Leukocytes, also known as white blood cells, are an integral component of the equine immune system, responsible for defending horses against infections and foreign substances. These cells are produced in the bone marrow and circulate throughout the bloodstream and tissues. In horses, leukocytes are categorized into several types, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils, each with specific functions in immune response. Neutrophils are involved in phagocytosis and the destruction of pathogens, while lymphocytes are key players in adaptive immunity. Monocytes differentiate into macrophages and dendritic cells, contributing to pathogen clearance and antigen presentation. Eosinophils and basophils are associated with allergic reactions and parasitic infections. Variations in leukocyte counts and distribution can indicate underlying health conditions, making them valuable in veterinary diagnostics. This page aggregates peer-reviewed research studies and scholarly articles that explore the physiology, function, and diagnostic relevance of leukocytes in equine health.
Edington N, Bridges CG, Huckle A.Eight ponies were experimentally infected with equid herpesvirus 1 (EHV 1) (subtype 1). All animals showed clinical and serological evidence of infection and virus was isolated from nasal swabs and leucocytes. These ponies were kept in isolation for a further three months during which time complement fixing antibody decreased at least four-fold. Following immunosuppression with dexamethasone and prednisolone subtype 1 virus was recovered from six of the eight animals within 14 days. Five of these six ponies were viraemic and three of them shed virus in nasal secretions; only four displayed sig...
Rikihisa Y, Perry BD.An ehrlichia was consistently isolated from the peripheral blood leukocyte fraction of ponies that had been experimentally infected with Potomac horse fever by whole blood transfusion from naturally infected horses. The organism was propagated in a human histiocyte cell line for 3 to 5 weeks and then inoculated intravenously or intradermally into healthy adult ponies. Clinical signs of Potomac horse fever, which varied in the degree of severity, occurred 9 to 14 days post-inoculation in all of the ponies. One pony died 20 days post-inoculation. The ehrlichial organism was reisolated in the hum...
Cheung AT, Liu IK, Walsh EM, Miller ME.The host defense competence of uterine-derived polymorphonuclear leukocytes (PMN) from mares considered resistant (grade I uteri) and susceptible (grade III uteri) to chronic endometritis was evaluated for phagocytic and killing (bactericidal) capacities, using a fluorochrome assay. Peripheral blood PMN from noncategorized mares and from grade I and grade III mares were used as controls. Uterine-derived PMN from mares with grade I uteri were functionally competent for phagocytosis and killing of Candida albicans, whereas uterine-derived PMN from mares with grade III uteri had significantly les...
Matthews SM.Leucocyte antigens are cell-surface glycoproteins, the structure of which is under the genetic control of a chromosome region called the major histocompatibility complex. Progress in the study of the equine leucocyte antigen (ELA) system has been achieved in two ways; first by the fact that the ELA system is intensively investigated in different laboratories all over the world and parallels can be drawn to the information gained from research in more extensively studied species, and secondly by the collaborative efforts of the participants in three international workshops. The potential applic...
Lazary S, Gerber H, Glatt PA, Straub R.The distribution of equine leucocyte antigens (ELA) in horses affected by equine sarcoid tumours was determined and compared with unaffected controls. ELA-haplotype W3,B1 occurred more frequently in affected riding horses of Irish, Swiss and French background. The combined data for the three breeds resulted in a chi 2 value of 20.35 (P less than 0.0005 after correction). Simultaneously, ELA-specificity W11 was more frequently found in horses of Irish background, while W5 was found in Swiss and French horses with sarcoids. The combined data for haplotype W3,B1 and/or W5 specificity demonstrated...
Wimberly HC, Slauson DO, Neilsen NR.Antigen-specific challenge of equine leukocytes induced the non-lytic release of a platelet-activating factor in vitro. The equine platelet-activating factor stimulated the release of serotonin from equine platelets in a dose-responsive manner, independent of the presence of cyclo-oxygenase pathway inhibitors such as indomethacin. Rabbit platelets were also responsive to equine platelet-activating factor. The release of equine platelet-activating factor was a rapid reaction with near maximal secretion taking place in 30 seconds. Addition of equine platelet-activating factor to washed equine pl...
Koblik PD, Lofstedt J, Jakowski RM, Johnson KL.Indium 111-labeled autologous leukocytes were used to image an abdominal abscess in a horse with a palpable abdominal mass and history of Streptococcus equi infection. A focal area of radioactivity was identified in the location corresponding to the abscess. Imaging of this focal uptake was optimal 48 hours after injection. Similar scans obtained in 2 clinically normal horses revealed no evidence of focal radioactivity in this region. The cell labeling procedure gave acceptable labeling efficiency (87.5%) but an excessive number of damaged WBC, resulting in persistent lung radioactivity on all...
Duncan SG, Meyers KM, Reed SM, Grant B.This experiment was designed to establish a model for the study of gastrointestinal disturbances as a result of prolonged endotoxin uptake in the horse. The hepatic portal vein of 7 horses was catheterized (through flank incisions) to give chronic hepatic portal infusions of lipopolysaccharide (LPS, endotoxin). Lipopolysaccharide was infused at a rate of 1 microgram/kg of body weight/hr for 24 hours. Two of the horses were infused with saline solution for 12 hours before LPS infusions were given. Lipopolysaccharide was shown to affect behavior and hematologic and coagulation values. The 1st ho...
Liu IK, Cheung AT, Walsh EM, Miller ME, Lindenberg PM.The functional competence of peripheral blood and uterine-derived polymorphonuclear leukocytes (PMN) from 12 mares were analyzed for chemotactic responsiveness using a chemotactic chamber (filter) assay and for deformability by cell elastimetry analysis. Peripheral blood PMN obtained from control mares and from 8 mares experimentally inoculated via the uterus with 1 x 10(9) Streptococcus zooepidemicus had similar normal chemotactic responsiveness and were highly deformable before and at 12 hours after inoculation. Uterine PMN obtained 12 hours after uterine inoculation with S zooepidemicus fro...
Turek JJ, Templeton CB, Bottoms GD, Fessler JF.Endotoxic shock was induced in 5 ponies by intraperitoneal injections of 20, 40, 60, 80, and 80 micrograms of Escherichia coli endotoxin (LPS)/kg of body weight at 0, 6, 12, 18, and 24 hours, respectively. At 24 hours, the ponies also were given 20 micrograms of LPS/kg via catheter in the left ventricle of the heart. A 2nd group of 4 ponies was given 1.1 mg of flunixin meglumine (FM)/kg, IV, at 6, 12, 18, and 24 hours just before the corresponding LPS injection. Two hours after the 24-hour LPS injection, the ponies in both groups were anesthetized, the lungs were perfused with fixative, and po...
Ostlund C, Pero RW, Johnson DB.This study compares the relationship between N-acetoxy-2-acetylaminofluorene (NA-AAF) and u.v. induced unscheduled DNA synthesis (UDS) and their respective relationships to age and blood pressure in horse mononuclear leukocytes with earlier, similar investigations on human leukocytes. U.v. induced UDS was found to proceed more rapidly than NA-AAF induced UDS. A pronounced lag period associated with the rapid demand for 3H-dThd into DNA after u.v. damage was observed. NA-AAF induced UDS correlated significantly with NA-AAF binding, age and the blood pressure of male horses. UDS values, induced ...
Dubin A, Potempa J, Silberring J.Horse leucocyte neutral proteinase inhibitor reacts with all tested elastases at the molar ratios of 1:1 and yielding stable complexes (Ki = 10(-10) M). The above reactions are very rapid, characterized by the high values of association rate constant kon = 10(7) M-1s-1.
Gill J, Kompanowska-Jezierska E, Jakubow K, Kott A, Szumska D.In 34 pure-breed Arabian horses divided into four groups (Gr. I, ten pregnant mares; Gr. II, seven barren mares; Gr. III, ten foals born in 1981; Gr. IV, seven foals born in 1982) seasonal changes in the white blood cell system, cortisol level and lyzozyme activity were studied. Seasonal periodicity was found in all groups for the number of lymphocytes, segmented neutrophils and eosinophils and cortisol level. Leukocyte periodicity was found in three groups, but not in the barren mares. In lyzozyme activity there was periodicity in three groups but not in the youngest foals. In the stab neutro...
Bottoms GD, Johnson MA, Lamar CH, Fessler JF, Turek JJ.Dispersed equine vascular endothelial cells grown in tissue culture, and freshly isolated neutrophils were used to determine direct effects of endotoxin on cyclooxygenase and lipoxygenase products. Endothelial cells (10(7)/ml) or neutrophils (2 X 10(6)/ml) were incubated with (a) buffer, (b) endotoxin (10 micrograms/ml), (c) endotoxin + flunixin meglumine (10 micrograms/ml), or (d) calcium ionophore, A23187 (10 micrograms/ml). Thromboxane (TxB2), prostacyclin (6-keto-PGF1 alpha), and leukotriene C4 (LTC4) were determined in the incubation fluid by radioimmunoassay. Thromboxane and prostacyclin...
Bertram TA.Differences in neutrophil morphology between various species of domestic animals are evident when morphometric techniques are used. Morphometric analysis can be coupled with functional assays of degranulation to demonstrate changes in granule volume after neutrophil activation (Bertram and Jensen, 1984). Morphometric and functional analysis of the neutrophil can also be used to evaluate the response of neutrophils to infectious agents (Coignoul et al., 1984a). Comparison of these assays between animal species may provide insight into the susceptibility of animals to various microbial pathogens...
Ewert KM, Fessler JF, Templeton CB, Bottoms GD, Latshaw HS, Johnson MA.To evaluate the effect of certain drugs on hematologic changes, blood chemical values, and survival in endotoxin shock, anesthetized ponies were given (IV) endotoxin (Escherichia coli O55:B5) and then treated as follows: Group A ponies--given a saline infusion at 5 minutes and at 3 hours after they were given endotoxin; group B ponies--given flunixin meglumine at 5 minutes and at 3, 6, 9, and 24 hours after they were given endotoxin; group C ponies--treated with dexamethasone; and group D ponies--treated with prednisolone at 5 minutes and at 3, 9, and 24 hours after they were given endotoxin. ...
Broström H, Hellström U, Ziverts I, Obel N, Perlmann P.In a preceding report we have shown that the lectin Helix pomatia A hemagglutinin (HP) binds to two subpopulations of neuraminidase-treated equine peripheral blood lymphocytes (PBL), constituting about 20% and 75% of PBL, respectively. The aim of the present study was to further characterize these HP+ cells in regard to other surface markers such as receptors for guinea pig erythrocytes (GPR+ cells), membrane-bound immunoglobulins (sIg+ cells), receptors for activated complement (C3R+ cells) and receptors for IgG (Fc alpha R+ cells). This was done by double marker analysis and by lymphocyte fr...
Lees P, Higgins AJ.A model of acute inflammation was used in a cross-over study in Welsh mountain ponies to assess the actions of flunixin meglumine on selected components of a localised inflammatory reaction induced by injecting 0.5 ml of a 2 per cent carrageenin solution into subcutaneously implanted tissue cages. Samples of exudate were harvested at predetermined times between three and 48 hours. Increases in leucocyte numbers and protein concentration were not prevented by flunixin treatment. Prostaglandin E2-like activity was present in exudates from untreated ponies with the highest mean concentration occu...
Coignoul FL, Bertram TA, Cheville NF.Three pony mares and 4 pony foals were inoculated with a subtype 2 strain of equine herpesvirus 1. Foals had periods of fever 12 h and 2.5 days after inoculation and leukopenia, involving both neutrophils and lymphocytes, followed by leukocytosis. Mares had transient fever and leukopenia 24 hours after inoculation that were less severe than in foals. An increase in circulating virus-neutralizing antibody was seen in 2 of 3 inoculated mares, but not in foals. Attempts to isolate virus from blood were unsuccessful. These studies show that equine herpesvirus 1 subtype 2 is a mild pathogen for pon...
Coignoul FL, Bertram TA, Cheville NF.Neutrophils isolated from venous blood of adult and foal ponies inoculated with equine herpesvirus-1 were evaluated by in vitro function tests and by electron microscopy. Foals had fever and severe neutropenia 24 hours after inoculation; increased neutrophil random migration under agarose and decreased antibody-dependent cell-mediated cytotoxicity were significant at 24 hours, but values had returned to preinoculation levels by 72 hours. Mares had fever and leukopenia of less severity, increases in neutrophil migration, and longer persistence of primary granule release than were seen in foals....
Ellenberger MA, Kaeberle ML, Roth JA.A procedure was developed for isolating large numbers of purified polymorphonuclear leukocytes (PMNs) from the peripheral blood of horses. Equine PMN function was evaluated by three procedures: 1) Staphylococcus aureus ingestion, 2) nitroblue tetrazolium reduction, and 3) iodination. Four preparations of R. equi were added to polymorphonuclear leukocytes (PMNs) in each test system. Live bacteria, heat-killed bacteria, the washed pellet from heat-killed bacteria, and the supernatant fluid from heat-killed bacteria were evaluated for effects on equine PMN function. None of the R. equi preparatio...
Higgins AJ, Lees P, Taylor JB.In a two part cross-over experiment, acute inflammatory exudates were induced in 7 ponies by subcutaneous implantation of 3 sterile carrageenin-soaked polyester sponge strips. Treatment comprised a single therapeutic geenin-soaked polyester sponge strips. Treatment comprised a single therapeutic dose of 4.4 mg/kg phenylbutazone (PBZ) administered intravenously at the time of sponge implantation. Exudates were harvested at 6, 12 and 24 hours and examined for leukocyte and erythrocyte numbers using the improved Neubauer technique; for eicosanoids by radioimmunoassay and by high performance liqui...
Harvey JW, Asquith RL, McNulty PK, Kivipelto J, Bauer JE.Packed cell volume, haemoglobin concentration, erythrocyte counts, erythrocyte indices, serum iron, iron binding capacities, total and differential leucocyte counts, platelet counts, total plasma protein, fibrinogen, haptoglobin and icterus index values were determined at 14 different ages in eight Thoroughbred and 14 Quarterhorse foals during the first year of life. Absolute neutrophil numbers in blood decreased and lymphocyte numbers increased during the first months. Absolute eosinophil numbers tended to increase until three months old. Haemoglobin concentration and packed cell volume decre...
Burkhardt E, von Saldern F, Huskamp B.On clinical examination, a six-year-old Hassian gray gelding with a history of impaired performance, slight cough, colic, and edema of the ventral abdomen, prepuce and the legs had reduced skin turgor, pale mucous membranes, forced costoabdominal breathing, reduced venous return, enlarged lymph nodes, and splenomegaly. Hematologic findings revealed anemia, leukocytosis and a high percentage of monocytoid leukemic cells. Generalized lymphadenopathy, splenomegaly, ascites, hydrothorax, and a diffusely thickened gut wall were found at necropsy. Massive infiltration with monocytoid leukemic cells ...
Higgins AJ, Lees P, Wright JA.In a series of experiments to examine equine inflammatory exudates for the presence of metabolites of arachidonic acid, including prostaglandin E2 (PGE2), a model for the induction and collection of exudates in ponies has been developed. Multiperforated polypropylene practice golf balls implanted subcutaneously in the mid-neck region were well tolerated and proved to be the most successful model. One such cage was implanted in the neck of each of seven ponies. Inflammatory exudates were induced by injecting 3.0 or 0.5 ml carrageenin into the cages and aspirates collected between three and 48 h...
Allen BV, Kane CE, Powell DG.Total and differential leucocyte counts have been determined by electronic counting techniques in 474, two-to-four-year-old healthy Thoroughbreds in training. The ranges of values observed (particular those for neutrophils and lymphocytes) were narrower than previously described. Absolute and percentage lymphocyte values were significantly decreased with advancing age causing a relative increase in percentage neutrophils. The fall in absolute lymphocyte numbers was the main cause for a significant decrease in total leucocytes with age. Frequency plots for each variable showed that, with the ex...
Nyack B, Padmore CL, Dunn D, Kufuor-Mensan E, Mobini S.A 10-year-old Tennessee Walker gelding, with a history of progressive weight loss, intermittent colic and lethargy, had a slight fever, tachycardia, tachypnea, pallor, ascites and marked ventral edema. Blood analyses revealed anemia, leukocytosis, neutrophilia with a left shift, lymphopenia, monocytosis, hypoproteinemia and a slightly increased SDH level. Abdominocentesis produced red-orange fluid with many RBC and an increased fibrinogen content. Rectal palpation revealed a large mass in the left caudal abdominal quadrant. The animal died shortly after resection of the mass. The histopatholog...
Matthews SM, Joysey VC.Fifteen equine leucocyte antigens were defined by absorption and titration analysis of alloantisera obtained by natural sensitisation through pregnancy and by planned experimental immunisation. Definitive sera were tested on the cells of 90 unrelated horses and members of eight equine families. The family data suggested that 13 specificities were coded by a single locus (first locus) and one specificity (Eq 14) was coded by a second linked locus. The remaining specificity (Eq 7) was controlled by a third locus unlinked to the first or second loci. Tests on the cells of unrelated horses showed ...
Thielebein J, Bartling B, Hönicke C, Schmicke M.Semi-feral, free-roaming Konik polski horses are used in some European countries for preserving semi-open pasture landscapes. The estimation of their health status is still limited by insufficient data on various blood parameters. Therefore, our study aimed at the sex- and age-dependent analysis of haemogram and selected biochemistry parameters in healthy, semi-feral Koniks. In order to reach this aim, we took blood samples from 53 female and 18 male (8 uncastrated, 10 castrated) Koniks living in two Middle German nature reserves. They were of different age (9-266 months) and without signs of ...
Hemberg E, Einarsson S, Jones B, Mikko S.The objective of this study was to investigate the presence and origin of polymorphonuclear leucocytes (PMNLs) in the amniotic fluid of mares giving birth to healthy foals. Material from 25 mares was included. Amniotic fluid was collected during parturition before breakage of the amniotic vesicle. Manual microscopic cytologic evaluation was made on cytospin preparations after staining. PMNLs were found in all amniotic samples examined. The genomic DNA was extracted from 12 of the amniotic fluid samples and was genotyped. The results indicate that the PMNLs originate from the foetus.
Newman MJ, Beegle KH, Antczak DF.Monoclonal antibodies to equine lymphocyte antigens were produced, using normal peripheral blood lymphocytes as the immunogen and standard hybridoma techniques. Antibody producing hybridomas were detected by a solid-phase enzyme-linked immunosorbent assay. Antibodies produced by 6 cloned hybrids were characterized further by microlymphocytotoxicity, indirect immunofluorescence, and agglutination assays on peripheral blood lymphocytes, platelets, and erythrocytes. Reaction patterns on leukocytes indicated that these antibodies may recognize at least 3 different cell-surface antigens: (1) an ant...
May SA, Hooke RE, Lees P.The concentration of Percoll required for isolating equine peripheral blood mononuclear cells has been reinvestigated. A poor cell yield was obtained at the 60 per cent concentration already reported. It is recommended that workers specifically interested in high yields of mononuclear cells, for investigation of lymphocyte and monocyte functions, use a concentration of 65 per cent Percoll. However, workers wishing to isolate pure populations of equine neutrophils might consider a concentration of 70 per cent in the upper layer of Percoll used to retain the mononuclear cells.
Ghaeli T, Karimi B, Kojouri GA, Dehkordi RR, Ahadi AM.One of the initial responses of the host's innate immunity of newborns against pathogens is the use of oxidative enzymes. This study aimed to evaluate changes in serum xanthine oxidoreductase (XOR) activity, the leukocyte myeloperoxidase (MPO) and XOR genes expression, and some biochemical parameters in healthy Darehshuri newborn foals up to 60 days of life. Blood samples were collected from 16 foals at 1, 7, 15, 30, and 60 days and used for detecting XOR activity, biochemical parameters, and also gene expression by real-time RT-PCR. High activity of XOR was observed at birth, explained by phy...
Ostlund C, Pero RW, Johnson DB.This study compares the relationship between N-acetoxy-2-acetylaminofluorene (NA-AAF) and u.v. induced unscheduled DNA synthesis (UDS) and their respective relationships to age and blood pressure in horse mononuclear leukocytes with earlier, similar investigations on human leukocytes. U.v. induced UDS was found to proceed more rapidly than NA-AAF induced UDS. A pronounced lag period associated with the rapid demand for 3H-dThd into DNA after u.v. damage was observed. NA-AAF induced UDS correlated significantly with NA-AAF binding, age and the blood pressure of male horses. UDS values, induced ...
Stover SM, Steffey EP, Dybdal NO, Franti CE.Five horses were anesthetized similarly by use of xylazine, guaifenesin, thiamylal sodium, and halothane in oxygen on 3 consecutive days, and minor surgical procedures were performed. For 1 to 10 days after the last anesthetic exposure, clinical, hematologic, and serum biochemical features were monitored, and after necropsy, histologic examination of major organ tissues was performed. Predominant hematologic changes from base-line values included leukocytosis (maximal at 27 hours, 10,500 +/- 1,750 cells/microliter), neutrophilia (maximal at 51 hours, 7,485 +/- 1,719 cells/microliter), and lymp...
Furr MO, Crisman MV, Robertson J, Barta O, Swecker WS.Immune system dysfunction and immunoglobulin deficiency was diagnosed in a 2-year-old horse with disseminated lymphosarcoma. Prolonged (35 days) parenteral nutrition was delivered to support the horse during a period in which immune function studies could be performed. Correction of nutritional compromise by use of parenteral nutrition did not correct the immunoglobulin deficiency, and results of lymphocyte phenotype testing did not indicate abnormal proportions of leukocytes. Lymphoblast transformation studies were suggestive of a circulating immunosuppressive factor in the horse's serum. Nor...
Long CD, Galuppo LD, Waters NK, Hornof WJ.The aim of this study was to evaluate the diagnostic value of 99mTc-HMPAO leukocyte scintigraphy (LS) by means of a retrospective review of its use in 14 horses that were evaluated for orthopedic infection as a cause of lameness. A total of 17 LS exams were performed in 14 horses. LS studies were positive in 10 of 14 horses. A bacterial infection was confirmed with cytology or culture in 9 of 10 positive horses. Negative LS studies occurred in 4 of 14 horses. Necropsy confirmed the lack of infection in 2 of the 4 horses. Other clinical data and a favorable clinical outcome supported a negative...
Fischer A, Lechner J, Kraft W, Hirschberger J.The QBC is a centrifugal haematology system. Modified haematocrit capillaries are measured optically. The parameters haematocrit, total leukocyte count, relative and absolute values of granulocyte and lympho-/monocyte fractions, and total thrombocyte count are stated. The microhaematocrit method, the counting chamber, and the differential blood count are reference methods. Blood samples of the dog, cat and horse were used for the study. As a screening method the QBC analysis meets all requirements for the veterinary practice.
Allen BV.A technique for automating equine differential leucocyte counts by analysis of volume distribution curves using the Coulter Channelyzer has been developed and evaluated. A comparison between the results obtained by this method and standard microscopic techniques showed good agreement in most cases. Blood samples can be analysed for both differential and total leucocyte counts at a rate of 25/h. For each sample an average 16,000 leucocytes are classified by the Channelyzer. The method of volume analysis is suitable for the precise counting of polymorphonuclear neutrophils, lymphocytes and eosin...
Dubin A, Potempa J, Silberring J.Horse leucocyte neutral proteinase inhibitor reacts with all tested elastases at the molar ratios of 1:1 and yielding stable complexes (Ki = 10(-10) M). The above reactions are very rapid, characterized by the high values of association rate constant kon = 10(7) M-1s-1.
Watson ED.Incubation of equine neutrophils with povidone-iodine solutions of greater than or equal to 0.2 per cent resulted in total inhibition of migration under agarose. This was caused by the cytotoxic effects of the solutions as shown by pyknosis and cell lysis. Lower concentrations of povidone-iodine, however, did not adversely affect neutrophil viability or locomotion.
Meister D, Tschudi P, Hermann M, Lutz H.The QBC V hematology system was tested with respect to its application in veterinary medicine. PCV's and counts of total leukocytes, granulocytes, lympho/monocytes and platelets collected from 435 horses, dogs and cats were determined and compared with conventionally measured values. Precision and accuracy were found to be good for the majority of parameters. In the authors' opinion the QBC V hematology system is well suited for use in veterinary practice.
Marr KA, Lees P, Page CP, Cunningham FM.The leukotrienes (LT) LTD4 and LTB4 have been shown to cause bronchoconstriction and neutrophil accumulation, respectively, in horse lungs. Such changes are characteristic of the equine allergic respiratory disease, chronic obstructive pulmonary disease (COPD). To further investigate the role of these putative mediators in the pathogenesis of equine COPD the effect of a 5-lipoxygenase inhibitor, fenleuton, on antigen-induced changes in horses with this condition has been examined. Six horses with COPD underwent a series of four antigen challenges, one month apart, with placebo pre-treatment on...
Wagner B.Host immune analyses require specific reagents to identify cellular and soluble components of the immune system. These immune reagents are often species-specific. For horses, various immunological tools have been developed and tested by different initiatives during the past decades. This article summarizes the development of well characterized monoclonal antibodies (mAbs) for equine immune cells, immunoglobulin isotypes, cytokines, and chemokines.
Morris DD, Bruce J, Gaulin G, Whitlock RH.Granulocyte transfusions (GT), 0.98 X 10(9) neutrophils/kg of body weight, were performed on 7 healthy pony foals between 2 and 7 days old. The mean neutrophil count of the foals was significantly (P less than 0.05) greater than base line (4,830 +/- 1,260/microliter) 1 hour after GT (8,870 +/- 3,350/microliter) and was similar to base line by 15 to 18 hours after GT (6,550 +/- 2,310/microliter). Leukocyte concentrates (LC) used for GT were harvested from clinically normal adult horses by continuous-flow centrifugation leukapheresis (CL), 3 to 6 hours after hydrocortisone sodium succinate was a...
Higgins AJ, Lees P, Taylor JB.In a two part cross-over experiment, acute inflammatory exudates were induced in 7 ponies by subcutaneous implantation of 3 sterile carrageenin-soaked polyester sponge strips. Treatment comprised a single therapeutic geenin-soaked polyester sponge strips. Treatment comprised a single therapeutic dose of 4.4 mg/kg phenylbutazone (PBZ) administered intravenously at the time of sponge implantation. Exudates were harvested at 6, 12 and 24 hours and examined for leukocyte and erythrocyte numbers using the improved Neubauer technique; for eicosanoids by radioimmunoassay and by high performance liqui...
Causey RC, Paccamonti DL, Todd WJ.A total of 22 clinical streptococcal isolates, predominantly Streptococcus zooepidemicus, associated with endometritis in horses were tested for their ability to withstand the natural bactericidal properties of freshly obtained blood. During a 3-hour incubation in blood from a single horse, 8 of these isolates survived and grew, the remainder were killed. To determine whether this ability to grow extended to blood of other horses, 5 of these growing isolates were tested for their ability to grow in the blood of 5 additional horses. The same 5 horses were used for each isolate. The isolates gre...
Rupić V, Bacar-Huskić L, Lojkić M, Habe F, Ergotić N.Research was carried out into the effect that different quantities and compositions of concentrated portions of meal had on certain haematological properties and on the immune response of mares in the course of hyper-immune antitetanus sera production. The experiment involved 24 Nonius and Lipizzaner cross-bred mares divided into two groups of 12 animals each, a control group and a trial group. The experiment lasted 12 months, with haematological and immunological tests being carried out every 30 days. During the course of the experiment each mare was subjected to 11 immunisation cycles, and i...
Stadler P, van Amstel SR.The results of a study conducted to determine the clinico-pathological changes in 4 experimentally-induced cases of endotoxaemia in the horse are reported on. Endotoxaemia was induced by injecting commercially available E. coli 055:B5 lipopolysaccharide intravenously at a dose of 1 microgram kg-1. The haematocrit, red cell count, total and differential white cell counts, thrombocyte count, prothrombin time, partial thromboplastin time, fibrinogen level, level of fibrin degradation products, arterial acid-base status, serum lactate and blood glucose were determined repeatedly. Changes that occu...
Orellana-Guerrero D, Dini P, Santos E, de la Fuente A, Meyers S, Koshak S, Dujovne G.Transvaginal aspiration of oocytes (TVA) is a commonly used clinical procedure to obtain oocytes for in vitro production of embryos in horses. The goal of this study was to evaluate the effect of the TVA procedure on blood and peritoneal parameters, and to investigate the association of these findings with variables such as use of antibiotics, number of ovarian punctures, and length of the procedure. Physical examination was performed and blood and peritoneal fluid were obtained from 14 mares before they underwent TVA and the same parameters were assessed 24 hours after the procedure. On exami...
Benbarek H, Deby-Dupont G, Caudron I, Deby C, Lamy M, Serteyn D.Divergent results have been reported on the effects of lipopolysaccharides (LPS) on the activation of equine polymorphonuclear leukocytes (PMN). We therefore attempted to determine whether LPS alone can stimulate equine PMN or whether plasma factors are necessary. PMN were isolated from citrated blood on a discontinuous density gradient of Percoll. The luminol (10(-3) mol/L)-enhanced chemiluminescence (CL) of 1.25 x 10(6) cells was measured after addition of Escherichia coli LPS (0.001-10 micrograms/ml) alone or after incubation in autologous plasma (1 h, 37 degrees C). After direct stimulatio...
Martin RG, Penhale WJ, Williamson P.The influx of protein and polymorphonuclear leucocytes (PMN) into the uterine lumen was examined at different intervals after intrauterine infusion of fluids. The intrauterine infusion of both phosphate buffered saline (PBS) and a solution of lipopolysaccharide (LPS) derived from Escherichia coli resulted in a biphasic influx of protein in the uterine flushings peaking three and six hours after infusion. LPS infusion caused an additional influx of protein at 24 hours. The initial influx of protein preceded a biphasic influx of PMN which peaked six and 24 hours after both infusions. Uterine flu...
Waelchli RO, Lutz H, Hermann M, Rüegg C, Eggenberger E.Hematologic reference values were established in 18 healthy foals in the first two months of life. Blood samples were collected prior to colostrum consumption and at 30 hours, 1 week, 3, 5, 7 and 9 weeks of age. PCV, Hb and RBC decreased during the first week and RBC, but not PCV and Hb, increased toward the end of the second month. With the exception of the sample at 1 week, the foals had mean RBC values significantly higher than those of controls. Mean MCV and MCH did not change during the first week, but decreased slightly thereafter; all means were smaller than in controls. The numbers of ...
Gordon BJ, Latimer KS, Murray CM, Moore JN.In a continuous-flow centrifugation apheresis technique adapted for blood-component separation and collection in horses, hydroxyethyl starch was not required for erythrocyte sedimentation. The efficacy and separation characteristics of whole blood from 10 horses were evaluated at various gravitational forces (700 to 1,500 rpm), using a constant withdrawal rate (100 ml/min). Maximum leukocyte collection occurred at 700 rpm (P less than 0.01), and optimal neutrophil collection occurred at 700 to 750 rpm (P less than 0.01). Although neutrophil counts decreased and lymphocyte counts remained const...
