The study of blood in horses encompasses the examination of its components, functions, and its role in equine health and disease. Blood consists of various elements, including red blood cells, white blood cells, platelets, and plasma, each serving specific functions such as oxygen transport, immune response, clotting, and nutrient distribution. Analyzing blood parameters can provide insights into the physiological and pathological states of horses. Common blood tests in equine medicine assess parameters like hematocrit, hemoglobin concentration, and white cell counts to monitor health status, diagnose conditions, and guide treatment decisions. This page compiles peer-reviewed research studies and scholarly articles that explore the composition, function, and clinical applications of blood analysis in horses.
Hinchcliff KW, Kohn CW, Geor R, McCutcheon LJ, Foreman J, Andrews FM, Allen AK, White SL, Williamson LH, Maykuth PL.We examined the effects of participation in each of 3 modifications of Day 2 of a 3-day-event on blood and serum variables indicative of hydration, acid:base status and electrolyte homeostasis of horses. Three groups of horses - 8 European (E) horses and 2 groups each of 9 North American horses performed identical Days 1 (dressage) and 3 (stadium jumping) of a 3-day-event. E horses and one group of the North American horses (TD) performed modifications of Day 2 of a 1 Star 3-day-event and the other group of North American horses (HT) performed a Horse Trial on Day 2. Jugular venous blood was c...
Jansson A, Nyman S, Morgan K, Palmgren-Karlsson C, Lindholm A, Dahlborn K.In this study 4 Standardbred geldings (age 3-8 years, weight 431-531 kg) were used. The horses were fed a hay and oat diet and the total sodium intake was about 32 mg/kg bwt (690 mmol/day). An exercise test (ET) which contained 3 phases was performed. Phase I consisted of 23.5 min of mainly submaximal exercise, Phase 2 of 2 h of box rest and Phase 3 of 26 min of exercise including an intensive trot over 2600 m at 90% of VO2max. The ET was repeated 3 times: the first at 20 degrees C (30-40% RH), the second at 35 degrees C (30-40% RH) and the third at 35 degrees C (30-40% RH) after a nasogastric...
Geiser DR, Andrews FM, Rohrbach BW, White SL, Maykuth PL, Green EM, Provenza MK.Blood ionized calcium (Ca2+) and pH; plasma lactate concentrations; and total protein, total calcium (CaT), albumin, and phosphorus concentrations in serum were determined in 40 healthy horses before (T1), at the finish line (T2), and 10 minutes after the finish (T3) of the cross-country phase of a 3-day-event competition. Mean (+/- SEM) Ca2+ concentrations decreased from 6.22 +/- 0.04 mg/dl at T1 to 5.04 +/- 0.07 mg/dl at T2 (P < or = 0.05). This decrease was accompanied by a nonsignificant increase in CaT between T1 and T2. The mean (+/- SEM) percent ionization of calcium decreased significa...
Ecker GL, Lindinger MI.Loss of total body water and ions during prolonged exercise can predispose the horse to health and performance problems. This study examined total body water (TBW) losses and extracellular (ECF) ion losses during the cross-country (XC) phase of Preliminary, Intermediate and Advanced Horse Trials and CCI level 3-day-events. Jugular venous blood samples and body mass (BM) were collected on 49 horses at rest, Pre-XC, Post-XC and following 30 min of recovery. Plasma was separated from blood cells within 10 min of collection. Plasma was analysed for [Na+], [K+], [Cl-], ionised [Ca+2], [glucose], [l...
Andrews FM, White SL, Williamson LH, Maykuth PL, Geiser DR, Green EM, Ralston SL, Mannsman RA.Thirty-four horses competing in the Endurance Test of a 3-day-event were divided into 3 groups: horses in Group 1 (n = 15) competing in a 3.5 min steeplechase phase; horses in Group 2 (n = 13) in a 3 min steeplechase phase (Phase B) and horses in Group 3 (n = 6) in a 2.5 min steeplechase phase. The shortening of Phase B was associated with a lengthening of Phase C so that the total distance of the event for all horses was 14,940 m. Bodyweight (BW) was measured and total body water (TBW) and water loss estimated. Blood samples were collected from the horses prior to the Endurance Test, at the e...
Lindinger MI, Geor RJ, Ecker GL, McCutcheon LJ.We studied the effects of heat and relative humidity (RH) on plasma volume (PV) and ion responses to submaximal exercise and 60 min recovery in Thoroughbreds. Five horses were exercised at 50% of peak VO2 in cool, dry (CD, T = 22 degrees C, RH = 45-55%), and hot, humid (HH, T = 30-34 degrees C, RH = 80-85%) conditions until a pulmonary artery temperature of 41.5 degrees C was reached. Blood was obtained from the carotid artery. Body mass was measured at rest and after 30 min of recovery. The thermal conditions had no effect on the PV and ion responses during exercise and initial 30 min of reco...
Leo M, Kolb E, Siebert P, Dittrich H.The activity of adenosine deaminase in the cerebrum, cerebellum, brain stem, heart, skeletal muscle, lung, liver, spleen, kidney and testes of horses of the breeds Haflinger and Thüringer Kaltblut was not different from each other. In the erythrocytes and the plasma no activity of the ADA exists.
Glatzel PS, Belz JP.Because of the mare's ability to conceive very soon post partum a thoroughly performed control of the puerperal period is of particular importance. In addition to cytological and histological examinations of the uterus, rectal palpation and vaginoscopic inspection as well as microbiological examinations of uterine swabs and the evaluation of the mare's hormonal status during the puerperal period provide useful information which can be used either prognostically or to initiate a specific therapy. 55 mares were examined on days 3, 6 and 9 post partum. Rectal palpation, vaginoscopic inspection, m...
Manohar M, Goetz TE, Saupe B, Hutchens E, Coney E.Using radionuclide-labeled 15-microm-diameter microspheres injected into the left ventricle, we examined blood flow to the thyroid gland, adrenal glands, kidneys, and various gastrointestinal tract tissues in 9 healthy horses while they were standing quietly (rest) and during exercise at 2 work intensities (8 and 1 m/s). Hemodynamic measurements were made during steady-state conditions, as judged by the stability of heart rate as well as aortic, pulmonary, and right atrial pressures. The similarity of blood flow values for the left and the right kidneys during each of the 3 conditions indicate...
McKane SA, Rose RJ, Evans DL.Twenty-four Thoroughbred and twelve Standardbred racehorses aged between 2 and 6 years, presented for reported poor racing performance, underwent clinical exercise testing. During the last 10 s of exercise at each speed throughout an incremental speed exercise test on a treadmill inclined at a 10% slope, samples of arterial blood and expired gases were collected. Maximum oxygen uptake and the partial pressures of oxygen and carbon dioxide in arterial blood were determined. These values were compared between the two breeds of horses and also with reference to cytological findings of bronchoalve...
Riber C, Rubio MD, Marquez F, Pinedo M, Muñoz A, Castejon F.Clinical blood chemistry was studied on 13 Andalusian horses with laminitis. Ten healthy horses were used as controls. Blood samples were taken within the first 24 hr after the onset of the disease in Obel grade 3 before any type of treatment was given. No significant differences were observed in the number of red blood cells and white blood cells between Andalusian horses affected by laminitis and healthy animals. Significant decrease in the number of neutrophils and increased number of lymphocytes were noted. A significant increase in the enzymatic activity of CPK, LDH and AST in these anima...
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...
Marchi PR, Rawlings P, Burroughs JN, Wellby M, Mertens PP, Mellor PS, Wade-Evans AM.Purified African horse sickness virus (AHSV) was fed, as part of a blood meal, to adult females from a susceptible colony of Culicoides variipennis, established in the insectories at the Institute for Animal Health, Pirbright Laboratory, UK. The meal consisted of heparinized blood obtained from ovine, bovine, equine (horse and donkey) or canine sources spiked with AHSV serotype 9 (AHSV9). The infectivity levels observed for C. variipennis varied significantly, according to the source of the blood sample. Comparison of the protein profiles obtained from AHSV9 incubated with the individual serum...
Mitten LA, Hinchcliff KW, Sams R.Evaluation of a portable blood gas analyzer, (StatPal II, Unifet, Inc, La Jolla, CA) was performed using tonometered solutions and equine blood. Samples were analyzed by the StatPal II and either an Instrument Laboratory IL1306 (Lexington, MA) or a Radiometer ABL50 blood gas analyzer (Radiometer America Inc., Westlake, OH). Comparison of the StatPal II and the IL1306 was done by analysis of 3 tonometered solutions (acidic, normal, and alkalotic) and 27 equine venous blood samples. Blood pH, PCO2, PO2, and [HCO3] values were altered by IV infusion of 5% sodium bicarbonate or exercising the hors...
Monzón CM, Jara GA, Hoyos CB.The microhaematocrit (MH) technique was used to study the survival of Trypanosoma evansi in blood from two herds of naturally-infected horses. A comparison was made between samples treated with ethylenediaminetetraacetic acid and sodium citrate (alone or with 1% glucose), and sent to the laboratory packed in ice. In general, the number of samples yielding positive results by the MH technique showed the least variation during the first 24-36 h after sample collection. Survival varied with the anticoagulant used, but it declined rapidly from 48 h after collection, although live parasites were st...
Blissitt KJ, Bonagura JD.Colour flow Doppler echocardiography is a technique that is used with two-dimensional (2-D) echocardiography to study blood flow patterns in the heart and blood vessels. This method was used to define normal flow patterns and to evaluate valvular function in 40 clinically normal Thoroughbred and Thoroughbred cross horses. Flow patterns from 10 standardised echocardiographic images were described in relation to anatomic landmarks and timing during the cardiac cycle. Consistent intracardiac flow patterns were identified in the normal horses. High velocity flow signals or regurgitant jets were re...
Uboh CE, Rudy JA, Railing FA, Enright JM, Shoemaker JM, Kahler MC, Shellenberger JM, Kemecsei Z, Das DN.Although urine is the sample of choice for drug tests in racehorses, it is rarely obtained following the sudden death of a racehorse on the track while racing. The purpose of this study was to demonstrate the significance of postmortem tissue samples as an alternative to urine and blood samples in equine drug analysis following the sudden death of a racehorse on the track while participating in a competitive race. Postmortem tissue samples were frozen (-80 degrees C) until analyzed. A 30-40-g portion of each organ was homogenized in a 0.1 M phosphate buffer (pH 7.4), deproteinized, hydrolyzed ...
Lloyd DR, Rose RJ.Sodium bicarbonate given by nasogastric tube has been used by some trainers as the key ingredient in a 'milkshake'. It has been suggested that such treatment given 3-5 h prior to racing may enhance a horse's racing performance by increasing the blood buffering capacity and enhancing lactate clearance from skeletal muscle, thereby delaying the onset of fatigue. Several experiments were conducted to examine the effects on fluid, electrolyte and acid-base values of 0.5 g kg-1 dose of sodium bicarbonate, were examined. The effects of fasting, the simultaneous administration of glucose (0.5 g kg-1)...
Young LE, Blissitt KJ, Clutton RE, Molony V, Darke PG.Transoesophageal Doppler echocardiography was performed in 7 Thoroughbred horses anaesthetised with halothane. The procedure was performed on 4 occasions under standard conditions. On one occasion dobutamine hydrochloride was infused at 4 micrograms/kg/min for 20 min. Recordings of aortic blood velocity, obtained using high pulsed repetition frequency Doppler echocardiography (HPRF), were used to derive maximum acceleration (dv/dtmax), maximum velocity (Vmax), left ventricular ejection time (ET), pre-ejection period (PEP), velocity time integral (VTI) and cardiac output (CO). The coefficient o...
Mealey RH, Carter GK, Roussel AJ, Ruoff WW.Two different fluid solutions were infused through percutaneous cecal catheters in 6 healthy ponies to determine the effects on body weight; CBC; packed cell volume (PCV); total plasma protein concentration; plasma fibrinogen concentration; abdominal fluid analysis; concentrations of blood urea nitrogen (BUN), serum creatinine, Ca, total CO2 (TCO2), Na, Cl, K, and P; and fractional clearance (FC) of Na, Cl, K, and P. During intracecal administration of solution 1, FCNa and FCCl were significantly increased, whereas FCK and BUN were significantly decreased. During administration of solution 2, ...
Collatos C, Barton MH, Prasse KW, Moore JN.Components of the coagulation and fibrinolytic cascades, prothrombin and activated partial thromboplastin times, endotoxin activity, and albumin concentration were measured in blood and peritoneal fluid from 20 healthy horses and from 153 horses with acute gastrointestinal tract diseases at admission. Overall, 77% (117/153) of affected horses survived to discharge from the hospital, and 85% (82/97) of horses discharged were reported to be normal 9 to 14 months later. Significant differences in hemostatic factors were more common in peritoneal fluid than in blood. Tissue plasminogen activator, ...
Moore EH, Shelton DK, Wisner ER, Richardson ML, Bishop DM, Brock JM.To reexamine the blood patch technique in a laboratory model of lung biopsy free of confounding clinical variables. Methods: An equine model of lung biopsy was developed with an excised lobe connected to an insufflation bulb and pressure monitor. Patched and control unpatched punctures were made in the lung surface, and the pressure within the lung was raised to the maximum achievable. Whether air leakage from the puncture sites could be induced was determined and, if so, at what pressure it occurred. Results: At statistical analysis with the Kaplan-Meier test and the Cox proportional hazards ...
Manohar M.Strenuously exercising Thoroughbreds exhibit a dramatic increase in pulmonary capillary blood pressure, which contributes to stress failure of pulmonary capillaries resulting in exercise induced pulmonary haemorrhage (EIPH). One strategy to prevent EIPH is, therefore, to lower the pulmonary capillary blood pressure of exercising horses. Recent work in several species suggests that nitric oxide plays a significant role in maintaining low vascular resistance in the pulmonary circulation; however, the effects of nitrovasodilators (which work via the same mechanism as nitric oxide) on equine pulmo...
Khanna AK, McDonell WN, Dyson DH, Taylor PM.The cardiopulmonary effects of eucapnia (arterial CO2 tension [PaCO2] 40.4 +/- 2.9 mm Hg, mean +/- SD), mild hypercapnia (PaCO2, 59.1 +/- 3.5 mm Hg), moderate hypercapnia (PaCO2, 82.6 +/- 4.9 mm Hg), and severe hypercapnia (PaCO2, 110.3 +/- 12.2 mm Hg) were studied in 8 horses during isoflurane anesthesia with volume controlled intermittent positive pressure ventilation (IPPV) and neuromuscular blockade. The sequence of changes in PaCO2 was randomized. Mild hypercapnia produced bradycardia resulting in a significant (P < 0.05) decrease in cardiac index (CI) and oxygen delivery (DO2), while ...
Barton MH, Morris DD, Crowe N, Collatos C, Prasse KW.Hemostatic indices were determined in 45 healthy light breed foals, from birth to 1 month of age, and in 20 healthy adult (> 2 years of age) light breed horses. Blood samples were obtained from each foal at 4 ages: 1) < 24 hours, 2) 4-7 days, 3) 10-14 days, and 4) 25-30 days. The following hemostatic indices were determined: platelet count; prothrombin and activated partial thromboplastin times; activity concentrations of protein C, antithrombin III, plasminogen, alpha-2 antiplasmin, tissue plasminogen activator, and plasminogen activator inhibitor-1; plasma protein C antigen and fibrino...
Moore RM, Hardy J, Muir WW.Six horses were subjected to 3 hours of low-flow ischemia and 3 hours of reperfusion of the large colon. After induction of anesthesia, the large colon was exteriorized through a ventral midline celiotomy. Colonic blood flow was measured continuously, using Doppler ultrasonic flow probes placed on the colonic arteries supplying the dorsal and ventral colons and was allowed to stabilize for 15 to 30 minutes after instrumentation. Low-flow ischemia was induced by reducing colonic arterial blood flow to 20% of baseline (BL) flow. Colonic mucosal, seromuscular, and full-thickness blood flow were d...
Agüera EI, Rubio MD, Vivo R, Santisteban R, Muñoz A, Castejón F.A study was performed on Andalusian horses in order to assess the response of heart rate and various blood parameters to training. Two tests were performed, at two and four months of training respectively. Exercise schedules were of increasing intensity, over a distance of 1000 meters. Speed was progressively increased, from 4 m/s to 8.5 m/s, over four exercise stages. In both tests, a recovery period of 5 min followed each stage. Sample collection (by puncture of the external jugular vein) was performed with the animals at rest, within the first minute after each exercise stage, and at 10, 15...
Moore RM, Muir WW, Cawrse M, Bertone AL, Beard WL.Twenty-four horses were randomly allocated to 3 groups. Horses were anesthetized, subjected to a ventral midline celiotomy, and the large colon was exteriorized and instrumented. Group-1 horses served as sham-operated controls. Group-2 horses were subjected to 6 hours of low-flow colonic arterial ischemia, and group-3 horses were subjected to 3 hours of ischemia and 3 hours of reperfusion. Baseline (BL) samples were collected, then low-flow ischemia was induced by reducing ventral colonic arterial blood flow to 20% of BL. All horses were monitored for 6 hours after BL data were collected. Bloo...
Lopes-Pereira CM, Harun M, Schmidtova D, Timane I, Mabasso M, Otto F, Bogin E.Adapting the concept of "bed-side" patient analysis, the Boehringer-Mannheim Reflotron was evaluated for its possible use in veterinary medicine under outdoor-field conditions. Horse blood was analysed with the Cobas Bio analyzer, and indoor and outdoor analyses were also performed with the Reflotron. All values showed close agreement with no significant differences. Good correlation coefficients (r values around 0.9000) were also seen between all methods used. The Reflotron was operated under outdoor-field conditions by using, whenever available, an on-farm electricity source, or a gas operat...
Menzies-Gow NJ, Sepulveda MF, Bailey SR, Cunningham FM, Elliott J.To evaluate the roles of 5-hydroxytryptamine (5-HT), thromboxane A2 (TxA2), and platelet-activating factor (PAF) in endotoxin-induced digital hypoperfusion in horses. Methods: 6 healthy adult Thoroughbreds. Methods: Horses were treated with IV administration of saline (0.9% NaCl) solution (control treatment) or the 5-HT 1B/D selective antagonist, GR55562 (0.3 mg/kg), prior to tryptamine infusion (1.6 microg/kg/min for 30 minutes) to establish an effective GR55562 dose. In a crossover study, horses were treated with IV administration of saline solution (control treatment), aspirin (4 mg/kg, 2 h...
Aboashia FA, Alatrag F, Elmarimi A.Hematological and biochemical values are widely used in veterinary clinics for disease prognosis, nutritional and therapeutic monitoring, as well as in understanding the disease process in farm animals, including equines. This study aims to assess the alterations in hematological and biochemical parameters in pure Arabian horses infested with internal parasites. Samples of feces and blood were collected from 20 adult mares. Fecal samples were proceeded by flotation test. The blood samples were analyzed for hematological and biochemical parameters to determine their means ± standard error (M Â...
Ohta M, Kurimoto S, Tokushige H, Kuroda T, Ishikawa Y.To determine hemodynamic effects of hydroxyethyl starch (HES) infusion during anesthesia in horses, incremental doses of 6% HES were administered to 6 healthy Thoroughbred horses. Anesthesia was induced with xylazine, guaifenesin and thiopental and maintained with sevoflurane at 2.8% of end-tidal concentration in all horses. The horses were positioned in right lateral recumbency and administered 3 intravenous dose of 6% HES (5 ml/kg) over 15 min with 15-min intervals in addition to constant infusion of lactated Ringer's solution at 10 ml/kg/hr. Hemodynamic parameters were measured before and e...
MartÃnez-Bovà R, Zagrajczuk A, Donadeu FX, Skarzynski DJ, Piotrowska-Tomala K, Cuervo-Arango J.Haemorrhagic anovulatory follicles (HAFs) are the most common pathological anovulatory condition in the mare. To enhance understanding of the physiopathology of HAFs, the aim of the present study was to determine the effects of an induced-follicular wave on LH concentrations and follicular fluid factors relevant to the ovulatory process. Mares were allocated to treatment or control groups (n = 7/group) in a crossed over design during 14 oestrous cycles with a period of one cycle occurring when there were no treatments between the times when treatments were administered. In the treatment gr...
Pelletier N, Leith DE.Horses have high mean pulmonary artery pressure (Ppa) both at rest and during exercise (approximately 30 and > or = 80 mmHg, respectively). The mechanisms are unknown. To see if hypoxic pulmonary vasoconstriction (HPV) plays a role, we compared pulmonary artery pressure-flow (Ppa-Q) curves when inspired O2 fraction (FIO2) was 0.16, 0.21, and 0.30, in 5 normal Thoroughbred horses standing quietly and while galloping at 10 and 14 m/sec on a level treadmill. We calculated O2 consumption (VO2) from measurements of respired gas composition and flow, and calculated Q from VO2 and measurements of ...
Sobral GG, Neto OCG, da Silva AM, Carneiro GF.The aim of the present study is to evaluate the correlation between the total protein measured by an optical refractometer and the concentration of IgG by radial immunodiffusion (RID) to determine the performance of the optical refractometer to diagnose the failure of passive transfer of immunity (FPTI) in 12-hour-old foals. Blood was collected from foals (n = 30) 12 hours after birth. A study was carried out to measure the serum IgG concentration by RID test and measure total protein (TP) by optical refractometer. The correlation coefficient was measured between the TP concentration and the...
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 ...
Rueca F, Conti MB, Porciello F, Spaterna A, Antognoni MT, Mangili V, Fruganti G, Avellini G.The purpose of this study was to assess the possible relationship between maximal running speed, serum isoenzyme patterns of creatine kinase (CK) and lactate dehydrogenase (LDH) and echocardiographic indices of left ventricular function. A group of 15 healthy, 3-year-old Maremmano stallions were given a 100 day training programme. At the end of this the animals carried out a maximum speed test and were divided into 2 groups (A and B) according to whether or not they had attained a speed of 15 m/s. Venous blood samples were taken from each horse before exercise (T0), 2 min (T1) and 24 h (T2) af...
Gossett KA, French DD, Cleghorn B, Church GE.L-Lactic acid and D,L-lactic acid infusion in ponies resulted in metabolic acidosis with high anion gap (AG). Increased AG was explained entirely by increased blood L- and D-lactate concentrations. Hydrochloric acid infusion caused metabolic acidosis with decreased AG. Saline (NaCl) infusion caused mild metabolic acidosis, with no significant change in AG. Plasma K+ concentration was decreased by all types of infusions, with a maximum of 0.50, 0.25, 0.40, 0.50 mmol/L below baseline at the end of infusion in the L-lactic acid-, D,L-lactic acid-, HCl-, and NaCl-infused ponies, respectively. Only...
Mendoza FJ, Serrano-Rodriguez JM, Buzon-Cuevas A, Perez-Ecija A.Alternatives to surgical castration are necessary for controlling the sexual behaviour of stallions with breeding potential in training and competition. Flutamide is a potent selective non-steroidal androgen receptor competitive antagonist that has been used in human beings as an anti-androgenic drug. In this study, the pharmacokinetics and bioavailability of flutamide and its main active metabolite, 2-hydroflutamide, were determined in seven healthy mature stallions. Single doses of flutamide (1mg/kg intravenously, 1mg/kg orally in fasted horses, 5mg/kg orally in fasted horses and 5mg/kg oral...
Vandeplassche M, Podliachouk L, Beaud R.A study has been made of 44 cases of twin pregnancy in mares. The fetuses, foals, fetal membranes and blood groups of parents and foals were examined in order to determine the incidence of chorio-vascular anastomosis, blood chimaerism and freemartinism. All of the twins proved to be dizygotic and 33 of the 34 pregnancies were bicornual. Fusion of the chorion was seen in 14 of 22 placentas and macroscopic choriovascular bridges were observed in five of these, although blood chimaerism was diagnosed in 11 of 25 cases (44 per cent) examined. This would indicate a high incidence of microchoriovasc...
Berhane Y, Bailey SR, Harris PA, Griffiths MJ, Elliott J.Elevated plasma homocysteine (HCy) concentration is a risk factor for cardiovascular diseases associated with endothelial dysfunction, including the human digital ischaemic disease, Raynaud's phenomenon. Objective: HCy causes dysfunction of equine vascular endothelium and elevated plasma concentrations predispose to laminitis. Objective: To determine 1) the concentration of HCy in vitro, which inhibits equine vascular endothelial cell function and 2) any association between risk of laminitis and plasma HCy concentration. Methods: Endothelial function was studied by measuring endothelium-depend...
Serpa PB, Garbade P, Natalini CC, Pires AR, Tisotti TM.OBJECTIVE To develop a high-resolution melting (HRM) assay to detect the g.66493737C>T polymorphism in the myostatin gene (MSTN) and determine the frequency of 3 previously defined g.66493737 genotypes (T/T, T/C, and C/C) in warmblood horses. SAMPLES Blood samples from 23 horses. PROCEDURES From each blood sample, DNA was extracted and analyzed by standard PCR methods and an HRM assay to determine the MSTN genotype. Three protocols (standard protocol, protocol in which a high-salt solution was added to the reaction mixture before the first melting cycle, and protocol in which an unlabeled p...
Yamamoto K, Yasuda J, Too K.In 101 newborn Thoroughbred foals and foaling mares, 45 fetal (FECGs) and 101 neonatal electrocardiograms (NECGs) were obtained to investigate neonatal arrhythmias and other parameters including changes in fetal (FHR) and neonatal heart rate (NHR). Moreover, umbilical arterial, venous and jugular venous blood gas tensions and pH immediately after birth were analyzed to compare with the type and the degree of neonatal arrhythmias. Before delivery, in 37 fetuses FHR gradually decreased while in 8 cases it increased after rupture of the chorio-allantois. Abnormal deliveries were related in 5 of t...
Baumwart CA, Doherty TJ, Schumacher J, Willis RS, Adair HS, Rohrbach BW.To determine the effectiveness of preinduction hyperbaric oxygen treatment (HBOT) in ameliorating signs of experimentally induced endotoxemia in horses. Methods: 18 healthy adult horses. Methods: Horses were randomly assigned to 1 of 3 equal-sized treatment groups to receive normobaric ambient air and lipopolysaccharide (LPS), HBOT and LPS, or HBOT and physiologic saline (0.9% NaCl) solution. Horses were physically examined, and blood was obtained for a CBC and to determine concentration or activity of plasma tissue necrosis factor-α, blood lactate, and blood glucose before the horses were tr...
Afonso T, Giguère S, Rapoport G, Berghaus LJ, Barton MH, Coleman AE.Angiotensin-converting enzyme (ACE) inhibitors are used in horses with cardiovascular disorders despite the paucity of available data regarding their efficacy. Objective: The degree of serum ACE inhibition varies considerably between drugs. Methods: Eight healthy adult horses. Methods: Randomized prospective study. Horses were fasted overnight prior to receiving one of 4 ACE inhibitors intragastrically, administered at one of 2 dosages, using a randomized Latin square design (benazepril: 0.5 and 0.25 mg/kg; ramipril: 0.3 and 0.1 mg/kg; quinapril: 0.25 and 0.125 mg/kg; perindopril: 0.1 and 0.05...
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...
Sorrell-Raschi LA, Tomasic M.To evaluate the accuracy of 3 automated methods of determining Hct and hemoglobin (Hb) concentration, compared with manual methods. Animals-22 clinically normal adult horses of various breeds. Methods: A blood sample was obtained from each horse. Six dilutions (representing Hct of 0, 10, 20, 40, 60, or 70%) were prepared from each sample and analyzed, using 1 of 2 blood gas analyzers or a hemoximeter (for automated determinations) or the Wintrobe macrohematocrit and cyanmethemoglobin methods (for manual determinations). Regression analysis was used to determine mean slope relationships between...
Lloyd DR, Evans DL, Hodgson DR, Suann CJ, Rose RJ.We examined the effects of sodium bicarbonate in 6 Thoroughbred horses during submaximal and maximal treadmill exercise. Cardiorespiratory function was assessed together with the effect on exercise capacity by determining the run time to fatigue at maximal intensities. To discriminate between sodium bicarbonate's alkalinising effects and the fluid shifts that could result from the high osmotic load, we administered an equimolar solution of sodium chloride as a control. The horses were given sodium bicarbonate (1 g/kg bwt) or an equivalent number of moles of sodium chloride by nasogastric tube....
Geor RJ, Larsen L, Waterfall HL, Stewart-Hunt L, McCutcheon LJ.No studies in horses have examined the effect of route of carbohydrate (glucose) administration on the rate of muscle glycogen storage following glycogen-depleting exercise. Objective: Glucose delivery from the gastrointestinal tract limits the rate of muscle glycogen storage following glycogen-depleting exercise. Methods: In a crossover design, 7 fit horses completed treadmill exercise (EX) on 3 occasions to deplete muscle glycogen by approximately 50%. After EX horses received: 1) i.v. glucose infusion (IV; 0.5 g/kg bwt/h for 6 h), 2) oral glucose boluses (OR; 1 g/kg bwt at 0, 2 and 4 h post...
Connelly C, Norton NA, Hurley DJ, Hart KA, Meichner K, Gogal RM.Peripheral blood is commonly sampled to assess the health status of human and veterinary patients. Venous blood collection is a minimally invasive procedure, and in the horse, the common collection site is the jugular vein. Post blood collection, sample processing for leukocyte enrichment can vary by research laboratory with the potential to yield different effects on the enriched cells and their function. The focus of the present study was to compare a common blood dilution-leukocyte enrichment technique using a Histopaque gradient medium (His) to a modified leukocyte buffy coat syringe-lymph...
Tonekaboni FR, Narenjisani R, Staji H, Ahmadi-Hamedani M.This investigation aimed to compare the cell-free fetal DNA (cffDNA) plasma present in three trimesters of pregnancy in Torkaman pregnant mare. Peripheral blood samples of 32 pregnant mares in three trimesters of pregnancy were collected in tubes containing ethylenediaminetetraacetic acid at three time points. Circulating cffDNA was extracted from 3Â mL of maternal plasma. Using outer and inner primers, a conventional polymerase chain reaction was performed for the sex-determining region Y (SRY) gene present in the Y chromosome. Of the total 32 Torkaman pregnant mares, 24 were carrying male fe...
Henry M, Amaral D, Tavares FF, Santos NR.The aim of the present study was to analyse the effect of hydrocoele of the vaginal cavity of stallions on semen characteristics, libido and fertility, and to contribute to the understanding of the aetiopathology of this condition in stallions. Hydrocoele did not substantially affect either the libido or semen characteristics of affected stallions compared with a control group, and had no effect on fertility. However, the protein content of hydrocoelic fluid was significantly higher than that of peritoneal fluid and was lower than the protein content of blood serum. Electrophoretic profiles of...
Stewart AJ, Wright JC, Behrend EN, Martin LG, Kemppainen RJ, Busch KA.To determine the lowest ACTH dose that would induce a significant increase in serum cortisol concentration and identify the time to peak cortisol concentration in healthy neonatal foals. Methods: Prospective randomized crossover study. Methods: 11 healthy neonatal foals. Methods: Saline (0.9% NaCl) solution or 1 of 4 doses (0.02, 0.1, 0.25, and 0.5 μg/kg [0.009, 0.045, 0.114, and 0.227 μg/lb]) of cosyntropin (synthetic ACTH) was administered IV. Serum cortisol concentrations were measured before and 10, 20, 30, 60, 90, 120, 180, and 240 minutes after administration of cosyntropin or saline s...
Littlejohn A, Bowles F.Radiometer Blood Micro-system 2 was used in studies designed to, (a) compare the mean blood gas and acid-base values of 38 normal horses and 20 horses with chronic obstructive pulmonary disease (COPD), (b) determine the means and standard deviations of blood gas and acid-base values of Thoroughbred horses in training, and (c) investigate the relationships between clinical data, blood gas values, intracardiac and pulmonary arterial pressures in subjects with COPD. There were significant differences between the mean values for partial pressure of arterial oxygen (PaO2), arterial carbon dioxide (...
Ghassab S, Dulin J, Bertone AL.To compare clotting efficiency of platelet-rich plasma (PRP) and concentrated platelet-poor plasma (cPPP) to citrated whole blood after activation by autologous thrombin, bovine thrombin, or calcium chloride (CaCl2 ). Methods: Experimental study. Methods: Healthy adult horses (n = 6). Methods: PRP and cPPP were prepared by commercial devices. Using thromboelastography, clotting variables were compared after activation of citrated autologous blood, PRP, and cPPP by autologous thrombin, bovine thrombin, or CaCl2 , respectively. Results: PRP had the greatest clot strength and quickest clot rate, ...
Buss DD, Bisgard GE.Hemodynamics and myocardial contractility were evaluated in 6 unanesthetized ponies during hypocapnic and isocapnic hypoxia and during hypocapnic hypoxia after beta adrenergic blockade with propranolol. Hypocapnic hypoxia, with a mean arterial oxygen pressure (PaO2) of 41.9 mm of Hg, produced a decrease in stroke index and an increase in heart rate, with no change of cardiac index. A moderate increase in left ventricular contractility occurred during hypocapnic hypoxia. Beta adrenergic blockade abolished changes in nearly all indices of left ventricular contractility during hypocapnic hypoxia,...
Iwaszko A, Borowicz H, Graczyk S, Slowikowska M, Pliszczak-Krol A, Niedzwiedz A.Recurrent airway obstruction (RAO), also known as heaves, is an allergic respiratory condition that develops in horses following an exposure to aeroallergens in hay and straw. This is manifested by airway hyperreactivity, inflammation, bronchoconstriction, as well as a leukocyte and platelet infiltration into the airways. Platelet activation and an increase in circulating platelet-leukocyte aggregates may lead to airway remodeling. The aim of this study was to explore the effect of seven-day antigen challenge on dynamics of platelet indices and CD41/61 and CD62 P expression on platelets in h...
Watson ED.Incubation of blood neutrophils with uterine flushings collected from ovariectomised mares treated with oestradiol, stimulated migration under agarose, whereas flushings from mares treated with progesterone or oily vehicle, inhibited migration. After intra-uterine infusion of bacteria, however, flushings from oestradiol-treated and vehicle-treated mares inhibited migration, whereas progesterone treatment stimulated migration. Migration of uterine-derived neutrophils under agarose was less than that of blood neutrophils and was not influenced by treatment with ovarian steroids. Uterine suscepti...
