Urine analysis in horses involves the examination of urine to assess the health and physiological status of the animal. This diagnostic tool provides insights into the renal function, hydration status, and potential presence of systemic diseases. Key parameters evaluated in equine urine analysis include pH, specific gravity, protein levels, glucose, ketones, and the presence of blood or sediment. Variations in these parameters can indicate metabolic disorders, infections, or other health issues. This page compiles peer-reviewed research studies and scholarly articles that explore the methodologies, findings, and clinical implications of urine analysis in equine veterinary practice.
Waraksa E, Woźniak MK, Kłodzińska E, Wrzesień R, Bobrowska-Korczak B, Namieśnik J.Ibuprofen is widely used in human and veterinary medicine for the treatment of chronic pain as well as rheumatic and musculoskeletal disorders. However, the analgesic and anti-inflammatory properties of Ibuprofen have contributed to frequent drug abuse in equestrian sports. A sensitive and rapid gas chromatography with tandem mass spectrometry based method with a simple liquid-liquid extraction and derivatization requiring 200 μL volume of sample and 2 mL of extraction solvent for the simultaneous determination of ibuprofen and its metabolites was developed. The proposed procedure was optim...
Zhu C, Faillace V, Laus F, Bazzano M, Laghi L.Metabolomics has been recognized as a powerful approach for disease screening. In order to highlight potential health issues in subjects, a key factor is the possibility to compare quantitatively the metabolome of their biofluids with reference values from healthy individuals. Such efforts towards the systematic characterization of the metabolome of biofluids in perfect health conditions, far from concluded for humans, have barely begun on horses. The present work attempts, for the first time, to give reference quantitative values for the molecules mostly represented in the urine metabolome of...
Viljanto M, Hincks P, Hillyer L, Cawley A, Suann C, Noble G, Walker CJ, Parkin MC, Kicman AT, Scarth J.The use of testosterone and its pro-drugs, such as dehydroepiandrosterone (DHEA), is currently regulated in horseracing by the application of international testosterone thresholds. However, additional steroidomic approaches, such as steroid ratios, to distinguish overall adrenal stimulation from drug administrations and an equine biological passport for longitudinal steroid profiling of individual animals could be advantageous in equine doping testing. Thus, DHEA concentrations and related ratios (testosterone [T] to DHEA and DHEA to epitestosterone [E]) were assessed in the reference populati...
Knych HK, McKemie DS, Seminoff K, Hartmann P, Hovda L, Benson D.Ethylphenidate is a psychostimulant and analog of the commonly prescribed compound, methylphenidate (Ritalin®). There are a limited number of studies describing the disposition and pharmacologic/toxicological effects of ethylphenidate in any species. The abuse potential in equine athletes along with the limited data available regarding administration in horses necessitates further study. The objectives of the current study were to describe drug concentrations, develop an analytical method that could be used to regulate its use, and describe the pharmacodynamic effects of ethylphenidate in hor...
Shelver WL, Smith DJ.Zilpaterol is a β-adrenergic agonist feed additive approved in the United States to increase weight gain and improve feed efficiency of cattle. A zilpaterol immunochromatographic assay was developed as an economical and user-friendly rapid detection method for zilpaterol and validated using urine and tissue samples derived from animal studies. The assay sensitivity was 1.7-23.2 ng g or mL across a variety of feed and animal matrices and did not cross-react with clenbuterol or ractopamine. No sample pre-treatment of cattle and sheep urine was needed, but horse urine and feed required dilution;...
Wenzel R, Major D, Hesp K, Doble P.Regulating authorities in the racing industry have restricted the administration of potentially performance enhancing cobalt salts to horses. There are severe penalties for trainers presenting horses with elevated urine cobalt concentrations, and compliance is ensured via analysis of total urinary cobalt at thresholds of 100 μg/L. When cobalt is present as part of the cobalamin molecule it is not considered performance enhancing. This paper demonstrates that a horse can excrete a significant proportion of a commercially available vitamin B12 injection in urine without metabolic modification...
The attention of sports community toward probiotic supplementation as a way to promote exercise and training performance, together with good health, has increased in recent years. This has applied also to horses, with promising results. Here, for the first time, we tested a probiotic mix of several strains of live bacteria typically employed for humans to improve the training performance of Standardbred horses in athletic activity. To evaluate its effects on the horse performance, we measured lactate concentration in blood, a translational outcome largely employed for the purpose, combined wit...
Sandbaumhüter FA, Thormann W.Glucuronidation catalyzed by uridine-5'-diphospho-glucuronosyl-transferases (UGTs) is the most important reaction in phase II metabolism of drugs and other compounds. O-glucuronidation is more common than N-glucuronidation. The anesthetic, analgesic and antidepressive drug ketamine is metabolized in phase I by cytochrome P450 enzymes to norketamine, hydroxynorketamine (HNK) diastereomers and dehydronorketamine (DHNK). Equine urine samples collected two hours after ketamine injection were treated with β-glucuronidase and analyzed with three enantioselective capillary electrophoresis assays. Co...
Knych HK, Seminoff K, McKemie DS.Traditional therapeutic options for the treatment of lameness associated with inflammation in performance horses include administration of cyclooxygenase enzyme inhibiting non-steroidal anti-inflammatory drugs (NSAID). As long-term use of these drugs can adversely impact the health of the horse, anti-inflammatories with a more favorable safety profile are warranted. Grapiprant is a newly approved non-cyclooxygenase inhibiting NSAID that has demonstrated efficacy and safety in other species and which may be a valuable alternative to traditional NSAIDs used in the horse. The objectives of the cu...
Kim Y, Seo C, Oh S, Kwak J, Jung S, Sin E, Kim H, Ji M, Lee HS, Park HJ, Lee G, Yu J, Kim M, Lee W, Paik MJ.Loxoprofen is a non-steroidal anti-inflammatory drug of the 2-arylpropionic acid type, which has used to treat musculoskeletal disorders in the horse racing industry. However, it has also used illicitly to mask clinical signs of inflammation and pain in racehorses. Thus, its accurate analysis has become an important issue in horse doping laboratories. In this study, an analytical method of loxoprofen was developed as tert-butyldimethylsilyl (TBDMS) derivative by gas chromatography-mass spectrometry (GC-MS). Characteristic fragment ions of [M-15], [M-57], and [M-139] permitted the accurate and ...
Schaafstra FJWC, van Doorn DA, Schonewille JT, Roelfsema E, Westermann CM, Dansen O, Jacobs M, Lee JY, Spronck EA, Blok MC, Hendriks WH.Exercise and physical training are known to affect gastrointestinal function and digestibility in horses and can lead to inaccurate estimates of nutrient and energy digestibility when markers are used. The effect of exercise on apparent nutrient digestibility and faecal recoveries of ADL and TiO2 was studied in six Welsh pony geldings subjected to either a low- (LI) or high-intensity (HI) exercise regime according to a cross-over design. Ponies performing LI exercise were walked once per day for 45 min in a horse walker (5 km/h) for 47 consecutive days. Ponies submitted to HI exercise were gra...
Viljanto M, Hillyer L, Hincks P, Pearce C, Paine SW.Medication control and doping control have been established in horse racing to ensure the integrity of the sport and the welfare of the horses. This ensures that horses do not compete under the influence of any drugs, including omeprazole, a therapeutic medication used to treat equine gastric ulcer syndrome. In this study, pharmacokinetic data were produced in equine plasma and urine following an oral administration of 4 mg/kg of generic buffered formulation of omeprazole to six Thoroughbred horses in five daily doses to determine an appropriate screening limit and detection time in equine pl...
Choi TLS, Wong JKY, Kwok WH, Curl P, Mechie S, Wan TSM.Methylstenbolone (2,17α-dimethyl-5α-androst-1-en-17β-ol-3-one) is a synthetic anabolic and androgenic steroid (AAS) sold as an oral 'nutritional supplement' under the brand names 'Ultradrol', 'M-Sten' and 'Methyl-Sten'. Like other AASs, methylstenbolone is a prohibited substance in both human and equine sports. This paper describes the studies of the in vitro and in vivo metabolism of methylstenbolone in horses using LC/HRMS, GC/MS and GC/MS/MS. Phase I in vitro metabolic study of methylstenbolone was performed using homogenised horse liver. Hydroxylation was the only biotransformation obse...
Knych HK, Seminoff K, McKemie DS, Kass PH.Acepromazine is a tranquilizer used commonly in equine medicine. This study describes serum and urine concentrations and the pharmacokinetics and pharmacodynamics of acepromazine following intravenous, oral, and sublingual (SL) administration. Fifteen exercised adult Thoroughbred horses received a single intravenous, oral, and SL dose of 0.09 mg/kg of acepromazine. Blood and urine samples were collected at time 0 and at various times for up to 72 hr and analyzed for acepromazine and its two major metabolites (2-(1-hydroxyethyl) promazine and 2-(1-hydroxyethyl) promazine sulfoxide) using liqu...
Waraksa E, Wójtowicz-Zawadka M, Kwiatkowska D, Jarek A, Małkowska A, Wrzesień R, Namieśnik J.A novel assay for the simultaneous determination of ibuprofen (IBU) and its four probable metabolites, 1-hydroxyibuprofen (1-OH IBU), 2-hydroxyibuprofen (2-OH IBU), 3-hydroxyibuprofen (3-OH IBU) and carboxyibuprofen (CBX IBU) in equine urine samples with the application of Gas Chromatography-Electron Ionization-Mass Spectrometry (GC-EI-MS) has been developed and elaborated. The new approach for sample preparation including minimizing matrix effects by the application of weak cation exchange solid-phase extraction together with strong cation exchange solid-phase extraction has been applied. The...
Leng J, Proudman C, Darby A, Blow F, Townsend N, Miller A, Swann J.Equine grass sickness (EGS) is a frequently fatal disease of horses, responsible for the death of 1 to 2% of the U.K. horse population annually. The etiology of this disease is currently uncharacterized, although there is evidence it is associated with Clostridium botulinum neurotoxin in the gut. Prevention is currently not possible, and ileal biopsy diagnosis is invasive. The aim of this study was to characterize the fecal microbiota and biofluid metabolic profiles of EGS horses, to further understand the mechanisms underlying this disease, and to identify metabolic biomarkers to aid in diagn...
Guillaume D, Moussu C, de Geoffroy F, Chesneau D, Keller M.Stallions show decreased sexual responses and activities during short days in winter. To evaluate the importance of sexual olfactory communication in horses, we tested whether sexual responses could be stimulated through various sexual olfactory stimulations in winter. To this end, we presented stallions with various olfactory stimulations (urine from mares at different stages of the reproductive cycle, urine from stallions or geldings, or chemically defined synthetic odorant) during the non-breeding season and measured their behavioral responses through (1) a test of olfactory investigation (...
Hillyer LL, Ridd Z, Fenwick S, Hincks P, Paine SW.While cobalt is an essential micronutrient for vitamin B synthesis in the horse, at supraphysiological concentrations, it has been shown to enhance performance in human subjects and rats, and there is evidence that its administration in high doses to horses poses a welfare threat. Animal sport regulators currently control cobalt abuse via international race day thresholds, but this work was initiated to explore means of potentially adding to application of those thresholds since cobalt may be present in physiological concentrations. Objective: To devise a scientific basis for differentiation b...
Knych HK, Vale A, Wilson WD, Kass PH, Arthur RM, Jones JH.Furosemide is a diuretic agent used commonly in racehorses to attenuate the bleeding associated with exercise-induced pulmonary hemorrhage (EIPH). The current study describes serum and urine concentrations and the pharmacokinetics of furosemide following administration at 4 and 24 hrs prior to maximal exercise. Eight exercised adult Thoroughbred horses received a single IV administration of 250 mg of furosemide at 4 and 24 hrs prior to maximal exercise on a high-speed treadmill. Blood and urine samples were collected at time 0 and at various times for up to 72 hrs and furosemide concentrat...
Yuan M, Breitkopf SB, Asara JM.Horse urine is easily collected and contains molecules readily measurable using mass spectrometry that can be used as biomarkers representative of health, disease or drug tampering. This study aimed at analyzing microliter levels of horse urine to purify, identify and quantify proteins, polar metabolites and non-polar lipids. Urine from a healthy 12 year old quarter horse mare on a diet of grass hay and vitamin/mineral supplements with limited pasture access was collected for serial-omics characterization. The urine was treated with methyl tert-butyl ether (MTBE) and methanol to partition into...
Knych HK, Mama KR, Steffey EP, Stanley SD, Kass PH.OBJECTIVE To measure concentrations of trazodone and its major metabolite in plasma and urine after administration to healthy horses and concurrently assess selected physiologic and behavioral effects of the drug. ANIMALS 11 Thoroughbred horses enrolled in a fitness training program. PROCEDURES In a pilot investigation, 4 horses received trazodone IV (n = 2) or orally (2) to select a dose for the full study; 1 horse received a vehicle control treatment IV. For the full study, trazodone was initially administered IV (1.5 mg/kg) to 6 horses and subsequently given orally (4 mg/kg), with a 5-week ...
Takagi M, Uno S, Kokushi E, Sato F, Wijayagunawardane M, Fink-Gremmels J.Mycotoxins may affect animal health, including reproduction. Little is known about the clinical relevance of exposure of horses to contaminated feed. This study aimed at (i) monitoring the levels of the mycotoxins zearalenone (ZEN), with its metabolites α- and β-zearalenol (α- and β-ZOL), and sterigmatocystin (STC) in urine samples from thoroughbred mares in Japan and (ii) relating these findings to the potential effects on reproductive efficacy of breeding mares. Sixty-three urine samples of breeding mares from 59 breeding farms were used. Urine samples and reproductive records were colle...
Joré C, Loup B, Garcia P, Paris AC, Popot MA, Audran M, Bonnaire Y, Varlet-Marie E, Bailly-Chouriberry L.Erythropoiesis Stimulating Agents (ESAs) were developed for therapeutic purposes to stimulate red blood cell (RBC) production. Consequently, tissue oxygenation is enhanced as athlete's endurance and ESAs misuse now benefits doping. Our hypothesis is that most of ESAs should have similar mechanisms and thus have the same effects on metabolism. Studying the metabolome variations could allow suspecting the use of any ESAs with a single method by targeting their effects. In this objective, a metabolomic study was carried out on 3 thoroughbred horses with a single administration of 4.2μg/kg of Mir...
Weir J, Li H, Warren LK, Macon E, Wickens C.Evaluating impact of animal agriculture on air quality has been the focus of recent research. Ammonia (NH) volatilization occurs when undigested protein in feces and urea in urine is broken down by bacteria and enzymes. Information regarding NH emission from equine facilities is limited, and effects of CP intake on NH emissions have not been investigated. Nine mature geldings were used in a 3 × 3 replicated Latin square design study to determine effects of dietary CP on potential NH losses from feces and urine. We hypothesized feeding horses above the CP requirement would result in an increas...
Knych HK, Stanley SD, McKemie DS, Arthur RM, Bondesson U, Hedeland M, Thevis M, Kass PH.Although developed as a therapeutic medication, meldonium has found widespread use in human sports and was recently added to the World Anti-Doping Agency's list of prohibited substances. Its reported abuse potential in human sports has led to concern by regulatory authorities about the possible misuse of meldonium in equine athletics. The potential abuse in equine athletes along with the limited data available regarding the pharmacokinetics and pharmacodynamics of meldonium in horses necessitates further study. Eight exercised adult thoroughbred horses received a single oral dose of 3.5, 7.1, ...
Guan F, Robinson MA.The ability to analyze biological samples for multitudinous exogenous peptides with a single analytical method is desired for doping control in horse racing. The key to achieving this goal is the capability of extracting all target peptides from the sample matrix. In the present study, theory of mixed-mode solid-phase extraction (SPE) of peptides from plasma is described, and a generic mixed-mode SPE procedure has been developed for recovering multitudinous exogenous peptides with remarkable sequence diversity, from equine plasma and urine in a single procedure. Both the theory and the develop...
Popot MA, Ho ENM, Stojiljkovic N, Bagilet F, Remy P, Maciejewski P, Loup B, Chan GHM, Hargrave S, Arthur RM, Russo C, White J, Hincks P, Pearce C....Cobalt is an essential mineral micronutrient and is regularly present in equine nutritional and feed supplements. Therefore, cobalt is naturally present at low concentrations in biological samples. The administration of cobalt chloride is considered to be blood doping and is thus prohibited. To control the misuse of cobalt, it was mandatory to establish an international threshold for cobalt in plasma and/or in urine. To achieve this goal, an international collaboration, consisting of an interlaboratory comparison between 5 laboratories for the urine study and 8 laboratories for the plasma stud...
Shin HD, Suh JH, Kim J, Cho HD, Lee SD, Han KS, Wang Y, Han SB.A high throughput method for simultaneous screening of anabolic steroids and their metabolites (4-esterendione, trenbolone, boldenone, oxandrolone, nandrolone, methandrostenolone, testosterone, 1-androstendione, ethisterone, normethandrolone, methyltestosterone, 16β-Hydroxystanozolol, epitestosterone, bolasterone, norethandrolone, danazol, stanozolol and androstadienone) in equine urine by online turbulent flow extraction coupled with liquid chromatography-tandem mass spectrometry was developed. The use of turbulent flow chromatography could simplify pretreatment of horse urine, which has com...
Hipp B, Südekum KH, Zeyner A, Goren G, Kienzle E.The prediction of renal energy excretion is crucial in a metabolizable energy system for horses. Phenolic acids from forage cell walls may affect renal energy losses by increasing hippuric acid excretion. Therefore, the relationships were investigated between renal energy, nitrogen (N) and hippuric acid excretion of four adult ponies (230-384 kg body weight (BW)) consuming diets based on fresh grass, grass silage, grass cobs (heat-dried, finely chopped, pressed grass), alfalfa hay, straw, extruded straw and soybean meal. Feed intake was measured; urine and faeces were quantitatively collected...
Edwards DJ, Brownlow MA, Hutchins DR.Urine and blood samples were taken at the same time from normal adult horses presented for routine investigations to establish reference values for a variety of parameters reported to be useful in the clinical evaluation of renal function. Blood biochemical values were consistent with previous studies and had well-defined normal ranges. Parameters representing urine concentration and electrolyte excretion however, varied widely reflecting the ability of the healthy kidney to change the composition of urine in response to differences in environment and management. Percent creatinine clearance r...
Cox S, Sommardahl C, Fortner C, Davis R, Bergman J, Doherty T.Non-steroidal anti-inflammatory drugs are inhibitors of cyclooxygenase (COX) in tissues and used as therapeutic agents in different species. Grapiprant, a member of the piprant class of compounds, antagonizes prostaglandin receptors. It is a highly selective EP4 prostaglandin E receptor inhibitor, thereby limiting the potential for adverse effects caused by wider COX inhibition. The objectives of this study were to determine if the approved canine dose would result in measurable concentrations in horses, and to validate a chromatographic method of analysis for grapiprant in urine and plasma. M...
Creighton CM, Lemke KA, Lamont LA, Horney BS, Doyle AJ.To compare the effect of xylazine bolus versus medetomidine constant rate infusion (MCRI) on serum cortisol and glucose concentrations, urine production, and anesthetic recovery characteristics in dorsally recumbent, spontaneously breathing, isoflurane-anesthetized horses. Methods: Prospective, randomized crossover study. Methods: 10 healthy Standardbreds. Methods: Horses were premedicated with xylazine or medetomidine IV. Anesthesia was induced with diazepam and ketamine and maintained with isoflurane for 150 minutes. For the xylazine treatment, end-tidal isoflurane concentration was maintain...
Kwok KY, Choi TLS, Kwok WH, Lau MY, Leung EMK, Leung GNW, Wong JKY, Wan TSM, Adrian FF, Prabhu A, Ho ENM.The use of bioactive peptides as a doping agent in both human and animal sports has become increasingly popular in recent years. As such, methods to control the misuse of bioactive peptides in equine sports have received attention. This paper describes a sensitive accurate mass method for the detection of 40 bioactive peptides and two non-peptide growth hormone secretagogues (< 2 kDa) at low pg/mL levels in horse urine using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC/HRMS). A simple mixed-mode cation exchange solid-phase extraction (SPE) cartridge was...
Knych HK, Seminoff K, McKemie DS.Traditional therapeutic options for the treatment of lameness associated with inflammation in performance horses include administration of cyclooxygenase enzyme inhibiting non-steroidal anti-inflammatory drugs (NSAID). As long-term use of these drugs can adversely impact the health of the horse, anti-inflammatories with a more favorable safety profile are warranted. Grapiprant is a newly approved non-cyclooxygenase inhibiting NSAID that has demonstrated efficacy and safety in other species and which may be a valuable alternative to traditional NSAIDs used in the horse. The objectives of the cu...
Giguère S, Burton AJ, Berghaus LJ, Haspel AD.The objective of this study was to compare the pharmacokinetics of minocycline in foals vs. adult horses. Minocycline was administered to six healthy 6- to 9-week-old foals and six adult horses at a dose of 4 mg/kg intragastrically (IG) and 2 mg/kg intravenously (i.v.) in a cross-over design. Five additional oral doses were administered at 12-h intervals in foals. A microbiologic assay was used to measure minocycline concentration in plasma, urine, synovial fluid, and cerebrospinal fluid (CSF). Liquid chromatography-tandem mass spectrometry was used to measure minocycline concentrations in ...
Steel R, Timms M, Levina V, Vine J.The Dermorphins are a family of peptides that act as potent agonists of the opioid μ receptor. Originally identified as a seven amino acid peptide on the skin of the South American Phyllomedusa frog, peptide chemists have since developed a large number of Dermorphin variants, many with superior opioid activity to the original peptide. Dermorphins are unique among the peptide opioid agonists as they appear to have a limited ability to cross the blood brain barrier, producing effects on both the central and peripheral nervous systems. It is this ability of Dermorphins to provide central anaesth...
Heer F, Dobenecker B, Kienzle E.In the present investigation, the impact of diet composition on urine pH in rabbits was compared with previous studies on rabbits, cats, dogs, pigs and horses. A total of 13 dwarf rabbits were fed six different diets with a cation-anion balance (CAB) between -39 and +320 mmol/kg dry matter (DM) using ammonium chloride (NH Cl) as an acidifier. CAB was calculated as follows: CAB (mmol/kg DM) = 49.9*Ca + 82.3*Mg +43.5*Na + 25.6*K - 59*P - 62.4*S - 28.2*Cl; minerals in g/kg DM. Urine, faeces and blood were collected. Urine pH ranged from 5.26 ± 0.22 at a CAB of -39 mmol/kg DM to ...
Lindberg JE, Karlsson CP.The objective of the present work was to assess the influence of partial replacement of oats with dried unmolassed sugar beet pulp (SBP) and/or maize oil on nutrient utilisation in horses fed a traditional hay and concentrate diet. The total tract digestibility of nutrients, urinary excretion and plasma parameters were studied in a 4 x 4 Latin-square design experiment with purebred Arabian geldings. Horses fed the SBP diets responded with a reduced (P<0.05) apparent digestibility of crude protein and feeding of maize oil resulted in an increased (P<0.05) apparent digestibility of crude f...
Joré C, Loup B, Garcia P, Paris AC, Popot MA, Audran M, Bonnaire Y, Varlet-Marie E, Bailly-Chouriberry L.Erythropoiesis Stimulating Agents (ESAs) were developed for therapeutic purposes to stimulate red blood cell (RBC) production. Consequently, tissue oxygenation is enhanced as athlete's endurance and ESAs misuse now benefits doping. Our hypothesis is that most of ESAs should have similar mechanisms and thus have the same effects on metabolism. Studying the metabolome variations could allow suspecting the use of any ESAs with a single method by targeting their effects. In this objective, a metabolomic study was carried out on 3 thoroughbred horses with a single administration of 4.2μg/kg of Mir...
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...
Ekstrand C, Bondesson U, Gabrielsson J, Hedeland M, Kallings P, Olsén L, Ingvast-Larsson C.Detection times and screening limits (SL) are methods used to ensure that the performance of horses in equestrian sports is not altered by drugs. Drug concentration-response relationship and knowledge of concentration-time profiles in both plasma and urine are required. In this study, dexamethasone plasma and urine concentration-time profiles were investigated. Endogenous hydrocortisone plasma concentrations and their relationship to dexamethasone plasma concentrations were also explored. A single dose of dexamethasone-21-isonicotinate suspension (0.03 mg/kg) was administered intramuscularly t...
Cutler C, Viljanto M, Hincks P, Habershon-Butcher J, Muir T, Biddle S.LGD-4033 is one of a number of selective androgen receptor modulators (SARMs) that are being developed by the pharmaceutical industry to provide the therapeutic benefits of anabolic androgenic steroids, without the less desirable side effects. Though not available therapeutically, SARMs are available for purchase online as supplement products. The potential for performance enhancing effects associated with these products makes them a significant concern with regards to doping control in sports. The purpose of this study was to investigate the metabolism of LGD-4033 in the horse following oral ...
Kwok WH, Leung GN, Wan TS, Curl P, Schiff PJ.Androsta-1,4,6-triene-3,17-dione (ATD) is an irreversible steroidal aromatase inhibitor and is marketed as a supplement. It has been reported to effectively reduce estrogen biosynthesis and significantly increase the levels of endogenous steroids such as dihydrotestosterone and testosterone in human. ATD abuses have been reported in human sports. Its metabolism in human has been studied, and the in vitro metabolic study of ATD in horses has been reported, however, little is known about its biotransformation and elimination in horses. This paper describes the in vitro and in vivo metabolism stu...
Soma LR, Behrend E, Rudy J, Sweeney RW.The disposition of flunixin meglumine administered IV at a dosage of 1.1 mg/kg was described by a 2-compartment model; the alpha and beta half-lives (t1/2) were 0.61 and 1.5 hours, respectively. When administered IV at a rate of 2.2 mg/kg, the disposition was best described by a 3-compartment model, and the alpha, beta, and lambda t1/2 were 0.16, 1.52, and 6.00 hours, respectively. The zero-time plasma concentrations after flunixin meglumine was administered at 1.1 and 2.2 mg/kg were 9.3 +/- 0.76 and 21.5 +/- 7.4 mg/L, respectively. The bioavailability after oral administration of 1.1 mg/kg wa...
Colas C, Garcia P, Popot MA, Bonnaire Y, Bouchonnet S.A method has been developed for the analysis and characterization in equine urine and plasma of iridoid glycosides: harpagide, harpagoside and 8-para-coumaroyl harpagide, which are the main active principles of Harpagophytum, a plant with antiinflammatory properties. The method involves liquid chromatography coupled with positive electrospray ionization mass spectrometry. The addition of sodium or lithium chloride instead of formic acid in the eluting solvent has been studied in order to enhance the signal and to modify the ion's internal energy. Fragmentation pathways and associated patterns ...
Haines GR, Brown MP, Gronwall RR, Merritt KA, Baltzley LK.Pharmacokinetics and distribution of orbifloxacin into body fluids and endometrium was studied in 6 mares after intragastric (IG) administration at a single dose rate of 7.5 mg/kg body weight. Orbifloxacin concentrations were serially measured in serum, synovial fluid, peritoneal fluid, urine, cerebrospinal fluid, and endometrial tissues over 24 hours. Minimum inhibitory concentrations of orbifloxacin were determined for 120 equine pathogens over an 11-month period. The mean peak serum concentration (Cmax) was 2.41+/-0.30 microg/mL at 1.5 hours after administration and decreased to 0.17+/-0.01...
Divers TJ, Whitlock RH, Byars TD, Leitch M, Crowell WA.Six horses had been admitted to the hospital because of illness other than renal failure; diarrhoea, myositis, abdominal pain and/or suspected bacterial sepsis. Hypotension and disseminated intravascular coagulopathy were frequent findings in the horses. Abnormally high serum creatinine concentration and urine specific gravity of less than 1.022 were found in the horses with acute renal failure. Hyponatraemia and hypochloraemia were the most common abnormal electrolyte findings. Pronounced hyperkalaemia was not found. Variable degrees of tubular necrosis were seen in three of the four horses t...
Colas C, Garcia P, Popot MA, Bonnaire Y, Bouchonnet S.Solid-phase extraction cartridges among those usually used for screening in horse doping analyses are tested to optimize the extraction of harpagoside (HS), harpagide (HG), and 8-para-coumaroyl harpagide (8PCHG) from plasma and urine. Extracts are analyzed by liquid chromatography coupled with multi-step tandem mass spectrometry. The extraction process retained for plasma applies BondElut PPL cartridges and provides extraction recoveries between 91% and 93%, with RSD values between 8 and 13% at 0.5 ng/mL. Two different procedures are needed to extract analytes from urine. HS and 8PCHG are extr...
Knych HK, Weiner D, Arthur RM, Baden R, McKemie DS, Kass PH.Corticosteroids are potent anti-inflammatory drugs and as such are commonly administered to performance and racehorses. The objectives of the current study were to describe blood and urine concentrations and the pharmacokinetics and effects on cortisol and inflammatory mediator concentrations, following intravenous and oral administration to 12 exercised horses. Horses received an intravenous administration of 40 mg of dexamethasone sodium phosphate and 20 mg of dexamethasone tablets with a 4 week washout in between administrations. Blood and urine samples were collected prior to and for up to...
Watson ZE, Steffey EP, VanHoogmoed LM, Snyder JR.To characterize the effect of general anesthesia and minor surgery on renal function in horses. Methods: 9 mares with a mean (+/- SE) age and body weight of 9+/-2 years and 492+/-17 kg, respectively. Methods: The day before anesthesia, urine was collected (catheterization) for 3 hours to quantitate baseline values, and serum biochemical analysis was performed. The following day, xylazine (1.1 mg/kg, IV) was administered, and general anesthesia was induced 5 minutes later with diazepam (0.04 mg/kg, IV) and ketamine (2.2 mg/kg, IV). During 2 hours of anesthesia with isoflurane, Paco2 was maintai...
Lee W, Ko BJ, Sim YE, Suh S, Yoon D, Kim S.Urine was most commonly used biological sample in drug test. To create a false-negative test result, some drug abusers were reported to submit animal urine instead of their own. So, the purpose of this study was to compare and differentiate human from animal urine (Rat 370, Pig 12, Horse 10, Cat 8, Dog 13, Cow 10, Monkey 10) samples through the uses of quantitative 1H-NMR and to find biomarkers that can be used for the discrimination of human urine from animal urine. The 1H-NMR spectroscopy was employed and metabolomic analysis with multivariate statistics was carried out. Human urine samples ...
Hipp B, Südekum KH, Zeyner A, Goren G, Kienzle E.The prediction of renal energy excretion is crucial in a metabolizable energy system for horses. Phenolic acids from forage cell walls may affect renal energy losses by increasing hippuric acid excretion. Therefore, the relationships were investigated between renal energy, nitrogen (N) and hippuric acid excretion of four adult ponies (230-384 kg body weight (BW)) consuming diets based on fresh grass, grass silage, grass cobs (heat-dried, finely chopped, pressed grass), alfalfa hay, straw, extruded straw and soybean meal. Feed intake was measured; urine and faeces were quantitatively collected...
Knych HK, Finno CJ, Katzman S, Ryan D, McKemie DS, Kass PH, Arthur RM.Clodronate is a potent antiresorptive agent labelled for use in horses over 4 years of age, for the treatment of navicular syndrome. Concerns regarding the extra-label use of clodronate in equine athletes, such as racehorses, have been raised as inhibition of osteoclast activity by clodronate has been postulated to interfere with normal bone healing, which is imperative to the repair of microfractures. The paucity of data describing the long-term pharmacokinetics of clodronate and effects on biomarkers of bone resorption necessitates further study. Objective: (1) To determine clodronate conc...
Waller P, Lomnicka I, Lucas C, Johnson S, Dirikolu L.The number of publications for most common drug violations in racehorses is limited. This study reports the most common medication violations in racehorses at four major racetracks in Louisiana between 2016 and 2020. During this 5-year period, 27,237 blood samples and 25,672 urine samples collected during the course of normal race meeting activities were analysed by initial screening procedure utilizing Liquid Chromatography Mass Spectrometry (LC-MS/MS). Following initial screening, suspect samples were subject to quantitative or semi- quantitative confirmation analysis by LC-MS/MS. The total ...
Bickhardt K, Deegen E, Espelage W.Investigations of renal function have been done on the basis of renal clearance (Clr) and excretion (E) of endogenous creatinine in healthy horses of different body weight (23 female, 7 male). Creatinine was measured by enzymatic PAP-method. Creatinine-E of female horses was poor positively correlated with body weight. The creatinine-Clr was highly correlated with the inulin-Clr (r = 0,896, p < 0,001). The excretion of creatinine was 35% higher than the filtration of creatinine, determined by inulin-Clr. That demonstrate a tubular net secretion of 26% of the total creatinine excretion. However...
Kollias-Baker C, Maxwell L, Stanley S, Boone T.Cocaine is a naturally occurring alkaloid that is commonly abused by human-beings for its psychostimulatory effects. Occasionally, very small concentrations (i.e. <100 ng/mL) of the primary cocaine metabolite, benzoylecgonine (BZE) have been detected in urine collected from horses competing in athletic events. In this study urine samples, collected from four horses following the administration of 2.5 and 20 mg of cocaine sublingually and 50 mg of cocaine intravenously, were analyzed for the presence of cocaine and/or its metabolites by enzyme-linked immunosorbent assay (ELISA) and gas chrom...
