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.
KAMINSKI M, GAJOS E.TWENTY-THREE fresh and 28 frozen (1–11 years old) samples of horse sera, 62 frozen donkey sera (3–11 years old), 24 frozen mule sera (2–10 years old), and 1 frozen 2-year-old serum sample of a hinny (offspring of a she-ass by a stallion) were studied by starch- and agar-gel electrophoresis (starch gel: horizontal migration, discontinued buffer system; tris-citrate pH 8.7 and borate 0.3 M, pH 8.2; 2 V/cm for 14 h; 10 samples analysed simultaneously; 0.1 ml. serum mixed with soluble starch Merck; agar gel: 0.8 per cent agar in veronal buffer 0.025 M, pH 8.2; 4.5 V/cm; 2½ h; 10 samples on ...
HORI J, AOKI K.Electrophoretic studies were made of normal horse and human serum albumins over the pH range 3.6–6.8 and at 25 °. The ionic strength of acetate or phosphate buffer used was 0.1, and the concentration of protein was 0.5% (g./100 ml.). Patterns were usually enantiographic and there were two (N and F1) or three (N, F1, and F2) boundaries in the pH range 3.6–5.2. The areas of the N and F1 boundaries changed continuously with pH, and the area of F2 was almost constant. The results were interpreted, in the same way as was previously done in the case of bovine serum albumin, by the isomerization...
Wang Z, Li Y, Xi X, Zou Q, Zhang Y.In this paper, a novel molecularly imprinted polymer membrane modified glassy carbon electrode for electrochemical sensors (MIP-OH-MWCNTs-GCE) for epinephrine (EP) was successfully prepared by a gel-sol method using an optimized functional monomer oligosilsesquioxane-AlO sol-ITO composite sol (ITO-POSS-AlO). Hydroxylated multi-walled carbon nanotubes (OH-MWCNTs) were introduced during the modification of the electrodes, and the electrochemical behavior of EP on the molecularly imprinted electrochemical sensors was probed by the differential pulse velocity (DPV) method. The experimental conditi...
Myćka G, Ropka-Molik K, Cywińska A, Stefaniuk-Szmukier M.Among numerous genes that have been a focus of equine genetic research, the (Klotho) and (Alpha-actinin-3) genes stand out due to their significant roles in muscle function and overall health, as well as performance ability. Previous studies on Arabian horses and other mammalians have shown that both and occur in different isoforms that seem to have different roles in metabolism. The main purpose of this present study was to describe different isoforms (, , , , , ) expression levels affected by the endurance effort in Arabian horses. Methods: Blood samples were taken from a group of = 10 ...
Chow L, Kawahisa-Piquini G, Bass L, Hendrickson D, Patel A, Rockow M, Dow S, Pezzanite LM.Osteoarthritis (OA) is increasingly thought to be a multifactorial disease in which sustained gut inflammation serves as a continued source of inflammatory mediators driving degenerative processes at distant sites such as joints. The objective of this study was to use the equine model of naturally occurring obesity associated OA to compare the fecal microbiome in OA and health and correlate those findings to differential gene expression synovial fluid (SF) cells, circulating leukocytes and cytokine levels (plasma, SF) towards improved understanding of the interplay between microbiome and immun...
Shinn LT, Wagner CB, Desai R, Marini BL.Horse antithymocyte globulin carries a black box warning for life-threatening anaphylactic reactions, and prescribing information recommends test doses to identify patients at highest risk of this adverse effect. The predictive value of such test doses is not well validated, and practicality of use is unclear. Methods: This was a planned secondary analysis of a multicenter, retrospective cohort study in adults with severe aplastic anemia being managed with horse antithymocyte globulin as part of their treatment regimen. Qualitative and quantitative descriptions of test doses and infusion react...
Ha Y, Yi K, Park C, Kim G, Choi D, Lee J, Kim N.This study aimed to measure the whole blood viscosity (WBV) in racehorses using a new viscometer and establish reference values, as well as to investigate the correlation between the WBV and the haematological parameters and serum chemistry. WBV measurements were conducted on 51 Thoroughbred horses using a novel U-shaped scanning capillary-tube viscometer. The reference values for the WBV were determined at various shear rates ranging from 1 s to 1 000 s. Correlation analyses were performed to examine the correlation between the WBV and the haematological and serum chemistry parameters. The fi...
Novotna T, Samonilova E, Klan J, Frgelecova L, Mala A, Svobodova Z, Drabkova Z.This case report describes the poisoning of two mares from the same paddock with Robinia pseudoacacia (Black locust) bark. The poisoning manifested itself by the sudden onset of weakness and fever with transient improvement after the administration of non-steroidal anti-inflammatory drugs and fluids. After the initial stabilisation, the mares were left unattended overnight. One of them was found dead in the morning. The surviving mare developed colic and severe encephalopathy and had to be referred to the clinic. Blood tests revealed severe hyperammonaemia. After four days of symptomatic treat...
Johnston TJ, Stewart AJ, Dryburgh EL, Bertin FR.Pituitary pars intermedia dysfunction (PPID) is diagnosed by measuring the ACTH concentrations. Due to the reported instability of ACTH, it is recommended to transfer centrifuged plasma into cryovials; however, in practice, cryovials are infrequently used, and serum (red-top) tubes are used instead. This study investigated whether this procedure affects ACTH concentrations and the diagnosis of PPID. Unassigned: This was a cohort study. Blood was collected into EDTA tubes from 9 horses with PPID and 7 controls. After centrifugation, plasma was either aliquoted into a cryovial or into a serum tu...
Perera TRW, de Ruijter-Villani M, Gibb Z, Nixon B, Sheridan A, Stout TAE, Swegen A, Skerrett-Byrne DA.Embryo-maternal signaling during the establishment of pregnancy in horses remains one of the biggest mysteries in large animal physiology. Early pregnancy loss represents a major source of economic loss to the breeding industry. This study aimed to investigate the systemic changes associated with early pregnancy by mapping the proteome of blood plasma at 14 days in pregnant and non-pregnant mares. Methods: Plasma proteomes were analysed in commercially bred pregnant (n = 17) and non-pregnant (n = 17) Thoroughbred mares at 14 days after ovulation, using high-resolution mass spectrometry. D...
Boger BL, Kinsley MA, Yob CJ, Knott LE, Manfredi JM.To determine if equine platelet-rich plasma (PRP) contains Dickkopf-1 (Dkk-1) and, if so, to quantify the amount of Dkk-1 in bovine thrombin (BT)-activated PRP and a control platelet lysate created using a freeze-thaw (FT) method. Unassigned: 10 adult horses were used in this experimental study. Blood was collected and processed in November 2019 and stored at -80 °C until the ELISAs were performed in October of 2023. Blood was collected from each horse, and PRP was created using a commercially available kit. Known concentrations of platelets were activated using BT or by an FT cycle to create...
Palmisano MG, Colmer SF, Saw YL, Xu X, Stefanovski D, Murphy L, Johnson AL.To determine the prevalence of vitamin E deficiency in horses at admission and at the time of discharge. The hypothesis was that vitamin E concentrations would decrease during hospitalization. Methods: A prospective cohort study was performed of client-owned horses admitted as patients or companions through the emergency service at a tertiary referral center. Exclusion criteria included vitamin E supplementation. Whole blood was collected into an additive-free tube at the time of admission for all horses and at discharge if the horse was hospitalized for a minimum of 5 days. Serum vitamin E co...
Pusterla N, Barnum S, Lawton K, Craig B, James K.Equid alphaherpesvirus 4 (EqAHV4; Orthoherpesviridae, Varicellovirus equidalpha4; equine rhinopneumonitis virus) has seldom been associated with complications such as abortion and myeloencephalopathy, given the low tendency of this virus to induce viremia. We investigated the frequency of EqAHV4 viremia in horses with fever and respiratory signs. Case selection included all equids with EqAHV4 quantitative real-time PCR (qPCR)-positive nasal secretions (defined as EqAHV4 qPCR-positive cases) submitted to a diagnostic laboratory. Controls consisted of each case submitted before and after each Eq...
Halo M, Kirchner R, Tirpák F, Slanina T, Tokárová K, Kováčik A, Miškeje M, Greń A, Formicki G, Halo M, Madeddu R, Massányi P.The abundance of chemical elements in the blood of horses can indicate the physiological balance, health of animal as well as can be taken as an indicator of environmental pollution. The aim of this work was to analyse haematological, biochemical parameters, TOS, FRAP, SOD, Gpx, TAS and their correlations with concentrations of essential and risk elements in blood of horses stabled in two different locations: The National Stud Farm Topoľčianky (n = 11; 11 stallions, consisting of the breeds 6 Lipizzan, 3 Slovak warmblood, 2 Holsteiner) and Experimental Centre at Institute of Animal Husba...
Aziz KJ, Barwary LTOA, Issa NA, Abdulwahid MJ.This study aimed to determine the prevalence of Theileria equi (T. equi) and Babesia caballi (B. caballi) in racing horses in Erbil Province, Iraq, and to assess the associated hemato-biochemical changes in infected animals. Methods: A total of 196 horses, including 155 clinically healthy and 41 clinically suspected infected animals, were examined using Giemsa-stained blood films and PCR to determine the prevalence rates. Additionally, the hemato-biochemical parameters of infected horses were compared to a non-infected control group (n = 10). Results: The prevalence of T. equi and B. cabal...
Rossi HS, Mykkänen AK, Junnila JJT, Hyytiäinen HK.Pulse oximetry has not been thoroughly evaluated for assessment of oxygenation in conscious foals. Compared with invasive arterial blood sampling, it is a painless and non-invasive method for real-time monitoring of blood oxygen saturation. The aim of this prospective clinical study was to evaluate the usability, validity, and reliability of pulse oximetry at two measuring sites (lip and caudal abdominal skin fold) for blood oxygen saturation measurement in conscious foals with and without respiratory compromise. Thirty-two foals under one month of age were used. Nineteen foals had normal resp...
Sauter PK, Steblaj B, Kästner SBR, Söbbeler FJ, Reiners JK, Kutter APN, Bautitsta AJG, Neudeck S.Microcirculation is the essential link between macrocirculation and cellular metabolism. Objective: To test our hypotheses that microcirculation variables will show a heterogeneous flow pattern during experimental endotoxaemia, and that fluid therapy and noradrenaline (NA) infusion will normalise altered microcirculation variables. Methods: In vivo experiments. Methods: Six healthy adult horses were anaesthetised with dexmedetomidine, ketamine, and diazepam and were mechanically ventilated under isoflurane anaesthesia. Endotoxaemia was induced with 30 ng kg Escherichia coli lipopolysacchar...
Marichal G, Suárez G, Meikle A, Muriel M.The recovery of acid-base and hydro electrolytic balance at medical discharge after Raid races and its association with comfort index (CI) is unknown. Unassigned: To determine hydroelectrolytic and acid-base variations before and at the time of clinical discharge in horses that completed 90 km Raid competitions. Unassigned: Hematocrit, total protein, sodium, potassium, chloride, calcium, and serum pH were determined in samples before and after the race and after hydration in 276 horses and were analyzed using a mixed procedure, including the time of the race, the CI and its interaction. Unassi...
Page AE, Rauber-Ramos AM, Humiston M, McPeek JL, Adam EN.Given the metabolic effects of intra-articular (IA) corticosteroids, the goal of this project was to monitor the effects of IA betamethasone in both insulin dysregulated (ID)(n = 3) and non-ID (n = 5) horses. A cross-over design was used where eight geldings were injected with either 9 mg of betamethasone or saline into both metacarpophalangeal joints, followed by regular blood collections for adrenocorticotropin releasing hormone (ACTH), cortisol, insulin, and glucose, as well as pre- and post-administration oral sugar testing. Results were analyzed via two-way repeated measures analysis of v...
Sun Y, Yu YT, Castillo XO, Anderson R, Wang M, Sun Q, Tallmadge R, Sams K, Reboul G, Zehr J, Brown J, Wang X, Marra N, Stanhope B, Grenier J....Fever of unknown origin (FUO) without a respiratory component is a frequent clinical presentation in horses. Multiple pathogens, both tick-borne and enteric, can be involved as etiologic agents. An additional potential mechanism is intestinal barrier dysfunction. This case-control study aimed to detect and associate microbial taxa in blood with disease state. Areas known for a high prevalence of tick-borne diseases in humans were chosen to survey horses with FUO, which was defined as fever of 101.5°F or higher with no signs of respiratory illness or other recognisable diseases. Blood samples ...
Tsujimura K, Bannai H, Kambayashi Y, Nemoto M, Ohta M.Equid alphaherpesvirus 1 (EqAHV1; Orthoherpesviridae, Varicellovirus equidalpha1) spreads by viremia to susceptible organs. Because EqAHV1 circulates in the bloodstream in a cell-associated manner, serum samples are not considered valuable for detecting EqAHV1 and have therefore not been tested by highly sensitive detection methods such as real-time PCR (rtPCR). We investigated whether EqAHV1 could be detected by this method in equine serum samples. We performed rtPCR on archived sera and peripheral blood mononuclear cells (PBMCs) collected from 3 horses experimentally inoculated with EqAHV1. ...
Hisaeda K, Ono T, Shimokawa-Miyama T, Hata A, Iwata E, Hiasa Y, Ohzawa E, Tozaki T, Murase H, Takasu M, Nishii N, Kitagawa H.We examined the differences in serum iron (Fe) concentrations and related variables between summer and winter in Noma horses. Blood samples were collected from 37 clinically normal horses seven consecutive times: September 2018, February 2019, October 2019, February 2020, September 2020, February 2021, and February 2022. Serum Fe concentrations ranged from 74 μg/dl to 316 μg/dl with a median of 176 μg/dl. The concentrations were lower in stallions compared with mares and geldings, tended to be low at 10-14 years of age, and then increased with age. Serum Fe concentrations were repeatedly lo...
Loos CMM, Urschel KL.Insulin dysregulation (ID) is a common metabolic disorder in horses, characterized by hyperinsulinemia and/or peripheral insulin resistance. The critical role of hyperinsulinemia in endocrinopathic laminitis has driven research into the insulinotropic effects of dietary nutrients and the reciprocal impact of ID on nutrient metabolism. The relationship between ID and carbohydrate metabolism has been extensively studied; however, the effects of ID on protein metabolism in horses remain largely unexplored. This review begins with an overview of the importance of insulin in the regulation of muscl...
Holbrook T, Hernandez J, McCarrel T, Lester G, Sleeper M, Domenig O, Adin D.The impact of exercise on the classical and alternative renin-angiotensin-aldosterone system (RAAS) pathways has not been studied in horses. Objective: We hypothesized that exercise would activate both RAAS pathways and that endurance exercise would cause more activation of the classical pathway compared to short-duration, high-intensity exercise in horses. Methods: Twenty-five horses (21 client-owned and 4 research) were included in 4 exercise groups (10 Arabians, 50-mile ride [A-E]; 4 thoroughbreds, 1-mile treadmill exercise [TB-TM]; 5 thoroughbreds, 1-1/16th-mile race [TB-R]; and 6 quarter ...
Bindi F, Nocera I, Meucci V, Vallesi G, Sala G, Spadari A, Rinnovati R, Bonelli F, Sgorbini M.This study investigated the plasma concentrations of symmetric dimethylarginine (SDMA) and asymmetric dimethylarginine (ADMA) in healthy horses and in horses affected by colic in relation to the type of colic and systemic inflammation response syndrome (SIRS) status. Upon admission (T0), horses underwent a physical examination, and the SIRS status was assessed. The horses with colic were divided retrospectively based on the type of colic, SIRS status, treatment, and outcome. SDMA and ADMA levels were measured at T0 and then every 24 h at four time points (T1, T2, T3, T4). Differences between ...
Stapley ED, Bertin FR.Pituitary pars intermedia dysfunction is diagnosed using immunoreactive ACTH concentrations. Glass reportedly binds ACTH, but the clinical relevance of using glass blood tubes for measuring equine ACTH concentrations is controversial. This study investigates whether the collection of whole blood into glass EDTA tubes and storage for up to 6 hours changes ACTH concentrations compared to plastic EDTA tubes. Unassigned: This was a cohort study. Whole blood was collected into both glass and plastic EDTA tubes from 9 horses > 12 years of age, including 4 with pituitary pars intermedia dysfunction a...
Simms N, Bertone JJ, Melgarejo T, O'Shea C, Linde A.Emerging research suggests the presence of a blood microbiome in clinically healthy individuals. Characterizing bacterial composition and abundance in blood from a group of healthy horses is of clinical interest. Objective: Horses in a closed herd environment will have blood microbiomes with similarities among individuals. Methods: Twenty trail-riding horses of different breeds and ages living in relative isolation on a dry lot pasture in Colorado at 7680 ft elevation. Methods: Cross-sectional study. Blood was collected from the jugular vein into serum, blood collection, and EDTA tubes. Samp...
Muir WW, Yiew XT, Bateman SW, Hahn RG.Fluid therapy in horses is primarily empirical. Evidence-based quantification of the disposition of intravenous (IV) crystalloids used in clinical practice could enhance the effectiveness of fluid therapy. Objective: To determine the pharmacokinetics (i.e., volume kinetics: VK) and associated haemodynamic effects of IV lactated Ringer's solution (LRS) in adult euvolemic horses. Methods: Unmasked multiple subjects, single baseline design. Methods: Thirteen healthy, euvolemic adult female horses were administered an IV bolus of LRS and monitored over 4 h. Haemoglobin, albumin and haematocrit c...
Davis EL, Wood AD, Potier JFN.Prevalence of endocrine disease in sport horses has been sparsely reported. They often compete well into their teenage years; thus, diagnosis and control of endocrine disease could be important to maintain performance and optimise health and welfare. The aim was to compare the prevalence of pituitary pars intermedia dysfunction (PPID), insulin dysregulation (ID) and metabolic obesity between sport and non-sport type breeds and assess disease progression. Blood samples submitted for plasma adrenocorticotropic hormone (ACTH), serum insulin or adiponectin were included in this study. Horses were ...
Poh KC, Oyen K, Onzere CK, Kappmeyer LS, Bastos RG.The recent discovery of , a tick-borne hemoparasite that causes mild clinical signs of equine piroplasmosis, has added complexity to the diagnosis of this reportable disease, which is prevalent among equids globally. Knowledge gaps regarding competent tick vectors that can transmit and the recent outbreak of in the US has prompted us to conduct this study. Our objective was to investigate whether can transstadially transmit to horses. Unassigned: larvae (0.5 g) and nymphs ( = 500) were fed on a splenectomized -infected horse for parasite acquisition. During the tick feeding period, ...
Hallman IAM, Raekallio MR, Karikoski NP.Vatinoxan is a peripherally acting alpha2-adrenoceptor antagonist used in veterinary medicine to attenuate the side effects of alpha2-adrenoceptor agonists. Vatinoxan also increases insulin response and reduces blood glucose (BG) after intravenous glucose in other species. The aim of this study was to investigate the effects of vatinoxan on BG and insulin concentration in horses after intravenous glucose. The design was an assessor-blind cross-over study. Nine horses were assigned to intravenous vatinoxan (0.2 mg/kg; VAT) or saline (SAL). Horses were administered an intravenous glucose bolus (...
Buzelato Carli I, Fielding L.Many horses receive firocoxib over multiple years, and studies evaluating hematologic and biochemical values in these animals are lacking. Objective: To describe the hematologic and biochemical values of horses receiving long-term firocoxib. Methods: A total of 79 horses receiving long-term firocoxib and 153 horses not receiving long-term firocoxib and not presenting for a specific medical problem. Methods: Retrospective study comparing horses receiving firocoxib (F group) and no firocoxib (NF group). Signalment, hematologic, and biochemical values were compared between the two groups. Simple ...
