Omneity® Pellets
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Topic:Plasma
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.
Oxidant-antioxidant status in the blood of horses with symptomatic recurrent airway obstruction (RAO). Systemic oxidative stress in horses with recurrent airway obstruction (RAO) is poorly characterized. Objective: The goal of this study was to investigate whether equine RAO is associated with systemic disturbances in the oxidant-antioxidant equilibrium. Methods: Seven healthy horses and 7 horses with symptomatic RAO. Methods: A prospective study. Healthy and RAO-affected horses were exposed to a 48-hour challenge with moldy hay and straw to induce clinical exacerbation of RAO. Venous blood was collected and the activities of the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidas...
The pharmacokinetics of dexmedetomidine administered as a constant rate infusion in horses. 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...
Antinociceptive effects of three escalating dexmedetomidine and lignocaine constant rate infusions in conscious horses. Dexmedetomidine and lignocaine IV are used clinically to provide analgesia in horses. The aims of this study were to investigate the antinociceptive effects, plasma concentrations and sedative effects of 2, 4 and 6 µg/kg/h dexmedetomidine IV, with a bolus of 0.96 µg/kg preceding each continuous rate infusion (CRI), and 20, 40 and 60 µg/kg/min lignocaine IV, with a bolus of 550 µg/kg preceding each CRI, in 10 Swiss Warmblood horses. Electrically elicited nociceptive withdrawal reflexes were evaluated by deltoid muscle electromyography. Nociceptive threshold and tolerance were determ...
Equine total carbon dioxide testing in Illinois in 2012. During prolonged strenuous exercise, racehorses can experience acidemia. To counteract this phenomenon, trainers can administer blood alkalizing agents that raise the plasma pH and total carbon dioxide (TCO2) concentration. In Illinois, the administrative threshold for TCO2 in plasma is 37.0 mmol/L. Because accuracy in the reported measurement of TCO2 must be ensured, uncertainty measurements are often issued alongside the reported concentrations. We report a validated method for measuring TCO2 levels in equine plasma using the Beckman UniCel DxC 600. A six-point calibration curve ranging from...
Pulmonary pharmacokinetics of desfuroylceftiofur acetamide after nebulisation or intramuscular administration of ceftiofur sodium to weanling foals. Administration of ceftiofur sodium via nebulisation has been recommended for the treatment of bronchopneumonia in horses, despite the lack of pharmacokinetic and safety data. Objective: To compare concentrations of desfuroylceftiofur acetamide (DCA) in plasma and pulmonary epithelial lining fluid (PELF) of foals after nebulisation or i.m. administration of ceftiofur sodium and to determine if nebulisation of ceftiofur sodium induces airway inflammation. Methods: Randomised experimental study. Methods: Six weanling foals received ceftiofur sodium (2.2 mg/kg bwt daily for 5 doses) by the i.m. ...
Changes in plasma leptin concentration during different types of exercises performed by horses. Leptin is a tissue-derivative adipokine that regulates appetite, food intake and energy expenditure. It is still not clear how exercise affects plasma leptin concentration in horses. The aim of this study was to evaluate the influence of exercise intensity and duration on plasma leptin levels in working horses. A total of 38 horses were prospectively included in the study and grouped according to the type of exercise they performed: dressage (six stallions, group D), jumping (12 stallions, group J), race (12 Thoroughbred horses, six stallions and six mares, group R) and harness (10 light draft...
Antiluteogenic effects of serial prostaglandin F2α administration in cycling mares. A single dose of PGF2α does not consistently induce luteolysis in the equine CL until at least 5 days after ovulation, leading to the erroneous assumption that the early CL is refractory to the luteolytic effects of PGF2α. We hypothesized that serial administration of PGF2α in early diestrus would induce a return to estrus similar to mares treated with a single injection in mid-diestrus, and fertility of the induced estrus would not differ. The objectives of the study were to evaluate the effects of the 2 approaches as reflected by: (1) concentrations of plasma progesterone; (2) interovulat...
Bacteriostatic effect of equine pure platelet-rich plasma and other blood products against methicillin-sensitive Staphylococcus aureus. An in vitro study. 1) To evaluate the bacteriostatic in vitro effect of pure platelet-rich plasma (P-PRP), pure platelet-rich gel (P-PRG), leukocyte-poor gel (LPG), platelet-poor plasma (PPP), and heat inactivated plasma (IP) against methicillin-sensitive Staphylococcus aureus (MSSA) over a period of 24 hours. 2) To determine the degradation of platelet factor-4 (PF-4), transforming growth factor beta 1 (TGF-β1), and platelet-derived growth factor isoform BB (PDGF-BB) in these equine blood components. 3) To establish correlations between platelet and leukocyte counts, PF-4 concentrations, and MSSA growth. Metho...
Effects of oral powder electrolyte administration on packed cell volume, plasma chemistry parameters, and incidence of colic in horses participating in a 6-day 162-km trail ride. This study evaluated the effects of administering oral powder electrolytes on packed cell volume (PCV), plasma chemistry parameters, and incidence of colic in horses participating on a 6-day 162-km trail ride in which water was not offered ad libitum. Twenty-three horses received grain with powder electrolytes daily while 19 control horses received grain only. Horses were ridden approximately 32 km a day at a walk or trot. Packed cell volume and plasma chemistry parameters were analyzed daily. Episodes of colic were diagnosed and treated by a veterinarian unaware of treatment group allocation....
Pituitary pars intermedia dysfunction does not necessarily impair insulin sensitivity in old horses. Equine pituitary pars intermedia dysfunction (PPID) has been associated with reduced insulin sensitivity in comparison with younger adult horses; however, the difference in insulin sensitivity between horses with PPID and aged-matched controls has not been well characterized. The objective of the study was to determine if aged horses with PPID had reduced insulin sensitivity and alterations in the insulin-mediated signaling pathways in the skeletal muscle when compared with healthy aged horses. Isoglycemic hyperinsulinemic clamp procedures were conducted in 12 horses that were classified as ei...
Endogenous concentrations, pharmacokinetics, and selected pharmacodynamic effects of a single dose of exogenous GABA in horses. The anti-anxiety and calming effects following activation of the GABA receptor have been exploited in performance horses by administering products containing GABA. The primary goal of the study reported here was to describe endogenous concentrations of GABA in horses and the pharmacokinetics, selected pharmacodynamic effects, and CSF concentrations following administration of a GABA-containing product. The mean (±SD) endogenous GABA level was 36.4 ± 12.5 ng/mL (n = 147). Sixteen of these horses received a single intravenous and oral dose of GABA (1650 mg). Blood, urine, and cerebrospin...
The influence of nutrition on the insulin-like growth factor system and the concentrations of growth hormone, glucose, insulin, gonadotropins and progesterone in ovarian follicular fluid and plasma from adult female horses (Equus caballus). Feed intake affects the GH-IGF system and may be a key factor in determining the ovarian follicular growth rate. In fat mares, the plasma IGF-1 concentration is high with low GH and a quick follicular growth rate, in contrast to values observed in thin mares. Nothing is known regarding the long-term effects of differential feed intake on the IGF system. The objective of this experiment was to quantify IGFs, IGFBPs, GH, glucose, insulin, gonadotropin and progesterone (P4) in blood and in preovulatory follicular fluid (FF) in relation to feeding levels in mares. Methods: Three years prior to the...
Pharmacokinetics and pharmacodynamics of intravenous dexmedetomidine in the horse. The aim of the study was to describe the pharmacokinetics and selected pharmacodynamics of intravenous dexmedetomidine in horses. Eight adult horses received 5 μg/kg dexmedetomidine IV. Blood samples were collected before and for 10 h after drug administration to determine dexmedetomidine plasma concentrations. Pharmacokinetic parameters were calculated using noncompartmental analysis. Data from one outlier were excluded from the statistical summary. Behavioral and physiological responses were recorded before and for 6 h after dexmedetomidine administration. Dexmedetomidine concentrations dec...
Concentrations of stromal cell-derived factor-1 in serum, plasma, and synovial fluid of horses with osteochondral injury. To determine whether stromal cell-derived factor-1 (SDF-1) concentrations in serum, plasma, and synovial fluid differed among untrained, race-trained, and osteochondral-injured Thoroughbred racehorses. Methods: 22 racehorses without osteochondral injury and 37 racehorses with osteochondral injury. Methods: Horses without osteochondral injury were examined before and after 5 to 6 months of race training. Horses with osteochondral injury were undergoing arthroscopic surgery for removal of osteochondral fragments from carpal or metacarpophalangeal or metatarsophalangeal joints (fetlock joints). S...
Seventy day safety assessment of an orally ingested, l-glutamine-containing oat and yeast supplement for horses. We describe a safety assessment of an oral supplement designed to nutritionally support the gastrointestinal system of horses. The supplement comprised a mixture of essential (l-threonine) and conditionally essential (l-glutamine) amino acids, polar lipids, oat bran rich in beta glucans and yeast extract. Young (1-2years) horses of both sexes were allocated to control (n=7) and treatment groups (n=7) and studied for 9weeks. Horses in the treatment group received the supplement daily for 8weeks. After 8weeks of supplementation, horses were studied for one additional week. Outcome measures inclu...
Parallel testing of plasma iron and fibrinogen concentrations to detect systemic inflammation in hospitalized horses. To determine if plasma iron concentration is different between horses with and without systemic inflammation (SI) and to assess the accuracy for the detection of SI by assaying plasma iron and fibrinogen concentrations, individually or combined. To assess the prognostic value of plasma iron concentration and to describe the progression of plasma iron and fibrinogen concentrations during hospital follow-up, and its relation to SI and survival. Methods: Prospective observational study evaluating plasma iron and fibrinogen. Methods: University veterinary teaching hospital. Methods: Equine patient...
The effect of colloid formulation on colloid osmotic pressure in horses with naturally occurring gastrointestinal disease. Naturally occurring gastrointestinal disease is an important cause of acute hypoproteinemia in adult horses and hydroxyethyl starch colloid fluid treatment is a component of supportive care in these cases to improve plasma volume and maintain colloid osmotic pressure (COP). The objectives of the present study were to compare 2 formulations of high molecular weight hydroxyethyl starch and their relative effect on COP, acid-base status, and survival of horses with acute hypoproteinemia secondary to gastrointestinal disease. Methods: Twenty adult horses, ≥ 1 year of age, were prospectively enro...
Evaluation of plasma muscle enzyme activity as an indicator of lesion characteristics and prognosis in horses undergoing celiotomy for acute gastrointestinal pain. In horses undergoing celiotomy for acute gastrointestinal pain, identification of variables correlating with lesion severity and location, and survival provide veterinarians and owners with information that aids in making informed decisions regarding appropriate treatment. Muscle enzyme activity is often increased in horses undergoing celiotomy for acute gastrointestinal pain and it is not known if muscle enzyme activity increase is specific to lesion type or impacts prognosis for survival. The objective of this study was to evaluate the relationship of pre-operative increase in muscle enzyme ...
Whole-body phenylalanine kinetics and skeletal muscle protein signaling in horses with pituitary pars intermedia dysfunction. To compare whole-body phenylalanine kinetics and the abundance of factors in signaling pathways associated with skeletal muscle protein synthesis and protein breakdown between horses with pituitary pars intermedia dysfunction (PPID) and age-matched control horses without PPID. Methods: 12 aged horses (6 horses with PPID and 6 control horses; mean age, 25.0 and 25.7 years, respectively). Methods: Plasma glucose, insulin, and amino acids concentrations were determined before and 90 minutes after feeding. Gluteal muscle biopsy samples were obtained from horses 90 minutes after feeding, and the ab...
A new ELISA for the quantification of equine procalcitonin in plasma as potential inflammation biomarker in horses. In human medicine, procalcitonin (PCT) is a very common and well-established biomarker for sepsis. Even though sepsis is also a leading cause of death in foals and adult horses, up to now, no data about the role of equine PCT in septic horses has been available. Based on monoclonal antibodies targeted against human PCT, we report here the development of a sandwich ELISA for the quantification of equine PCT in equine plasma samples. The ELISA was characterized for intra- and interassay variance and a working range from 25 to 1,000 ng mL(-1) was defined as within this range; both intra- and in...
Serum amyloid A and haptoglobin concentrations are increased in plasma of mares with ascending placentitis in the absence of changes in peripheral leukocyte counts or fibrinogen concentration. Currently, placentitis, an important cause of late pregnancy loss in mares, is diagnosed by clinical signs and ultrasonography. Acute phase proteins (APP) are mainly produced and secreted by the liver in response to acute inflammatory stimuli. We hypothesized that APP are increased in mares with placentitis. Methods: Concentrations of serum amyloid A (SAA), haptoglobin (Hp), fibrinogen (Fb), and white blood cell counts (WBC) were determined in plasma of mares with experimentally induced placentitis and gestationally age-matched control mares. Placentitis was induced via intracervical inoculati...
Dietary crude protein intake influences rates of whole-body protein synthesis in weanling horses. The objective of this study was to measure whole-body protein kinetics in weanling horses receiving forage and one of two different concentrates: (1) commercial crude protein (CCP) concentrate, which with the forage provided 4.1 g CP/kg bodyweight (BW)/day (189 mg lysine (Lys)/kg BW/day), and (2) recommended crude protein (RCP) concentrate which, with the same forage, provided 3.1 g CP/kg BW/day (194 mg Lys/kg BW/day). Blood samples were taken to determine the response of plasma amino acid concentrations to half the daily concentrate allocation. The next day, a 2 h-primed, constant inf...
Update on the management of neonatal sepsis in horses. Despite advances in neonatal intensive care sepsis, severe sepsis and septic shock remain the biggest killers of neonatal foals. Management of this severe syndrome remains difficult, requiring intensive intervention. Key aspects of management include infection control, hemodynamic support, immunomodulatory interventions, and metabolic/endocrine support. Infection control largely consists of early antimicrobial therapy, plasma transfusions, and local therapy for the infected focus. In cases with severe sepsis or septic shock, hemodynamic support with fluids, vasoactive agents, and respiratory s...
The effect of long-term oral L-carnitine administration on insulin sensitivity, glucose disposal, plasma concentrations of leptin and acylcarnitines, and urinary acylcarnitine excretion in warmblood horses. Insulin resistance in horses is an emerging field of interest as it is thought to be a contributing factor in the pathogenesis of many equine conditions. Objective: The objectives of the present study were to determine the effects of long-term oral administration of L-carnitine on insulin sensitivity, glucose disposal, plasma leptin concentrations and acylcarnitine spectrum both in plasma and urine. Methods: Six 3-year-old healthy warmblood geldings were used. In a double blind 2 × 2 Latin square design at a dosage of 100 mg/kg body weight (BW)/day for 28 days the effects of oral supplementat...
Control of the misuse of testosterone in castrated horses based on an international threshold in plasma. Testosterone is an endogenous steroid produced primarily in the testes. Trace levels of testosterone are found in urine samples from geldings, as testosterone is also secreted by the adrenal. An international threshold of free and conjugated testosterone in urine (20 ng/mL) was adopted by the International Federation of Horseracing Authorities (IFHA) in 1996 for controlling testosterone misuse in geldings. In view of the recent popularity of using blood in doping control testing, it is necessary to establish a threshold for testosterone in gelding plasma. A liquid chromatography-mass spectro...
Fibre digestibility, abundance of faecal bacteria and plasma acetate concentrations in overweight adult mares. The purpose of the present study was to compare digestibility of grass hay, faecal and plasma volatile fatty acid (VFA) concentrations, and faecal bacterial abundance in overweight and moderate-condition mares. Five overweight adult mixed-breed mares and five adult mixed-breed mares in moderate condition were housed individually and limit-fed orchard grass (Dactylis glomerata) hay at 20 g/kg body weight (as fed) daily for 14 d. Forage DM and fibre digestibility were determined using AOAC methods; digestible energy was measured using bomb calorimetry; plasma and faecal VFA concentrations were ...
Plasma adrenomedullin concentrations in critically ill neonatal foals. Bacterial sepsis remains a leading cause of morbidity and mortality in neonatal foals, but accurate diagnostic and prognostic markers are lacking. Adrenomedullin (AM) is a polypeptide with diverse biologic effects on the cardiovascular system that increases in septic humans and laboratory animals. Objective: Plasma AM concentration (p[AM]) is increased in septic neonatal foals compared to sick nonseptic and healthy control foals, and p[AM] is predictive of survival in septic neonatal foals. Methods: Ninety critically ill (42 septic, 48 sick nonseptic) and 61 healthy foals <1 week of age. Me...
Inhibitory effect of triamcinolone acetonide on synthesis of inflammatory mediators in the equine. Glucocorticoids (corticosteroids) are widely used anti-inflammatory agents in veterinary medical practice. These drugs are considered doping agents because they mask pain and thus, increase injury potential in equine athletes. They exhibit anti-inflammatory property by binding to glucocorticoids receptor (GR) to control the transcription of pro- and anti-inflammatory cytokines and enzymes involved in the synthesis of bioactive eicosanoids. To evaluate the role of triamcinolone acetonide (TA) on concentrations of bioactive eicosanoids in equine plasma, TA (0.04 mg/kg) was intravenously administ...
Pharmacokinetic-pharmacodynamic modelling of intravenous buprenorphine in conscious horses. Describe the pharmacokinetics of buprenorphine and norbuprenorphine in horses and to relate the plasma buprenorphine concentration to the pharmacodynamic effects. Methods: Single phase non-blinded study. Methods: Six dedicated research horses, aged 3-10 years and weighing 480-515 kg. Methods: Thermal and mechanical nociceptive thresholds, heart and respiratory rates and locomotor activity were measured before and 15, 30, 45 & 60 minutes and 2, 4, 6, 8, 12 & 24 hours post-administration of 10 μg kg(-1) buprenorphine IV. Intestinal motility was measured 1, 6, 12 & 24 hours af...
Pharmacokinetics and bone resorption evaluation of a novel Cathepsin K inhibitor (VEL-0230) in healthy adult horses. Plasma pharmacokinetic (PK) and bone resorption biomarker [carboxy-terminal cross-linking telopeptide of type I collagen (CTX-1)] analyses were performed following single and multiple oral dose protocols of a Cathepsin K inhibitor (VEL-0230) in horses. Outcomes included plasma and urine drug and CTX-1 concentrations. In the dose range study, 2, 4, and 8 mg/kg body weight (b.w.) doses were administered in a Latin square design to three mares and evaluated for 1 week. Based on the PK characteristics of VEL-0230, 4 mg/kg b.w. was selected for the dose interval study in which 3.25 days (d) and 7 d...
