The study of blood in horses encompasses the examination of its components, functions, and its role in equine health and disease. Blood consists of various elements, including red blood cells, white blood cells, platelets, and plasma, each serving specific functions such as oxygen transport, immune response, clotting, and nutrient distribution. Analyzing blood parameters can provide insights into the physiological and pathological states of horses. Common blood tests in equine medicine assess parameters like hematocrit, hemoglobin concentration, and white cell counts to monitor health status, diagnose conditions, and guide treatment decisions. This page compiles peer-reviewed research studies and scholarly articles that explore the composition, function, and clinical applications of blood analysis in horses.
Mackowski M, Kajdasz A, Laskowska K, Cieslak J.Although serological and genetic studies of equine blood group systems have been conducted for many years, the molecular basis of erythrocyte antigens' variability has remained largely unexplored. In this study, we aimed to elucidate the genetic basis of serological variation within equine blood group K. Using mRNA extracted from peripheral blood samples (n = 100) collected from horses with known serological blood types (Ka or K-), we performed a transcriptome-wide association study (TWAS), which revealed a significantly associated region on equine chromosome 2 (ECA2). A detailed analysis ...
Wickizer LF, Burk SV, Lehman JS.Red maple toxicosis arises when horses consume wilted maple leaves, resulting in methemoglobinemia and hemolytic anemia due to oxidative damage to erythrocytes. Objective: The objective of this study was to determine how maple species (red versus Freeman maple) and horse characteristics, management, and barn site contributed to in vitro methemoglobin production and hemolysis. Methods: Horse information was obtained through an owner questionnaire. Extracts from red and Freeman maple leaves were separately incubated with washed erythrocytes from each horse (n=120). The in vitro percentage methem...
Andrews KE, Sibthorpe PEM, Fitzgerald DM, de Laat MA.Equine insulin dysregulation (ID) is a common condition that predisposes to hyperinsulinaemia-associated laminitis. Improved pathophysiological understanding would enable better management of ID and reduce the risk of laminitis. The incretin peptides, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), augment the insulin response to dietary glucose and GLP-1 has been implicated in the pathophysiology of ID. However, their temporal variation in response to a low-energy diet has not been reported. This study determined the variation in GLP-1, GIP and insulin ...
Dąbrowska I, Grzędzicka-Agko J, Kiełbik P, Trela M, Witkowska-Piłaszewicz O.The molecular mechanisms underlying adaptation to physical exertion and racing stress in horses remain incompletely understood. Peripheral blood transcriptomics offers a minimally invasive method to monitor systemic responses to exercise and identify biomarkers of adaptation or overload. Objective: To evaluate transcriptomic changes in peripheral blood of racehorses during different phases of training and competition and to identify molecular markers of physiological adaptation and race-induced stress. Methods: Prospective transcriptomic profiling of trained racehorses across three exercise co...
de Luna Paiva TD, de Melo Lopes AR, Silva ÁJC, Figueiredo MAF, da Cunha Nogueira SS, Nogueira-Filho SLG.Medical ozone is used in various treatments due to its oxidising properties. Objective: We aimed in this study to evaluate the impact of intrarectal ozone therapy on haematological and biochemical parameters, as well as the pain induced by the procedure in sport horses. Methods: In vivo experiment with 12 Quarter Horses (3 males and 9 females) used as their own controls to assess the effects of ozone therapy. Methods: Blood samples were collected before treatment (Control), 24 h after ozone therapy (24 h post-treatment), and 7 days after the last day of ozone therapy (7 days post-treatment). ...
van den Brom-Spierenburg AJ, Siegers EW, Westermann CM, Vernooij JCM, Sloet van Oldruitenborgh-Oosterbaan MM, Theelen MJP.In hospitalized foals, limited data are available on the utility of sequential measurement of SAA concentrations and the value of these data in a clinical setting. Objective: To determine serum amyloid A (SAA) concentrations in ill neonatal foals at multiple timepoints during hospitalization, and to evaluate a potential association with systemic inflammatory response syndrome (SIRS) status, blood culture (BC) result, and survival. Methods: Hospitalized ill foals (n = 90, ≤ 14 days). Methods: In this retrospective study, foals were classified based on SIRS criteria: "SIRS" or "NonSIRS," ...
McKenna KD, Struble SE, Max LNF, Linardi RL, Ortved KF.To quantify platelets, leukocytes, cytokines, and growth factors in ProVet autologous platelet concentrate (APC). We hypothesized that APC would contain significantly increased leukocytes and platelets compared to whole blood and significantly increased concentrations of anti-inflammatory cytokines and growth factors compared to serum. Unassigned: Blood was obtained from 6 horses and processed to produce APC. Leukocyte and platelet concentrations were quantified in whole blood and APC. Cytokines, including interleukin (IL)-1β, IL-4, IL-6, IL-10, tumor necrosis factor-α, and IL-1Ra, and growt...
Dörsam K, Nischang V, Büttner K, Fey K, Werz O, Jordan PM.Equine asthma (EA) is a chronic inflammatory disease of the lower respiratory tract in horses, which is mainly triggered by dusty hay. EA is becoming increasingly acknowledged as a valuable animal model for studying human asthma. Research on the pathogenesis of EA has primarily focused on the associated cells and cytokines involved. However, the role of inflammation-related lipid mediators (LM) in the development and progression of equine asthma remains elusive. LMs are categorized into pro-inflammatory arachidonic acid (AA)-derived leukotrienes (LTs) and prostaglandins (PGs), as well as infla...
Lungu GM, Barshick MR, Shafron AJ, El-Kadi SW, Williams BD, Wesolowski LT, Disilvestro AN, White-Springer SH, Johnson SE.High-intensity exercise in horses resulting in fatigue requires a better understanding of biomarkers defining the condition such that protocols detailing the return to work can be established. This study examined blood metabolite profiles after multiple sessions of high-intensity exercise to define physiological exhaustion. Adult Thoroughbred geldings (n = 10) underwent a standardized exercise test (SET) on a high-speed treadmill, with BHB, BCAAs, alanine, lactate, and CK measurements at regular intervals up to 6 h post-SET. Before and 24 h post-SET gluteus medius muscle samples were t...
Massie S, Léguillette R, Jones JH, Guigand C, Sides RH, Jones KB, Warlick LM, Thueson EL, Troudt TA, Bayly WM.Maximal intensity exercise in equine athletes induces pulmonary capillary stress failure and exercise-induced pulmonary hemorrhage (EIPH) secondary to excessive transmural pressure (Ptm). Furosemide decreases EIPH severity and pulmonary arterial (PAP) and pulmonary wedge (PAW) pressures. Objective: Assess the effects of furosemide on Ptm and EIPH during supramaximal exercise. Methods: Six fit retired Thoroughbreds with consistent EIPH Grade ≥ 2. Methods: Horses performed a controlled crossover design protocol, completing standardized treadmill tests (120%V̇O2max) before and 4 h after int...
Bindi F, de Marchi L, Elias-Cortajarena A, Sala G, Vitale V, Spadari A, Rinnovati R, Bonelli F, Sgorbini M.Colic is a major cause of morbidity and mortality in horses, with oxidative stress implicated in its pathophysiology. Objective: Evaluate biomarkers (BIOs) of oxidative stress and antioxidant defense in healthy horses and those with non-strangulating colic (NSC) and strangulating colic (SC) and assess correlations with survival. Methods: Seventy-one adult horses: 10 healthy and 61 colic-affected (42 NSC, 19 SC) admitted to 3 veterinary teaching hospitals. Methods: Prospective, multicenter cohort study. Blood samples were collected at admission (T0) and up to 96 h post-admission. Biomarkers me...
Loy J, Sornalingam K, Cawley A, Scrivener C, Keledjian J, Noble GK.Altrenogest is a synthetic progestogen widely used in equine reproductive management. Adverse effects to altrenogest have been reported in people with cutaneous exposure reported as the highest exposure pathway. Despite these reports, there has been no quantitative research to determine the capacity for altrenogest to be absorbed through skin. This study aimed to determine if cutaneous application of oral altrenogest results in systemic absorption in mares and to evaluate the influence of application site. A randomized, two-period, two-treatment crossover study was undertaken in eight mares. M...
Hendrikx AL, Vendrig JC, Gehring R, van den Boom R, van Alphen J, Vernooij JCM, Teske E, Roelfsema E.To determine the effect of repeated IV administration of dexamethasone (0.06 mg/kg, q 24 h, twice) on WBC parameters in healthy adult horses. Unassigned: This prospective, longitudinal study was conducted from October 7 through November 5, 2024. Five warmblood mares received an IV dexamethasone sodium phosphate injection (DMI) at 0 and 24 hours and an IV injection with 0.9% sodium chloride solution at 48 and 72 hours. Blood samples were collected at 0, 6, 12, 24, 30, 36, 48, 72, 96, and 168 hours, and WBC parameters were evaluated using linear mixed-effects models. Unassigned: Leukocyte count,...
Cifuentes V, Zuluaga-Cabrera AM, Vargas-Muñoz LJ, Estrada-Gómez S.Albumin is one of the most abundant and physiologically important blood protein in horses due to its ability to regulate vascular volume and transport blood metabolites or drugs. Despite the importance of this protein, in Colombia there is no previous reference of the use of equine albumin in horses as a pharmacological therapy and there is no available any pharmaceutical preparation of this protein to be administrated in horses. This study aims to evaluate for first time the preliminary clinical response of healthy adult Colombian Creole horses after the intravenous administration of an equin...
Hallowell KL, van Eps AW, Kulp JC, Schnabel LV.Lipemia is a common comorbidity in horses with obesity or equine metabolic syndrome, but the impact of lipemia on the measurement of insulin and adiponectin has not been evaluated. Objective: To evaluate endogenous and exogenous lipemic interference with equine insulin and adiponectin measurements via several commercial assays. Methods: Endogenous lipemia was evaluated using plasma and serum samples with triglyceride concentrations of 1000 mg/dL (n = 6 each). Sample insulin concentrations were determined via fluorescence enzyme immunoassay (FEIA), ELISA, and lateral flow assay (LFA). ...
Vasco ACCM, Warren LK, Silva GM, Cuervo-Vivas W, Brandi RA, Silva VP, Lance JM, Dubeux JC, Wickens CL.Rhizoma peanut (RP, Arachis glabrata Benth) is an alternative legume forage to alfalfa (ALF, Medicago sativa L.) with less non-structural carbohydrates and crude protein. Yet, metabolic responses to consuming RP hay have never been evaluated in horses. Objective: The objective of this study was to investigate the effect of feeding RP 'Florigraze' hay on fecal and blood metabolic variables compared to alfalfa 'Legendary XHD' and bermudagrass (BMG, Cynodon dactylon L. 'Coastal') hays fed to maintenance horses. Methods: Six mature Quarter Horse geldings (596±40 kg) were randomly assigned to one ...
Sullivan J, Blea J, McKemie DS, Kass PH, Knych HK.The pharmacokinetics and pharmacodynamics of betamethasone following intra-articular administration to horses have been described; however, studies characterizing intramuscular administration are lacking. Twenty-four horses received an intramuscular dose of 12 mg betamethasone sodium phosphate/betamethasone acetate. Blood and urine were collected at post administration for up to 408 h. Concentrations of betamethasone were determined using LC-MS/MS and pharmacokinetic parameters determined using a Population PK three-compartment model. The duration of pharmacodynamic effects was assessed by...
Golestani NG, Paton MP, Ross BR, Wildish AW, Duarte MSD, Williams CAW, Pearson WP.Horses experience rapid physiological, inflammatory, and oxidative responses during exercise. Spirulina, a nutrient-dense microalga with antioxidant and anti-inflammatory properties, may help modulate these responses and support recovery. Objective: This study evaluated the effects of 30-day dietary Spirulina supplementation on physiological, inflammatory, and oxidative stress responses to moderate-intensity exercise in sedentary horses. We hypothesized that 30-day Spirulina supplementation would modulate hematologic and inflammatory responses and support recovery from moderate-intensity exerc...
Amaral TM, Ramos PDCA, Silva RA, Ferreira MM, Filho EDS.In the context of Brazilian equestrian sports, the Quarter Horse (QH) breed has the third largest population of registered horses and stands out for its numerous abilities in various disciplines. Studies on equine health and athletic performance parameters are scarce, especially involving molecular markers. Objective: This study aimed to investigate the differential expression of microRNAs and target genes involved in metabolic pathways of exercise and to assess hematological and clinical changes in 10 horses (Equus caballus Linnaeus) of the QH breed under different physiological conditions. H...
Bindi F, Cingottini D, Sorvillo B, Sala G, De Marchi L, Monni G, Celardo S, Bonelli F, Sgorbini M.During the perinatal period, neonates experience a sudden increase in oxygen exposure, predisposing them to oxidative stress. Objective: This prospective, in vivo study aimed to evaluate biomarkers of oxidative stress and antioxidant defence in healthy neonatal foals during the first 48 hours of life. Methods: Ten Standardbred foals were enrolled. Blood samples were collected at birth, 24 hours, and 48 hours after birth and analyzed for biomarkers using spectrophotometry assays. Statistical analysis was performed using non-parametric tests and linear regression. Results: The results revealed s...
Shan D, Yao X, Ren W, Huang Q, Su Y, Li Z, Li L, Wang R, Ma S, Wang J.Whole-genome bisulfite sequencing (WGBS) was employed in this article to map blood DNA methylation profiles at single-base resolution in Yili horses before a 5000 m speed race, with comparative analysis of epigenetic differences between the 'elite group' and 'ordinary group' across six four-year-old stallions. The overall methylation level in the elite group was generally higher than that in the ordinary groups, with a minority of regions showing hypomethylation. For instance, the promoter regions of key metabolic and neuro-related genes exhibited significant hypomethylation. The article ident...
Milczek-Haduch D, Żmigrodzka M, Kiełbik P, Świderska B, Olędzki J, Witkowska-Piłaszewicz O.Extracellular vesicles (EVs) are promising biomarkers and mediators of intercellular communication, but their isolation from equine biofluids remains challenging. This study compared two isolation workflows-size-exclusion chromatography (SEC) and differential ultracentrifugation followed by SEC (UC + SEC)-to evaluate their efficiency, reproducibility, and the proteomic composition of EVs derived from equine serum and plasma. Blood from six healthy horses was processed to obtain platelet-free plasma and serum. EVs were isolated using SEC or UC + SEC and characterized by transmission ele...
So YM, Kwok WH, Yap C, Wong COL, Smalley SGR, Forbes BS, Chow DWY, Ho ENM.This paper describes the detection and longitudinal monitoring of cyclosporine in plasma and urine after subconjunctival implant administration in a horse. Sensitive liquid chromatography tandem mass spectroscopy (LC-MS/MS) methods for detecting cyclosporine in horse plasma and urine have been developed and validated, with estimated limits of detection down to 1 pg/mL in both matrices. The developed methods enabled longitudinal monitoring of cyclosporine levels in blood and urine samples collected over 6 months from a horse that had received an ocular cyclosporine implant.
Friend MM, McGaffigan EM, Hall SM, Staniar WB, Smarsh DN.Equine blood samples are often collected in uncontrolled, distant environments and stored for later analysis. Objective: This study aimed to determine how sample storage methods influence complete blood count (CBC) parameters, hypothesizing that temperature and time elapsed from collection to analysis would affect CBC parameters. Methods: Blood samples were collected from 10 healthy Quarter Horse mares (age: 13 ± 4.5 years old) and stored in EDTA tubes at room temperature (22°C), above ice (8°C), refrigerated (4°C), or in contact with ice (2°C). The IDEXX ProcyteDx was used to obtain CBCs...
Freitas Silva D, Passagli Barbosa D, de Paula Rodrigues J, Robaina Sancler-Silva YF, Saules Ignácio F, Lucena Fredou M, Segabinazzi L, Monteiro GA.Doppler ultrasonography is a valuable tool for monitoring testicular hemodynamics, offering improved diagnostic insight and supporting treatment monitoring. However, its use in equine andrology remains limited due to a scarcity of published data and reference values. Therefore, this study aimed to characterize the testicular arterial blood flow patterns in clinically normal stallions and stallions with 180° spermatic cord torsion. Spectral Doppler ultrasonography was performed on both testes of 48 Mangalarga Marchador stallions. Thirty stallions with normal testes were divided into three age ...
Dorrego A, Olvera-Maneu S, Jose-Cunilleras E, Gago P, Raez A, Rivera B, Oporto A, Gonzalez S, Cruz-Lopez F.The forest fly ) is an obligate haematophagous dipteran insect (order Diptera) that primarily infests horses and may contribute to the circulation of vector-borne pathogens. This study aimed to investigate the presence of , s.l., , and , important vector-borne pathogens of equids, in forest flies collected from horses in endemic areas of Spain. A total of 170 forest flies were collected from 39 equids across four geographical regions in Spain (Segovia, Madrid, Toledo, and Menorca) and blood samples were collected from 27 of these horses. All flies were morphologically and molecularly identifi...
Konstantinović N, Gotić J, Baban M, Csik G, Listeš E, Gagović E, Jurković Žilić D, Arežina I, Šubara G, Čulina FE, Delić N, Višal D....Hemotropic mycoplasmas (hemoplasmas) are uncultivable, cell wall-less bacteria that parasitizeon the surface of red blood cells of mammals, potentially causing anemia and other systemic signs. While widely distributed among domestic and wild animals, their occurrence in equids remains poorly understood, and no species has been identified as host-specific to horses or donkeys. This study presents the first systematic survey of hemoplasmas in equids from southeastern Europe and only the second molecularly confirmed case in horses in Europe. A total of 843 equids (817 horses and 26 donkeys) from ...
Ferreira C, Palhares MS, de Melo UP, Leme FOP, Maranhão RPA, Garcia HC, Gheller VA.Starvation and nutritional support clinically influence horses, particularly during the treatment of gastrointestinal diseases and post-surgical recovery. In this study, we aimed to evaluate the effects of different nutritional strategies on the endocrine response of horses subjected to exploratory laparotomy followed by food deprivation. Sixteen healthy adult horses were randomly allocated into four groups (n=4) based on treatments: enteral fluid therapy without (ENTFL) or with glutamine (ENTGL), and parenteral fluid therapy with glucose (PARFL) or total parenteral nutrition with glutamine (P...
Ventura Lopes Carvalho B, Neves de Souza MC, Souza Moreira N, Parisi Marliere J, Mesquita Mota JV, Drumond Bento L, de Castro Benitez A, Avanza MFB....Two routes of administration for electrolyte solutions are commonly used in horses with fluid, electrolyte, and acid-base imbalances: intravenous and nasogastric. Despite the frequent use of these routes, there are situations in which they cannot be applied. In such cases, intracecal fluid therapy represents a viable alternative, as this route enables the administration of enteral electrolyte solutions even in animals lacking normal anterior gastrointestinal function. This study aimed to evaluate the effects of a neutral hypotonic enteral electrolyte solution administered intracecally at two d...
In horses, heat exposure modulates the hypothalamic-pituitary-adrenal axis, autonomic nervous system, and hypothalamic-pituitary-thyroid axis to maintain body temperature and prevent excessive heat accumulation. However, during strenuous exercise under hot and humid conditions, heat production may exceed dissipation, leading to heat stress, anhidrosis, heat stroke, or brain damage. Unassigned: Incremental field standardized exercise tests (fSETs) provide a reliable approach to assess training and fitness levels. Six Arabian horses from Italia Endurance Stable and Academy were monitored during ...
Kohn RA, Dinneen MM, Russek-Cohen E.The objectives of this study were to evaluate the potential for using blood urea N concentration to predict urinary N excretion rate, and to develop a mathematical model to estimate important variables of N utilization for several different species of farm animals and for rats. Treatment means (n = 251) from 41 research publications were used to develop mathematical relationships. There was a strong linear relationship between blood urea N concentration (mg/100 mL) and rate of N excretion (g x d(-1) x kg BW(-1)) for all animal species investigated. The N clearance rate of the kidney (L of bloo...
Schnabel LV, Mohammed HO, Miller BJ, McDermott WG, Jacobson MS, Santangelo KS, Fortier LA.Platelet rich plasma (PRP) has recently been investigated for use in tissue regeneration studies that seek to utilize the numerous growth factors released from platelet alpha-granules. This study examined gene expression patterns, DNA, and collagen content of equine flexor digitorum superficialis tendon (SDFT) explants cultured in media consisting of PRP and other blood products. Blood and bone marrow aspirate (BMA) were collected from horses and processed to obtain plasma, PRP, and platelet poor plasma (PPP). IGF-I, TGF-beta1, and PDGF-BB were quantified in all blood products using ELISA. Ten...
Windberger U, Bartholovitsch A, Plasenzotti R, Korak KJ, Heinze G.In this study species-specific values for whole blood viscosity (WBV), plasma viscosity (PV) and erythrocyte aggregation (EA) were determined in a total of 360 animals. We used 40 individual adult animals of nine mammalian species: horse, pig, dog, cat, rat, cattle, sheep, rabbit and mouse. WBV measurements were carried out using a LS30 viscometer, PV was measured using OCR-D and EA was measured using a Myrenne aggregometer and the LS30 (aggregation index at low shear rate). At low shear rates (0.7 s(-1) and 2.4 s(-1)) haematocrit (Hct)-standardized (40 % Hct) samples showed a higher value of ...
Carter RA, Geor RJ, Burton Staniar W, Cubitt TA, Harris PA.This study described a scoring system for the assessment of apparent neck adiposity and evaluated morphometric measurements for assessment of neck and overall adiposity. Twenty-one barren Thoroughbred mares, 13 Arabian geldings and 75 Welsh, Dartmoor, or crossbred pony mares, were clinically examined and blood samples analysed for insulin, glucose, leptin, and triglycerides. Bodyweight (BW), height, length, girth and abdominal circumferences, neck length, neck crest height and neck circumference were measured, and body condition scores (BCS) and cresty neck scores (CNS) were rated. Girth:heigh...
Bussières G, Jacques C, Lainay O, Beauchamp G, Leblond A, Cadoré JL, Desmaizières LM, Cuvelliez SG, Troncy E.This study addresses development and validation of a composite multifactorial pain scale (CPS) in an experimental equine model of acute orthopaedic pain. Eighteen horses were allocated to control (sedation with/without epidural analgesia - mixture of morphine, ropivacaine, detomidine and ketamine) and experimental groups: amphotericin-B injection in the tarsocrural joint induced pain and analgesia was either i.v. phenylbutazone administered post-induction of synovitis, or pre-emptive epidural mixture, or a pre-emptive combination of the 2. Inter- and intra-observer reproducibility was good (0....
Liu X, Zhang Y, Li Y, Pan J, Wang D, Chen W, Zheng Z, He X, Zhao Q, Pu Y, Guan W, Han J, Orlando L, Ma Y, Jiang L.High altitude represents some of the most extreme environments worldwide. The genetic changes underlying adaptation to such environments have been recently identified in multiple animals but remain unknown in horses. Here, we sequence the complete genome of 138 domestic horses encompassing a whole altitudinal range across China to uncover the genetic basis for adaptation to high-altitude hypoxia. Our genome data set includes 65 lowland animals across ten Chinese native breeds, 61 horses living at least 3,300 m above sea level across seven locations along Qinghai-Tibetan Plateau, as well as 7...
Schmoldt A, Benthe HF, Haberland G, Tarentino AL, Maley F, Berkmen YM, Lande A, Fine JM, Lambin P, Derycke C, North ML, Chataing B, Goudemand M.The chest roentgenographic findings in Takayasu's arteritis include widening of the ascending aorta, contour irregularities of the descending aorta, arotic calcifications, pulmonary arterial changes, rib notching, and hilar lymphadenopathy. The single most important diagnostic sign is a segmental calcification outlining a localized or diffuse narrowing of the aorta. The other signs may be suspicious or suggestive, but the diagnostic accuracy increases when several findings are present simultaneously. A routine screening of monoclonal gammopathies (M.G.) was performed in the serum from 36, 015 ...
Treiber KH, Kronfeld DS, Hess TM, Byrd BM, Splan RK, Staniar WB.To evaluate genetic and metabolic predispositions and nutritional risk factors for development of pasture-associated laminitis in ponies. Methods: Observational cohort study. Methods: 160 ponies. Methods: A previous diagnosis of laminitis was used to differentiate 54 ponies (PL group) from 106 nonlaminitic ponies (NL group). Pedigree analysis was used to determine a mode of inheritance for ponies with a previous diagnosis of laminitis. In early March, ponies were weighed and scored for body condition and basal venous blood samples were obtained. Plasma was analyzed for glucose, insulin, trigly...
Tobaly-Tapiero J, Bittoun P, Neves M, Guillemin MC, Lecellier CH, Puvion-Dutilleul F, Gicquel B, Zientara S, Giron ML, de Thé H, Saïb A.Foamy viruses (FVs) are complex retroviruses which have been isolated from different animal species including nonhuman primates, cattle, and cats. Here, we report the isolation and characterization of a new FV isolated from blood samples of horses. Similar to other FVs, the equine foamy virus (EFV) exhibits a highly characteristic ultrastructure and induces syncytium formation and subsequent cell lysis on a large number of cell lines. Molecular cloning of EFV reveals that the general organization is that of other known FVs, whereas sequence similarity with its bovine FV counterpart is only 40%...
Whittle BJ, Moncada S, Vane JR.The activity of prostacyclin (PGI2), PGE1 or PGD2 as inhibitors of platelet aggregation in plasma from human, dog, rabbit, rat, sheep and horse was investigated. Prostacyclin was the most potent inhibitor in all species. PGD2 was a weak inhibitor in dog, rabbit and rat plasma whereas PGE1 and prostacyclin were highly active. Theophylline or dipyridamole potentiated the inhibition of human platelet aggregation by prostacyclin, PGE1 or PGD2. Compound N-0164 abolished the inhibition by PGD2 of human platelet aggregation but did not inhibit the effects of PGE1 or prostacyclin. The results suggest ...
Carter RA, Treiber KH, Geor RJ, Douglass L, Harris PA.The ability to predict ponies at increased risk of laminitic episodes, when exposed to nutrient dense pasture, would facilitate management to avoid disease. Objective: To identify variables and clinically useful cut-off values with reproducible diagnostic accuracy for the prediction of ponies that subsequently developed laminitis when exposed to nutrient dense pasture. Methods: A cohort of predominantly Welsh and Dartmoor ponies from a closed herd was evaluated in March 2006 (n = 74) and March 2007 (n = 57). Ponies were categorised as never laminitic or previously laminitic according to report...
Vick MM, Adams AA, Murphy BA, Sessions DR, Horohov DW, Cook RF, Shelton BJ, Fitzgerald BP.Recent studies associate obesity and insulin resistance in horses with development of abnormal reproductive function and debilitating laminitis. The factors contributing to insulin resistance in obese horses are unknown. However, human studies provide evidence that elevated inflammatory cytokines such as tumor necrosis factor alpha (TNFalpha), IL1, and IL6 play direct roles in development of obesity-associated insulin resistance. Thus, inflammation may be a key link between obesity and insulin resistance in horses. The aim of the current investigation was to examine possible relationships betw...
Ayliffe LK, Cerling TE, Robinson T, West AG, Sponheimer M, Passey BH, Hammer J, Roeder B, Dearing MD, Ehleringer JR.Temporal stable isotope records derived from animal tissues are increasingly studied to determine dietary and climatic histories. Despite this, the turnover times governing rates of isotope equilibration in specific tissues following a dietary isotope change are poorly known. The dietary isotope changes recorded in the hair and blood bicarbonate of two adult horses in this study are found to be successfully described by a model having three exponential isotope pools. For horse tail hair, the carbon isotope response observed following a dietary change from a C3 to a C4 grass was consistent with...
Hassan HK, Cupp EW, Hill GE, Katholi CR, Klingler K, Unnasch TR.An important variable in the amplification and escape from the enzootic cycle of the arboviral encephalitides is the degree of contact between avian hosts and mosquito vectors. To analyze this interaction in detail, blood-fed mosquitoes that were confirmed vectors of eastern equine encephalomyelitis (EEE) virus were collected in 2002 from an enzootic site in central Alabama during the time this virus was actively transmitted. Avian-derived blood meals were identified to the species level of the host, and the proportion derived from each species was compared with the overall composition of the ...
Alhassan A, Pumidonming W, Okamura M, Hirata H, Battsetseg B, Fujisaki K, Yokoyama N, Igarashi I.With the aim of developing more simple diagnostic alternatives, a differential single-round and multiplex polymerase chain reaction (PCR) method was designed for the simultaneous detection of Babesia caballi and Babesia equi, by targeting 18S ribosomal RNA genes. The multiplex PCR amplified DNA fragments of 540 and 392 bp from B. caballi and B. equi, respectively, in one reaction. The PCR method evaluated on 39 blood samples collected from domestic horses in Mongolia yielded similar results to those obtained from confirmative PCR methods that had been established earlier. Thus, the single-roun...
Bartsch S, Bauer B, Wiemann A, Clausen PH, Steuber S.Host feeding patterns of engorged sibling species of the Culicoides obsoletus and Culicoides pulicaris groups captured during three nights on two selected farms maintaining either cattle, sheep, horses, and pigs (Seedorf, Brandenburg) or cattle, sheep, moufflons, and red and fallow deer (Paulinenaue, Brandenburg) were determined by polymerase chain reaction amplification using conserved primers and sets of species-specific primers derived from vertebrates mitochondrial cytochrome b. Out of a total of 177 blood meals analysed, 115 (65%) tested positive for a blood meal from vertebrates. 63.5% (...
de Laat MA, McGree JM, Sillence MN.Compared with some other species, insulin dysregulation in equids is poorly understood. However, hyperinsulinemia causes laminitis, a significant and often lethal disease affecting the pedal bone/hoof wall attachment site. Until recently, hyperinsulinemia has been considered a counterregulatory response to insulin resistance (IR), but there is growing evidence to support a gastrointestinal etiology. Incretin hormones released from the proximal intestine, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide, augment insulin secretion in several species but require invest...
Magneson GR, Puvathingal JM, Ray WJ.The enzyme phosphoglucomutase can be used as a metal ion indicator to measure the concentrations of free Mg2+ and free Zn2+ in physiological fluids. In horse plasma, the concentration of free Mg2+ is close to 0.5 mM, whereas that of free Zn2+ is about 2 X 10(-10) M, although numerous physiological roles for Zn2+ have been postulated that would require free Zn2+ concentration orders of magnitude higher than this. A titration of plasma with Zn2+ shows that the fractional increase in free Zn2+ is essentially the same as the fractional increase in total exchangeable Zn2+, and the results are consi...
McGowan TW, Pinchbeck GP, McGowan CM.Equine pituitary pars intermedia dysfunction (PPID) is an ageing-related neurodegenerative disorder. The prevalence and risk factors for PPID using seasonally adjusted basal adrenocorticotropic hormone (ACTH) concentrations in aged horses have not been previously reported. Objective: To determine the prevalence, risk factors and clinical signs predictive for PPID in a population of horses aged ≥ 15 years in Queensland, Australia. Methods: Owner-reported data was obtained using a postal questionnaire distributed to an equestrian group. A subgroup of surveyed owners were visited and a veterina...
Singh AK, Jiang Y, White T, Spassova D.The performances of a radioimmunoassay method, a chemiluminescent immunoassay method, and a chemiluminescent-enzyme immunoassay method were evaluated for the analysis of cortisol and total thyroxine in blood samples obtained from dogs, cats, horses, and humans (reference samples). The analysis of cortisol in human and animal samples exhibited good precision, linearity, and recovery. The 3 methods gave comparable values for the ACTH-induced increase and the dexamethasone-induced decrease in cortisol concentrations in animal samples. The recoveries of total thyroxine from human samples, analyzed...
Koerner J, Nesic D, Romero JD, Brehm W, Mainil-Varlet P, Grogan SP.Fibroblast-like cells isolated from peripheral blood of human, canine, guinea pig, and rat have been demonstrated to possess the capacity to differentiate into several mesenchymal lineages. The aim of this work was to investigate the possibility of isolating pluripotent precursor cells from equine peripheral blood and compare them with equine bone marrow-derived mesenchymal stem cells. Human mesenchymal stem cells (MSCs) were used as a control for cell multipotency assessment. Venous blood (n = 33) and bone marrow (n = 5) were obtained from adult horses. Mononuclear cells were obtained by Fico...
Textor JA, Tablin F.To investigate and compare clinically relevant Platelet-rich plasma (PRP) activation methods. Methods: Experimental. Methods: PRP was prepared from 6 equine subjects. Activation of the PRP was performed by 4 methods (autologous thrombin, bovine thrombin, calcium chloride (CaCl(2) ), or freeze-thaw). The resultant PDGF-BB (where PDGF is platelet-derived growth factor) and TGFβ1 (where TGFβ is transforming growth factor beta) levels in PRP releasates were quantified by Enzyme-linked immunosorbent assay (ELISA) and compared. Growth factor contents were also compared between platelet-rich clots ...
Allen GP.To identify risk factors associated with development of clinical neurologic signs in horses exposed to equine herpesvirus-1 (EHV-1). Methods: 36 adult horses. Methods: Blood samples collected before and after challenge inoculation with nonneuropathogenic or neuropathogenic EHV-1 were analyzed for leukocyte-associated viremia, serum neutralizing antibody, and EHV-1-specific cytotoxic T-lymphocyte precursors (CTLPs). Associations between variables and neurologic disease and correlations between age category or breed and development of neurologic disease were examined. Results: 9 horses developed...
Frank N, Elliott SB, Brandt LE, Keisler DH.To compare obese horses with insulin resistance (IR) with nonobese horses and determine whether blood resting glucose, insulin, leptin, and lipid concentrations differed between groups and were correlated with combined glucose-insulin test (CGIT) results. Methods: 7 obese adult horses with IR (OB-IR group) and 5 nonobese mares. Methods: Physical measurements were taken, and blood samples were collected after horses had acclimated to the hospital for 3 days. Response to insulin was assessed by use of the CGIT, and maintenance of plasma glucose concentrations greater than the preinjection value ...
Biddle AS, Tomb JF, Fan Z.Due to modern management practices and the availability of energy dense feeds, obesity is a serious and increasingly common health problem for horses. Equine obesity is linked to insulin resistance and exacerbation of inflammatory issues such as osteoarthritis and laminitis. While the gut microbiome is thought to play a part in metabolic status in horses, bacterial communities associated with obesity have yet to be described. Here we report differences in metabolic factors in the blood of obese, normal and lean horses correlated with differences in gut microbiome composition. We report that ob...
Monteiro-Riviere NA, Bristol DG, Manning TO, Rogers RA, Riviere JE.Studies in dermatology, cutaneous pharmacology, and toxicology utilize skin from different animal species and body sites. However, regional differences exist in topical chemical percutaneous absorption studies in man and in animal. The objective of this study was to compare epidermal thickness and number of cell layers across species and body sites using both formalin-fixed paraffin and frozen sections. Cutaneous blood flow determined by laser Doppler velocimetry (LDV) was compared to histologic data. Six animals of each of the following species were used: monkeys, pigs, dogs, cats, cows, hors...
Mach N, Plancade S, Pacholewska A, Lecardonnel J, Rivière J, Moroldo M, Vaiman A, Morgenthaler C, Beinat M, Nevot A, Robert C, Barrey E.The adaptive response to extreme endurance exercise might involve transcriptional and translational regulation by microRNAs (miRNAs). Therefore, the objective of the present study was to perform an integrated analysis of the blood transcriptome and miRNome (using microarrays) in the horse before and after a 160 km endurance competition. A total of 2,453 differentially expressed genes and 167 differentially expressed microRNAs were identified when comparing pre- and post-ride samples. We used a hypergeometric test and its generalization to gain a better understanding of the biological functio...
Giraldo CE, López C, Álvarez ME, Samudio IJ, Prades M, Carmona JU.There is no information on the effects of the breed, gender and age on the cellular content and growth factor (GF) release from equine pure-platelet rich plasma (P-PRP) and pure-platelet rich gel (P-PRG). The objectives of this study were: 1) to compare the cellular composition of P-PRP with whole blood and platelet poor plasma (PPP); 2) to compare the concentration of transforming GF beta 1 (TGF-β1) and platelet derived GF isoform BB (PDGF-BB) between P-PRP treated with non-ionic detergent (P-PRP+NID), P-PRG (activated with calcium gluconate -CG-), PPP+NID, PPP gel (PPG), and plasma and; 3) ...
Scheinberg P, Marte M, Nunez O, Young NS.Clones of glycosylphosphatidylinositol-anchor protein-deficient cells are characteristic in paroxysmal nocturnal hemoglobinuria and are present in about 40-50% of patients with severe aplastic anemia. Flow cytometry has allowed for sensitive and precise measurement of glycosylphosphatidylinositol-anchor protein-deficient red blood cells and neutrophils in severe aplastic anemia. Methods: We conducted a retrospective analysis of paroxysmal nocturnal hemoglobinuria clones measured by flow cytometry in 207 consecutive severe aplastic anemia patients who received immunosuppressive therapy with a h...
Menzies-Gow NJ, Harris PA, Elliott J.Certain individuals appear to be predisposed to recurrent pasture-associated laminitis. Previous studies have predominantly investigated risk factors only after disease occurrence. Objective: To investigate risk factors for pasture-associated laminitis prior to disease occurrence. Methods: Prospective cohort study. Methods: Non-laminitic ponies aged ≥7 years were recruited. Body condition score (BCS), height, weight, crest height and thickness were measured and an overnight dexamethasone suppression test performed. Plasma or serum adiponectin, leptin, triglyceride, basal insulin, insulin pos...
