White blood cells (WBCs) are integral components of the equine immune system, responsible for protecting horses against infections and foreign invaders. These cells circulate in the bloodstream and are produced in the bone marrow. The primary types of white blood cells in horses include neutrophils, lymphocytes, monocytes, eosinophils, and basophils, each with distinct functions in immune defense. Neutrophils are involved in the immediate response to infections, while lymphocytes play a role in adaptive immunity. Monocytes are involved in phagocytosis and the regulation of immune responses. Eosinophils and basophils are associated with allergic reactions and parasitic infections. Variations in white blood cell counts can indicate health conditions, making them valuable in veterinary diagnostics. This page compiles peer-reviewed research studies and scholarly articles that explore the function, regulation, and clinical relevance of white blood cells in equine health.
Tugirimana PL, De Clercq D, Holderbeke AL, Kint JA, De Cooman L, Deprez P, Delanghe JR.A turbidimetric method to determine serum C-reactive protein (CRP) concentration, based on soybean oil-phosphocholine interaction, was performed on horse serum samples to evaluate its potential diagnostic value in veterinary medicine. Intralipid 20% in 0.1 M Tris-calcium buffer (pH 7.5) was added to horse serum. After 30 min of incubation at 37 °C, the CRP-phosphocholine complexes were turbidimetrically, bichromatically (660 nm/700 nm) quantified on a commercial analyzer. Furthermore, comparison between CRP and other inflammatory markers, including white blood cell and neutrophil counts, was ...
Andersen SA, Petersen HH, Ersbøll AK, Falk-Rønne J, Jacobsen S.European and American guidelines for vaccination against tetanus and influenza in horses recommend annual and annual/semi-annual vaccinations, respectively, against the two pathogens. Too-frequent vaccination may, however, have adverse effects, among other things because an inflammatory response is elicited with subsequent alterations in homeostasis. The objective of the study was to compare the acute phase response (APR) in 10 horses following administration of two different types of vaccines, namely, an inactivated Immune Stimulating COMplex (ISCOM) vaccine and a live recombinant vector vacc...
Schwarz BC, van den Hoven R, Schwendenwein I.The myeloperoxidase index (MPXI) was investigated as a diagnostic indicator of systemic inflammation in a retrospective study using data from 859 hospitalised horses. A reference interval of 8.5-10.4 for the MPXI was established. In horses with systemic inflammatory response syndrome (SIRS), the MPXI was significantly lower than in healthy horses, those with localised inflammation and those with sepsis. The MPXI in horses with sepsis was also significantly lower than in healthy animals and those with localised inflammation. Horses in the SIRS group with leucopenia, white blood cell (WBC) count...
Heimann M, Janda J, Sigurdardottir OG, Svansson V, Klukowska J, von Tscharner C, Doherr M, Broström H, Andersson LS, Einarsson S, Marti E....Equine insect bite hypersensitivity (IBH) is a seasonally recurrent, pruritic skin disorder caused by an IgE-mediated reaction to salivary proteins of biting flies, predominantly of the genus Culicoides. The aim of this study was to define T cell subsets and cytokine profile in the skin of IBH-affected Icelandic horses with particular focus on the balance between T helper (Th) 1, Th2 and T regulatory (Treg) cells. Distribution and number of CD4+, CD8+ and Forkhead box P3 (FoxP3)+ T cells were characterized by immunohistochemical staining in lesional and non-lesional skin of moderately and seve...
Robbin MG, Wagner B, Noronha LE, Antczak DF, de Mestre AM.Several distinct T lymphocyte subpopulations with immunoregulatory activity have been described in a number of mammalian species. This study performed a phenotypic analysis of cells expressing regulatory T cell (Treg) markers in the peripheral blood of a cohort of 18 horses aged 6 months to 23 years, using antibodies to both intracellular and cell surface markers, including Forkhead box P3 (FOXP3), CD4, CD8, CD25, interferon gamma (IFNγ) and interleukin 10 (IL-10). In peripheral blood, a mean of 2.2 ± 0.2% CD4+ and 0.5 ± 0.1% CD8+ lymphocytes expressed FOXP3. The mean percentage of CD4+FOXP...
Capomaccio S, Cappelli K, Barrey E, Felicetti M, Silvestrelli M, Verini-Supplizi A.It is known that moderate physical activity may have beneficial effects on health, whereas strenuous effort induces a state resembling inflammation. The molecular mechanisms underlying the cellular response to exercise remain unclear, although it is clear that the immune system plays a key role. It has been hypothesized that the physio-pathological condition that develops in athletes subjected to heavy training is caused by derangement of cellular immune regulation. The purpose of the present study was to obtain information on endurance horse gene transcription under strenuous conditions and t...
Wilsterman S, Soboll-Hussey G, Lunn DP, Ashton LV, Callan RJ, Hussey SB, Rao S, Goehring LS.Infection with equine herpesvirus-1 (EHV-1) causes respiratory disease, late term abortions and equine herpesvirus myeloencephalitis (EHM) and remains an important problem in horses worldwide. Despite increasing outbreaks of EHM in recent years, our understanding of EHM pathogenesis is still limited except for the knowledge that a cell-associated viremia in peripheral blood mononuclear cells (PBMCs) is a critical link between primary respiratory EHV-1 infection and secondary complications such as late-term abortion or EHM. To address this question our objective was to identify which PBMC subpo...
Fazio F, Assenza A, Tosto F, Casella S, Piccione G, Caola G.The concentrations of plasma fibrinogen and serum haptoglobin and the white blood cell count (WBC) were assessed in 17 thoroughbreds. All horses were trained for 80 days, six days a week, with one day of rest per week. Blood samples were collected from each animal by jugular venepuncture, at 06.00, every 20 days for a period of 80 days, and the fibrinogen and haptoglobin concentrations and WBC were determined. One-way repeated measures analysis of variance, followed by the Bonferroni test, was used to determine significant differences. Training was associated with a significant increase in the...
Pawlas-Opiela M, Sołtysiak Z, Gorczykowski M.Gasterophilus sp. constitute a group of specific parasites, which larval forms are found in horses and other phylogenetically related species--donkeys, mules and zebras. Their invasion is associated with marked fluctuations of hematological and biochemical blood parameters, including the activity of many enzymes and the electrolyte concentration. The purpose of the study was to analyze changes in selected biochemical and morphological blood parameters of horses infected with botfly larvae. The experimental group was formed of horses infested by Gasterophilus sp. larvae whereas the control grou...
Cywińska A, Wyszyńska Z, Górecka R, Szarska E, Witkowski L, Dziekan P, Winnicka A, Schollenberger A.Strenuous exercise is recognized as a stress, which may induce functional immunodeficiency and increase individual susceptibility to infection. It has been shown in equine athletes, that alterations in leukocyte functions occur after moderate and submaximal exertion, however, no data deal with the effect of extreme physical exertion. In this study, we evaluated leukocyte functions (neutrophil oxidative burst and lymphocyte proliferation activity in response to mitogens) in horses following the CEI 3* 162 km endurance ride. Exercise-induced stress was manifested as neutrophilic leukocytosis and...
Rashid A, Mubarak A, Hussain A.Equine babesiosis is a tick-borne haematological disease of equidae that can affect acutely, subacutely and chronically. The disease is manifested by intermittent fever, anaemia, icterus and haemoglobinuria. The authors describe the clinical, haematological and therapeutic aspects of babesiosis in equines at two units in Kotley and at two units in Jehlum of the Remount Veterinary and Farms Corps (RVFC). Animals on these units showed the signs of illness. On clinical examination, intermittent temperature, increased respiratory rate, anaemia, lacrimation, conjunctivitis and pale mucous membranes...
Wagner B, Burton A, Ainsworth D.Cytokines produced by T helper (Th) cells are important in orchestrating the immune response during health and disease. Recent reports indicated that cytokine mRNA expression in foals is often quantitatively lower than that of adult horses suggesting that foal T cells are not fully mature. Here, peripheral blood mononuclear cells from foals and adult horses were stimulated with phorbol 12-myristate 13-acetate and analyzed for intracellular interferon-gamma (IFN-gamma), interleukin-4 (IL-4) and IL-10 production, representing the Th1, Th2 and regulatory TR1 cell phenotypes respectively, by flow ...
Harris SP, Fujiwara N, Mealey RH, Alperin DC, Naka T, Goda R, Hines SA.Immune adult horses have CD8(+) cytotoxic T lymphocytes (CTLs) that recognize and lyse Rhodococcus equi-infected cells in an equine lymphocyte alloantigen (ELA)-A [classical major histocompatibility complex (MHC) class I]-unrestricted fashion. As protein antigens are MHC class I-restricted, the lack of restriction suggests that the bacterial antigens being recognized by the host are not proteins. The goals of this study were to test the hypothesis that these CTLs recognize unique R. equi cell-wall lipids related to mycobacterial lipids. Initial experiments showed that treatment of soluble R. e...
Go YY, Zhang J, Timoney PJ, Cook RF, Horohov DW, Balasuriya UB.Extensive cell culture passage of the virulent Bucyrus (VB) strain of equine arteritis virus (EAV) to produce the modified live virus (MLV) vaccine strain has altered its tropism for equine CD3(+) T lymphocytes and CD14(+) monocytes. The VB strain primarily infects CD14(+) monocytes and a small subpopulation of CD3(+) T lymphocytes (predominantly CD4(+) T lymphocytes), as determined by dual-color flow cytometry. In contrast, the MLV vaccine strain has a significantly reduced ability to infect CD14(+) monocytes and has lost its capability to infect CD3(+) T lymphocytes. Using a panel of five re...
Krakowski L, Krawczyk CH, Wrona Z, Dabrowski R, Jarosz Ł.The objective of the present study was to analyse the immune status of mares in the early stages of pregnancy and mares which experienced early embryonic death (EED). Forty-eight fertile purebred Arabian mares were used for the study. The mares were divided into two groups. Group I was the control group composed of 32 mares in the early stages of a normal pregnancy. Group II was composed of 12 mares which had experienced EED. In both groups, subpopulations of T lymphocytes containing CD2(+), CD4(+) and CD8(+) were characterized using flow cytometry. The percentages of CD3(+) lymphocytes (addin...
Muñoz A, Riber C, Trigo P, Castejón F.Leukemia, i.e., the neoplasia of one or more cell lines of the bone marrow, although less common than in other species, it is also reported in horses. Leukemia can be classified according to the affected cells (myeloproliferative or lymphoproliferative disorders), evolution of clinical signs (acute or chronic) and the presence or lack of abnormal cells in peripheral blood (leukemic, subleukemic and aleukemic leukemia). The main myeloproliferative disorders in horses are malignant histiocytosis and myeloid leukemia, the latter being classified as monocytic and myelomonocytic, granulocytic, prim...
Platt R, Sponseller BA, Chiang YW, Roth JA.The cell-mediated immune (CMI) response of foals to virulent equine herpesvirus-1 (EHV-1) infection was evaluated by multi-parameter flow cytometry (FCM). Ten 7-8-month-old EHV-1 seronegative foals were infected intranasally with virulent EHV-1 and 10 foals served as uninfected controls. Blood samples were collected 6 and 7 weeks after infection to test for specific CMI responses to live heterologous EHV-1 recall antigen. The activation markers included major histocompatibility complex class II (MHC II), intracellular interferon gamma (IFN-gamma) and interleukin 4 (IL-4). The results from both...
Lindegaard C, Gleerup KB, Thomsen MH, Martinussen T, Jacobsen S, Andersen PH.To compare the effects of intra-articular (IA) versus IV administration of morphine on local and systemic inflammatory responses in horses with experimentally induced acute synovitis. Methods: 8 horses. Methods: Each horse received the following 2 treatments 4 hours after synovitis was induced: IA administration of morphine (0.05 mg/kg) with IV administration of 1 mL of saline (0.9% NaCl) solution/100 kg, and IA administration of 1 mL of saline solution/100 kg with IV administration of morphine (0.05 mg/kg). Treatments were administered in randomized order with a washout period of 3 weeks betw...
Dawson TRMY, Horohov DW, Meijer WG, Muscatello G.Rhodococcus equi is recognised to cause chronic purulent bronchopneumonia in foals of less than 6 months of age. Virulent strains of the bacteria possess a large 80-90 kb plasmid encoding several virulence-associated proteins, including virulence-associated protein A (VapA), which is associated with disease. R. equi pneumonia can represent significant costs and wastage to the equine breeding industry, especially on stud farms where the disease is endemic. This article reviews knowledge of the equine immune response, both in the immune adult and susceptible neonate, with respect to this pathoge...
Leclere M, Magdesian KG, Kass PH, Pusterla N, Rhodes DM.The purpose of this study was to compare the clinical, microbiological, radiological, haematological and cytological features of foals with pneumonia caused by Rhodococcus equi infection and with other bacteria, in order to provide markers for early diagnosis and treatment. A retrospective study of 113 cases of bacterial pneumonia was undertaken. Although there was considerable overlap in the affected populations, foals with R. equi pneumonia were significantly younger and had higher respiratory rates. Radiological evidence of thoracic abscessation had a sensitivity of 71% and a specificity of...
Calamari L, Abeni F, Bertin G.This study was conducted to determine the effects of dietary Se source and dose on metabolic and hematological profiles, and their relationships with oxidative status in horses. Twenty-five mature horses were blocked by BW and randomly allocated to 1 of 5 dietary treatments: negative control (CTRL: 0.085 mg of Se/kg of DM), 3 different dietary concentrations of organic Se provided by Se yeast (SY02, SY03, and SY04 containing 0.2, 0.3, and 0.4 mg of total Se/kg of DM, respectively), and 1 positive control provided by sodium selenite (SS03 containing 0.3 mg of total Se/kg of DM). Horses were fed...
Satué K, Hernández A, Lorente C, O'Connor JE.Assessment of lymphocyte subsets is an effective method for characterizing disorders such as leukemia, lymphomas, autoimmune and infectious diseases. In order to clinically interpret these parameters, normal reference values should be set, estimating age- and gender-related variations. This research aimed to: (1) characterize lymphocyte subpopulations in Andalusian horse, and (2) evaluate age and gender-related variations of lymphocyte subsets. Jugular blood samples were obtained from 159 animals, 77 males and 82 females, belonging to four age groups-1: 1-2 years (N=39; 21 males and 18 females...
Newquist JM, Baxter GM.To determine whether high plasma fibrinogen concentration (> or = 900 mg/dL) is a valid indicator of physeal or epiphyseal osteomyelitis in foals. Methods: Retrospective case series. Methods: 17 foals with physeal or epiphyseal osteomyelitis with or without septic arthritis, 17 foals with septic arthritis alone, 20 foals with non-Rhodococcus equi pneumonia, and 22 healthy foals. Methods: Medical records were reviewed for information regarding signalment and total WBC count, segmented neutrophil count, and plasma fibrinogen concentration measured when foals were initially evaluated at the ho...
Jacobsen S, Nielsen JV, Kjelgaard-Hansen M, Toelboell T, Fjeldborg J, Halling-Thomsen M, Martinussen T, Thoefner MB.To evaluate the postoperative inflammatory response of horses to elective surgery of varying intensity. Methods: Prospective longitudinal study. Methods: Horses referred to 2 hospitals for either arthroscopic removal of a unilateral osteochondritic lesion in the tibiotarsal joint (minimal surgical trauma, n=11), correction of recurrent laryngeal neuropathy by laryngoplasty and ventriculectomy (intermediate surgical trauma, n=10) or removal of an ovarian tumor by laparotomy (major surgical trauma, n=5). Methods: Horses had a thorough clinical examination every day. White blood cell (WBC) counts...
Haase B, Obexer-Ruff G, Dolf G, Rieder S, Burger D, Poncet PA, Gerber V, Howard J, Leeb T.The KIT receptor protein-tyrosine kinase plays an important role during embryonic development. Activation of KIT is crucial for the development of various cell lineages such as melanoblasts, stem cells of the haematopoietic system, spermatogonia and intestinal cells of Cajal. In mice, many mutations in the Kit gene cause pigmentation disorders accompanied by pleiotropic effects on blood cells and male fertility. Previous work has demonstrated that dominant white Franches-Montagnes horses carry one copy of the KIT gene with the p.Y717X mutation. The targeted breeding of white horses would be et...
Svansson V, Roelse M, Olafsdóttir G, Thorsteinsdóttir L, Torfason EG, Torsteinsdóttir S.Horses are hosts to two types of gammaherpesviruses, equine herpes virus (EHV) 2 and 5. While EHV-2 is ubiquitous in adult horses, EHV-5 has been less frequently described. Due to strong serological cross-reactivity, EHV-2 and -5 cannot be discriminated in broad spectrum antibody tests and are thus commonly referred to as gamma-EHV. Total IgG and IgG subclass response against gamma-EHV were determined in serum from 41 healthy Icelandic horses, thereof 20 adults, 10 foals aged 10 months, and 11 foals aged 1-4 months. Additionally, in 10 of the adult horses, interferon (IFN)-gamma and interleuki...
Akai M, Hobo S, Wada S.To assess the effect of human interferon-alpha (IFNα) on shipping fever of Thoroughbred racehorses subjected to long-distance transportation, an IFNα preparation was orally administered to 48 horses three times (once daily, 3 successive days) before transportation (IFNα group). In the control group (25 horses), maltose was administered in the same way. These treatments induced no abnormal findings in Thoroughbred racehorses before transportation. Immediately after transportation, significant increases in rectal temperature were observed in both treatment groups, whereas the rectal temperatu...
Kusano K, Hobo S, Ode H, Ishikawa Y.Cytology of tracheal aspirates, tracheal endoscopic and blood tests were carried out to 86 Thoroughbred racehorses presenting coughs or poor performance which were suspected to have lower respiratory tract disease (LRTD) to assess the conditions of the disorders. Racehorses were classified into coughing (66 horses) and non-coughing (20 horses) groups based on clinical symptoms. Nine Thoroughbred racehorses without respiratory abnormality were used as controls. Assessment of grades of airway mucus, cytology of tracheal aspirates and serum amyloid A (SAA), fibrinogen (Fbg) and pulmonary surfacta...
Cook VL, Neuder LE, Blikslager AT, Jones SL.The effect of lidocaine on in vitro migration and adhesion of equine neutrophils was evaluated. Neutrophils were isolated from equine whole blood using a Percoll-gradient centrifugation protocol. Purified neutrophils were incubated with lidocaine at concentrations from 0.1 to 1000 microg/ml for 30 min at 37 degrees C, after calcein loading. Neutrophil integrin-mediated adhesion in response to stimulation with 100 nM LTB(4), 100 nM PAF, or 100 ng/ml IL-8, or integrin-mediated migration in response to stimulation with 100 nM LTB(4), 150 nM PAF, or 100 ng/ml IL-8 was assessed. Statistical signifi...
Kay AT, Bolt DM, Ishihara A, Rajala-Schultz PJ, Bertone AL.To assess analgesia, inflammation, potency, and duration of action associated with intra-articular injection of triamcinolone acetonide (TA), mepivacaine hydrochloride, or both in metacarpophalangeal (MCP) joints of horses with experimentally induced acute synovitis. Methods: 18 horses. Methods: Both forelimbs of each horse were injected with lipopolysaccharide (LPS) 3 times. After the first LPS injection, 1 forelimb of each horse was treated with intra-articular injection of mepivacaine (80 mg; n=6), TA (9 mg; 6), or mepivacaine with TA (same doses of each; 6) 12 hours after the initial LPS i...
Brewer BD, Clement SF, Lotz WS, Gronwall R.Urine (U) and serum (S) were obtained every 2 hours during a 12- or 24-hour period from eight healthy 96-hour-old pony or horse foals. Dams' milk samples were obtained concurrently. Urine volume was measured during this 12- or 24-hour period. The mean amount of urine produced was 148 +/- 20 ml/kg/day. Baseline urinalyses were evaluated on all foals at two days of age, before any manipulation. Urine generally was dilute (less than 1.008) but the specific gravity was as high as 1.027 in one normal foal. Continuous (12 or 24 hour) urinary catheterization resulted in bacteriuria but not white bloo...
McCulloch J, Williamson SA, Powis SJ, Edington N.It has been suggested that EHV-1 infection may perturb immune responsiveness in the natural equine host. The mechanism underlying this phenomenon is not clear, but disturbances of circulating leucocyte populations could contribute. In order to objectively assess the nature of the haematological changes provoked by EHV-1 infection, two groups of conventionally-maintained Welsh mountain ponies were challenge-infected intra-nasally with the Ab4 isolate of EHV-1. These groups were controlled by similarly-sized groups of non-infected ponies. All data generated was subjected to rigorous statistical ...
Wassmuth AK, Riond B, Hofmann-Lehmann R, Lutz H.The Mythic 18 is a fully automated hematology bench-top analyzer using impedance technology for a complete blood cell count (CBC) and a 3-part white blood cell count (WBC) differential. The purpose of the current study was to evaluate the Mythic for assessment of agreement, precision, linearity, carry-over, stability, and usability under practice conditions. Ethylenediamine tetra-acetic acid-blood samples from 122 dogs, 140 cats, and 123 horses were analyzed with the Mythic and reference methods (Sysmex XT-2000iV, manual hematocrit, and microscopic WBC differentiation). Pearson's coefficient o...
Anderson SL, Townsend HGG, Singh B.OBJECTIVE To evaluate the effect of lipopolysaccharide (LPS) on apoptosis of equine neutrophils in vitro. SAMPLE Venous blood samples from 40 adult horses. PROCEDURES Neutrophils were isolated from blood samples and cultured with or without LPS from Escherichia coli O55:B5 for 12 or 24 hours. Neutrophil apoptosis was assessed by use of cytologic examination, annexin V and propidium iodide staining quantified with flow cytometry, coincubation with inducers of intrinsic and extrinsic apoptosis or a toll-like receptor (TLR) 4 inhibitor, and measurement of caspase-3, -8, and -9 activities. RESULTS...
Coelho CS, Silva ASBA, Santos CMR, Santos AMR, Vintem CMBL, Leite AG, Fonseca JMC, Prazeres JMCS, Souza VRC, Siqueira RF, Manso Filho HC, Simões JSA.The purpose of this study was to investigate stressful responses during a 6-week training protocol in young Lusitano horses used for dressage. The hypothesis was that the proposed training protocol would improve fitness and ensure the welfare of the animals by reducing stress predictors. Nine 4-year-old horses were evaluated before (M1) and six weeks after (M2) beginning a training protocol. The training program was performed six times per week and included 40−80 min of individually intensity-adjusted preparatory exercises for dressage. For both moments, the horses were examined before (T0) ...
Davis EG, Wilkerson MJ, Rush BR.The use of flow cytometry in veterinary diagnostics is becoming a valuable clinical tool with a broad range of applications. Physical characteristics of cells can be determined by the flow cytometer laser and electronics through the measurement of changes in light scatter properties. Other components and functions of cells can be defined through the application of fluorochrome dyes that have an affinity for cellular components. Traditionally, common clinical applications are immunophenotyping of cells of the hematopoietic system with fluorescent-labeled antibodies raised against specific cell ...
Hannant D, Mumford JA.Cytotoxic cell precursors and/or cytotoxic memory cells were demonstrated in the peripheral blood of ponies after aerosol infection with influenza A/equine/Newmarket/79 (H3N8). In order to reveal their cytotoxic potential, peripheral blood mononuclear cells required a secondary antigenic stimulation. In vitro induced cytotoxic cells showed activity against influenza infected target cells in a 3-4 h 51Cr-release assay. The reactivity of cytotoxic cells was markedly influenced by the conditions of the secondary induction culture. If high concentrations of exogenous crude equine IL-2 were used, v...
Svansson V, Roelse M, Olafsdóttir G, Thorsteinsdóttir L, Torfason EG, Torsteinsdóttir S.Horses are hosts to two types of gammaherpesviruses, equine herpes virus (EHV) 2 and 5. While EHV-2 is ubiquitous in adult horses, EHV-5 has been less frequently described. Due to strong serological cross-reactivity, EHV-2 and -5 cannot be discriminated in broad spectrum antibody tests and are thus commonly referred to as gamma-EHV. Total IgG and IgG subclass response against gamma-EHV were determined in serum from 41 healthy Icelandic horses, thereof 20 adults, 10 foals aged 10 months, and 11 foals aged 1-4 months. Additionally, in 10 of the adult horses, interferon (IFN)-gamma and interleuki...
Raidal SL, Love DN, Bailey GD, Rose RJ.The effect of strenuous exercise on the functional capacity of pulmonary alveolar macrophages (PAM) and bronchoalveolar lavage-derived lymphocytes was determined in eight horses prior to and after 7 weeks of training. Strenuous exercise had no effect on the total cell count or the percentage of live cells in bronchoalveolar lavage (BAL) samples prior to or following training. However, training was associated with a significant increase in the total cell count of pre-exercise BAL samples and a significant reduction in the percentage of live cells in post-exercise samples. Strenuous exercise was...
Williams CA, Gordon ME, Betros CL, McKeever KH.Eight mature (12 +/- 2 yr; MAT) and 5 older (22 +/- 2 yr; OLD) Standardbred mares were used to test the hypothesis that aging and exercise training would alter apoptosis in white blood cells and antioxidant status. The horses were housed indoors overnight (16 h/d) in 3 m x 3 m stalls and were turned out in a drylot during the day. They were fed a diet consisting of total mixed ration, hay cubes fed ad libitum or an equine senior diet plus grass hay. Horses were trained for 20 to 30 min/d, 3 to 5 d/wk for 8 wk at a submaximal work intensity between 60 to 70% of maximal heart rate. A graded exer...
Pretorius A, Van Kleef M, Van Wyngaardt W, Heath J.African horsesickness (AHS) is an infectious but noncontagious viral disease affecting all species of Equidae. The recall immune response of AHSV naïve horses immunised with an attenuated African horsesickness virus serotype 4 (AHSV4) was characterised using immune assays including ELISPOT, real-time PCR (qPCR) and flow cytometry. The recall immune response detected in PBMC isolated from three inoculated horses showed an upregulation of circulating B lymphocytes that correlated with elevated IL-4 mRNA expression indicative of humoral immunity, but reduced frequency of CD4⁺ cells. In additio...
Kidd JA, Barr AR, Tarlton JF.Thirty-nine samples of synovial fluid were collected from the joints of 32 horses with suspected septic arthritis and 39 samples were collected from horses euthanased for non-orthopaedic conditions. The white blood cell counts (WBCC) were determined and the pro and active forms of matrix metalloproteinases (MMPs) 2 and 9 were measured by gelatin zymography and image analysis in each sample. The initial measurements of the ratio of proMMP9:proMMp2 and WBCC were good prognostic indicators of the survival of the horses. There was no significant relationship between the interval between the injury...
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...
Tsuchiya T, Hobo S, Endo Y, Narita S, Sakamoto K.To evaluate effects of a single dose of enrofloxacin (5 mg/kg, IV) on body temperature and tracheobronchial neutrophil count in healthy Thoroughbreds premedicated with interferon-α and undergoing long-distance transportation. Methods: 32 healthy Thoroughbreds. Methods: All horses received interferon-α (0.5 U/kg, sublingually, q 24 h) as an immunologic stimulant for 2 days before transportation and on the day of transportation. Horses were randomly assigned to receive enrofloxacin (5 mg/kg, IV, once; enrofloxacin group) or saline (0.9% NaCl) solution (50 mL, IV, once; control group) ≤ 1 hou...
Roleff S, Arndt G, Bottema B, Junker L, Grabner A, Kohn B.The CA530-VET is a completely automated impedance cell hematology analyzer, which yields a 16-parameter blood count including a 3-part leukocyte differential. Objective: The aim of this study was to examine the operational potential of the CA530-VET and its value for use in veterinary practice. Methods: The analyzer was tested for blood carry-over, precision, and accuracy. Comparison methods included the CELL-DYN 3500, microhematocrit centrifugation, manual platelet (PLT) counting for feline and equine species, and a 100-cell manual WBC differential. Blood samples for comparison of the methods...
Wong DM, Sponseller BA, Alcott CJ, Agbedanu PN, Wang C, Hsu WH.To evaluate the effect of IV administration of polymyxin B on clinical and serum biochemical variables in foals with experimental endotoxemia. Methods: Prospective experimental study. Methods: 14 healthy neonatal foals. Methods: Foals were randomly assigned to a treatment or control group and were administered a single dose of lipopolysaccharide (0.5 μg/kg [0.23 μg/lb]) IV over 30 minutes. The treatment group received polymyxin B (6,000 U/kg [2,727 U/lb], IV) immediately after completion of lipopolysaccharide infusion; the control group was administered an equal volume of saline (0.9% NaCl) ...
Vendrig JC, Coffeng LE, Fink-Gremmels J.Deficient innate and adaptive immune responses cause newborn mammals to be more susceptible to bacterial infections than adult individuals. Toll-like receptors (TLRs) are known to play a pivotal role in bacterial recognition and subsequent immune responses. Several studies have indicated that activation of certain TLRs, in particular TLR-2, can result in suppression of inflammatory pathology. In this study, we isolated peripheral blood mononuclear cells (PBMCs) from adult and newborn horses to investigate the influence of TLR-2 activation on the inflammatory response mediated by TLR-4. Data we...
Cywińska A, Wyszyńska Z, Górecka R, Szarska E, Witkowski L, Dziekan P, Winnicka A, Schollenberger A.Strenuous exercise is recognized as a stress, which may induce functional immunodeficiency and increase individual susceptibility to infection. It has been shown in equine athletes, that alterations in leukocyte functions occur after moderate and submaximal exertion, however, no data deal with the effect of extreme physical exertion. In this study, we evaluated leukocyte functions (neutrophil oxidative burst and lymphocyte proliferation activity in response to mitogens) in horses following the CEI 3* 162 km endurance ride. Exercise-induced stress was manifested as neutrophilic leukocytosis and...
Anderson SL, Singh B.Horses are susceptible to a multitude of inflammatory conditions that are characterized by a strong neutrophilic response. Here, we review basic equine neutrophil biology and explore the role of neutrophils in inflammatory conditions with emphasis on intestinal ischemia and reperfusion injury and lung inflammation. In addition, unique aspects of equine neutrophil biology have been highlighted. Neutrophils comprise the highest proportion of circulating white blood cells in equine blood. The concentration of circulating equine neutrophils is a primary indicator of systemic inflammation. Addition...
Hellman S, Hjertner B, Morein B, Fossum C.The immunomodulatory effect of a new particulate adjuvant, G3, alone or in combination with agonists to TLR2/1 or TLR5 was evaluated in cultures of equine PBMC. Exposure to the G3 adjuvant up-regulated genes encoding IFN-γ, IL-1β, IL-6, IL-8, IL-12p40 and IL-23p19 in the majority of the horses tested, indicating that the G3 adjuvant induced a pro-inflammatory and Th1 dominated profile. In accordance, genes encoding IL-13, IL-4, IL-10 and TGF-β remained unaffected and genes encoding IFN-α, IL-17A and TNF-α were only occasionally and weakly induced. The two TLR agonists Pam3CSK4 (TLR2/1) an...
Rossdale PD, Ousey JC, Silver M, Fowden A.This paper describes criteria used to assess maturity of the newborn foal and their clinical application to field cases of prematurity and dysmaturity. Premature and mature foals may be clearly distinguished by their behavioural and physical characteristics. Measurement of haematological parameters (mean cell volume, total white cell and differential counts), pancreatic beta cell activity (plasma glucose and insulin levels), adrenocortical-medullary function (plasma cortisol, adrenocorticotrophic hormone and catecholamines) and the renin-angiotensin system (plasma renin substrate concentration...
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...
Witonsky S, Gogal RM, Buechner-Maxwell V, Ahmed SA.To determine whether immune function can be accurately assessed in blood samples obtained from horses and refrigerated overnight and whether a nonradioactive lymphocyte proliferation assay can be used to evaluate samples obtained from horses. Methods: 224 blood samples from 28 clinically normal adult horses. Methods: Heparinized blood samples were collected. Each sample was divided into 2 equal aliquots. One aliquot was refrigerated overnight to simulate overnight shipping of blood samples, and the other aliquot was evaluated on the day of blood collection. Lymphocytes were isolated and enumer...
Healy PJ.Activities of lysosomal hydrolases were measured in the leucocytes of cattle, sheep, goats, horses and pigs. There was high activity of arylsulphatase in leucocytes from cattle, high activities of alpha-fucosidase and beta-glucuronidase in leucocytes from horses and high activity of acid phosphatase in granulocytes from pigs. Within species, arylsulphatase and beta-galactosidase activities were higher in granulocytes than in mononuclear cells, but beta-glucuronidase, phosphodiesterase and alpha-galactosidase activities were higher in mononuclear cells than in granulocytes. Eosinophils of cattl...
Leclere M, Magdesian KG, Kass PH, Pusterla N, Rhodes DM.The purpose of this study was to compare the clinical, microbiological, radiological, haematological and cytological features of foals with pneumonia caused by Rhodococcus equi infection and with other bacteria, in order to provide markers for early diagnosis and treatment. A retrospective study of 113 cases of bacterial pneumonia was undertaken. Although there was considerable overlap in the affected populations, foals with R. equi pneumonia were significantly younger and had higher respiratory rates. Radiological evidence of thoracic abscessation had a sensitivity of 71% and a specificity of...
Witkowska-Piłaszewicz O, Pingwara R, Szczepaniak J, Winnicka A.Clenbuterol, the β2-adrenoceptor agonist, is gaining growing popularity because of its effects on weight loss (i.e., chemical liposuction). It is also popular in bodybuilding and professional sports, due to its effects that are similar to anabolic steroids. However, it is prohibited by anti-doping control. On the other hand, it is suggested that clenbuterol can inhibit the inflammatory process. The cells from 14 untrained and 14 well-trained race horses were collected after acute exercise and cultured with clenbuterol. The expressions of CD4, CD8, FoxP3, CD14, MHCII, and CD5 in PBMC, and reac...
Chikhaoui M, Smail F, Adda F.The Barb horse this famous Maghreb horse, symbol of the pride of the Berber peoples It is particularly significant in the Algerian history, tradition and culture. This study consists in establishing the hematologic values specific to the Barb horse in the national stud farm "Chaou-Chaoua" in Tiaret. Algeria. Age of the study animals varied between 1 and 23 years. The effects of age and sex were analyzed by dividing animals into four groups, A (1 - 2 years, n=5), B (3-5 years, n=5), C (5-10 years, n=5) and D (11-23 years, n=5); for females and E (2 - 3 years, n=5), F (5-7, n=5), G (10, n=5) and...
Fischer AT, Lloyd KC, Carlson GP, Madigan JE.Laparoscopy was performed in 5 clinically normal horses. Abdominal fluid protein content and WBC count increased markedly in all horses. Necropsy findings were confined to an increased amount of slightly turbid abdominal fluid. Five examples of applications of laparoscopy in horses with abdominal problems indicated that laparoscopy can be a valuable diagnostic procedure in the horse.
Ferrante A, Thong YH.Results presented show that highly purified populations of mononuclear (MN) and polymorphonuclear (PMN) leucocytes can be obtained from horse blood by a procedure similar to that previously described for the separation of these leucocytes from human blood. This involved centrifugation of horse blood on a Ficoll-Hypaque medium with a density of 1.095 g/ml. The procedure required approximately 1 h for completion and resulted in the simultaneous preparation of MN (greater than 98% purity) and PMN (greater than 96% purity) leucocytes. Cell viability exceeded 95% and cells retained immunological fu...
