3-loop pulley (3LP); however, its effects on intrinsic tendon vasculature remain unknown. The objective of this study was to compare perfusion of intrinsic vasculature of the equine superficial digital flexor tendon (SDFT) after 3LP and SSS tenorrhaphies. We hypothesized that the SSS technique would significantly decrease vascular perfusion compared to the 3LP technique. Methods: Ex vivo, randomized, paired design. Methods: Horses (n = 9) METHODS: Under general anesthesia, 9 pairs of forelimb...
Alonso JM, Schmidt EMS, Eckersall PD, Kjelgaard-Hansen M, Alves ALG, Rodrigues CA, Watanabe MJ, Crescencio AP, Hussni CA.The acute phase response is a response to injury and depends on the severity of the trauma. Heparin is routinely used for postsurgical treatment of horses to prevent abdominal adhesions; however, its effect on inflammation is unknown. This study aimed to assess systemic inflammatory response of horses subjected to small colon enterotomy and to evaluate heparin effects on postsurgical inflammation. Ten adult horses were subjected to small colon enterotomy and were assigned to a control or a treatment group. Both groups received prophylactic antibiotics and flunixin, and the treatment group rece...
