Plasma is the liquid component of blood in horses, consisting primarily of water, electrolytes, proteins, and waste products. It serves as a transport medium for nutrients, hormones, and waste products throughout the body. Plasma also plays a role in maintaining blood pressure and volume, as well as serving as a reservoir for critical proteins involved in clotting and immune responses. Research on equine plasma often focuses on its composition, functions, and applications in veterinary medicine, such as transfusions and diagnostic testing. This page compiles peer-reviewed research studies and scholarly articles that explore the properties, functions, and clinical applications of plasma in equine health.
Noble GK, Li X, Zhang D, Sillence MN.Tryptophan (TRP) is marketed as a calmative for horses despite reservations about its efficacy. The aim of this study was to measure the effect of oral TRP administration on the reaction speed of horses. Sixty mature horses were used in a two stage randomised, blind, cross-over study, receiving a placebo and an oral dose of TRP (30, 60 or 120 mg/kg body weight), before undergoing a reaction speed test. Blood samples were taken up to 96 h after TRP administration, to identify signs of acute haemolytic anaemia. Plasma TRP concentrations were increased (P <0.001) by the administration of...
Fogle J, Jacob M, Blikslager A, Edwards A, Wagner B, Dean K, Fogle C.Clinically useful biomarkers are needed for early identification of endotoxaemic horses. Soluble CD14 (sCD14) is amplified early in response to inflammatory signals, including bacterial lipopolysaccharide (LPS), and may prove a useful biomarker for clinical endotoxaemia. Objective: The aim of this study was to determine if sCD14 could serve as a more reliable biomarker of the clinical signs of endotoxaemia, compared to measuring LPS alone. Methods: Prospective observational study in horses at a veterinary teaching hospital. Methods: Plasma samples were collected from 20 healthy horses and 35 h...
Salciccia A, Grulke S, de la Rebière de Pouyade G, Franck T, Detilleux J, Serteyn D, Sandersen C.To determine changes in blood granulocyte counts and in plasma myeloperoxidase (MPO) and elastase (ELT) concentrations in surgical colic cases, and to determine the relationship between these changes and the surgical procedure performed, occurrence of postoperative ileus, and final outcome. Methods: Prospective clinical study conducted over a 12-month period. Methods: University teaching hospital. Methods: Fifty-three horses undergoing emergency laparotomy and surviving at least 12 hours postoperatively. Methods: Blood samples were taken before surgery, during surgery, at the recovery from ane...
Kwok WH, Choi TLS, Kwok KY, Chan GHM, Wong JKY, Wan TSM.The high sensitivity of ultra high performance liquid chromatography coupled with high resolution mass spectrometry (UHPLC-HRMS) allows the identification of many prohibited substances without pre-concentration, leading to the development of simple and fast 'dilute-and-shoot' methods for doping control for human and equine sports. While the detection of polar drugs in plasma and urine is difficult using liquid-liquid or solid-phase extraction as these substances are poorly extracted, the 'dilute-and-shoot' approach is plausible. This paper describes a 'dilute-and-shoot' UHPLC-HRMS screening me...
Westerman TL, Foster CM, Tornquist SJ, Poulsen KP.To evaluate the use of the acute-phase proteins serum amyloid A (SAA) and haptoglobin as prognostic indicators in horses with colic with regard to the need for surgical intervention, development of complications, and hospitalization cost and duration. Methods: Prospective observational study. Methods: 20 clinically normal horses and 42 horses with colic. Methods: Total WBC and neutrophil counts and plasma fibrinogen, SAA, and haptoglobin concentrations were compared between healthy (control) horses and horses admitted to a veterinary teaching hospital for colic. Clinicopathologic values were c...
Gokbulut C, Ozuicli M, Aksit D, Aksoz E, Korkut O, Yalcinkaya M, Cirak VY.The horse milk gains increasing interest as a food product for sensitive consumers, such as children with food allergies or elderly people. We investigated the plasma and milk disposition, faecal excretion and efficacy of per os ivermectin (IVM) and pour-on eprinomectin (EPM) in horses. Ten mares were divided into two groups. The equine paste formulation of IVM and bovine pour-on formulation of EPM were administered orally and topically at dosage of 0.2 and 0.5Â mg/kg bodyweight. Blood, milk and faecal samples were analysed using high-performance liquid chromatography. The plasma concentration...
Hansson A, Knych H, Stanley S, Thevis M, Bondesson U, Hedeland M.Selective androgen receptor modulators (SARMs) are prohibited in sports due to their performance enhancing ability. It is important to investigate the metabolism to determine appropriate targets for doping control. This is the first study where the equine metabolites of SARMs S1, S4 (Andarine) and S22 (Ostarine) have been studied in plasma. Methods: Each SARM was administered to three horses as an intravenous bolus dose and plasma samples were collected. The samples were pretreated with protein precipitation using cold acetonitrile before separation by liquid chromatography. The mass spectrome...
Sanz MG, Loynachan A, Horohov DW.Since a vaccine is not available against Rhodococcus equi, R equi-specific hyperimmune plasma (HIP) is commonly used, although its efficacy remains controversial. The objective of this study was to evaluate the ability of a commercially available HIP to prevent clinical rhodococcal pneumonia in neonatal foals after experimental challenge.
Lindåse SS, Nostell KE, Müller CE, Jensen-Waern M, Bröjer JT.To quantify insulin sensitivity and monitor glucose, insulin, and lipid concentrations in a group of moderately insulin-resistant horses during induction of obesity by use of a forage diet supplemented with fat and during subsequent turnout to pasture. ANIMALS 9 adult Standardbred mares (11 to 20 years old). Methods: Weight gain of horses was induced during 22 weeks by use of a forage diet supplemented with fat fed in gradually increasing amounts, followed by feeding of that fat-supplemented diet at 2.5 times the daily maintenance requirements. Horses were then turned out to pasture. Insulin s...
Martin-Gimenez T, de Blas I, Aguilera-Tejero E, Diez de Castro E, Aguirre-Pascasio CN.Equine metabolic syndrome (EMS) can be diagnosed by hormonal measurements; however, it would be important to find simpler measurements that allow easy identification of affected or at risk individuals. In horses, the dorsal neck region is one of the most frequent anatomical sites for fat deposition and neck obesity has been linked to EMS. The aim of this study was to evaluate the association of hormonal markers of obesity (leptin) and insulin resistance (insulin) with morphometric and ultrasonographic neck measurements in Andalusian horses. Plasma leptin and insulin concentrations were measure...
Mori M, Ichibangase T, Yamashita S, Kijima-Suda I, Kawahara M, Imai K.In the doping tests currently used in horse racing, prohibited substances or their metabolites are usually directly detected in urine or blood samples. However, despite their lasting pharmaceutical effects, some prohibited substances are rapidly eliminated from horse urine and blood, making them difficult to detect. Therefore, new indirect biomarkers for doping, such as plasma proteins that are increased by the prohibited substances, have recently attracted much attention. Here, a fluorogenic derivatization-liquid chromatography-tandem mass spectrometry (FD-LC-MS/MS) method was adopted for hor...
Legacki EL, Scholtz EL, Ball BA, Stanley SD, Berger T, Conley AJ.Liquid chromatography-tandem mass spectrometry (LC-MS/MS) allowed comprehensive analysis of various steroids detectable in plasma throughout equine gestation. Mares (n=9) were bled serially until they foaled. Certain steroids dominated the profile at different stages of gestation, clearly defining key physiological and developmental transitions. The period (weeks 6-20) coincident with equine chorionic gonadotropic (eCG) stimulation of primary corpora lutea and subsequent formation of secondary luteal structures was defined by increased progesterone, 17OH-progesterone and androstenedione, all Î...
Brøkner C, Austbø D, Næsset JA, Blache D, Bach Knudsen KE, Tauson AH.The hypothesis for this study was that a higher dietary proportion of soluble fibre would result in stable and constant plasma metabolite and regulatory hormone concentrations. The study was a 4×4 Latin Square design with a sequence of 17 days adaptation to the ration followed by 8 sampling days. The feed rations consisted of only timothy hay (H), hay plus molassed sugar beet pulp combined with either whole oats (OB) or barley (BB) and hay plus a loose chaff-based concentrate (M). Four horses were fitted with permanent caecal cannulas and liquid caecal content was withdrawn manually and blood...
Irvine KL, Burt K, Hill AJ, Shaw S, Papasouliotis K.Equine pituitary pars intermedia dysfunction (PPID) may be diagnosed by measuring baseline plasma adrenocorticotrophic hormone (ACTH). The Immulite 1000 analyzer uses an automated chemiluminescence enzyme assay, previously validated for measuring equine ACTH. Recently, an automated bench-top immunoassay analyzer (AIA-360), designed for analytes in people, became available for veterinary use. Objective: Objectives were to evaluate analytic performance of the AIA immunoassay for measuring equine ACTH, and compare the results with those obtained by the Immulite. Methods: Adrenocorticotrophic horm...
Knych HK, Vidal MA, Chouicha N, Mitchell M, Kass PH.The frequent use of intra-articular triamcinolone acetonide (TA) in performance horses warrants further study of the duration of as well as the beneficial and detrimental effects on gene expression associated with administration. Objective: To assess the effects of intra-articular administration of TA on the expression of selected anti- and proinflammatory and structural matrix genes following its administration into joints of exercised Thoroughbred horses and to correlate these effects with plasma and synovial fluid drug concentrations. Methods: Block design experiment. Methods: Eight exercis...
Lee S, Hwang S, Yu HJ, Oh D, Choi YJ, Kim MC, Kim Y, Ryu DY.MicroRNAs (miRNAs) in blood plasma are stable under high levels of ribonuclease activity and could function in tissue-to-tissue communication, suggesting that they may have distinctive structural characteristics compared with non-circulating miRNAs. In this study, the expression of miRNAs in horse plasma and their characteristic nucleotide composition were examined and compared with non-plasma miRNAs. Highly expressed plasma miRNA species were not part of the abundant group of miRNAs in non-plasma tissues, except for the eca-let-7 family. eca-miR-486-5p, -92a, and -21 were among the most abund...
Gokbulut C, Aksit D, Santoro M, Roncoroni C, Mariani U, Buono F, Rufrano D, Fagiolo A, Veneziano V.Mebendazole (MBZ) has been licensed for use in horses and donkeys, however there are no data available in the literature regarding its pharmacokinetic disposition and efficacy in donkeys. This study was designed to determine the plasma disposition, milk excretion and anthelmintic efficacy of MBZ in donkeys naturally infected by Cyathostominae. The animals were allocated to three groups, each of six donkeys. One group was untreated control (C-group) and the others were treated using a paste formulation of MBZ administered per os at the manufacturer's recommended horse dosage of 10 mg/kg body we...
Chen JW, Uboh CE, Robinson MA, Jiang Z, Soma LR.To evaluate plasma interleukin 6 (IL-6) concentration in Standardbred racehorses by means of a novel ELISA following validation of the assay for use with equine plasma samples. Methods: Plasma samples obtained from 25 Thoroughbreds for use in assay validation and from 319 Standardbred racehorses at rest 2 to 2.5 hours prior to warm-up and racing. Methods: A sandwich ELISA was developed with equine anti-IL-6 polyclonal antibody and the biotin-streptavidin chemical interaction to enhance sensitivity. The assay was validated for specificity, sensitivity, precision, and accuracy by use of both rec...
Bauquier JR, Forbes G, Nath L, Tudor E, Bailey SR.Acute gastrointestinal disease occurs commonly in horses. Novel biomarkers might improve the understanding of SIRS and aid diagnosis and determination of prognosis. Objective: Increased plasma concentrations of the biomarkers HMGB-1 and nucleosomes are associated with severity of gastrointestinal lesions in horses; concentrations of these biomarkers will be greater in horses with lesions more likely to cause SIRS; and will provide additional information compared with standard biomarkers fibrinogen and SAA. Methods: Thirty horses with gastrointestinal disease, 22 healthy horses. Methods: Prospe...
Albright JD, Witte TH, Rohrbach BW, Reed A, Houpt KA.Crib-biting is a common oral stereotypy. Although most treatments involve prevention, the efficacy of various anti-crib devices, including surgically implanted gingival rings, has thus far not been empirically tested. Objective: Demonstrate the effect that 2 anti-crib collars, muzzle and gingival rings have on crib-biting, other maintenance behaviours, and cortisol levels in established crib-biting horses. Methods: Randomised, crossover clinical trial. Methods: In Experiment I, 2 anti-crib collars and a muzzle were used on 8 established crib-biting horses; horses wore each of 3 devices for 7 d...
Teixeira FA, Araújo AL, Ramalho LO, Adamkosky MS, Lacerda TF, Coelho CS.The aim of this study was to evaluate the effects of oral creatine supplementation on the athletic performance of equines used for barrel racing. Ten healthy Quarter Horses, or Quarter Horse crossbred, weighing 429.7 ± 25.3 kg and with mean age of 3.8 ± 1.2 years, were used. Animals were evaluated in four different moments (M1, M2, M3, M4), and between M3 and M4, they were supplemented with 28 g of creatine/100 kg of body weight, orally, for 45 days. Although significant alterations for LDH activity, plasma glucose and packed cell volume were observed, it was possible to conclude th...
Van Der Vekens N, Hunter I, Timm A, Decloedt A, De Clercq D, Deprez P, Goetze JP, van Loon G.Equine atrial natriuretic peptide (ANP) plasma concentrations are correlated with left atrial size. However, species-specific assays are lacking and the results from human assays are poorly reproducible. A new methodology called processing independent analysis (PIA) that measures the total proANP product in plasma has proven to be successful in human medicine, but has never been used in horses. The aims were to establish an equine proANP reference interval by measurement of the total proANP product using PIA and to examine the proANP concentrations in horses with atrial dilatation. Sample stab...
Santos FC, Corcini CD, Costa VG, Gheller SM, Nogueira CE, da Rosa Curcio B, Varel AS.Solid storage medium prevents cellular sedimentation, reduces metabolic demand via limiting movement, and avoids the modification of an extender composition in the sedimentary microenvironment. It has been proven to prolong spermatozoa viability in mammalians. Objective: This experiment aims to evaluate the effect of cool storage in solid phase extender on stallion sperms. Methods: Semen was collected from 10 Crioulo stallions (n=30) and submitted to treatments: control group (semen extender) and groups with gelatin addition in different concentrations (semen extender + 1%, 2% and 3%). Seminal...
Kusano K, Nomura M, Toju K, Ishikawa Y, Minamijima Y, Yamashita S, Nagata S.Procaterol (PCR) is a beta-2-adrenergic bronchodilator widely used in Japanese racehorses for treating lower respiratory disease. The pharmacokinetics of PCR following single intravenous (0.5 μg/kg) and oral (2.0 μg/kg) administrations were investigated in six thoroughbred horses. Plasma and urine concentrations of PCR were measured using liquid chromatography-mass spectrometry. Plasma PCR concentration following intravenous administration showed a biphasic elimination pattern. The systemic clearance was 0.47 ± 0.16 L/h/kg, the steady-state volume of the distribution was 1.21 ± 0.23 L/kg, ...
Kawasumi K, Yamamoto M, Koide M, Okada Y, Mori N, Yamamoto I, Arai T.Age effects on plasma metabolites, hormone concentrations, and enzyme activities related to energy metabolism were investigated in 20 riding horses. Animals were divided into two groups: Young (3-8 years) and aged (11-18 years). They were clinically healthy, and not obese. Plasma adiponectin (ADN) concentrations in aged horses were significantly lower than those in young horses (mean±SE, 6.5±1.3 µg mL(-1) vs, 10.9±1.7 µg mL(-1), Mann-Whitney U test, respectively; P=0.0233). Plasma non-esterified fatty acid levels and Insulin and malondialdehyde concentrations in aged group tended to incre...
Bonelli F, Meucci V, Divers TJ, Jose-Cunilleras E, Corazza M, Tognetti R, Guidi G, Intorre L, Sgorbini M.The diseases most frequent associated with SIRS in adult horses are those involving the gastrointestinal tract. An early diagnosis should be the goal in the management of horses with SIRS. Objective: The objective of this study was to evaluate the plasma procalcitonin (PCT) concentration in healthy and SIRS horses to assess differences between the two groups. Methods: Seventy-eight horses (30 healthy and 48 SIRS). Methods: Prospective in vivo multicentric study. Horses were classified as SIRS if at least 2 of the following criteria were met: abnormal leukocyte count or distribution, hypertherm...
Mastellar SL, Moffet A, Harris PA, Urschel KL.Current equine threonine requirement estimates do not account for probable use of threonine to maintain gut health and mucin synthesis. The objective of this study was to determine if threonine supplementation (+Thr) would increase whole-body protein synthesis (WBPS) in weanling colts (Study 1) and adult mares (Study 2). Both studies used a crossover design, where each of six animals was studied twice while receiving the isonitrogenous diets. The basal diets contained lower threonine levels (Basal) than the threonine (+Thr) supplemented diets. Threonine intakes in mg/kg BW/day were as follows:...
Frank N, Sojka JE, Latour MA.To measure and compare the concentration and composition of very low-density lipoprotein (VLDL) in plasma and selected lipids in serum of horses fed mixed grass hay ad libitum or denied feed for 36 hours. Methods: 4 healthy adult mares. Methods: Mares were either fed mixed grass hay ad libitum or denied feed for 36 hours beginning at 8:00 AM. Blood samples were collected every 2 hours during the study period and analyzed for nonesterified fatty acid (NEFA), triglyceride (TG), VLDL, and glucose concentrations and composition of VLDL. Results: Withholding feed significantly increased mean serum ...
Clarke LL, Argenzio RA, Roberts MC.The effect of meal size and frequency on plasma volume, plasma aldosterone concentration and urinary Na and K clearances was determined in ponies. A daily maintenance ration of hay-grain pellets was provided either as a multiple feeding regimen, ie, 12 equal portions fed at 2-hour intervals, or as single large feedings, ie, half the ration fed every 12 hours at 0800 and 2000 hours. Only the effect of the single morning feeding was studied, using the latter regimen. Serial measurements of plasma volume were made by use of an indicator-dilution technique and indocyanine green (0.15 mg/kg of body...
Gokbulut C, Aksit D, Santoro M, Roncoroni C, Mariani U, Buono F, Rufrano D, Fagiolo A, Veneziano V.Mebendazole (MBZ) has been licensed for use in horses and donkeys, however there are no data available in the literature regarding its pharmacokinetic disposition and efficacy in donkeys. This study was designed to determine the plasma disposition, milk excretion and anthelmintic efficacy of MBZ in donkeys naturally infected by Cyathostominae. The animals were allocated to three groups, each of six donkeys. One group was untreated control (C-group) and the others were treated using a paste formulation of MBZ administered per os at the manufacturer's recommended horse dosage of 10 mg/kg body we...
Muir WW, Sams R.Eight adult horses were used in a study to determine ketamine's ability to reduce halothane requirement. To obtain steady-state plasma concentrations of 0.5, 1.0, 2.0, 4.0, and 8.0 micrograms/ml, loading doses and constant infusions for ketamine were calculated for each horse on the basis of data from other studies in which the pharmacokinetic properties of ketamine were investigated. Blood samples for determination of plasma ketamine concentrations were collected periodically during each experiment. Plasma ketamine concentrations were determined by capillary gas chromatography/mass spectromet...
Weber JM, Parkhouse WS, Dobson GP, Harman JC, Snow DH, Hochachka PW.Plasma lactate turnover rate of Thoroughbred racehorses was measured by bolus injection of [U-14C]lactate at rest and two levels of submaximal treadmill exercise (3-4 m/s trot, 6% incline, and 6.5 m/s horizontal canter). Our goals were 1) to determine the relative effects of changes in cardiac output and in plasma lactate concentration on turnover rate [using cardiac output data from Weber et al. (28)] and 2) to assess the importance of lactate as a metabolic fuel in a trained animal athlete. Lactate turnover rates were 9.3 mumol.min-1.kg-1 (rest), 75.9 mumol.min-1.kg-1 at the beginning of the...
Hodson NP, Wright JA, Hunt J.Plasma levels of adrenocorticotropic hormone (ACTH), cortisol and catecholamines were used to study the role of the sympatho-adrenal system in equine grass sickness. Statistical evaluation determined differences of hormone levels between seven horses with grass sickness (one acute, five subacute and one chronic), six horses with colic (one with laminitis) and 16 control horses before and after mild stress. Plasma levels of the hormones were higher in horses with acute and subacute grass sickness than in the other groups. No differences were detected between horses with colic and stressed contr...
Juneja RK, Gahne B, Lukka M, Ehnholm C.By using immunoblotting with antiserum specific to human plasma apolipoprotein A-IV (apoA-IV), a previously reported polymorphic plasma protein of dogs viz postalbumin-2 (Pa2) and one of horses viz serum protein 2 (SP2), were identified as apoA-IV of these species. This along with earlier published results implied that: (1) both dog and horse show a high degree of polymorphism at the APOA4 locus with three common alleles in each of the two species; and (2) apoA-IV phenotyping in these two species can be done by analysing plasma/serum samples by a simple method of two-dimensional electrophoresi...
Gokbulut C, Akar F, McKellar QA.Fenbendazole (FBZ), oxfendazole (fenbendazole sulphoxide, FBZSO), and albendazole (ABZ) were administered orally to donkeys at 10mg/kg bodyweight. Blood and faecal samples were collected from 1 to 120 h post-treatment. The plasma and faecal samples were analysed by high performance liquid chromatography (HPLC). The parent molecule and its sulphoxide and sulphone (FBZSO(2)) metabolites did not reach detectable concentrations in any plasma samples following FBZ administration. ABZ was also not detected in any plasma samples, but its sulphoxide and sulphone metabolites were detected, demonstratin...
Sosa León LA, Davie AJ, Hodgson DR, Rose RJ.Effects of different tonicities, glucose concentrations and temperatures of an oral rehydration solution (ORS) on its uptake and elimination in resting horses were studied. Fluid and electrolyte deficits similar to those occurring during prolonged exercise were induced by the administration of 1 mg/kg bwt of frusemide i.m., 3 h prior to the ORS. Fluid was administered via nasogastric tube at a volume equivalent to 4% bodyweight, which approximated diuretic induced losses. The uptake of fluid was evaluated by changes in haematocrit (PCV) and plasma total protein concentration (TP). Changes in e...
Papas M, Catalán J, Recuero S, Morrell JM, Yeste M, Miró J.This study sought to determine whether single layer centrifugation (SLC) of fresh donkey semen with Equicoll has any impact on sperm quality parameters and on the modulation of endometrial reaction following semen deposition using an in vitro model. Seventeen ejaculates from five jackasses were obtained using an artificial vagina and diluted in a skim-milk extender. Samples were either selected through SLC (Equicoll) or non-treated (control). Two experiments were performed. The first one consisted of incubating selected or non-selected spermatozoa at 38 °C for 180 min. Integrity and lipid dis...
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...
Owens JG, Kamerling SG, Barker SA.The pharmacokinetic properties of a single intravenous dose of ketoprofen (2.2 mg/kg) in plasma and synovial fluid were compared in four healthy animals and four horses with experimentally induced acute synovitis. Synovitis was induced by the injection of a 1% solution of sterile carrageenan into the left intercarpal joint. Ketoprofen was administered at the same time as carrageenan infection. The plasma disposition followed a biexponential equation or a two-compartment model in most horses. The plasma harmonic mean half-life in healthy horses (0.88 h) was longer than in horses with synovitis ...
Ranheim B, Risberg ÅI, Spadavecchia C, Landsem R, Haga HA.Dexmedetomidine, the most selective α2-adrenoceptor agonist in clinical use, is increasingly being used in both conscious and anaesthetized horses; however, the pharmacokinetics and sedative effects of this drug administered alone as an infusion are not previously described in horses. Seven horses received an infusion of 8 μg dexmedetomidine/kg/h for 150 min, venous blood samples were collected, and dexmedetomidine concentrations were assayed using liquid chromatography-mass spectrometry (LC/MS) and analyzed using noncompartmental pharmacokinetic analysis. Sedation was scored as the distance...
Jiang Z, Haughan J, Moss KL, Stefanovski D, Ortved KF, Robinson MA.Gene therapy is currently prohibited in human and equine athletes and novel analytical methods are needed for its detection. Most in vivo products use non-integrating, recombinant viral vectors derived from adeno-associated virus (AAV) to deliver transgenes into cells, where they are transcribed and translated into functional proteins. Although the majority of wild-type AAV (WTAAV) DNA is removed from recombinant AAV (rAAV) vectors, some sequences are conserved. The goal of this study was to develop a quantitative polymerase chain reaction (QPCR) screening test targeting conserved AAV sequence...
Hedberg Y, Dalin AM, Forsberg M, Lundeheim N, Hoffmann B, Ludwig C, Kindahl H.Ovariectomized mares and mares with inactive ovaries may show signs of estrus. The reason behind this phenomenon is not clear; however, steroid hormones of adrenal origin have been suggested. Moreover, aberrant adrenal hormone production has been implied as a reason why some intact mares may change behavior. In the present study, the effect of ACTH on plasma levels of cortisol, progesterone, androstenedione and testosterone was investigated in intact mares with normal estrous behavior ('controls', n=5) and intact mares that according to their owners showed deviant estrous behavior ('problem' m...
Pearson W, Wood K, Stanley S, MacNicol J.Obesity is associated with inflammatory disorders in humans, including degenerative joint disease. While obesity is endemic in horses, its relationship to equine degenerative joint disease has not been explored. The current study sought to describe relationships between: body weight (BW), body condition score (BCS), lameness grade (AAEP), total body fat mass (kg; FM) and fat per cent (FP) [multifrequency bioelectrical impedance analysis (mfBIA)], age, gender, activity level (AL), synovial fluid (SF) and plasma (PL) PGE and glycosaminoglycan (GAG) in horses. During this field investigation, the...
Gray PR, Derksen FJ, Robinson NE, Carpenter-Deyo LJ, Johnson HG, Roth RA.Airway obstruction and hyperreactivity are characteristics of human asthma and of "heaves," a naturally occurring respiratory disorder of horses and ponies. To document the role of cyclooxygenase products of arachidonic acid metabolism in the pathogenesis of heaves, we measured plasma and bronchoalveolar lavage (BAL) fluid concentrations of metabolites of thromboxane (TX)A2 and prostaglandins (PG) I2 and D2 in five affected ponies and their age- and gender-matched controls prior to and during acute airway obstruction precipitated by housing the ponies in a barn and exposing them to hay dust. P...
Gold JR, Grubb TL, Cox S, Malavasi L, Villarino NL.The repeated administration of high doses of gabapentin may provide better analgesia in horses than current clinical protocols. Objective: Administration of gabapentin at 40 and 120 mg/kg PO q 12 h for 14 days will not alter serum biochemistry findings or cause adverse effects. Our objectives were to evaluate the effect of gabapentin on serum biochemistry, physical examination, and plasma pharmacokinetics of gabapentin. Methods: Six healthy adult mares. Methods: Horses received 40 and 120 mg/kg of gabapentin orally q 12 h for 14 days. Horses were examined and scored for ataxia and ...
Schnabel LV, Papich MG, Divers TJ, Altier C, Aprea MS, McCarrel TM, Fortier LA.Minocycline holds great potential for use in horses not only for its antimicrobial effects but also for its anti-inflammatory and neuroprotective properties. However, there are no pharmacokinetic or safety data available regarding the use of oral minocycline in horses. Objective: To determine pharmacokinetics, safety and penetration into plasma, synovial fluid, aqueous humour (AH) and cerebral spinal fluid (CSF) of minocycline after oral administration of multiple doses in horses and to determine the minimum inhibitory concentrations (MIC) of minocycline for equine pathogenic bacteria. Methods...
Veldman JE, Keuning FJ, Molenaar I.Two times sublethal total body-X-irradiation with weekly local thymus irradiation established a T-cell deprived experimental model in rabbits. Humoral immunity reactions in draining lymph nodes have been analyzed histologically and at the submicroscopical level after challenge with Salmonella Java vaccine, horse spleen ferritin, horse-gamma-globulin, a chemical sensitizer oxazolone (2 phenyl-4-ethoxymethylene-5-oxazolone) and after skin allografting respectively. The time sequence studies in these animals with an 'isolated B-cell system' are compared with similar experiments in normal non-irra...
Torfs SC, Maes AA, Delesalle CJ, Deprez P, Croubels SM.Serotonin is regularly measured in equine platelet-poor plasma in research settings. However, reported reference values vary between studies, partially because plasma serotonin concentrations are very low and a reliable and affordable detection method is lacking. A simple, rapid, and sensitive method for serotonin determination in equine platelet-poor plasma using liquid chromatography--tandem mass spectrometry (LC-MS/MS) was developed and validated. Results of a commercially available enzyme-linked immunosorbent assay (ELISA) were compared to the LC-MS/MS results, in order to validate a test ...
Mills PC, Ng JC, Kramer H, Auer DE.Five clinically healthy Thoroughbred geldings were injected with Freund's adjuvant 3 times to induce a chronic inflammatory response. Blood was collected at various times before and after adjuvant administration. Clinical responses (rectal temperature and general demeanor) were also monitored. Adjuvant injection induced increases in rectal temperature and plasma fibrinogen concentration (maximum levels measured were mean +/- s.d. 39.7 +/- 0.5 degrees C and 8.2 +/- 0.3 g/l, respectively), indicative of an inflammatory response. A mild clinical depression was also observed in the horses for 24 h...
Matsuda Y, Hobo S, Naito H.Five Thoroughbreds were classified into 4 groups according to the administration method used for saline solution (saline), ambroxol, and cephalothin sodium (cephalothin). In group A, cephalothin was injected intravenously after oral administration of ambroxol. In group B, cephalothin was injected intravenously after oral administration of saline. Groups C and D were used as control groups. The dose of cephalothin or ambroxol was clinically administrated. Venous blood and bronchoalveolar lavage fluid (BALF) were sampled from each group. In groups A and B, cephalothin concentrations in plasma re...
Fessler JF, Bottoms GD, Roesel OF, Moore AB, Frauenfelder HC, Boon GD.A study was made of flunixin meglumine (FM), an analgesic agent with antiprostaglandin activity, in the management of endotoxin-induced changes in ponies. Three groups of 5 ponies each were used: A--controls, B--nontreated ponies with endotoxin-induced shock, and C--ponies with endotoxin-induced shock treated with FM. Shock was induced in anesthetized ponies with IV injections of Escherichia coli endotoxin. Disruption of glucose homeostasis, insulin levels, hemograms, aerobic metabolism, and cell damage as indicated by plasma enzymes were observed. Treatment with FM (5 minutes) after shock was...
Dimaio Knych HK, Stanley SD.To characterize pharmacokinetics and pharmacodynamics of detomidine gel administered sublingually in accordance with label instructions to establish appropriate withdrawal guidelines for horses before competition. Methods: 12 adult racehorses. Methods: Horses received a single sublingual administration of 0.04 mg of detomidine/kg. Blood samples were collected before and up to 72 hours after drug administration. Urine samples were collected for 5 days after detomidine administration. Plasma and urine samples were analyzed via liquid chromatography-mass spectrometry, and resulting data were anal...
Huang L, Palmieri C, Bertin FR.Pituitary pars intermedia dysfunction (PPID) is an endocrinopathy commonly affecting old horses. It is a spontaneously occurring, progressive disease that is still poorly understood. Previous studies have observed neurodegeneration of the dopaminergic inhibition of melanotrophs, which leads to decreased dopamine (DA) in the pars intermedia (PI) and increased pro-opiomelanocortin-derived peptides circulating in plasma. However, rats knockout for the dopamine D2 receptor (D2r) similarly develop PI hypertrophy and hyperplasia. Thus, based on the current pathophysiological theory of PPID, whether ...
Halama A, Oliveira JM, Filho SA, Qasim M, Achkar IW, Johnson S, Suhre K, Vinardell T.Equine performance in endurance racing depends on the interplay between physiological and metabolic processes. However, there is currently no parameter for estimating the readiness of animals for competition. Our objectives were to provide an in-depth characterization of metabolic consequences of endurance racing and to establish a metabolic performance profile for those animals. We monitored metabolite composition, using a broad non-targeted metabolomics approach, in blood plasma samples from 47 Arabian horses participating in endurance races. The samples were collected before and after the c...
Stoltz MA, van der Merwe CF, Coetzee J, Huismans H.The subcellular localization of the minor nonstructural protein NS3 of African horsesickness virus (AHSV) has been investigated by means of immunogold electron-microscopical analysis. NS3 was observed in perturbed regions of the plasma membrane of AHSV-infected VERO cells, and its presence appears to be associated with events of viral release. These events are budding, whereby released viruses acquire fragments from the host-cell membrane, as well as by the extrusion of nonenveloped particles through the cell membrane. The membrane association of NS3 was confirmed by its detection in the disru...
