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.
Epizootic lymphangitis (EEL), caused by Histoplasma capsulatum var. farciminosum (HCF), is a neglected equine fungal disease lacking effective vaccines. The newly developed inactivated '8ZH' vaccine requires safety validation in the target species. Objective: To evaluate the biochemical, haematological and clinical safety of the inactivated HCF '8ZH' vaccine in foals. Methods: A controlled, single-blinded study was conducted on 30 clinically healthy foals (4-6 months), randomized into vaccinated (n = 15) and control (n = 15) groups. Vaccinated animals received a 5 mL intramuscular dose (...
Sjolin E, Espinosa D, Arroyo L, Kenney D, Lack A, Baird J.Listeriosis is caused by , a Gram-positive, facultative anaerobic, intracellular rod bacterium that can infect a wide variety of species. Listeriosis occurs in a diverse range of domestic and wild animals but is most commonly a disease of ruminants. Clinical signs include meningoencephalitis, typhlocolitis, septic arthritis, and abortions. Listeriosis in horses has been reported in several countries but is an uncommon diagnosis. This report describes clinical, bacteriological, histopathological, and immunohistochemical findings in 6 foals with neonatal septicemia from which was isolated. Key ...
Baird JD, Arroyo LG, Lumsden JH.The objective of this study was to determine the effect of either oral supplementation of sodium selenite and alpha-tocopherol or intramuscular administration of a commercial preparation of selenium (Se) and vitamin E to Standardbred broodmares with low (21.0 ± 18.1 IU/g Hb) whole blood glutathione peroxidase (GPx) activity. Ten mares received 3 weekly intramuscular (IM) doses, whereas 9 mares were orally supplemented daily for 10 wk. Blood samples were collected jugular venipuncture and the whole blood GPx activity was measured at each sampling time for the 32-week period. Both oral and int...
Grzędzicka J, Świderska B, Sitkiewicz E, Dąbrowska I, Witkowska-Piłaszewicz O.Racehorses undergo profound physiological changes with training and competition, but current biomarkers inadequately capture the complex molecular dynamics of exercise. This study aimed to identify novel plasma biomarkers of training adaptation and peak load using high-throughput proteomics. Objective: We hypothesised that systematic training and racing induce distinct plasma proteomic signatures, enabling the discovery of candidate biomarkers linked to training status, oxidative stress, inflammation and metabolic remodelling. Methods: In vivo longitudinal study. Methods: Forty-nine Arabian an...
Eskandari G, Ahmadi Sheikhsarmast S, Ghasemi S, Mohri M.Neutrophil gelatinase-associated lipocalin (NGAL) is a glycoprotein involved in immune responses and inflammation, with established diagnostic utility in acute kidney injury (AKI) and systemic diseases. However, reference values for NGAL in healthy horses, particularly the Turkmen breed, remain poorly defined. Objective: This study aimed to establish reference values for serum NGAL concentrations in healthy Turkmen horses and to evaluate the influence of age, sex, pregnancy status and physical activity on its levels, as well as its correlations with haematological and serum biochemical variabl...
Decoster C, Lefère L, Raes E, van Loon G, Dufourni A.Leptospirosis is a widespread zoonotic, infectious disease associated with abortion, stillbirth, as well as liver and kidney failure. Leptospiral Pulmonary Haemorrhage Syndrome (LPHS) has increasingly been reported in human and canine patients infected by Leptospira and is associated with a high fatality rate. In equine medicine, pulmonary haemorrhage has mainly been described in foals with leptospiral infections, but rarely in adult horses. Objective: To characterise the clinicopathological features of pulmonary haemorrhage as a distinct disease entity in adult horses with leptospirosis, term...
Crossland WL, Aviles-Rosa EO, Perry EB, Crowell C, Webberson E, Brown J, Fassbender J.Our objective was to evaluate the effect of transdermal melatonin on physiological stress biomarkers in horses, with some subjected to transport stress. Sixteen horses were assigned to a 2 × 2 factorial design assessing treatment (melatonin vs. no melatonin) and transport status (transported vs. non-transported), creating four groups: Control (CON), Transport only (TRS), Melatonin only (MEL), and Melatonin plus Transport (MELTRS). Horses in melatonin groups received 24 mg/day transdermally for 21 days and transported groups underwent a 3-hour trailer ride on day 21. Day 21 blood samples were ...
Pourmahdi Borujeni M, Ghobadian Diali H, Mashhadi AG, Aliabad MJ.The recent identification of novel viruses associated with hepatitis in horses has prompted equine veterinarians to investigate the viral factors contributing to equine hepatitis. Hepacivirus equi (EqHV), a member of the Flaviviridae family within the Hepacivirus genus, has been detected in horses affected by hepatitis. Globally, EqHV is highly conserved, existing as a single genotype with three distinct subtypes (Subtypes 1-3). Numerous studies have detected the virus by PCR and identified EqHV-specific antibodies through serological tests in different regions worldwide. However, to the best ...
Reemtsma FP, Giers J, Horstmann S, Stoeckle SD, Gehlen H.Amino acid (AA) metabolism and the adaptation of muscles to increased physical performance are interdependent. This field study examined changes in plasma amino acid (PAA) concentrations and two metabolites (ammonia and urea) before and after cross-country (CC) competitions throughout an entire eventing season and their associations with performance outcomes in eventing horses. Twenty horses from nine different Warmblood breeds were evaluated between two and seven times across 14 international eventing competitions over a 23-week period. A total of 55 rides were sampled. Blood samples were col...
Parker M, Arnade H, Parker JL, Gordon J, Peroni JF.Investigation of alternative antibiotic therapies is critical for the future of medicine. Platelet lysate (PL) is a blood product that has shown antibiotic potential, which could be used to augment or replace current antibiotics. Objective: To compare the effects of equine PL versus antibiotics on growth of clinically isolated antibiotic resistant bacteria. We hypothesized that PL would exert an antimicrobial effect on equine bacterial isolates resistant to antibiotics. Methods: In vitro experimental study. Platelets were collected via apheresis from nine donor horses and underwent two freeze-...
James C, Sheahan J, Arthur P.Thoroughbred race performance is influenced by genetics, training, recovery, and management, but decisions about race readiness are often subjective and lack validated physiological markers. This study evaluated thiol-oxidised albumin, a blood-based indicator of oxidative stress, as a potential biomarker of pre-race fitness in Australian Thoroughbreds. Seventy-five clinically healthy racehorses from seven stables were monitored across 216 competitive events (150 races, 66 trials). Blood samples were collected from the jugular at baseline, 48 h pre-race, and for each day up to 8 days post-race ...
Deniz Ö, Erol HS, van den Hoven R, Onmaz AC, Aragona F, Fazio F.Weaning represents a major developmental milestone for foals, especially when 4- to 7-month-old foals are abruptly separated from their dams. Studies have shown that the post-weaning period is associated with physiological and psychological stress, which may affect immune function. The present study aimed to describe and analyze the pattern of blood inflammatory biomarkers related to the innate immune system. A gradual foal-dam separation procedure was chosen, which included post-weaning social buffering by a familiar adult horse. Twelve Thoroughbred foals (six fillies, six colts) aged 4-6 mon...
Environmental contamination with heavy metals, resulting from industrialization, urbanization, and agricultural intensification, poses serious ecological and health risks. Horses, due to their grazing behavior and close association with human environments, serve as reliable sentinel species for assessing environmental pollution. This study aimed to evaluate the bioaccumulation of heavy metals and trace elements in different biological matrices of horses-blood, hair, hooves, and synovial fluid-and to investigate their relationship with hematological biomarkers as indicators of physiological str...
Fresa K, Catandi GD, Gonzalez-Castro R, Omar A, Whitcomb LA, Cheng MH, Chen TW, Carnevale EM, Chicco AJ.Advancing age is associated with a decline in fertility and functional capacity, which may result in part from suboptimal nutrition and impaired mitochondrial function. Dietary essential polyunsaturated fatty acids (PUFA) are broadly recommended to mitigate weight loss and reduce risk of chronic disease in aged populations, but their effects on mitochondrial function are less clear. The present study investigated the impacts of dietary supplementation with essential omega-3 PUFA (flaxseed oil; N3) or omega-6 PUFA (corn oil, N6) on blood, muscle and follicular cell fatty acid composition and mi...
Aiche S, Chikhaoui M, Smail F, Benamor N, Benia AR.Pregnancy causes increased oxidative stress in mares, possibly harming both the mare and the foal, whereas the effects of different exercise levels on oxidative stress and lipid metabolism during pregnancy remain unclear. Objective: For this reason, the aim of this research was to explore the impacts of different training intensities on oxidative stress and lipid metabolism during pregnancy. Methods: The study comprised 22 clinically normal Purebred Arabian mares from Algeria, which were divided into three groups according to age and exercise frequency. Blood samples were collected during both...
Brito G, Damián JP, Trigo P, Ruprechter G.The Raid Hípico Uruguayo (RHU) is the oldest equestrian endurance sport in Uruguay. A high percentage of horses fail to complete RHU rides. Therefore, the aim of this study was to investigate whether weather conditions (comfort index [CI]), horse experience, and ride distance affect horse performance (finishing ride [FR] or nonfinishing ride [NFR]) in the RHU. An additional objective was to determine whether finishing the ride affects the hematological and biochemical parameters of the horses. This study involved 17 RHU rides over distances of 60-90 km and 284 horses. Blood samples were tak...
Zuluaga-Cabrera AM, Barbosa da Costa G, Martinez ID, Arias MP.Colombian Paso horses (CPs) excel in gait competitions due to their endurance, speed, and precision, which demand a high level of cardiorespiratory fitness. However, their training regimes often lack scientific support, and few studies have linked physiological parameters to optimal training zones. This study aimed to estimate the aerobic lactate threshold (LTaer) using mathematical methods and to correlate it with heart rate (HR) zones and blood lactate. Eighteen CPs were evaluated and classified into trained (GT) and untrained (GD) groups. All animals underwent a field-based incremental exer...
Mitlyng N, Hobbs KJ, Cooper BL, Sheats MK.Lipopolysaccharide (LPS) is frequently used in equine research to model clinical endotoxemia; however, there is no standardized protocol for inducing cytokine production in equine whole blood. To address this knowledge gap, the goal of this study was to compare the cytokine responses elicited by three different LPS stimulation protocols. Whole blood was collected from six healthy horses (aged 5-30 years; mixed breeds and genders) from the North Carolina State University teaching herd (IACUC #23-412). Sixty milliliters of heparinized blood were aseptically drawn and divided into 15 mL aliquots....
Meng C, Wang J, Zeng Y, Yao X, Meng J.This study investigated the effects of varying proline supplementation doses in weaned foals. Twenty-eight weaned foals (approximately 5 months of age; body weight: 54.45 ± 11.33 kg; with an equal number of males and females) were randomly assigned to one of four groups-a control group, a low-dose group (20 mg/kg·d), a medium-dose group (40 mg/kg·d), and a high-dose group (60 mg/kg·d)- receiving continuous supplementation for 60 days. Blood samples were collected periodically for the analysis of hormones, antioxidants, immune parameters, and plasma amino acids. Concurrently, fecal 16S rRNA...
Alsultan A, Karim SM, Al-Saadi M, Alsallami D, Ben Said M, Belkahia H.Equine piroplasmosis (EP), caused by the intracellular protozoa Theileria equi, Babesia caballi, and Theileria haneyi, represents a major health and economic threat to the equine industry worldwide. Existing diagnostic methods, including PCR, serology, and microscopy, are constrained by their dependence on specialized equipment, lengthy protocols, and the requirement for skilled personnel. Objective: This study aimed to develop a rapid, accurate, and field-deployable molecular diagnostic assay for T. equi. Methods: A nucleic acid-based diagnostic platform combining recombinase polymerase ampli...
Hanousek K, O'Hara V, Riddell DO, Piercy RJ.In Thoroughbred horses, a highly prevalent short interspersed nuclear element (SINE) mutation in the myostatin gene (MSTN) promoter influences circulating myostatin concentration and is associated with muscle morphology, fracture risk and optimal race distance. Our prior data reveal that within horses there is substantial variation in serum myostatin concentration, particularly in MSTN heterozygotes and wild type horses but it was unclear whether such variation relates to within-horse differences or to environmental or temporal effects. Here we report the intra-horse consistency of circulating...
The aim of the study was to identify proteomic signatures from the serum of horses affected by simple obstructive intestinal colic to characterize the pathological process and to assess potential biomarkers for early diagnosis. Seven horses with obstructive colic received venous blood samples for determination of standard hematobiochemical, inflammatory, and lipid profiles at the time of initial clinical examination and after conservative therapy upon recovery. Proteomic profiling was also performed on all samples by means of a within-group analysis (sick horses at discharge vs. sick horses at...
Kranenburg LC, Reinke KS, van den Broek J, Zaal EA, van den Boom R, van Doorn DA.Hydrolysed collagen is used as a supplement for horses with osteoarthritis, hoof horn growth problems, and gastric ulcers. To determine the oral availability of a specific hydrolysed collagen supplement and the appropriate dose, six Warmblood mares were fed two different concentrations of the supplement: 100 g HC (C), 50 g HC (C), and a control of 0 g HC (C) during one week in a randomised cross-over design. On day 7, 14 and 21, blood sampling for amino acid (AA) analysis was performed, just prior to feeding the supplement (t = 0) and every hour after feeding for 8 h (t = 1-8). Statistical ana...
Tallmadge RL, Laverack M, Lejeune M, Crossley B, Diel DG.Equid herpesvirus (EHV) 1 and -4 are common viral pathogens of horses that can cause upper respiratory disease, neurological disease, abortion, and death. As characteristic alphaherpesviruses, both EHV-1 and EHV-4 can establish latency, resulting in a lifelong carrier state in infected animals. Here we describe the development and validation of a rapid and sensitive multiplex real-time PCR assay (EHV1-4MP) that simultaneously detects EHV-1 and EHV-4 and includes an endogenous internal control - melanocortin 1 receptor (MC1R) - targeting the equid genome. The EHV1-4MP assay analytical sensitiv...
Mojsym W, Kowalik S, Chałabis-Mazurek A, Janczarek I, Kędzierski W.Some correlations between serum Cu, Zn and Se and cytokines have been reported in humans. Especially, the Cu:Zn ratio corresponded with inflammation. To date, relationships between microelements and proinflammatory proteins are poorly understood in horses. The aim of the study was to evaluate whether Cu, Zn and Se may influence turnover of IL-6, IL-8 and tissue factor (TF) in breeding and working horses. Blood samples obtained from 66 horses were analysed. There were 37 pregnant broodmares of different breeds, 13 barren broodmares and 16 race Thoroughbred horses. Serum Cu, Zn and Se concentrat...
Hammack SM, Moshage SG, Kersh ME, McCoy AM.To quantify circulating levels of myokines with a known role in bone remodeling (receptor activator of nuclear factor κ B ligand [RANK-L], matrix metalloproteinase 2 [MMP-2], and irisin) in foals in response to exercise and over the first year of life. Unassigned: 12 foals were enrolled in the study; 6 underwent an 8-week exercise program, and 6 were nonexercised controls. Blood samples were collected between 2 and 11 months of age. Receptor activator of nuclear factor κ B ligand, MMP-2, and irisin were quantified using equine-specific ELISAs. Unassigned: RANK-L, MMP-2, and irisin did not ch...
Training on deep sand is commonly employed in endurance horses, but its physiological adaptation remains poorly characterized. This study aimed to characterize locomotor adaptations during a 7 km controlled-speed canter on deep sand in eighteen endurance horses, to identify heart rate variability (HRV) components, and to investigate changes in hematological variables before and after exercise. Stride frequency (SF) and stride length (SL), HRV, and hematological profiles were recorded during exercise and recovery with a fitness tracker. Associations between maximum speed and locomotor parameter...
Feijo LS, Ledeck J, Wolfsdorf K, Ponthier J, Parry S, Felippe MJB.Associations between the immune and endocrine systems during equine pregnancy remain poorly understood. Based on the hypothesis that distinct phases of the equine healthy gestation are characterized by specific associations between circulating immunological and hormonal parameters, contributing to pregnancy maintenance, this investigation aimed to: (i) evaluate how circulating immunological and hormonal parameters change across different phases of pregnancy; (ii) investigate associations between changes in circulating immunological and hormonal parameters; and (iii) propose potential hormonal ...
Hobbs KJ, Ludwig EK, Martin EM, Bayless R, Bauck AG, Freeman DE, Gonzalez LM.To determine if blood and peritoneal fluid levels of syndecan-1, heparan sulfate, and hyaluronan are elevated in horses with small intestinal disease compared to healthy counterparts. Unassigned: 61 horses were categorized into control (n = 20), inflammatory (11), and strangulating (30) groups. Paired peritoneal fluid and blood samples were obtained from each group from December 2016 through December 2024 and analyzed via equine-validated ELISAs for syndecan-1, heparan sulfate, and hyaluronan concentrations. Patient survival to discharge was recorded for all groups. Immunofluorescence staining...
Rocha IA, McPeek JL, Hulverson MA, Choi R, Orr K, Sponseller BT, Kennedy T, Ojo KK, Barrett LK, Ruby R, Janes J, Reed SM, Arnold SLM, Van Voorhis WC....To determine the systemic and CNS distribution of bumped-kinase inhibitors (BKIs) in healthy horses, assess potential side effects, and identify a candidate compound for a clinical trial in equine protozoal myeloencephalitis (EPM) cases. Unassigned: 9 pharmacokinetic (PK) experiments were conducted from March 2021 through November 2024. Bumped-kinase inhibitors 1708, 1748, and 1841 were screened in Sarcocystis neurona growth assays and IV PKs, followed by investigation of a lead BKI compound by single-dose or multiday oral administration. Serial plasma collections were performed to assess syst...
Rikihisa Y, Perry BD.An ehrlichia was consistently isolated from the peripheral blood leukocyte fraction of ponies that had been experimentally infected with Potomac horse fever by whole blood transfusion from naturally infected horses. The organism was propagated in a human histiocyte cell line for 3 to 5 weeks and then inoculated intravenously or intradermally into healthy adult ponies. Clinical signs of Potomac horse fever, which varied in the degree of severity, occurred 9 to 14 days post-inoculation in all of the ponies. One pony died 20 days post-inoculation. The ehrlichial organism was reisolated in the hum...
Bailey SR, Habershon-Butcher JL, Ransom KJ, Elliott J, Menzies-Gow NJ.To determine the metabolic phenotype of a group of laminitis-prone ponies when at pasture in summer, compared with when at pasture in winter. Methods: 40 ponies of various breeds predisposed to recurrent pasture-associated laminitis and 40 unaffected control ponies. Methods: Body condition score and size of the crest of the neck were assessed, blood samples obtained, and blood pressure measured by use of an indirect oscillometric technique, while ponies were kept on winter pasture (last week of November or beginning of December) and again on summer pasture (June). Serum insulin concentration a...
Lansade L, Nowak R, Lainé AL, Leterrier C, Bonneau C, Parias C, Bertin A.Behavioural and physiological markers of discrete positive emotions remain little investigated in animals. To characterise new markers in horses, we used tactile stimulations to induce emotional situation of contrasting valence. In the Gentle grooming group (G, N = 13) horses were gently groomed during 11 sessions on the body areas they appreciated the most. Horses in the Standard grooming group (S, N = 14) were groomed using a fixed procedure, reported to induce avoidance reactions in some horses. At session 11, G horses expressed significantly more contact-seeking behaviours than S h...
Beretta C, Garavaglia G, Cavalli M.We report on the inhibitory activity of the NSAIDs meloxicam, carprofen, phenylbutazone and flunixin, on blood cyclooxygenases in the horse using in vitro enzyme-linked assays. As expected, comparison of IC50 indicated that meloxicam and carprofen are more selective inhibitors of COX-2 than phenylbutazone and flunixin; meloxicam was the most advantageous for horses of four NSAIDs examined. However at IC80, phenylbutazone (+134.4%) and flunixin (+29.7%) had greater COX-2 selectivity than at IC50, and meloxicam (-41.2%) and carprofen (-12.9%) had lower COX-2 selectivity than at IC50. We therefor...
Beck C, Leparc Goffart I, Franke F, Gonzalez G, Dumarest M, Lowenski S, Blanchard Y, Lucas P, Lamballerie X, Grard G, Durand GA, Zientara S....Since 2015, annual West Nile virus (WNV) outbreaks of varying intensities have been reported in France. Recent intensification of enzootic WNV circulation was observed in the South of France with most horse cases detected in 2015 ( = 49), 2018 ( = 13), and 2019 ( = 13). A WNV lineage 1 strain was isolated from a horse suffering from West Nile neuro-invasive disease (WNND) during the 2015 episode in the Camargue area. A breaking point in WNV epidemiology was achieved in 2018, when WNV lineage 2 emerged in Southeastern areas. This virus most probably originated from WNV spread from Northern Ital...
Brideau C, Van Staden C, Chan CC.To determine potency and selectivity of nonsteroidal anti-inflammatory drugs (NSAID) and cyclooxygenase- (COX-) specific inhibitors in whole blood from horses, dogs, and cats. Methods: Blood samples from 30 healthy horses, 48 healthy dogs, and 9 healthy cats. Methods: Activities of COX-1 and COX-2 were determined by measuring coagulation-induced thromboxane and lipopolysaccharide-induced prostaglandin E2 concentrations, respectively, in whole blood with and without the addition of various concentrations of phenylbutazone, flunixin meglumine, ketoprofen, diclofenac, indomethacin, meloxicam, car...
Guedes AG, Morisseau C, Sole A, Soares JH, Ulu A, Dong H, Hammock BD.A 4-year old, 500 kg Thoroughbred female horse diagnosed with bilateral forelimb laminitis and cellulitis on the left forelimb became severely painful and refractory to non-steroidal anti-inflammatory therapy (flunixin meglumine on days 1, 2, 3 and 4; and phenylbutazone on days 5, 6 and 7) alone or in combination with gabapentin (days 6 and 7). Methods: Pain scores assessed independently by three individuals with a visual analog scale (VAS; 0 = no pain and 10 = worst possible pain) were 8.5 on day 6, and it increased to 9.5 on day 7. Non-invasive blood pressure monitoring revealed severe hyper...
Rikihisa Y, Perry BD, Cordes DO.Potomac horse fever is characterized by fever, anorexia, leukopenia, profuse watery diarrhea, dehydration, and high mortality. An ultrastructural investigation was made to search for any unusual microorganisms in the digestive system, lymphatic organs, and blood cells of ponies that had developed clinical signs after transfusion with whole blood from horses naturally infected with Potomac horse fever. A consistent finding was the presence of rickettsial organisms in the wall of the intestinal tract of these ponies. The organisms were found mostly in the wall of the large colon, but fewer organ...
Hraha TH, Doremus KM, McIlwraith CW, Frisbie DD.Osteoarthritis (OA) is one of the most prevalent and debilitating conditions affecting the horse. Autologous conditioned serum (ACS), commercially available as IRAP and IRAP II, is a recently developed treatment for OA in which plasma is prepared from venous blood by incubation with glass beads for 24 h. This product has been shown to increase anti-inflammatory cytokines and growth factors in human blood. However, data for equine ACS preparations are lacking. Objective: To characterise the protein profiles produced by commercially available ACS systems in equine blood. Methods: Blood was dra...
Witkowska-Piłaszewicz OD, Żmigrodzka M, Winnicka A, Miśkiewicz A, Strzelec K, Cywińska A.Serum amyloid A (SAA) is the major acute phase protein in horses. It is produced during the acute phase response (APR), a nonspecific systemic reaction to any type of tissue injury. In the blood of healthy horses, SAA concentration is very low, but it increases dramatically with inflammation. Due to the short half-life of SAA, changes in its concentration in blood closely reflect the onset of inflammation and, therefore, measurement of SAA useful in the diagnosis and monitoring of disease and response to treatment. Increases in SAA concentration have been described in equine digestive, reprodu...
Crisman MV, Scarratt WK, Zimmerman KL.Activation of the host response to infection, the "acute-phase response," is a highly organized physiologic reaction that includes changes in concentrations of plasma acute-phase proteins (APPs). The APPs are increasingly being used as markers for prognosis and monitoring response to therapy along with general determinants of equine health. Use of APPs in veterinary medicine is becoming more widespread as more commercial diagnostic kits are being validated. This article reviews the salient features of APPs and examines their current application and potential utility in equine inflammatory diso...
Kim CM, Blanco LB, Alhassan A, Iseki H, Yokoyama N, Xuan X, Igarashi I.We developed a TaqMan real-time polymerase chain reaction (PCR) assay for the quantitative detection of Theileria equi from the in vitro-cultured parasite and field blood samples collected from horses living in Ghana and Brazil. The detection limit for the assay was determined to be 1.5 parasites/microl per sample, and the quantitative capacity was demonstrated using the in vitro-cultured parasite. For field applications, the real-time PCR assay was compared to a previously established nested PCR assay used as the gold standard for the real-time PCR assay. Of 65 field blood samples, 46 samples...
Tomlinson JE, Kapoor A, Kumar A, Tennant BC, Laverack MA, Beard L, Delph K, Davis E, Schott Ii H, Lascola K, Holbrook TC, Johnson P, Taylor SD....Three flaviviruses (equine pegivirus [EPgV]; Theiler's disease-associated virus [TDAV]; non-primate hepacivirus [NPHV]) and equine parvovirus (EqPV-H) are present in equine blood products; the TDAV, NPHV, and EqPV-H have been suggested as potential causes of serum hepatitis. Objective: To determine the prevalence of these viruses in horses with equine serum hepatitis. Methods: Eighteen horses diagnosed with serum hepatitis, enrolled from US referral hospitals. Methods: In the prospective case study, liver, serum, or both samples were tested for EPgV, TDAV, NPHV, and EqPV-H by PCR. Results: Bot...
Chang MH, Kim KH, Kim HS, Jun HJ, Kim DH, Jang JH, Kim K, Jung CW.Immunosuppressive therapy (IST) with antithymocyte globulin (ATG) plus cyclosporine (CSA) is standard therapy in patients with severe aplastic anemia (SAA) who do not have an available HLA-matched sibling donor. Methods: The current study aimed to determine the predictive factors for response to IST in patients with SAA and to identify prognostic factors following IST. A total of 62 patients diagnosed with SAA who received IST with either rabbit ATG (n = 33) or horse ATG (n = 29) plus CSA between October 1994 and December 2007 were included. Results: With a median follow-up duration of 60.5 mo...
Olstad K, Ytrehus B, Ekman S, Carlson CS, Dolvik NI.Pathological changes in the blood supply to growth cartilage have been implicated in the pathogenesis of osteochondrosis (OC) in horses, but have not been reported using vascular perfusion techniques. Objective: To describe the developmental pattern of cartilage canal vessels in the distal tibial epiphysis and talar growth cartilage of foals. Methods: Nine foals bred from parents with OC were sacrificed between the ages of 0 and 7 weeks to undergo a barium perfusion procedure. The distal end of the tibia and the entire talus were cleared in methyl salicylate and perfused vessels studied in the...
Wagner PD, Gillespie JR, Landgren GL, Fedde MR, Jones BW, DeBowes RM, Pieschl RL, Erickson HH.Arterial hypoxemia has been reported in horses during heavy exercise, but its mechanism has not been determined. With the use of the multiple inert gas elimination technique, we studied five horses, each on two separate occasions, to determine the physiological basis of the hypoxemia that developed during horizontal treadmill exercise at speeds of 4, 10, 12, and 13-14 m/s. Mean, blood temperature-corrected, arterial PO2 fell from 89.4 Torr at rest to 80.7 and 72.1 Torr at 12 and 13-14 m/s, respectively, whereas corresponding PaCO2 values were 40.3, 40.3, and 39.2 Torr. Alveolar-arterial PO2 di...
Pleasant RS, Suagee JK, Thatcher CD, Elvinger F, Geor RJ.Increased blood insulin levels are associated with an increased risk of pasture-associated laminitis in equids. Objective: To determine the relationship between plasma insulin, leptin, and lipid levels, and measures of oxidative stress with adiposity in mature light breed horses. Methods: 300 randomly selected light breed horses, aged 4-20 years. Methods: A random sample of horses (140 mares, 151 geldings, and 9 stallions) was drawn from the VMRCVM Equine Field Service practice client list. Evaluations occurred June 15 - August 15, 2006, with all sampling performed between 0600 and 1200 hours....
Bashiruddin JB, Cammà C, Rebêlo E.Babesia equi and Babesia caballi are tick-borne haemoparasites that may cause babesiosis of Equidae. In southern Europe B. equi is enzootic and infections may occur asymptomatically and more frequently than those due to B. caballi. Complement fixation test (CFT) is the official serological test for the diagnosis of equine babesiosis, but it has low sensitivity during early and latent stages of the disease. With the aim of developing more sensitive and rapid direct diagnostic alternatives, PCR systems that amplified DNA targets of 664 or 659 bp regions of the 16S rRNA genes were designed and de...
Meier AD, de Laat MA, Reiche DB, Pollitt CC, Walsh DM, McGree JM, Sillence MN.The aim of this study was to investigate the relationship between laminitis development in ponies and insulin/glucose concentrations in response to the oral glucose test (OGT) and a dietary challenge high in nonstructural carbohydrates (NSCs). After undergoing an OGT (1 g dextrose/kg BW in feed), 37 ponies with 2-h serum insulin concentrations ranging from 22 to 1,133 μIU/mL were subjected to a diet challenge period (DCP), consuming 12 g NSC/kg BW/d for up to 18 d. Insulin and glucose responses were measured on day 2 of the DCP. Clinical laminitis was diagnosed by blinded experts and confi...
Czub MP, Venkataramany BS, Majorek KA, Handing KB, Porebski PJ, Beeram SR, Suh K, Woolfork AG, Hage DS, Shabalin IG, Minor W.Serum albumin is the most abundant protein in mammalian blood plasma and is responsible for the transport of metals, drugs, and various metabolites, including hormones. We report the first albumin structure in complex with testosterone, the primary male sex hormone. Testosterone is bound in two sites, neither of which overlaps with the previously suggested Sudlow site I. We determined the binding constant of testosterone to equine and human albumins by two different methods: tryptophan fluorescence quenching and ultrafast affinity extraction. The binding studies and similarities between residu...
Ueti MW, Mealey RH, Kappmeyer LS, White SN, Kumpula-McWhirter N, Pelzel AM, Grause JF, Bunn TO, Schwartz A, Traub-Dargatz JL, Hendrickson A, Espy B....Arthropod-borne apicomplexan pathogens that cause asymptomatic persistent infections present a significant challenge due to their life-long transmission potential. Although anti-microbials have been used to ameliorate acute disease in animals and humans, chemotherapeutic efficacy for apicomplexan pathogen elimination from a persistently infected host and removal of transmission risk is largely unconfirmed. The recent re-emergence of the apicomplexan Theileria equi in U.S. horses prompted testing whether imidocarb dipropionate was able to eliminate T. equi from naturally infected horses and rem...
Horvath S, Haghani A, Peng S, Hales EN, Zoller JA, Raj K, Larison B, Robeck TR, Petersen JL, Bellone RR, Finno CJ.Cytosine methylation patterns have not yet been thoroughly studied in horses. Here, we profile n = 333 samples from 42 horse tissue types at loci that are highly conserved between mammalian species using a custom array (HorvathMammalMethylChip40). Using the blood and liver tissues from horses, we develop five epigenetic aging clocks: a multi-tissue clock, a blood clock, a liver clock and two dual-species clocks that apply to both horses and humans. In addition, using blood methylation data from three additional equid species (plains zebra, Grevy's zebras and Somali asses), we develop anoth...
Argüelles D, Carmona JU, Pastor J, Iborra A, Viñals L, Martínez P, Bach E, Prades M.The aim of this study was to evaluate single and double centrifugation tube methods for concentrating equine platelets. Whole blood samples were collected from clinically normal horses and processed by use of single and double centrifugation tube methods to obtain four platelet concentrates (PCs): PC-A, PC-B, PC-C, and PC-D, which were analyzed using a flow cytometry hematology system for hemogram and additional platelet parameters (mean platelet volume, platelet distribution width, mean platelet component concentration, mean platelet component distribution width). Concentrations of transformi...
Belgrave RL, Dickey MM, Arheart KL, Cray C.To compare serum amyloid A (SAA) concentration, plasma fibrinogen concentration, total WBC count, and serum albumin-to-globulin concentration ratio (A:G ratio) in clinically normal (CN) and clinically abnormal (CA) horses. Methods: Prospective cohort study. Methods: 111 CN horses and 101 CA horses hospitalized at a specialty clinical practice. Methods: Shortly after admission, a blood sample (20 mL) was collected from each horse for a CBC, serum protein electrophoresis, and determination of plasma fibrinogen concentration; SAA concentration was assessed with a previously validated immunoturbid...
Pozor MA, McDonnell SM.The objectives of this study were to evaluate the potential use of color Doppler ultrasound to characterize blood flow to the stallion testis, and to establish reference values for Doppler measures of blood flow in the testicular artery of the stallion. Both testes from each of 52 horses were examined using a pulsed-wave color Doppler ultrasound with a sector array 5/7.5 MHz transducer with a 1mm gate setting. Peak systolic velocity (PSV), end diastolic velocity (EDV), resistive index (RI), and pulsatility index (PI) of the testicular artery were measured in each of two locations, the convolut...
Dunnett M, Harris RC.The aim of this work was to test the hypothesis that in vivo carnosine biosynthesis is dependent upon endogenous beta-alanine availability, by studying the effect of sustained dietary beta-alanine supplementation in the horse on the carnosine concentration in types I, IIA and IIB skeletal muscle fibres. The diets of 6 Thoroughbred horses were supplemented 3 times/day with beta-alanine (100 mg/kg bwt) and L-histidine (12.5 mg/kg bwt) for a period of 30 days. Percutaneous biopsies of the m. gluteus medius from a depth of 6 cm were taken on the days immediately before and after the supplementatio...
Sales KG, Costa PL, de Morais RC, Otranto D, Brandão-Filho SP, Cavalcanti Mde P, Dantas-Torres F.Phlebotomine sand flies are blood-feeding insects of great medical and veterinary significance acting as vectors of Leishmania parasites. Studying the blood-feeding pattern of these insects may help in the understanding of their interactions with potential reservoir hosts of Leishmania parasites. In this study, we developed real time PCR assays for the identification of sand fly blood meal. Methods: Six pairs of primers were designed based on cytochrome b gene sequences available in GenBank of the following potential hosts: dog, cat, horse, chicken, black rat, and human. Firstly, SYBR Green-ba...
Witkowska-Piłaszewicz O, Maśko M, Domino M, Winnicka A.In horse racing the most acceptable way to objectively evaluate adaptation to increased exertion is to measure lactate blood concentration. However, this may be stressful for the horse, therefore, a simple, noninvasive procedure to monitor race progress is desirable. Forty Thoroughbreds attended race training, with blood samples collected at rest, immediately after, and 30 min after exercise. The lactate concentration was determined 60 s after blood collection using an Accusport. Thermal imaging of the neck and trunk areas was performed following international veterinary standards from a dista...
Jones JH, Longworth KE, Lindholm A, Conley KE, Karas RH, Kayar SR, Taylor CR.This study investigated mechanisms used by horses and steers to increase O2 uptake and delivery (VO2) from resting to maximal rates and identified the mechanisms that enable horses to achieve higher maximal rates of O2 consumption (VO2max) than steers. VO2 and circulatory variables were measured while Standardbred trotting horses and steers (450-kg body mass) stood quietly and ran on a treadmill at speeds up to those eliciting VO2max. As VO2 increased in both species, heart rate and circulating hemoglobin (Hb) concentration increased, thereby increasing O2 delivery by the circulation, while ca...
Corley KT, Donaldson LL, Furr MO.Blood lactate concentration has been shown to be a useful clinical indicator in human patients, but has not been formally investigated in critically ill foals. Objective: To investigate the association of blood lactate with hospital survival, markers of cardiovascular status, metabolic acid base status, sepsis and systemic inflammatory response syndrome (SIRS). Methods: A database containing clinical, haematological, plasma biochemical and hospital outcome data on neonatal foals referred to an intensive care unit in 2000-2001 was analysed. Seventy-two foals for which arterial lactate was measu...
