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.
Pliszczak-Król A, Gemra M, Kozdrowski R, Zalewski D, Iwaszko A.Recurrent Airway Obstruction (RAO), also called severe asthma or heaves, is a chronic disease in adult horses caused by aeroallergens from straw or hay. Disturbances in hemostasis (intensified coagulation and depressed fibrinolysis) are considered one of the prominent reasons of inflammatory process, injury and dysfunction of the lungs. The aim of the study was to evaluate chosen parameters of hemostasis in horses with active form of RAO. Ten RAO-horses (group R) and ten healthy horses (group C) were exposed to straw and hay allergen challenge. The prothrombin time (PT), activated partial thro...
Bamford NJ, Harris PA, Bailey SR.To compare circannual plasma concentrations of adrenocorticotropic hormone (ACTH) and seasonal dexamethasone suppression test (DST) results between three different equine breed groups. Methods: Six Standardbred horses, six Andalusian horses and six mixed-breed ponies were followed over a 1-year period, during which time groups were managed identically. Blood samples were collected monthly (around the autumn equinox) or in every second month (other times of the year) for the determination of plasma ACTH concentrations using a chemiluminescent immunoassay. Overnight DSTs were performed quarterly...
Hamamoto-Hardman BD, Steffey EP, McKemie DS, Kass PH, Knych HK.Meperidine is a synthetic opioid that belongs to the phenylpiperidine class and is a weak mu receptor agonist. In horses there are a limited number of published studies describing the analgesic effects of systemically administered meperidine in horses. The objective of this study was to describe the pharmacokinetics, behavioral and physiologic effects and effect on thermal threshold of three doses of intravenously administered meperidine to horses. Eight University owned horses (four mares and four geldings, aged 3-8Â years were studied using a randomized balanced 4-way cross-over design. Hors...
Tonekaboni FR, Narenjisani R, Staji H, Ahmadi-Hamedani M.This investigation aimed to compare the cell-free fetal DNA (cffDNA) plasma present in three trimesters of pregnancy in Torkaman pregnant mare. Peripheral blood samples of 32 pregnant mares in three trimesters of pregnancy were collected in tubes containing ethylenediaminetetraacetic acid at three time points. Circulating cffDNA was extracted from 3Â mL of maternal plasma. Using outer and inner primers, a conventional polymerase chain reaction was performed for the sex-determining region Y (SRY) gene present in the Y chromosome. Of the total 32 Torkaman pregnant mares, 24 were carrying male fe...
Kuroda T, Nagata SI, Tamura N, Kinoshita Y, Niwa H, Mita H, Minami T, Fukuda K, Hobo S, Kuwano A.To determine plasma pharmacokinetics of metronidazole and imipenem following administration of a single dose PO (metronidazole, 15 mg/kg) or IV (imipenem, 10 mg/kg) in healthy Thoroughbreds and simulate pleural fluid concentrations following multiple dose administration every 8 hours. Methods: 4 healthy Thoroughbreds. Methods: Metronidazole and imipenem were administered, and samples of plasma and pleural fluid were collected at predetermined time points. Minimum concentrations of metronidazole and imipenem that inhibited growth of 90% of isolates (MIC90), including 22 clinical Bacteroides iso...
Novello G, Segabinazzi LGTM, Lisboa FP, Canuto LE, Freitas-Dell'Aqua CP, Dell'Aqua JA, Canisso IF.This study compared the postthaw semen parameters of stallions with high and low body condition score (BCS) and evaluated associations between body morphometric parameters and postthaw semen parameters. Twenty stallions were split into Low BCS (BCS<7, n = 11) and High BCS (BCS ≥7, n = 9) groups, and underwent a complete morphometric analysis (e.g., neck scores and circumference, crest neck height, body weight, and height), and subcutaneous body fat thickness (SFT) at the tail head, withers, shoulders, and retroperitoneal space. A fasted oral sugar test (OST) was conducted on all stallio...
So YM, Wong JKY, Choi TLS, Prabhu A, Stewart B, Farrington AF, Robinson P, Wan TSM, Ho ENM.This paper describes the studies of the in vitro biotransformation of two selective androgen receptor modulators (SARMs), namely, RAD140 and S-23, and the in vivo metabolism of RAD140 in horses using ultra-high performance liquid chromatography-high resolution mass spectrometry. in vitro metabolic studies of RAD140 and S-23 were performed using homogenised horse liver. The more prominent in vitro biotransformation pathways for RAD140 included hydrolysis, hydroxylation, glucuronidation and sulfation. Metabolic pathways for S-23 were similar to those for other arylpropionamide-based SARMs. The a...
Sierra-Rodriguez T, Groover ES, Lascola KM, Mora-Pereira M, Lee YH, Duran SH, Ravis WR, Spangler E, Hathcock T, Wooldridge AA.Voriconazole (VRC) is a potential treatment for pneumomycosis in horses. The objectives of this study were to determine if the delivery of Vfend using a Flexineb nebulizer produced clinically significant [VRC] in lower airways. The hypothesis was that [VRC] after delivery by nebulization would be greater in the pulmonary epithelial lining fluid than plasma. A secondary objective was to determine [VRC] in upper airways through the collection of nasopharyngeal wash (NPW) samples. Voriconazole solution [Vfend-6.25 mg/mL, 100 (n = 2), 200 (n = 3), 500 (n = 1) mg] was nebulized once in 6 health...
Battaglia F, Meucci V, Tognetti R, Bonelli F, Sgorbini M, Lubas G, Pretti C, Intorre L.In human medicine, procalcitonin (PCT), the precursor of calcitonin, is used for the rapid identification of the origin and severity of sepsis. In veterinary medicine, PCT has been studied in horses, cattle, and dogs, but the use of PCT in diagnostic and/or prognostic settings is not possible because of the lack of validated assays to obtain reference ranges. The aim of the present study was the investigation of commercially available ELISA kits for the detection of canine and equine PCT in plasma samples. Validation of the ELISA kits was performed by using species-specific recombinant protein...
Kopper JJ, Bolger ME, Kogan CJ et al. Outcome and complications in horses administered sterile or non-sterile fluids intravenously. J Vet Intern Med 2019; 33: 2739–2745 DIE INTRAVENöSE VERABREICHUNG VON LöSUNGEN DIENT ZUR ERHALTUNG ODER WIEDERHERSTELLUNG DES FLüSSIGKEITSVOLUMENS IN DEN GEFäßEN UND DER GEWEBEDURCHBLUTUNG. SIE IST ENTSCHEIDEND BEI DER BEHANDLUNG VON PFERDEN MIT ERKRANKUNGEN, DIE EINE HYPOVOLäMIE ZUR FOLGE HABEN. ZU DEN TYPISCHEN INDIKATIONEN GEHöREN EIN HOHER GASTROINTESTINALER WASSERVERLUST, EINE EINGESTELLTE WASSERAUFNAHME BZW. EINE NICHT TOLERIERTE ENTERALE FLüSSIGK...
Baieli MF, Urtasun N, Hirsch DB, Miranda MV, Cascone O, Wolman FJ.Equine chorionic gonadotrophin (eCG) is a hormone widely used in superovulation protocols because of its follicle-stimulating action, which increases reproductive efficiency in animals of productive interest. It contains 45% carbohydrate, 10% of which is N-acetylneuraminic acid (sialic acid). The eCG purification procedures from equine serum or plasma are mainly based on chromatographic methods. However, before these procedures, it is necessary to follow sample pre-conditioning steps, such as several precipitation stages and/or ultrafiltration/diafiltration processes. In this work, an efficien...
Ishii H, Leung GN, Yamashita S, Yamada M, Kushiro A, Kasashima Y, Okada J, Kawasaki K, Kijima-Suda I.GW1516 is a peroxisome proliferator-activated receptor-δ agonist in the class of hormones and metabolic modulators. The use of GW1516 is banned in both horseracing and equestrian competitions. To the best of our knowledge, this is the first metabolic study of GW1516 in horses. Methods: After protein precipitation of pre- and post-administration plasma GW1516 samples, the supernatants were analyzed using liquid chromatography/electrospray ionization Q-Exactive high-resolution mass spectrometry to detect GW1516 and its metabolites. Monoisotopic ions of GW1516 and its metabolites were monitored ...
Oberhaus EL, Thompson DL, Kerrigan LE, Chapman AM.Stress or excitement is a concern when performing endocrine tests on fractious horses. Sedation may be a solution; however, perturbation of test results may preclude useful information. Thyrotropin-releasing hormone (TRH) is a known stimulator of prolactin, thyroid-stimulating hormone (TSH), melanocyte-stimulating hormone (MSH), and ACTH. Thyrotropin-releasing hormone-induced ACTH is a diagnostic tool for the assessment of endocrinopathies such as pituitary pars intermedia dysfunction. It is unknown if drugs commonly used for sedation alter endocrine responses. The objective of this study was ...
Grady SE, Lescun TB, Moore GE, Cooper BR, Davern AJ, Brunner TJ, Taylor SD.The objective was to compare the analgesic efficacy of ketorolac tromethamine (KT) and two other nonsteroidal anti-inflammatory drugs (NSAIDs), including flunixin meglumine (FM) and phenylbutazone (PB), using a heart bar shoe (HBS) model of reversible foot lameness in horses. Nine adult horses were used in a blinded, randomized, placebo-controlled crossover study. After induction of left front limb lameness using a modified HBS model, one of three NSAIDs (KT, 2.0Â mg/kg IV; FM, 1.1Â mg/kg IV; PB, 4.4Â mg/kg IV) or saline (placebo) was administered IV as a single dose. Lameness was assessed eve...
Campos GA, Garcia VFC, Freitas-Dell'Aqua CP, Segabinazzi LGTM, Maciel LFS, Alvarenga MA, Papa FO, Dell'Aqua JA.This study aimed to assess the effects of sodium caseinate and cholesterol to extenders used for stallion semen cooling. Two ejaculates from 19 stallions were extended to 50 million/mL in four different extenders and cooled-stored for 24 hours at 5°C. The extender 1 (E1) consisted of a commercially available skim milk-based extender. The extender 2 (E2) consisted of E1 basic formula with the milk component being replaced by sodium caseinate (20 g/L). The extender 3 (E3) consisted of E1 basic formula added to cholesterol (1.5 mg/120 million sperm). The extender 4 (E4) consisted of a combinat...
Lopez BS, Hurley DJ, Giancola S, Giguère S, Hart KA.Immunological and endocrine immaturity in foals increases foal morbidity and mortality from bacterial sepsis. Dendritic cells (DC) are critical in activating the adaptive immune response, but foal DC are phenotypically and functionally different than those of adult horses. Age-related variations in availability of some soluble plasma factors, such as hormones, might govern some age-related differences in DC function. Effects of exposure to plasma factors on equine DC phenotype and function have not been described. We hypothesized that exposure to plasma from foals or adult horses would differe...
Chan GHM, Tang W, Curl P, Lin Y, Wan TSM, Ho ENM.Arsenic can be easily found in our surrounding environment. Because of its ubiquitous nature, horse urine and blood invariably contain low levels of arsenic. Nevertheless, inorganic arsenic, despite its general use as a tonic for horses, is an effective doping agent having a deleterious effect because of its ability to induce gastroenteritis. The misuse of arsenic in horseracing has been controlled by an international urinary threshold of total arsenic at 0.3 μg/mL. However, an equivalent threshold for total arsenic in plasma is yet to be established. In this study, an inductively coupled pla...
Pitel MO, McKenzie EC, Johns JL, Stuart RL.Selenium or alpha-tocopherol deficiency can cause neuromuscular disease. Beta-carotene has limited documentation in horses. Objective: To evaluate the effect of owner practices on plasma beta-carotene concentration and risk of selenium and alpha-tocopherol deficiencies. Methods: Three-hundred and forty-nine adult (≥1 year), university and privately owned horses and mules. Methods: Cross-sectional study. Whole blood selenium, plasma alpha-tocopherol, and plasma beta-carotene concentrations were measured once. Estimates of daily selenium and vitamin E intake, pasture access, and exercise loa...
Garcia P, Pinètre J, Morel S, Jaubert M, Deruy X, Perot I, Delcourt V, Loup B, Popot MA, Bailly-Chouriberry L.Bisphosphonates are prohibited drugs according to Article 6 of the International Agreement on Breeding, Racing and Wagering of the International Federation of Horseracing Authorities (IFHA) and the International Equestrian Federation (FEI). These compounds are used for the treatment of lameness, navicular and bone diseases in horses and are divided into two groups: non-nitrogen-containing bisphosphonate drugs (e.g. clodronic acid) and nitrogen-containing bisphosphonate drugs (e.g. zoledronic acid). Their hydrophilic properties and the high affinity for the bone matrix make the control of their...
Durham AE, Clarke BR, Potier JFN, Hammarstrand R, Malone GL.Pituitary pars intermedia dysfunction (PPID) is commonly investigated using plasma ACTH concentrations but problems exist with currently available diagnostic thresholds. Objective: To derive temporally specific diagnostic thresholds for equine plasma ACTH concentration to be used alongside clinical judgement in each individual week of the year and appropriate for the degree of clinical suspicion in any given case. Furthermore, to apply these thresholds to compare the prevalence of high and low ACTH in two subgroups of animals with high and low clinical suspicion of PPID. Methods: A retrospecti...
Schumacher SA, Toribio RE, Scansen B, Lakritz J, Bertone AL.The objectives of this study were to describe pharmacokinetic and pharmacodynamic changes as a result of a single intravenous administration of magnesium sulfate (MgSO ) to healthy horses. MgSO is a magnesium salt that has been used to calm horses in equestrian competition and is difficult to regulate because magnesium is an essential constituent of all mammals. Six healthy adult female horses were administered a single intravenous dose of MgSO at 60Â mg/kg of body weight over 5Â min. Blood, urine, and cerebrospinal fluid (CSF) samples were collected, and cardiovascular parameters were monitor...
Giannetto C, Carcangiu V, Luridiana S, Parmeggiani A, Piccione G.Photoperiodic treatments have been of practical interest in controlling seasonal reproduction in sheep, goats and horses. Melatonin is the principal mediator of the environmental photoperiodic message. To investigate the intra- and inter-subject variability of melatonin 24 h rhythm, ten female Italian Saddle horses (8-10 yrs old, mean body weight 525 ± 30 kg), ten female Sarda breed sheep (2-3 yrs old, mean body weight 40.5 ± 2.8 kg) and ten female Sarda breed goats (3-4 yrs old, mean body weight 38.9 ± 4.1 kg), housed individually in a 4 × 4 m soundproof box equipped with 50 Ã...
Shibany KA, Pratt SL, Aldurdunji M, Totemeyer S, Paine SW.Horses are exposed to various kinds of medication, however, there are limited determinations of plasma clearance (CL) for the drugs used due to the high cost of equine studies.Many of the CL values generated come from the equine sports industry for determining drug plasma screening limits in the control of medications at the time of competition.The kinetics of omeprazole metabolism were investigated in freshly isolated and cryopreserved equine hepatocytes and hepatic microsomes ( = 3 horses).The V, K and intrinsic clearance (CL) of omeprazole were determined via the substrate depletion me...
Hopster K, Soma LR, Li X, Hopster-Iversen C, Boston RC, Driessen B.Intravenous (i.v.) bolus administration of xylazine (XYL) (0.5 mg/kg) immediately followed by a continuous rate infusion (CRI) of 1 mg kg  hr for 2, 4, and 6 hr produced immediate sedation, which lasted throughout the duration of the CRI. Heart rate decreased and blood pressure increased significantly (p > .05) in all horses during the first 15 min of infusion, both returned to and then remained at baseline during the duration of the infusion. Compartmental models were used to investigate the pharmacokinetics of XYL administration. Plasma concentration-time curves following bolus an...
Radtke AV, Goodale MB, Fortier LA. Platelet rich plasma (PRP) is used extensively in equine regenerative medicine. Differences in preparation protocols give rise to significant variability in the cellular composition of PRP making it very difficult to establish a standard of care in the field. This study aimed to optimize the preparation protocol for leukocyte-reduced PRP (P-PRP). Blood (100 mL) was collected from horses ( = 5) and divided into 2 purple top EDTA tubes and 6 (15 mL) double syringes with a final concentration of 10% acid citrate dextrose anticoagulant. Six double syringes were collected from each horse; PRP sam...
Jonsdottir S, Fettelschoss V, Olomski F, Talker SC, Mirkovitch J, Rhiner T, Birkmann K, Thoms F, Wagner B, Bachmann MF, Kündig TM, Marti E....： Insect bite hypersensitivity (IBH) is an eosinophilic allergic dermatitis of horses caused by type I/IVb reactions against mainly bites. The vaccination of IBH-affected horses with equine IL-5 coupled to the Cucumber mosaic virus-like particle (eIL-5-CuMV) induces IL-5-specific auto-antibodies, resulting in a significant reduction in eosinophil levels in blood and clinical signs. the preclinical and clinical safety of the eIL-5-CuMV vaccine. The B cell responses were assessed by longitudinal measurement of IL-5- and CuMV-specific IgG in the serum and plasma of vaccinated and unvaccinate...
Fagan MM, Harris P, Adams A, Pazdro R, Krotky A, Call J, Duberstein KJ.Vitamin E is an essential antioxidant that may benefit athletes by reducing oxidative stress and influencing cytokine expression. Supplements can be derived from natural or manufactured synthetic sources. This study aimed to determine (1) if supplemental vitamin E is beneficial to exercising horses and (2) if there is a benefit of natural versus synthetic vitamin E. After 2 weeks on the control diet (vitamin E-deficient grain and hay), 18 horses were divided into three groups and fed the control diet plus (1) 1000 IU/d synthetic α-tocopherol (SYN-L), (2) 4000 IU/d synthetic α-tocopherol (SYN...
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...
Art T, Franck T, Gangl M, Votion D, Kohnen S, Deby-Dupont G, Serteyn D.In man, exercise of any type has been shown to induce neutrophil degranulation and respiratory burst activity, as well as an increase in plasma myeloperoxidase (MPO), a specific enzyme of neutrophil azurophilic granules with a strong oxidative activity. Until now, it is not known whether this is the same in horses. Objective: To study whether degranulation of blood neutrophils may be induced by exercise by measuring the total concentration of MPO and assess the possible influence of type of competition on this exercise-induced adjustment. Methods: Blood was sampled before, and 30 min after, th...
Horohov DW, Dimock A, Guirnalda P, Folsom RW, McKeever KH, Malinowski K.To compare exercise-induced immune modulation in young and older horses. Methods: 6 young and 6 aged horses that were vaccinated against equine influenza virus. Methods: Venous blood samples were collected for immunologic assessment before and immediately after exercise at targeted heart rates and after exercise for determination of plasma lactate and cortisol concentrations. Mononuclear cells were assayed for lymphoproliferative responses and incubated with interleukin-2 (IL-2) to induce lymphokine-activated killer (LAK) cells. Antibodies to equine influenza virus were measured. Results: Olde...
McCoy AM, Hackett ES, Wagner AE, Mama KR, Hendrickson DA.To characterize pulmonary gas exchange and arterial lactate in horses with gastrointestinal disease undergoing anesthesia, compared with elective surgical horses, and to correlate these variables with postoperative complications and mortality. Methods: Prospective clinical study. Methods: Horses undergoing emergency laparotomy for acute intestinal disease (n = 50) and healthy horses undergoing elective surgery in dorsal recumbency (n = 20). Methods: Arterial blood gas analysis was performed at predetermined intervals on horses undergoing a standardized anesthetic protocol. Alveolar-arterial ox...
Tennent-Brown BS, Wilkins PA, Lindborg S, Russell G, Boston RC.Blood lactate concentration [LAC] is considered a useful indicator of disease severity in horses. Agreement of point-of-care (POC) lactate monitors with laboratory standards has not been established for clinically abnormal horses. Objective: It was hypothesized that results from a POC lactate monitor would be in agreement with a laboratory-based measurement of [LAC]. Methods: The study included adult horses presented for emergency evaluation. Methods: A prospective observational study was performed. [LAC] was measured with whole blood (AWB) and plasma (APL) by means of a POC monitor (Accutrend...
Snow DH, Harris RC, MacDonald IA, Forster CD, Marlin DJ.In Study 1, a single speed test of 6 to 12 m/sec was performed for 2 mins at an incline of 5 degrees on a high-speed treadmill (single-step test). Only one speed was performed per session and blood samples were taken before and after the test. In Study 2 horses cantered for 1 min at increasing speeds of 6 to 13 m/sec on an incline of 3 degrees (multiple-step test). Blood samples were taken before exercise, throughout the test and during recovery. In the single-step test plasma concentrations of adrenaline and noradrenaline both increased at speeds of 9 m/sec, as did blood lactate. Mean concent...
Rose RJ, Arnold KS, Church S, Paris R.Blood samples were taken from 20 horses competing in a 100 km endurance ride and plasma concentrations of sodium, potassium, chloride, bicarbonate and protein measured. Measurements were performed on samples taken before the ride (pre-ride), at the mid point and end of the ride and after a 30 min recovery period (post-ride). Sweat samples were collected from 6 horses competing in the endurance ride and 14 horses competing in a 3-day event competition and sweat concentrations of sodium, potassium and chloride measured. There were substantial decreases in plasma electrolyte concentrations, which...
Tamzali Y, Guelfi JF, Braun JP.Plasma fibrinogen is widely used in horse practice as an unspecific positive marker of inflammatory diseases; it is also lowered in disseminated intravascular coagulation. Three fibrinogen measurement methods--Millar's heat-denaturation in a microhaematocrit tube, automated reader for heat-denaturation, and chronometric measurement of clot formation after addition of excess thrombin-were compared by means of Passing-Bablock's regression and Bland-Altman difference plots, in blood plasma of 30 clinically healthy and 57 diseased horses. Correlations between the three techniques were excellent (r...
Fradinho MJ, Correia MJ, Grácio V, Bliebernicht M, Farrim A, Mateus L, Martin-Rosset W, Bessa RJ, Caldeira RM, Ferreira-Dias G.The aim of this study was to investigate the effects of body condition (BC), BC changes, and plasma leptin concentrations on the reproductive performance of Lusitano broodmares on extensive systems. Data from 119 mares (ranging from 4 to 22 years of age) were collected over a period of four consecutive breeding seasons. Each case was considered as one foaled mare bred in 1 year. Body condition changes at conception (ΔBCScon) showed a strong effect on fertility at the first two postpartum estrous cycles and a significant interaction with body condition score at conception (BCScon) was observed...
Theurillat R, Knobloch M, Schmitz A, Lassahn PG, Mevissen M, Thormann W.CE with multiple isomer sulfated beta-CD as the chiral selector was assessed for the simultaneous analysis of the enantiomers of ketamine and metabolites in extracts of equine plasma and urine. Different lots of the commercial chiral selector provided significant changes in enantiomeric ketamine separability, a fact that can be related to the manufacturing variability. A mixture of two lots was found to provide high-resolution separations and interference-free detection of the enantiomers of ketamine, norketamine, dehydronorketamine, and an incompletely identified hydroxylated metabolite of no...
Barton MH, Moore JN, Norton N.To evaluate the effect of pentoxifylline on response of horses to in vivo challenge exposure with endotoxin. Methods: 24 healthy horses in 3 treatment groups: pentoxifylline, endotoxin, or endotoxin and pentoxifylline. Methods: Horses of the pentoxifylline group were given a bolus of pentoxifylline (7.5 mg/kg of body weight, i.v.), followed by an infusion (3 mg/kg/h) over 3 hours, and those of the endotoxin group were given 20 ng of endotoxin/kg i.v. over 30 minutes. Those of the combination group were given both of the aforementioned compounds; pentoxifylline was administered immediately afte...
Davis JL, Salmon JH, Papich MG.To determine the pharmacokinetics of itraconazole after IV or oral administration of a solution or capsules to horses and to examine disposition of itraconazole in the interstitial fluid (ISF), aqueous humor, and polymorphonuclear leukocytes after oral administration of the solution. Methods: 6 healthy horses. Methods: Horses were administered itraconazole solution (5 mg/kg) by nasogastric tube, and samples of plasma, ISF, aqueous humor, and leukocytes were obtained. Horses were then administered itraconazole capsules (5 mg/kg), and plasma was obtained. Three horses were administered itraconaz...
Nyman S, Jansson A, Lindholm A, Dahlborn K.In the present study, the main objective was to study factors affecting postexercise voluntary water intake in horses. Four Standardbred horses (mean +/- s.e. bwt 500 +/- 8 kg) were used to study water intake and effects of altering hydration status before an incremental exercise test (INCR) and a 40 min constant velocity exercise test (CONST) on a treadmill. Exercise was performed during normohydration (N), after dehydration for 24 h (DEH) and after hyperhydration with 12 l water 30 min before exercise (HH). DEH resulted in a bodyweight loss of 3% and there were signs of some fluid uptake pri...
Porr CA, Kronfeld DS, Lawrence LA, Pleasant RS, Harris PA.Diet and exercise are two management factors that affect bone density and strength. We proposed that bone density and calcium status would be affected by deconditioning for 12 wk and by dietary Ca concentration. Eleven highly conditioned Arabian horses were taken out of training and placed in stalls for 12 wk. Horses were walked on a mechanical walker in two 30-min sessions, 7 d/wk. Diets were designated CC (.36% Ca) and HC (.62% Ca). Data were collected every 21 d. Serum or plasma were analyzed for total and ionized Ca, parathyroid hormone, osteocalcin, hydroxyproline, electrolytes, and blood...
Berlin S, Randow T, Scheuch E, Grube M, Venner M, Siegmund W.The long-acting azalide antibiotic gamithromycin is marketed for intramuscular treatment of bovine and swine infections. Off-label use in foals leads to severe local lesions likely caused by hyperosmolality of the injected solution. We provide evidence from a pharmacokinetic study in 10 warm-blooded healthy foals for intravenous bolus injection of gamithromycin diluted in distilled water to be a safe and well tolerated alternative. By intravenous dosing, markedly higher plasma exposure and better penetration into bronchoalveolar lavage cells but lower distribution into epithelial lining fluid ...
Ruiz AJ, Tibary A, Heaton RA, Hargreaves IP, Leadon DP, Bayly WM.Although coenzyme Q10 (CoQ10) serves as an antioxidant and energy source for spermatozoa when added to stallion semen before cooling or freezing, the effects of feeding CoQ10 on semen quality have not been studied. We assessed the effects of daily oral ingestion of CoQ10-ubiquinol by stallions on their plasma CoQ10 concentrations and semen quality. Seven mature Andalusian stallions ate 1g ubiquinol/day for 4Â weeks followed by a 4-week washout period. Four horses initially completed an additional 4-week control period without ubiquinol. Blood was sampled weekly for determination of plasma CoQ1...
Soni Y, Talluri TR, Kumar A, Ravi SK, Mehta JS, Tripathi BN.Traditionally Glycerol (Gly) is being used as major cryoprotectant and its toxicity could be a reason for the variation on stallion sperm freezability and fertility. In an effort to minimize Gly toxicity alternative cryoprotective agents like Di-methyl Formamide (DMF) have been investigated. The effect of the cryoprotectant and dose of cryoprotective agent varies from breed to breed and also from stallion to stallion within the same breed. Considering these factors a study was designed to study the effects of Gly and DMF at different concentrations and combinations on the plasma membrane, acro...
Palmer J.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...
McGorum BC, Dixon PM, Halliwell RE.A commercial radioimmunoassay kit was used to quantify histamine concentrations of plasma, bronchoalveolar lavage fluid (BALF) and pulmonary epithelial lining fluid (PELF) of normal horses and horses with chronic obstructive pulmonary disease (COPD), before and after 'natural (hay and straw) challenge' (NC). There were no significant changes in the concentrations of histamine in plasma or BALF at 0.5 or 5 h after NC, but the PELF histamine concentration of COPD affected horses was significantly increased at 5 h, but not at 0.5 h, following NC. As the histamine concentrations of whole BALF lysa...
Ma J, Jiang C, Lin Y, Wang X, Zhao L, Xiang W, Shao Y, Shen R, Kong X, Zhou J.To study the in vivo evolution of the attenuated Chinese equine infectious anemia virus (EIAV) vaccine, viral gp90 gene variation and virus replication in immunosuppressed hosts were investigated. The results showed that after vaccination, the gp90 gene followed an evolutionary trend of declining diversity. The trend coincided with the maturation of immunity to EIAV, and eventually, the gp90 gene became highly homologous. The sequences of these predominant quasispecies were consistently detected up to 18 months after vaccination. Furthermore, after transient immune suppression with dexamethaso...
Hall JA, Van Saun RJ, Wander RC.The study objective was to determine the effect of feeding corn oil or fish oil to horses on plasma fatty acid profiles and leukotriene B (LTB) synthesis by stimulated peripheral blood neutrophils. Two groups of horses (n = 5) were randomly assigned to diets supplemented with either 3.0% (by weight) corn oil or fish oil for a period of 14 weeks. The ratio of (n-6) to (n-3) fatty acids in oil supplements was 68.1:1 for corn oil and 0.12:1 for fish oil. Production of LTB4 and LTB, by peripheral blood neutrophils stimulated with calcium ionophore A23187 and plasma cholesterol, triacylglycerol, an...
Gangl M, Serteyn D, Lejeune JP, Schneider N, Grulke S, Peters F, Vila T, Deby-Dupont G, Deberg M, Henrotin Y.Markers of cartilage breakdown enable studying the degradation of cartilage matrix in equine joint pathologies. This study was designed to determine the levels of Coll2-1, a peptide of the triple helix of type II collagen, and Coll2-1NO(2), its nitrated form in the plasma of healthy horses (controls; n=37) and horses suffering from osteochondrosis (n=34). Clinical and arthroscopic scores were attributed reflecting the severity of lesions and were related to the plasma levels of Coll2-1 and Coll2-1NO(2). The median of Coll2-1 was significantly higher in the control group, whereas the mean of Co...
Bayless RL, Cooper BL, Sheats MK.Plasma cell-free DNA (cfDNA) is a biomarker of ischemia, systemic inflammation, and mortality in humans with gastrointestinal disease. Cell-free DNA has not been investigated as a biomarker for equine colic, to our knowledge. We hypothesized that cfDNA could be measured accurately in neat equine plasma using a benchtop fluorometer and that plasma cfDNA would be elevated in emergency patients compared to healthy horses. Plasma was obtained from blood collected in Roche DNA stabilizing tubes. We used the Qubit 4 fluorometer and 1× dsDNA HS assay kit to measure cfDNA concentration in neat patien...
Fultz L, Giguère S, Berghaus LJ, Grover GS, Merritt DA.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. ...
Pösö AR, Viljanen-Tarifa E, Soveri T, Oksanen HE.Effects of graded intensity exercise on plasma lipids was studied in Standardbred and Finnishbred Trotters. The rate of lipolysis indicated by the elevated plasma concentrations of glycerol increased parallel with the intensity of the trot in the Standardbreds, but not as clearly in the Finnishbred trotters. During the exercise plasma triglyceride concentration increased significantly and the increase correlated with the intensity of the exercise as well as the activity of lipolysis. Together with the increase in plasma triglycerides, there was a parallel increase in the pre-beta fraction of l...
Colmer SF, Luethy D, Abraham M, Stefanovski D, Hurcombe SD.Plasma cell-free DNA (cfDNA) levels have been associated with disease and survival status in septic humans and dogs. To date, studies investigating cfDNA levels in association with critical illness in foals are lacking. We hypothesized that cfDNA would be detectable in the plasma of foals, that septic and sick-nonseptic foals would have significantly higher cfDNA levels compared to healthy foals, and that increased cfDNA levels would be associated with non-survival. Animals used include 80 foals of 10 days of age or less admitted to a tertiary referral center between January and July, 2020 wer...
The goal of the current study was to evaluate the comparative efficacy of ivermectin (IVM) against small strongyles (cyathostomins) following its oral and intramuscular (IM) administration, in naturally parasitized horses. The parasitological data were complemented with the assessment of the plasma disposition kinetics of IVM. The trial included two different experiments. In experiment I, 40 horses naturally infected with small strongyles were randomly allocated into four experimental groups (n=10) and treated with IVM (0.2mg/kg) as follows: IVM oral paste, animals were orally treated with Eqv...
Landoni MF, Lees P.Pharmacokinetic and pharmacodynamic parameters were established for enantiomers of the non-steroidal anti-inflammatory drug (NSAID) ketoprofen (KTP), each administered separately at a dose level of 1.1 mg/kg to a group of six New Forest geldings, in a three-period cross-over study using a tissue cage model of inflammation. For both S(+)-and R(-)-KTP, penetration into tissue cage fluid (transudate) and inflamed tissue cage fluid (exudate) was rapid, and clearances from exudate and transudate were much slower than from plasma. AUC values were, therefore, higher for exudate and, to a lesser degre...
Kwon S, Moore JN, Robertson TP, Hurley DJ, Wagner B, Vandenplas ML.Although clinical evidence of endotoxemia has been associated with the development of acute laminitis in hospitalized horses with gastrointestinal diseases and endotoxins have been detected in the circulation of horses with experimentally-induced laminitis, it is unclear what role, if any, endotoxins have play the pathogenesis of the disease. Therefore, in the present study we compared the effects of endotoxin infusion to that of intra-gastric administration of mixed carbohydrate (CHO) on clinical signs of laminitis, plasma concentrations of TNF-α and IL-10, and laminar tissue expression of 2...
Rose RJ, Hendrickson DK, Knight PK.To evaluate normal cardiorespiratory and metabolic responses of Thoroughbred horses to a standardised treadmill exercise test, we examined 28 horses ranging in age from 1 to 4 years. The group consisted of eight yearlings, eight 2-year-olds and twelve 3 and 4-year-olds. All horses except the yearlings were in training, and either racing or ready to race, at the time of examination. None of the horses had histories of performance problems. On the first day the horses received a full physical examination, resting electrocardiogram, upper respiratory tract endoscopy and either one or two acclimat...
