Red blood cells (RBCs) in horses are essential components of the circulatory system, responsible for the transport of oxygen from the lungs to tissues and the return of carbon dioxide from tissues to the lungs for exhalation. These cells contain hemoglobin, a protein that binds oxygen, facilitating efficient gas exchange. Equine red blood cells are characterized by their biconcave shape, which increases surface area for gas exchange and allows flexibility as they navigate through capillaries. The lifespan of equine RBCs is approximately 140-150 days, after which they are removed from circulation and broken down, primarily in the spleen. This page compiles peer-reviewed research studies and scholarly articles that explore the physiology, lifespan, and clinical implications of red blood cells in equine health, including their role in conditions such as anemia and their response to exercise and altitude.
Uluisik D, Keskin E, Ozaydın T.Hematological and biochemical profiles commonly are required in equine medicine. We studied hematological parameters including red blood cells (RBC), white blood cells (WBC), hemoglobin (Hb), hematocrit (PCV), differential leukocyte counts, mean cell volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) in thoroughbred foals at different ages and for both sexes. Sixty healthy thoroughbred foals, 1 day, 3 days and 1 year old were used. Each age group consisted of 10 male and 10 female animals. We found significant differences related to age in RBC...
Montgomery JB, Wichtel JJ, Wichtel MG, McNiven MA, McClure JT, Markham F, Horohov DW.The effects of selenium (Se) supplementation and source on equine immune function have not been extensively studied. This study examined the effects of oral Se supplementation and Se source on aspects of innate and adaptive immunity in horses. Fifteen horses were assigned to 1 of 3 groups (5 horses/group): control, inorganic Se (sodium selenite), organic Se (Se yeast). Immune function tests performed included: lymphocyte proliferation in response to mitogen concanavalin A, neutrophil phagocytosis, antibody production after rabies vaccination, relative cytokine gene expression in stimulated lym...
Valdéz-Cruz MP, Hernández-Gil M, Galindo-Rodríguez L, Alonso-Díaz MA.The east coast of Veracruz, Mexico, has an important equine population used for working in rural production systems. The objectives of this study were (1) to calculate the prevalence of tropical working equids (donkeys, mules and horses) infected with gastrointestinal nematodes (GINs) and the GINs involved, and (2) to measure the body condition score (BCS) and haematological values for each working equid and its relationship with faecal worm egg count (EPG). One hundred and forty working equids were randomly selected from five different villages along the central coast of the state of Veracruz...
Hess TM, Rexford JK, Hansen DK, Harris M, Schauermann N, Ross T, Engle TE, Allen KG, Mulligan CM.The objective of this study was to examine the effects of different sources of dietary omega-3 (n-3) fatty acid supplementation on plasma, red blood cell, and skeletal muscle fatty acid compositions in horses. Twenty-one mares were blocked by age, BW, and BCS and assigned to 1 of 3 dietary treatments with 7 mares per treatment. Dietary treatments were: 1) control or no fatty acid supplement (CON), 2) 38 g of n-3 long chain, highly unsaturated fatty acid (LCHUFA) supplement/d provided by algae and fish oil (MARINE) containing alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaen...
Hammond JM, Lee WC, DeNicola DB, Roche J.Automated in-house diagnostic analyzers, most commonly used for hematologic and biochemical analysis, are typically calibrated, and then control materials are used to confirm the quality of results. Although this approach provides indirect knowledge that the system is performing correctly, it does not provide direct knowledge of system performance between control runs. Objective: The objectives of this study were to apply analysis of weighted moving averages to assess performance of hematology analyzers using animal patient samples from dogs, cats, and horses as they were analyzed and apply co...
Muñoz A, Riber C, Trigo P, Castejón F.In order to assess which laboratorial parameters need specific age- and/or gender-related reference values, hematological and biochemical profiles (including hormones) were performed in 205 Spanish foals of 5 groups: A (1-2 months; 20 fillies, 10 colts), B (2-3 months; 24 fillies, 18 colts), C (3-6 months; 25 fillies, 16 colts), D (6-9 months; 20 fillies, 23 colts) and E (9-12 months; 25 fillies, 15 colts). Additionally, 120 adult horses were sampled in order to establish baseline data for this breed in our laboratory. Group E had lower red blood cell number and mean cell volume than B, C and ...
Watts TJ, Handy RD.The haemolytic effect of verapamil on red blood cells (RBCs) exposed to varying osmolarity was investigated. The experimental approach used a modified red cell haemolysis assay with concentrations of verapamil ranging from 50-1500 microM compared to drug free controls. The time-course of haemolytic effects was also investigated. We also briefly determined the haemolytic effects of verapamil in Ca2+-free conditions (with added EGTA). In conditions representing decreasing osmolarity (dilution from 140-0 mM NaCl) there was a significant increase in erythrocyte haemolysis that was also dependent o...
Portier K, Guichardant M, Debouzy JC, Crouzier D, Geraud I, Kirschvink N, Lekeux P, Fellmann N, Coudert J.Whether direct exposure to different concentrations (0%, 13%, 100%) of oxygen may affect horse erythrocyte membrane fluidity (EMF) and fatty acid (FA) composition was studied during 1 (T60) and 2h (T120) exposure. EMF was investigated at the head group level and hydrophobic core thanks to phosphorus nucleus 31 ((31)P) nuclear magnetic resonance ((31)P NMR) and electronic paramagnetic resonance (EPR) using two spin probes: 5-nitroxydestearic acid and 16-doxylstearic acid. Lipid structure of the membranes was studied by gas liquid chromatography. 4-Hydroxy-2E-nonenal was also analyzed as a marke...
Norman TE, Chaffin MK, Johnson MC, Spangler EA, Weeks BR, Knight R.Five horses were evaluated because of severe cutaneous burn injuries following a barn fire. Gross hemolysis and morphologic changes in RBCs consistent with oxidative damage were detected in all of the horses. Of these horses, 4 became azotemic. The overall goals of treatment included wound care, correction of dehydration and provision of diuresis, control of inflammation, pain management, and prophylaxis against sepsis. After treatment, 2 horses survived and were discharged from the hospital. Red blood cell damage and hemolysis following cutaneous burn injury have been investigated in other sp...
Hubert JD, Seahorn TL, Klei TR, Hosgood G, Horohov DW, Moore RM.The objective of this study was to determine the effect of infection with Strongylus vulgaris on serum cytokines and plasma nitric oxide (NO) concentrations in helminth-naive ponies. Group 1 (n = 21) was given 500 S. vulgaris L3 larvae and group 2 (n = 7) received a saline control. Ponies were monitored daily for clinical signs, and blood was collected for complete blood cell counts and serum cytokines (TNF, IL-1, IL-6) quantification. Group 1 ponies were depressed, anorexic, and febrile for variable periods of time. Plasma NO was increased on day 21 in group 1 and on days 9 and 21 in group 2....
Williams CA, Kronfeldt DS, Hess TM, Saker KE, Waldron JN, Crandell KM, Hoffman RM, Harris PA.This study tested the development of oxidative stress and the effects of antioxidant supplementation in an 80-km ride. A precompetition survey revealed that no competitor would participate without vitamin E supplementation; therefore, 46 horses were paired for past performances and randomly assigned to two groups of 23 each for 3 wk of supplementation before the ride. One group (E) was orally supplemented with 5,000 IU of vitamin E per day; the other group (E+C) received that dose of vitamin E plus 7 g/d of vitamin C. Blood samples, temperature, and heart rate were taken the day before the rac...
Golland LC, Evans DL, McGowan CM, Hodgson DR, Rose RJ.Red blood cell hypervolaemia has been used for diagnosis of overtraining in racehorses, and has been suggested as a mechanism of this cause of loss of racing performance. The effects of overload training (OLT) on the plasma, blood and red cell volumes were investigated in a prospective study in 12 Standardbred horses. Measurements of blood volumes were made after eight and 32 weeks of an exercise training study. Horses were randomly allocated to OLT and control groups (n=6) after 16 weeks of training. Training duration and intensity were increased more rapidly for the OLT group from week 16, u...
Allen AL, Myers SL, Searcy GP, Fretz PB.The Hematologic values of 19 equine fetuses between 202 and 238 days gestation were compared with those of their dams. The red blood cell (RBC) count, hemoglobin concentration, hematocrit, and mean corpuscular hemoglobin concentration were significantly lower in fetal blood, while the mean corpuscular volume, mean corpuscular hemoglobin, and red cell distribution width were significantly higher. Mares had a significantly higher nucleated blood cell count than fetuses, and all nucleated cells were leukocytes (WBC). Most WBC in mare blood were segmented neutrophils and lymphocytes. In contrast, ...
Cebulj-Kadunc N, Bozic M, Kosec M, Cestnik V.Haematological parameters [red blood cell count (RBC), white blood cell count (WBC), packed cell volume (PCV), haemoglobin concentration, mean cell volume (MCV), mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC)] in resting Lipizzan horses were determined for 143 stallions, 104 mares and 25 foals. The mean RBC and WBC values in Lipizzans were in the lower part of the normal range for warm-blooded horses. The mean PCV, MCV and MCH values were higher, but the mean haemoglobin concentration and MCHC values were lower than reported for other warm-blooded horses. In foals, ...
The Journal of nutritionJune 4, 2002
Volume 132, Issue 6 Suppl 2 1628S-31S doi: 10.1093/jn/132.6.1628S
Williams CA, Hoffman RM, Kronfeld DS, Hess TM, Saker KE, Harris PA.alpha-Lipoic acid (LA) has demonstrated antioxidant effects in humans and laboratory animals. The objective of this study was to determine whether the effects of LA are similar in horses. Five Thoroughbred geldings were supplemented with 10 mg/kg/d DL-alpha-lipoic acid in a molasses and sweet feed carrier and five received only the carrier as a placebo (CON). Blood samples were obtained at baseline (0 d), after 7 and 14 d of supplementation, and 48 h postsupplementation (16 d). Blood fractions of red and white blood cells (RBC and WBC, respectively) and plasma were analyzed for glutathione (GS...
Arai T, Takahashi M, Araki K, Washizu T.The activities of the enzymes related to the malate-aspartate shuttle, which convert cytosolic NADH into mitochondrial NADH, were measured in red and white blood cells from thoroughbred horses undergoing continuous training (race horses) and compared with those in blood cells from riding horses. The activities of malate dehydrogenase (MDH), a rate-limiting enzyme for the malate-aspartate shuttle, were significantly elevated in the white blood cells (WBC) from race horses compared with those from riding horses. There were no significant differences in the activities of the enzymes in the red bl...
Langsetmo I, Meyer MR, Erickson HH.Exercise-induced pulmonary haemorrhage (EIPH) is characterised by blood in the airways after strenuous exercise and results from stress failure of the pulmonary capillaries. The purpose of this experiment was to establish a threshold value of transmural pulmonary arterial pressure at which haemorrhage occurs in the exercising horse. Five geldings, age 4-14 years, were run in random order once every 2 weeks at 1 of 4 speeds (9, 11, 13, 15 m/s); one day with no run was used as a control. Heart rate, pulmonary arterial pressure and oesophageal pressure were recorded for the duration of the run. T...
Sweeney CR, Russell GE.To examine total protein concentration and cell counts of sequentially collected samples of CSF to determine whether blood contamination decreases in subsequent samples and whether formulas used to correct nucleated cell count and total protein concentration are accurate. Methods: Case series. Methods: 22 horses. Methods: For each horse, 3 or 4 sequential 2-ml samples of CSF were collected from the subarachnoid space in the lumbosacral region into separate syringes, and blood was obtained from the jugular vein. Total protein concentration, nucleated cell count, and RBC counts were determined i...
Persson SG, Osterberg I.The association between red blood cell hypervolaemia (RCHV) and racing performance was examined in 116 Standardbred trotters referred to the clinic during a 5 year period with histories of impaired racing performance. Red cell hypervolaemia was the only significant abnormality detected in a thorough clinical examination, cell volumes ranging 116-178% of the predicted normal values. They were also compared with the performance traits of the contemporary Swedish Standardbred trotter population (n = 58,058). The performance traits were based on earnings per year and start, best annual racing time...
Walton RM, Brown DE, Hamar DW, Meador VP, Horn JW, Thrall MA.Transient echinocytosis has been reported in association with snake envenomation in humans and dogs. An in vitro model of echinocytosis induced by venom of crotalus atrox (western diamondback rattlesnake) was established to characterize erythrocyte morphologic changes and to investigate potential mechanisms of echinocytic transformation. Erythrocyte morphologic changes produced after the addition of venom to canine, feline, equine, and human blood were characterized by dose-dependent echinocytosis. Type III echinocytosis were consistently induced in vitro at a dose comparable to in vivo enveno...
Speake PF, Gibson JS.The effect of urea and its interactions with oxygen tension (PO2), cell volume and inhibitors of protein phosphatases/kinases (PP/PK) on the K influx into equine red blood cells were studied. K influx was measured using 86Rb as a radioactive tracer for K. As in other species, Cl-dependent K influxes were stimulated by urea, with peak fluxes occurring at about 750 mM. This effect was not mediated via changes in cell volume or following formation of cyanate, the hydrolysis product of urea. Stimulation by urea was prevented by pre-treatment with calyculin A (100 nM) at all urea concentrations tes...
Mills PC, Smith NC, Harris RC, Harris P.Allopurinol was administered to six horses in a cross-over study to determine the relative contribution of xanthine oxidase (XO) activity to the formation of reactive oxygen species (ROS) in the horse during intense exercise. Exercise increased the mean (SEM) plasma lipid hydroperioxide concentration to a maximum of 492.7 (33.4) microM within one minute of exercise completion and maximum levels of both oxidised glutathione (GSSG) in haemolysates of red blood cells and the glutathione redox ratio (GRR) occurred 20 minutes after exercise (87.2 [12.2] microM and 8.9 [0.9] per cent, respectively)....
Souillard A, Audran M, Bressolle F, Jaussaud P, Gareau R.The pharmacokinetics of recombinant human Epo (rHuEpo) were investigated after subcutaneous administration to horses. Four horses received a single 30IU kg-1 dose of rHuEpo. One horse received three repeated doses of 120 IU kg-1 at 48 h intervals. Plasma erythropoietin (Epo) was measured by radioimmunoassay. In both cases pharmacokinetic parameters were evaluated using a one-compartment open model and first-order input and output rates. The mean values (+/-SD) for elimination half-life, CL/F, and Vd/F after a single dose were 12.9 +/- 3.34 h, 11.8 +/- 4.96 L h-1, and 233 +/- 126 L, respectivel...
Escribano BM, Castejon FM, Santisteban R, Aguera EI, Rubio MD.A study has been made of the variations experienced by the hemogram and blood volume indices in 16 Andalusian horses after carrying out an exercise test of increasing intensity consisting of 3 sequences of 1000 m each, before and after being subjected to a daily exercise programme for two months. Samples were taken by external jugular vein puncture: while at rest, within the first minute of finalizing each exercise stage and at 10 and 15 minutes of recovery. Both the red blood cells and the hematocrit value showed a significant decrease in their mean values after two months training; conversel...
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...
Rubio MD, Muñoz A, Santisteban R, Tovar P, Castejón FM.Exercise-induced hematological alterations were studied in 20 four-year old foals, 11 Andalusian and 9 Arabian. They were subjected to a test exercise program consisting of 4 levels of gradually increasing intensity (15, 20, 25 and 30 km/hr) with a duration of 5 min each. Blood samples were taken during resting, after each exercise level and at 10 and 30 min of recovery from exercise. The following hematic parameters were analyzed: red blood count, hematocrit value, hemoglobin, volumetric indexes (MCV, MCH and MHCH) and total plasma proteins. The alterations as a result of the physical effort ...
Schott HC, Hodgson DR, Bayly WM.The effects of exercise on urinary excretion of red blood cells, pigments (haemoglobin and myoglobin) and protein were studied in 8 mares performing treadmill exercise at speeds eliciting 40, 60 and 95% of the maximal oxygen consumption (VO2max). Gross haematuria and pigmenturia were observed in all horses during exercise at the 2 higher intensities, while these findings were detected in only one of 8 mares during exercise at 40% of the VO2max. For the remaining 7 mares exercised at 40% of the VO2max, increased urinary excretion of red blood cells (RBCs) and pigments was evident after centrifu...
Stockham SL, Harvey JW, Kinden DA.Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a well-characterized X-linked inherited disorder in humans but has not been reported in horses. We describe a persistent hemolytic anemia and hyperbilirubinemia due to a severe G6PD deficiency in an American Saddlebred colt. Other abnormalities in the colt's erythrocytes as compared with those of healthy horses (n = 22-35) included increased activities of hexokinase and pyruvate kinase, decreased concentrations of reduced glutathione and reduced nicotinamide adenine dinucleotide phosphate (NADP), and increased concentration of oxidized NAD...
Furr MO, Bender H.To determine the effects of age on each analyte, CSF variables were evaluated in healthy foals from birth through 42 days of age. Cerebrospinal fluid was collected from 14 clinically normal, naturally delivered cross-bred foals and was analyzed for glucose, sodium, potassium, magnesium, and total protein concentrations, total and differential WBC counts, RBC count, and lactate dehydrogenase, aspartate transaminase, and creatine kinase activities. Samples were collected in 3 foals < 48 hours old, and at 11 to 14 days of age in 4 foals, 21 to 22 days of age in 3 foals, and 31 to 42 days of ag...
Weaver BM, Staddon GE, Pearson MR.The blood content of tissue in eight anaesthetized sheep and three anaesthetized horses was measured using chromium labelled autologous red blood cells. 2. Approximately half the total blood volume was found to be distributed within the body tissues and, with the exception of the spleen and fat, the distribution was similar in these two species.
Kędzierski W, Janczarek I, Kowalik S, Jamioł M, Wawak T, Borsuk G, Przetacznik M.In humans and animals, aging leads to a decrease in immune function and an increased susceptibility to infection. Decreased immunity and an increase in the incidence of infectious diseases are particularly notable during the autumn. Bee pollen supplementation improves immunity and antioxidant enzyme activity, as well as general performance. The aim of this study was to evaluate the effects of bee pollen supplementation during the autumn on blood parameters in aged horses. The study was performed on 16 warmblood horses aged 15-26 years. Half of this group received 60 g of bee pollen (soaked i...
Spensley MS, Carlson GP, Harrold D.During the growth interval encompassing age 2 days through 24 weeks, plasma, RBC, total blood, and extracellular fluid (ECF) volumes were determined in 7 healthy, resting foals. Evans blue dye and sodium thiocyanate were used to estimate plasma and ECF volumes, respectively. Absolute plasma volume remained stable from 2 days through 2 weeks of age, then increased progressively through 24 weeks of age. After decreasing between 2 days and 2 weeks of age, absolute RBC and total blood volumes progressively increased. Absolute ECF volume increased progressively from 2 days of age through 24 weeks o...
Uluisik D, Keskin E, Ozaydın T.Hematological and biochemical profiles commonly are required in equine medicine. We studied hematological parameters including red blood cells (RBC), white blood cells (WBC), hemoglobin (Hb), hematocrit (PCV), differential leukocyte counts, mean cell volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) in thoroughbred foals at different ages and for both sexes. Sixty healthy thoroughbred foals, 1 day, 3 days and 1 year old were used. Each age group consisted of 10 male and 10 female animals. We found significant differences related to age in RBC...
Furr MO, Bender H.To determine the effects of age on each analyte, CSF variables were evaluated in healthy foals from birth through 42 days of age. Cerebrospinal fluid was collected from 14 clinically normal, naturally delivered cross-bred foals and was analyzed for glucose, sodium, potassium, magnesium, and total protein concentrations, total and differential WBC counts, RBC count, and lactate dehydrogenase, aspartate transaminase, and creatine kinase activities. Samples were collected in 3 foals < 48 hours old, and at 11 to 14 days of age in 4 foals, 21 to 22 days of age in 3 foals, and 31 to 42 days of ag...
Gill J, Rastawicka M.In 8 stallions and 6 mares of pure Arabian horses the diurnal changes in the number and certain parameters of red and white blood cells were studied. All of them showed distinct diurnal changes but they did not fulfill the conditions of circadian rhythm according to Halberg. It was found that most of peaks occurred during the dark phase of 24 hr period except the percentage of eosinophils, erythrocyte diameters and cell rate sedimentation. The majority of indices studied showed the higher mean diurnal levels in the mares than in the stallions.
The Journal of nutritionJune 4, 2002
Volume 132, Issue 6 Suppl 2 1628S-31S doi: 10.1093/jn/132.6.1628S
Williams CA, Hoffman RM, Kronfeld DS, Hess TM, Saker KE, Harris PA.alpha-Lipoic acid (LA) has demonstrated antioxidant effects in humans and laboratory animals. The objective of this study was to determine whether the effects of LA are similar in horses. Five Thoroughbred geldings were supplemented with 10 mg/kg/d DL-alpha-lipoic acid in a molasses and sweet feed carrier and five received only the carrier as a placebo (CON). Blood samples were obtained at baseline (0 d), after 7 and 14 d of supplementation, and 48 h postsupplementation (16 d). Blood fractions of red and white blood cells (RBC and WBC, respectively) and plasma were analyzed for glutathione (GS...
Escribano BM, Molina A, Valera M, Tovar P, Agüera EI, Santisteban R, Vivo R, Agüera S, Rubio MD.The novel aim of this study was to describe the reference values of different haematological and biochemical parameters in the Spanish purebred horse (Andalusian, SPB) in each of the stages of a programmed exercise on a treadmill system, and to establish heritability and genetic correlations for these haematological and biochemical parameters. For this, 94 young SPB male horses (4.22 ± 2.27 years old) were used. An increasing intensity exercise test at 4, 5, 6 and 7 m/s was carried out on a treadmill (6% inclination). Total red blood cells, total white blood cells, neutrophils and lymphocytes...
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...
Roberts MC.Vitamin B12 and folate concentrations were determined by radioimmunoassay in groups of horses in Queensland. Highest serum vitamin B12 levels were found in supplemented performance horses. These, together with pastured horses that included pregnant and lactating mares, had significantly greater serum folate activity than permanently stabled animals. The range of red cell folate concentrations was much narrower in horses in training than from any other group. Red cell folate may be a better indicator of a horse's folate status than the serum folate value. Vitamin B12 and folate concentrations w...
Kalantari M, Sharifiyazdi H, Ghane M, Nazifi S.Hemotropic mycoplasmas (haemoplasmas) are wall-less bacteria, which may lead to anemia and, even, mortality in mammals. The present study was aimed to characterize the causative agent(s) of haemoplasma infection in blood samples taken from horses (n = 133) in south of Iran. Microscopic examination of blood smears and PCR assay were performed for the detection of hemotropic Mycoplasma and equine piroplasma (Babesia caballi and Theileria equi). For the purpose of molecular characterization, 16S rDNA and 18S rDNA markers were used for hemotropic Mycoplasma and piroplasma pathogens, respective...
Rifkind JM.The reduced glutathione in the erythrocyte was found to inhibit the autoxidation of purified horse hemoglobin. It was observed that much higher concentrations of oxidized glutathione also stabilize hemoglobin. The stabilization by oxidized glutathione most likely involves the formation of a mixed disulfide with the reactive β-93 sulfhydryl groups on the hemoglobin. A similar effect is also observed with N-ethyl- maleimide and HgCl2 which also react with the sulfhydryl groups. The apparent stabilization by reduced glutathione is partially due to the reduction of ferrihemoglobin formed by autox...
Willett K, Blackmore DJ.A method is described for the measurement of haptoglobin in equine serum using the peroxidase activity of the haemoglobin-haptoglobin complex. The problems of interference with Fe2+ and Fe3+ ions are described. Normal values for haptoglobin in 629 blood samples from thoroughbreds in training are presented showing a log normal distribution with a 5 per cent to 95 per cent range of 0.42 to 1.7 g/litre. There was no consistent alteration in haptoglobin concentration throughout the season in spite of a change in red cell size and total bilirubin concentration. It is concluded that the measurement ...
Errecalde JO, Button C, Mülders MS.A single intravenous administration of theophylline as aminophylline at 10 mg/kg to four mares induced a diuresis in which maximal urine production was more than seven times the control volume. The diuretic effect was maximal within the first hour post-administration, and lasted approximately 6 h. Theophylline resulted in dose-related tachycardia, polypnoea and nervous symptoms (tactile, visual and auditory hypersensitivity, muscle tremor, sweating) in normal mares, but had only minor effects on arterial and central venous blood pressures, intrapleural pressure, red blood cell variables and pl...
Patterson SD, Auer D, Bell K.The induction of an acute phase response in four horses by adjuvant administration was used to examine the effect on the levels of plasma proteins. Blood parameters (packed cell volume, total plasma protein, red blood cell count, haemoglobin concentration) were monitored to follow the progress of the acute phase response in parallel with the examination of plasma proteins. Plasma protein levels were determined by densitometry from the electrophoretic patterns of three different gel systems. Haptoglobin and alpha 1 B glycoprotein were shown to be positive acute phase reactants whereas albumin w...
Magdesian KG, Barnum S, Pusterla N. and cause significant morbidity and mortality in foals. Antemortem diagnosis of infection has been complicated by a paucity of tests available for toxin detection. Fecal PCR panels have assays for a variety of toxin gene sequences as well as for several other foal gastrointestinal pathogens. We evaluated results of a comprehensive fecal diarrhea PCR panel in 28 foals that had been presented to a referral hospital because of diarrhea. Sixteen (57%) foals were positive for and/or toxin gene sequences on fecal PCR, including 3 foals positive for NetF toxin. These foals were younger ( = ...
da Conceição FFCB, de Mattos BHV, Sá PA, Marçola TG, da Silva GA, Teixeira HCA, Campebell RC.Due to the scarcity of information on Breton horses, the objective was to study hematobiochemical values of this breed. Blood samples were collected from 29 Bretons, males and females, of different ages, in Brasília-DF, distributed into groups, according to age, without distinction of sex (G1): animals from 4 to 9 years old (n=16) and (G2): from 10 to 26 years old (n=13). The horses were also distributed into males and females for comparisons between the sexes. Values for red blood cells, hemoglobin, creatinine, and urea were statistically higher in females. Fibrinogen was higher in males. Ly...
Hubert JD, Seahorn TL, Klei TR, Hosgood G, Horohov DW, Moore RM.The objective of this study was to determine the effect of infection with Strongylus vulgaris on serum cytokines and plasma nitric oxide (NO) concentrations in helminth-naive ponies. Group 1 (n = 21) was given 500 S. vulgaris L3 larvae and group 2 (n = 7) received a saline control. Ponies were monitored daily for clinical signs, and blood was collected for complete blood cell counts and serum cytokines (TNF, IL-1, IL-6) quantification. Group 1 ponies were depressed, anorexic, and febrile for variable periods of time. Plasma NO was increased on day 21 in group 1 and on days 9 and 21 in group 2....
Norman TE, Chaffin MK, Johnson MC, Spangler EA, Weeks BR, Knight R.Five horses were evaluated because of severe cutaneous burn injuries following a barn fire. Gross hemolysis and morphologic changes in RBCs consistent with oxidative damage were detected in all of the horses. Of these horses, 4 became azotemic. The overall goals of treatment included wound care, correction of dehydration and provision of diuresis, control of inflammation, pain management, and prophylaxis against sepsis. After treatment, 2 horses survived and were discharged from the hospital. Red blood cell damage and hemolysis following cutaneous burn injury have been investigated in other sp...
Persson SG, Osterberg I.The association between red blood cell hypervolaemia (RCHV) and racing performance was examined in 116 Standardbred trotters referred to the clinic during a 5 year period with histories of impaired racing performance. Red cell hypervolaemia was the only significant abnormality detected in a thorough clinical examination, cell volumes ranging 116-178% of the predicted normal values. They were also compared with the performance traits of the contemporary Swedish Standardbred trotter population (n = 58,058). The performance traits were based on earnings per year and start, best annual racing time...
Frohlich M, Knights K, Springer NL.Differentiating immune-mediated causes from other causes of anemia and thrombocytopenia can be challenging. Flow cytometry can detect surface-associated immunoglobulin (sIg) on red blood cells (RBC) and platelets (PLT) in dogs and horses. Sample storage parameters for ideal assay performance has not been evaluated in horses. The study objective is to identify optimal storage time and temperature of equine whole blood for the detection of RBC-sIg and PLT-sIg via flow cytometry. Both assays were performed on samples at time 0, 4, 24, 48, and 72 h post collection. RBC-sIg samples were stored at ...
Geor RJ, Lund EM, Weiss DJ.Retrospective review of CBC and serum chemical data from 124 horses admitted to the veterinary teaching hospital over a 9-month period (Feb 1, 1990 to Oct 31, 1990) indicated that 54 horses had echinocytosis (prevalence = 44%). In horses with echinocytosis, the most frequent diagnosis was colitis (23 horses; 43%). Odds ratios (measure of association) were calculated to determine the association of echinocytosis with specific hematologic and biochemical abnormalities. When evaluated in a multivariate model, low serum sodium concentration (< 136 mEq/L) was the only variable significantly associa...
Watts TJ, Handy RD.The haemolytic effect of verapamil on red blood cells (RBCs) exposed to varying osmolarity was investigated. The experimental approach used a modified red cell haemolysis assay with concentrations of verapamil ranging from 50-1500 microM compared to drug free controls. The time-course of haemolytic effects was also investigated. We also briefly determined the haemolytic effects of verapamil in Ca2+-free conditions (with added EGTA). In conditions representing decreasing osmolarity (dilution from 140-0 mM NaCl) there was a significant increase in erythrocyte haemolysis that was also dependent o...
Souillard A, Audran M, Bressolle F, Jaussaud P, Gareau R.The pharmacokinetics of recombinant human Epo (rHuEpo) were investigated after subcutaneous administration to horses. Four horses received a single 30IU kg-1 dose of rHuEpo. One horse received three repeated doses of 120 IU kg-1 at 48 h intervals. Plasma erythropoietin (Epo) was measured by radioimmunoassay. In both cases pharmacokinetic parameters were evaluated using a one-compartment open model and first-order input and output rates. The mean values (+/-SD) for elimination half-life, CL/F, and Vd/F after a single dose were 12.9 +/- 3.34 h, 11.8 +/- 4.96 L h-1, and 233 +/- 126 L, respectivel...
Portier K, Guichardant M, Debouzy JC, Crouzier D, Geraud I, Kirschvink N, Lekeux P, Fellmann N, Coudert J.Whether direct exposure to different concentrations (0%, 13%, 100%) of oxygen may affect horse erythrocyte membrane fluidity (EMF) and fatty acid (FA) composition was studied during 1 (T60) and 2h (T120) exposure. EMF was investigated at the head group level and hydrophobic core thanks to phosphorus nucleus 31 ((31)P) nuclear magnetic resonance ((31)P NMR) and electronic paramagnetic resonance (EPR) using two spin probes: 5-nitroxydestearic acid and 16-doxylstearic acid. Lipid structure of the membranes was studied by gas liquid chromatography. 4-Hydroxy-2E-nonenal was also analyzed as a marke...
Schumacher J, Schumacher J, Spano JS, McGuire J, Scrutchfield WL, Feldman RG.Twenty-four clinically normal horses were castrated by routine methods. Peritoneal fluid was collected prior to castration and at 1, 3, 5, and 7 days postcastration. Peritoneal fluid was collected on days 9 and 11 if nucleated cell (NC) counts were still markedly elevated on day 7. Peritonitis, defined as NC counts greater than 10,000/microliters, was evident in 15 horses following castration. Mean NC counts peaked on day 5 but were less than 10,000/microliters for 74% of the horses by day 7, and 90% of the horses by day 9. One horse had a NC count greater than 60,000/microliters on day 11 whe...
Hammond JM, Lee WC, DeNicola DB, Roche J.Automated in-house diagnostic analyzers, most commonly used for hematologic and biochemical analysis, are typically calibrated, and then control materials are used to confirm the quality of results. Although this approach provides indirect knowledge that the system is performing correctly, it does not provide direct knowledge of system performance between control runs. Objective: The objectives of this study were to apply analysis of weighted moving averages to assess performance of hematology analyzers using animal patient samples from dogs, cats, and horses as they were analyzed and apply co...
Feringer-Júnior WH, de Carvalho JRG, Moranza HG, de Almeida MLM, Lemos EGM, Soares OAB, Ribeiro G, de Camargo Ferraz G.Cost of transport (COT) and monocarboxylate transporters (MCTs) could affect the ability to perform fast actions during a jumping discipline. This study aimed to compare the COT and evaluate the MCT1, MCT4, and their auxiliary protein CD147 content in the gluteus medius and RBCs of Brazilian sport horses (BH), a breed developed for jumping competitions, with low-level (LL) or intermediate-level (IL) jumping capacities. The physiological difference between the horses was assessed by an incremental jump test (IJT), in which the cost of lactate (COT) and heart rate (COT) of running were determine...
