Neutrophils are a type of white blood cell that play a significant role in the immune system of horses. They are involved in the body's defense mechanisms against infections and are typically one of the first responders to microbial invasion or tissue damage. Neutrophils function by engulfing and destroying pathogens through processes such as phagocytosis and the release of antimicrobial substances. In horses, the number and activity of neutrophils can be indicative of immune status and are often assessed in the context of infectious diseases, inflammation, and other health conditions. This page compiles peer-reviewed research studies and scholarly articles that explore the function, regulation, and clinical implications of neutrophils in equine health.
Aktan I, Dunkel B, Cunningham FM.Activated platelets can contribute to host defense through release of products with bactericidal actions such as antimicrobial peptides and reactive oxygen species (ROS), as well as by forming heterotypic aggregates with neutrophils and enhancing their antimicrobial properties. Whilst release of vasoactive mediators from equine platelets in response to stimuli including bacterial lipopolysaccharide (LPS) has been documented, neither ROS production, nor the effects of activated platelets on equine neutrophil ROS production, have been reported. This study first sought evidence that activated equ...
Bullone M, Moran K, Lavoie-Lamoureux A, Lavoie JP.Neutrophils accumulate in the airways of horses with heaves. They likely play an important role in the disease pathogenesis. Understanding the pathways regulating their migration may help identifying new therapeutic targets. Objective: MAPK and PI3K pathways are involved in neutrophil migration toward the airway lumen in heaves. Methods: Twelve heaves-affected horses and 4 healthy horses. Methods: Migratory activity of bronchoalveolar lavage fluids (BALF) from horses with heaves and healthy horses was compared by means of a Boyden chamber. Involvement of MAPK and PI3K pathways in neutrophil mi...
Hahn S, Giaglis S, Hoesli I, Hasler P.The intention of this review is to provide an overview of the potential role of neutrophil extracellular traps (NETs) in mammalian reproduction. Neutrophil NETs appear to be involved in various stages of the reproductive cycle, starting with fertility and possibly ending with fetal loss. The first suggestion that NETs may play a role in pregnancy-related disorders was in preeclampsia, where vast numbers were detected in the intervillous space of affected placentae. The induction of NETosis involved an auto-inflammatory component, mediated by the increased release of placental micro-debris in p...
Wilson ME, Berney C, Behan AL, Robinson NE.Lidocaine decreases neutrophilic inflammation in models of acute lung injury and decreases inflammation in asthmatic patients. Neutrophilic bronchiolitis develops in recurrent airway obstruction (RAO), but it remains unknown if lidocaine infusion decreases neutrophil migration into the airways. Objective: Lidocaine decreases neutrophilic inflammation as measured in BALF in RAO-affected horses. Methods: Six RAO-susceptible horses in remission. Methods: In a randomized cross-over design, horses received lactated Ringer's solution (LRS) IV or lidocaine hydrochloride IV with a minimum of 4 weeks a...
Minguet G, de la Rebière G, Franck T, Joris J, Serteyn D, Sandersen C.To investigate the effects of the volatile anaesthetic sevoflurane on the release of total and active myeloperoxidase (MPO) by non-stimulated and stimulated polymorphonuclear neutrophils (PMNs) in whole blood from healthy horses. Methods: In vitro experimental study. Methods: Adult healthy horses. Methods: Samples of whole venous blood were collected and incubated in air or in air plus 2.3% or 4.6% sevoflurane for 1 hour. PMNs were stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP), with a combination of cytochalasin B (CB) and fMLP or with phorbol myristate acetate (PMA). Total an...
Ceusters JD, Serteyn DA, Minguet G, de la Rebière de Pouyade G, Romainville J, Deby-Dupont GP, Mouithys-Mickalad AA, Franck TJ.Horses are particularly sensitive and exposed to excessive inflammatory responses evolving toward an important stimulation of polymorphonuclear neutrophils (PMNs). The aim of this work was to stimulate equine neutrophils in whole blood and to evaluate their response by measuring the release of total and active myeloperoxidase (MPO) and total elastase, considered as markers of neutrophil stimulation and degranulation. Because of the critical importance of the concomitant presence of LPS and TNF-α in equine pathological situations, we combined these two natural mediators to stimulate PMN and co...
Hirsch G, Lavoie-Lamoureux A, Beauchamp G, Lavoie JP.Neutrophils are generally considered less responsive to glucocorticoids compared to other inflammatory cells. The reported increase in human neutrophil survival mediated by these drugs partly supports this assertion. However, it was recently shown that dexamethasone exerts potent anti-inflammatory effects in equine peripheral blood neutrophils. Few comparative studies of glucocorticoid effects in neutrophils and other leukocytes have been reported and a relative insensitivity of neutrophils to these drugs could not be ruled out. Objective: We assessed glucocorticoid-responsiveness in equine an...
Nogradi N, Spier SJ, Toth B, Vaughan B.To describe the clinical course and outcome in horses in which Corynebacterium pseudotuberculosis infections were associated with musculoskeletal disease and lameness. Methods: Retrospective case series. Methods: 35 horses. Methods: Clinical and clinicopathologic data were collected from horses diagnosed with lameness associated with C pseudotuberculosis infection between 1999 and 2009. Results: 32 (91.4%) horses had grade 4/5 lameness. Three (8.6%) horses had grade 5/5 lameness. Abscesses were diagnosed by clinical or ultrasonographic examination. Abscesses were located in the axillary or tri...
Wong DM, Moore RM, Brockus CW.Oxygen is essential to aerobic life, but it is also associated with the production of highly reactive compounds that can pose danger to physiologic systems when the oxygen concentration is excessive. Reactive oxygen species (ROS) are required for normal physiologic processes, but when produced in excess, they can overwhelm endogenous antioxidants, resulting in significant cellular damage and, eventually, cell death. Ischemic events can initiate numerous pathophysiologic mechanisms leading to increased production of ROS, loss of cellular energy production, and lipid peroxidation. Although reper...
Harrington JR, Wilkerson CP, Brake CN, Cohen ND.The innate immune system plays a critical role in protecting neonates against infections early in life and Toll-like receptors (TLRs) are key components of innate immune recognition of pathogens. This study examined the effects of age and stimulation with a TLR 7/8 agonist (R848) on TLR8 mRNA expression by foal neutrophils during the first month of life. We also examined the effects of R848 stimulation on mRNA expression of interleukin (IL)-6 and IL-8 at 1 and 14 days of life. We observed that TLR8 mRNA was constitutively expressed (P<0.05) at all ages examined, and its expression did not c...
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...
Krumrych W, Skórzewski R, Malinowski E.The aim of this study was to determine the effect of duration and temperature of sample storage on whole blood chemiluminescence measurement results. Venous blood from 18 clinically healthy Polish half-bred horses aged 4 to 11 years were used in the study. Luminol dependent chemiluminescence (CL) was used to measure neutrophil oxygen metabolism in whole blood. Blood samples were examined for spontaneous CL and stimulated by a surface receptor stimulus as well as extra-receptor stimulus. The assay was performed in two parallel experimental sets with samples stored at 4 and 22 °C, respectively....
Tee SY, Dart AJ, MacDonald MH, Perkins NR, Horadagoda N, Jeffcott LB.To evaluate the effect of collecting serial tracheal aspirate (TA) and bronchoalveolar lavage (BAL) samples on the cytological findings of subsequent fluid samples obtained from horses without clinical signs of respiratory disease. Methods: Experimental. Methods: Six healthy Standardbred horses. Methods: Endoscopically-guided TA samples, and BAL samples collected using the blind field technique were obtained from the six horses on days 1, 2, 3, 4, 5, 12, and 17. On day 17, horses were sampled three times: at baseline and at 2.5 h and 4 h apart. The differential cytology of the fluid samples co...
Aharonson-Raz K, Lohmann KL, Townsend HG, Marques F, Singh B.Heaves, an obstructive neutrophilic airway inflammation of horses, is triggered by dust components such as endotoxin and has similarities to human asthma. Pulmonary intravascular macrophages (PIMs) increase horses' sensitivity to endotoxin-induced lung inflammation; however, their role in an airborne pathology remains unknown. Therefore, we investigated the role of PIMs in the development of heaves in horses. Clinical and inflammatory responses were evaluated following induction of heaves by moldy hay exposure and PIM depletion with gadolinium chloride (GC). Mares (N = 9) were exposed to four ...
Walter J, Neuberg KP, Failing K, Wehrend A.Aim of this study was to compare uterine smears made using the Knudsen catheter, the cytology brush and a uterine culture swab with regard to diagnostic usefulness and the occurrence of neutrophils. Additionally correlation between culture results and the occurrence of neutrophils in uterine smears was investigated. Samples were collected from 340 mares, 81.5% of which were in estrus. Smears made using the cytology brush yielded more endometrial cells per high-power field than those made using the other two instruments (p<0.0001), and a larger proportion had PMNs compared with smears made u...
Morello S, Southwood LL, Engiles J, Slack J, Crack A, Springate CM.To evaluate the effect of PERIDAN™ Concentrate on clinical findings, infection, and tissue healing in adult horses undergoing celiotomy and jejunojejunostomy. Methods: Block randomized blinded experimental in vivo study. Methods: Adult horses (n = 12). Methods: Horses had jejunojejunostomy at 2 sites and were administered 5 L of diluted PERIDAN™ Concentrate (6 horses) or Lactated Ringer's Injection (LRS) control intraperitoneally (6 horses) before body wall closure. Postoperative monitoring comprised physical examinations, serial hematology, coagulation and chemistry panels, and ultrasonog...
Millerick-May ML, Karmaus W, Derksen FJ, Berthold B, Holcombe SJ, Robinson NE.Accumulations of tracheal mucus assessed by endoscopic examination are associated with poor performance in racehorses. The air quality in horses' stalls may contribute to this visible tracheal mucus. Objective: To determine whether the concentration and number of airborne particulates in stalls are associated with visible accumulations of tracheal mucus and with the number of inflammatory cells in tracheal aspirates. Methods: We studied 107 racehorses from 3 stables, in 3 different months, and measured airborne particulate matter 3 times daily in each of the stalls. On each monthly visit, hors...
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 ...
Zhang L, Franchini M, Wehrli Eser M, Jackson EK, Dip R.Several reports have suggested a role for adenosine in the pathogenesis of chronic airway conditions and this has led to new therapeutic strategies to limit airway inflammation. In this study, detectable levels of adenosine in bronchoalveolar lavage (BAL) samples from 11 horses with non-infectious lower-airway inflammation and 14 healthy controls are reported, with significantly higher values in horses with airway inflammation. Although these increased levels did not correlate with changes in neutrophil percentage in BAL, a positive association between adenosine levels and signs of lower airwa...
Walter J, Klein C, Wehrend A.Exfoliative endometrial cytology is an easy and valuable diagnostic tool for the detection of inflammatory processes of the uterus that correlates well to culture results. The practical use of this procedure is limited due to the time-consuming Papanicolaou-Shorr staining technique. In this study the suitability of the rapid eosin-thiazin staining for endometrial smears was investigated. Methods: Sample collection was carried out with a guarded culture swab (Knudsen-catheter) in 27 broodmares during routine gynaecological examination. Two smears were prepared from each collection. One was stai...
Beekman L, Tohver T, Léguillette R.The pathophysiology of inflammatory airway disease (IAD) is unknown, but in some cases involves the accumulation of mast cells, neutrophils, or both in the bronchoalveolar lavage fluid (BALF). The objective of this study was to characterize cytokine gene expression in the BALF cells of horses with IAD, including a comparison of cytokine gene expression between IAD horses with increased BALF mast cells (IAD-Mast) or neutrophils (IAD-Neutro). Methods: The mRNA expression of IL-4, IFN-γ, IL-17, IL-8, IL-1β, IL-5, IL-6, IL-10, IL-12p35, and eotaxin-2 was studied by quantitative polymerase chain ...
Leclere M, Magdesian KG, Cole CA, Szabo NJ, Ruby RE, Rhodes DM, Edman J, Vale A, Wilson WD, Tell LA.Azithromycin is widely used in foals but has not been studied in adult horses. The goals of this study were to determine the pharmacokinetic profile and to make a preliminary assessment of the safety of azithromycin in adult horses. Azithromycin was administered intravenously (5 mg/kg) and intragastrically (10 mg/kg) to six healthy mares in a crossover design. Serial plasma samples, blood neutrophils, and pulmonary macrophages were collected for the measurement of azithromycin concentrations. Azithromycin was also administered orally (10 mg/kg) once a day for 5 days to five healthy mares for p...
Tilley P, Sales Luis JP, Branco Ferreira M.As recurrent airway obstruction (RAO) is progressive and as medical history is frequently unknown by owners, it's important to suggest a score model to characterize RAO stages for a more accurate diagnosis and treatment. The authors correlated clinical (CS), endoscopic (ES), thoracic X-ray (XRS) and bronchoalveolar lavage fluid (BALFS) scores in horses with RAO, in an attempt to establish relevance of each factor's contribution for the characterization of RAO stages and to suggest a staging method. Thirty horses with RAO and ten healthy controls were studied. Pearson correlation coefficients w...
Bordin AI, Liu M, Nerren JR, Buntain SL, Brake CN, Kogut MH, Cohen ND.Rhodococcus equi is an intracellular bacterium that causes pneumonia in foals and immunocompromised adult horses. Evidence exists that foals become infected with R. equi early in life, a period when innate immune responses are critically important for protection against infection. Neutrophils are innate immune cells that play a key role in defense against this bacterium. Enhancing neutrophil function during early life could thus help to protect foals against R. equi infection. The objective of our study was to determine whether in vitro incubation with the TLR9 agonist CpG 2142 would enhance d...
Holbrook TC, Tipton T, McFarlane D.Equine metabolic syndrome is characterized by obesity and regional adiposity coupled with evidence of recurrent laminitis. Although inflammation has been well characterized in several experimental models of acute laminitis, the inflammatory events associated with endocrinopathic laminitis are not well documented. The aim of this study was to characterize selected markers of inflammation in horses with clinical evidence of equine metabolic syndrome (EMS). Neutrophil phagocytosis and oxidative burst, as well as endogenous and stimulated cytokine expression were evaluated. A marked increase in ne...
Brooks AC, Rickards KJ, Cunningham FM.Neutrophil activation, whilst a key component of host defence, must be tightly regulated in order to avoid an inappropriate cellular response. Annexin-1, which is present in large amounts in neutrophils, and its N-terminal peptides, reduce neutrophil accumulation but annexin peptides have also been shown to exhibit neutrophil activating properties. We have recently shown annexin-1 to be present in equine neutrophils and demonstrated that the annexin-1-derived peptide, Ac2-26, can both reduce superoxide production by these cells in response to other stimuli and directly induce free radical prod...
Dawson DR, Nydam DV, Price CT, Graham JE, Cynamon MH, Divers TJ, Felippe MJ.To investigate the effect of opsonization of Rhodococcus equi with R. equi-specific antibodies in plasma on bacterial viability and phagocyte activation in a cell culture model of infection. Methods: Neutrophils and monocyte-derived macrophages from 6 healthy 1-week-old foals and 1 adult horse. Methods: Foal and adult horse phagocytes were incubated with either opsonized or nonopsonized bacteria. Opsonization was achieved by use of plasma containing high or low concentrations of R. equi-specific antibodies. Phagocyte oxidative burst activity was measured by use of flow cytometry, and macrophag...
Benbarek H, Ayad A, Deby-Dupont G, Boukraa L, Serteyn D.The purpose of this study was to explore the potential modulation of equine neutrophil oxidative burst by a series of classical NSAIDs which was subsequently monitored by the luminol or lucigenin-enhanced chemiluminescence (CL) technique. A significant dose-dependent inhibition of the luminol CL was observed with the majority of investigated drugs. This inhibition was very significant for phenylbutazone and Indomethacin; while for aspirin, a higher concentration is required. The action of Ketoprofen was significant during the first 5 min and only when the concentration was above 1 mM. Indometh...
Wong DM, Alcott CJ, Clark SK, Jones DE, Fisher PG, Sponseller BA.A 3-day-old Thoroughbred colt was originally presented for treatment of neonatal isoerythrolysis, which was treated with a blood transfusion. However, persistent neutropenia was observed despite the absence of detectable infection. Subsequently, a granulocyte agglutination test was performed by incubating the colt's neutrophils with the mare's serum; results were positive, leading to a clinical diagnosis of alloimmune neonatal neutropenia. The diagnosis was further supported via flow cytometric analysis. The colt was hospitalized and treated prophylactically with antimicrobials and 4 separate ...
Wauters J, Franck T, Pille F, Martens A, Demeyere K, Sys S, Serteyn D, Gasthuys F, Meyer E.Myeloperoxidase (MPO) is a protein of interest due to its involvement in equine pathologies. Until now, results in equine diagnostic research were achieved through extracellular MPO detection. However, studying the cellular MPO content in neutrophils has revealed important insights in human diseases. This study aimed to develop a technique for the specific detection of MPO on the single cell level defining a flow cytometric protocol for the detection of both equine surface-bound and cellular MPO. Both indirect and direct labeling techniques are described which include the comparison of two sec...
Miller AB, Loynachan AT, Barker VD, Adams AA.In order to better understand the influence of age on innate immune function in horses, blood was collected from twelve adult horses (aged 10-16 years; mean: 13 years) and ten geriatric horses (aged 18-26 years; mean: 21.7 years) for analysis of plasma myeloperoxidase, complete blood counts, and cytokine and receptor expression in response to in vitro stimulation with heat-inactivated Rhodococcus equi, heat-inactivated Escherichia coli, and PMA/ionomycin. Gene expression was measured using RT-PCR for IFNγ, IL-1β, IL-6, IL-8, IL-10, IL-12α, IL-13, IL-17α, TLR2, TLR4, and TNFα. Endocrine fu...
Brazil TJ, Rossi AG, Haslett C, McGorum B, Dixon PM, Chilvers ER.The synthetic formylpeptide fMLP is widely used as a model chemoattractant and secretagogue for mammalian neutrophils. Despite possessing fMLP receptors, equine neutrophils do not produce superoxide anions in response to fMLP and there is no inflammatory reaction in the horse when fMLP is injected intradermally. The functional capability of these receptors was investigated after pretreatment with recognized priming agents. Purified neutrophils were pretreated with lipopolysaccharide (LPS), platelet-activating factor (PAF), or tumor necrosis factor alpha (TNF-alpha) and superoxide anion generat...
Morris DD, Moore JN.A study was performed to determine prevalence of tumor necrosis factor (TNF) activity in serum of equine neonates with presumed sepsis and to determine correlation between serum TNF activity and severity and outcome of disease. Twenty foals less than 21 days old were considered suitable for inclusion in this study by satisfying clinical and laboratory criteria suggestive of septicemia. At admission, blood samples were collected from all foals for determination of serum TNF activity, then clinical course and outcome of disease were recorded. Thirty-one clinically normal foals less than 21 days ...
McKane SA, Slocombe RF.Histological studies of exercise-induced pulmonary haemorrhage (EIPH) reveals inflammatory infiltrates within areas of lung that contain haemorrhage. This has resulted in the hypothesis that pulmonary inflammation could cause EIPH or contribute to an increased risk or severity of EIPH. Objective: To determine whether experimentally-induced pulmonary inflammation predisposes the lung to haemorrhage during exercise, by evaluating the bronchoalveolar lavage (BAL) cytology of normal and inflamed regions of lung following high speed treadmill exercise. Methods: Transendoscopic airway inoculations o...
Parrilla-Hernandez S, Ponthier J, Franck TY, Serteyn DD, Deleuze SC.Intraluminal fluid and excessive abnormal hyperedema are regularly used for the diagnosis of endometritis in the mare, which is routinely confirmed by the presence of neutrophils on endometrial smears. Studies show a relation between neutrophils and myeloperoxidase (MPO), an enzyme contained in and released by neutrophils during degranulation or after cell lysis. This enzyme has been found in many fluids and tissues, and associated with different inflammatory pathologies in the horse. The aims of this study were to assess the presence and concentration of MPO in the equine uterus, and to inves...
Mainguy-Seers S, Beaudry F, Fernandez-Prada C, Martin JG, Lavoie JP.Extracellular vesicles (EVs) contribute to intercellular communication through the transfer of their rich cargo to recipient cells. The EVs produced by LPS-stimulated neutrophils from healthy humans and horses increase airway smooth muscle (ASM) proliferation, but the roles of neutrophil EVs in asthma are largely unexplored. The aim of this study was to determine whether neutrophil-derived EVs isolated during the remission or exacerbation of asthma influence ASM proliferation differentially. Peripheral blood neutrophils were collected during remission and exacerbation in eight horses affected ...
Grosche A, Morton AJ, Polyak MM, Matyjaszek S, Freeman DE.The cytosolic protein complex, calprotectin, is abundant in neutrophils and could be used to improve the ability to localise and assess neutrophil infiltration in the equine intestine during ischaemia and reperfusion (I/R), but further study is required. Objective: To assess the number of calprotectin-containing cells by immunohistochemistry in correlation with direct counting and scoring of neutrophils in the equine colon during I/R. Methods: One and 2 h ischaemia of the left dorsal colon were induced, followed by 30 min reperfusion under general anaesthesia or by 18 h reperfusion after anaes...
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...
Endo Y, Tsuchiya T, Omura T, Nakai K, Korosue K, Ishimaru M, Ishikawa Y, Hobo S.The present study evaluated the effects of single-dose marbofloxacin in protecting horses against fever associated with transportation using 48 healthy Thoroughbreds. All horses were premedicated with interferon-α (0.5 U/kg, sublingually, every 24 hr) for 2 days before transportation and on the day of transportation. Horses were randomly assigned to receive marbofloxacin (2 mg/kg, IV, once; MRFX group), enrofloxacin (5 mg/kg, IV, once; ERFX group) or saline (0.9% NaCl) solution (10 ml, IV, once; control group) ≤1 hr before being transportation. Each group contained 16 horses (8 males, 8 fem...
Michelotto PV, Muehlmann LA, Zanatta AL, Bieberbach EW, Fernandes LC, Nishiyama A.Inflammatory airway disease (IAD) is prevalent in young racehorses during training, being the 2nd most commonly diagnosed ailment interrupting training of 2-year-old Thoroughbred racehorses. Objective: That stabling and exercise cause oxidative stress, release of platelet-activating factor (PAF) and inflammation in airways of Thoroughbred colts. Methods: Colts in breeding farms (NC, n = 45), stabled for 30 days (EC, n = 40), and race trained (EX, n = 34). Methods: Cytological profile and parameters of bronchoalveolar lavage fluid (BALF) related to oxidative stress, bioactivity of the proinflam...
Husulak ML, Manning ST, Meachem MD, Burgess HJ, Epp TY, Montgomery JB.The objective of this study was to observe the outcomes of adding an antimicrobial treatment to a conventional treatment regime in horses with severe equine asthma in a clinical setting. Eleven client-owned horses with a history consistent with severe equine asthma, increased respiratory effort and nostril flaring, ≥ 20% neutrophils on bronchoalveolar lavage (BAL), and a positive tracheal wash (TW) bacterial culture were treated with environmental management, corticosteroids, and bronchodilators. Six horses were also treated with an antimicrobial (principal group), while the other 5 were adm...
Koblinger K, Hecker K, Nicol J, Wasko A, Fernandez N, Léguillette R.The bronchoalveolar lavage (BAL) procedure can return variable volumes of fluid, possibly depending on the presence of bronchial collapse during fluid aspiration and on the severity of lung inflammation. Objective: We tested the hypothesis that horses with bronchial collapse during BAL are at higher risk of having severe lung inflammation. Methods: Prospective field study. Methods: Bronchial collapse was graded using a new simple scoring method (0, 1 or 2) during a standardised BAL procedure in the field on 131 horses with normal, mild/moderate or severe lower airway inflammation on cytology o...
Roberto Da Costa RP, Carvalho H, Agrícola R, Alpoim-Moreira J, Martins C, Ferreira-Dias G.The purpose of this study was to evaluate different parameters of the immune status in the mare, during the follicular and the luteal phases of the oestrous cycle, in two consecutive years. Functional competence of peripheral blood neutrophils, such as chemotaxis, phagocytosis and oxidative burst was assessed under physiological cyclic conditions (Exp. I). In the second year of this study (Exp. II), besides peripheral blood neutrophil phagocytosis and oxidative burst analysis, circulating lymphocyte subsets were also characterized. The reproductive status in a total of 17 adult cycling mares w...
Arfuso F, Giudice E, Di Pietro S, Piccione G, Giannetto C.This study aimed to evaluate the hematological and serum protein electrophoretic profiles of horses after inactivated West Nile virus (WNV) vaccine administration. Blood samples were collected from 10 horses before (T0), after 24 h, 48 h, 72 h, 1 week, 2 weeks and 3 weeks (T1, T2, T3, T4, T5 and T6) from the first WNV vaccine-dose administration, before the vaccine-booster (TPRE), and after 24 h, 48 h, 72 h, 1 week, 2 weeks and 3 weeks (T1, T2, T3, T4, T5, T6) from the WNV vaccine-booster. There was a significant increase in lymphocytes and a decrease in neutrophils after both the first vaccin...
Martens JG, Martens RJ, Renshaw HW.The capacity of hematogenous polymorphonuclear neutrophilic leukocytes (PMNL) to kill Rhodococcus equi was compared in horses of various ages. A radioisotope bactericidal assay was used to determine the capacity of PMNL to kill R equi. Assays were conducted on PMNL from horses in 3 groups: group I, 13 foals with a mean age of 3.3 days; group II, 10 group-I foals at a mean age of 35.7 days; and group III, adult dams of group-I foals. Bacteria were obtained from the lungs of a foal with R equi pneumonia and opsonized with fresh adult equine serum that contained R equi specific antibody. The mean...
Anderson MJ, Ibrahim AS, Cooper BR, Woolcock AD, Moore GE, Taylor SD.Sepsis is associated with ascorbic acid (AA) depletion and critical illness-related corticosteroid insufficiency (CIRCI) in humans. Objective: Intravenous infusion of lipopolysaccharide (LPS) would (a) decrease endogneous AA concentrations, (b) induce CIRCI and (c) administration of a combination of AA and hydrocortisone (HC) would have decreased indices of inflammation compared to either drug alone. Methods: Thirty-two healthy horses. Methods: Randomized placebo-controlled experimental trial. Horses were assigned to 1 of 4 groups (saline, AA and HC, AA only, or HC only). Treatments were admin...
Brooks AC, Menzies-Gow NJ, Wheeler-Jones C, Bailey SR, Cunningham FM, Elliott J.The endothelium plays a major role in the pathogenesis of endotoxemia. Binding of endotoxin (lipopolysaccharide; LPS) to endothelium initiates a range of signalling events, including activation of p38 mitogen activated protein kinases (MAPKs) that are involved in the initiation of inflammatory responses. In the present study we have examined whether clinically relevant concentrations of LPS can activate p38 MAPK in equine endothelial cells and have investigated the role of the kinase in neutrophil adhesion and mediator release. Cultured equine digital vein endothelial cells (EDVEC) were expose...
Pellegrini A, Waiblinger S, Von Fellenberg R.Lysozyme from equine neutrophil granulocytes was isolated in a pure form by fast performance liquid chromatography, i.e. ion-exchange chromatography and reversed-phase chromatography. The lysozyme lysed Micrococcus luteus, Bacillus subtilis and Staphylococcus lentus and was also bactericidal against the Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae, Bordetella bronchiseptica, and Serratia marcescens. Staphylococcus aureus and Staphylococcus epidermidis were not lysed. The lysozyme was only very slightly bactericidal for S. epidermidis and S. aureus. Equine neutrophil lysozyme ...
Hopster-Iversen CC, Hopster K, Staszyk C, Rohn K, Freeman DE, Rötting AK.To determine characteristics of the inflammatory reaction in the jejunum of horses in response to various mechanical manipulations. Methods: 12 adult warm blood horses without gastrointestinal tract disorders. Methods: The proximal aspect of the jejunum in each horse was divided into 5 segments, and the following manipulations were performed: manual emptying, placement of Doyen forceps, enterotomy alone, enterotomy with mucosal abrasion, and serosal abrasion. Jejunum samples were collected before (control), immediately after, and 30 minutes after the end of manipulations and histologically eva...
Mair TS, Stokes CR, Bourne FJ.Lavage procedures were used to obtain samples of respiratory secretions from the nasal cavity, trachea, bronchi and bronchoalveolar level of apparently normal conscious horses, and the cellular composition of the lavage fluids was assessed. There was a progressive increase in total cell count of the secretions obtained from the upper to the lower respiratory tracts. Nasal lavage fluid was composed chiefly of epithelial cells, whereas tracheal, bronchial and bronchoalveolar fluids contained higher proportions of macrophages, lymphocytes and neutrophils. Eosinophils and mast cells were identifie...
Zandoná Meleiro MC, de Carvalho HJC, Ribeiro RR, da Silva MD, Salles Gomes CM, Miglino MA, de Santis Prada IL.Racehorses are constantly exposed to stress. Aiming to verify the state of blood components and cortisol alterations during their routine and after races, phagocytosis and oxidative neutrophil burst assays, serum cortisol determination, erythrocytes apoptosis evaluation, lymphoproliferation assays, and blood count tests were performed in thirty Thoroughbred racehorses, which were divided in two groups. The samples were taken right after races (moment 0 d), during rest periods (-11 d, +1 d, +3 d), and after training (-8, +2, +5). In both groups, the phagocytosis showed a decrease in percentage ...
Labens R, Daniel C, Hall S, Xia XR, Schwarz T.Early diagnosis of cartilage disease at a time when changes are limited to depletion of extracellular matrix components represents an important diagnostic target to reduce patient morbidity. This report is to present proof of concept for nanoparticle dependent cartilage barrier imaging in a large animal model including the use of clinical magnetic resonance imaging (MRI). Conditioned (following matrix depletion) and unconditioned porcine metacarpophalangeal cartilage was evaluated on the basis of fluorophore conjugated 30 nm and 80 nm spherical gold nanoparticle permeation and multiphoton lase...
Faleiros RR, Leise BB, Westerman T, Yin C, Nuovo GJ, Belknap JK.C-X-C motif ligand 1 (CXCL1) is an important chemokine of epithelial origin in rodents and humans. Objective: To assess in vivo and in vitro the regulation of CXCL1 in equine laminitis. Methods: Twenty adult horses. Methods: Real-time quantitative polymerase chain reaction (PCR) was used to assess expression of CXCL1 in samples of laminae, liver, skin, and lung from the black walnut extract (BWE) model of laminitis, and in cultured equine epithelial cells (EpCs). Tissue was obtained from control animals (CON, n = 5), and at 1.5 hours (early time point [ETP] group, n = 5), at the onset of leuko...
Adaszek Ł, Winiarczyk S, Łukaszewska J.The study was aimed at determining the cause of a disease in a horse exhibiting symptoms of fever, joint effusion, weakness, and extravasations on the mucous membranes. Blood was drawn from the animal for haematological and biochemical molecular tests. The PCR technique revealed the presence of 16S RNA Ehrlichia spp. genetic material in the blood samples. DNA amplification by means of primers EHR 521 and EHR 747 gave a product with a volume of 247 bp.The sequence of the PCR product obtained showed a 97.6% similarity with a sequence of a fragment of 16S RNA Ehrlichia phagocytophila, gene number...
Deniz Ö, Ekinci G, Onmaz AC, Derelli FM, Fazio F, Aragona F, Hoven RVD.Rhodococcus equi (R. equi), a gram-positive facultative intracellular pathogen, is a common cause of pneumonia in foals and represents a major cause of disease and death. The aim of the present study was to investigate the time-depended changes in White Blood Cells (WBC), basophils (Baso), neutrophils (Neu), lymphocytes (Lymf), monocytes (Mon), eosinophils (Eos), platelet (PLT) counts, fibrinogen (Fbg) concentration, interferon (IFN-α, IFN-γ) and interleukins (IL-2 and IL-10) in foals with clinical R. equi pneumonia. The main treatment was with azithromycin-rifampicin for 14 days. Blood was ...
Franck T, Kohnen S, de la Rebière G, Deby-Dupont G, Deby C, Niesten A, Serteyn D.Neutrophil (PMN) contribution to the acute inflammatory processes may lead to an excessive generation of reactive oxygen metabolites species (ROS) and secretion of granule enzymes. We compared the effects of either phorbol myristate acetate (PMA) or N-formyl-methionyl-leucyl-phenylalanine (fMLP) in combination with a pre-treatment by cytochalasin B (CB) on the production of ROS and the release of total and active myeloperoxidase (MPO) by isolated equine PMNs. The ROS production was assessed by lucigenin dependent chemiluminescence (CL) and ethylene release by alpha-keto-gamma-methylthiobutyric...
Sweeney CR, Humber KA, Roby KA.Tracheobronchial aspirates obtained from 66 healthy Thoroughbred racehorses in training at the same track were examined. Twenty-seven percent of the horses had greater than 20% neutrophils in the aspirate. Eosinophils, mast cells, giant cells, and Curschmann's spirals of mucus were observed in 94, 83, 65, and 42% of the horses, respectively. Hemosiderophages were observed in 86% of the horses, half of which had previous confirmation of exercise-induced pulmonary hemorrhage. Although fungal elements were seen in 70% of the horses, bacteria were detected in only 3% of the horses. The authors con...
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...
Deaton CM, Marlin DJ, Smith NC, Harris PA, Dagleish MP, Schroter RC, Kelly FJ.Effects of acute airway inflammation induced by organic dust inhalation on pulmonary antioxidant status were investigated in healthy horses and horses affected by recurrent airway obstruction. Exposure to organic dust induced acute airway neutrophilia, which was associated with increases in elastase and decreases in ascorbic acid concentrations in bronchoalveolar lavage fluid. However, markers of oxidative stress were unaffected, as was hydrogen peroxide in breath condensate. Decreases in ascorbic acid correlated with increased respiratory resistance (P = .001) when both groups were combined. ...
