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.
FEGLER G.1. Volume p.c. of r.b.c., hæmoglobin concentration, relative viscosity of the plasma and blood, and the sedimentation rate of the r.b.c. have been estimated on 7 healthy horses.
2. Increase in the volume p.c. of r.b.c. was found in the excited or working horse. The concentration of r.b.c. in blood from the jugular vein in horses at rest is rather low in comparison with other animals.
3. Increase in the Hb. g. p.c./r.b.c. V. p.c. ratio was found in cases with the higher volume p.c. of r.b.c. with a significant correlation coefficient.
4. Apparent relative viscosity of horse blood at h...
Abramson HA.1. The cataphoretic velocity of blood platelets (horse) in plasma has been found to be between 40 and 51 micro per sec. per volt per cm. The mean velocity obtained from five horses is . 45 micro per sec. per volt per cm. 2. The cataphoretic velocity of polymorphonuclear leucocytes in similar specimens is practically identical with that of the platelets. This is noteworthy because of the fact that lymphocytes and red cells have different speeds. 3. With spontaneous agglutination of platelets, white cells and red cells, there is no change in the cataphoretic velocity incidental to aggregation. 4...
Reimann HA.It is conceivable that a change from the virulent, non-phagocytable S form of Pneumococcus to the avirulent phagocytable R form may take place in pneumococcus disease, but the experiments here reported do not settle the question whether or not this is an important factor in determining the outcome in natural infection. It has been shown experimentally that the degradation from the S form to the R form actually does take place in cultures of Pneumococcus growing in agar subcutaneously embedded in guinea pigs, in agar enclosed in vials subcutaneously embedded in rabbits, and spontaneously in the...
Gibson RB, Banzhaf EJ.Gravimetric determinations were recorded for the total and several individual proteins (in the sodium oxalate plasma) fractioned with ammonium sulphate and sodium chloride. At precipitation, the plasma salt mixture had been diluted to a final volume of ten times the amount of plasma employed. Coagulations were on aliquot portions of filtrates, and the individual protein constituents (except serumalbumin) were calculated by difference. The eleven horses had been subjected to simultaneous immunization against diphtheria and tetanus toxins, each horse being subsequently continued on the toxin to ...
Hiss PH, Atkinson JP.THE RESULTS OF THE FOREGOING EXPERIMENTS MAY BE BRIEFLY SUMMARIZED AS FOLLOWS: The amount of antitoxic substance obtained by precipitation with magnesium sulphate from the blood-serum of the horse corresponds, as nearly as can be determined by the use of test guinea-pigs, in full to the protective power of the serum from which it is obtained, i. e. the precipitate from 1 cc. of serum will protect against the same amount of toxin as 1 cc. of the serum itself. Equal amounts of the precipitates by magnesium sulphate from immunized and non-immunized horses act differently toward toxin; i. e. the p...
Giercuszkiewicz-Hecold B, Pajuelo D, Steczkiewicz Z, Cywinska A, Marycz K.Astaxanthin, a strong antioxidant carotenoid, has shown promising features in mitigating inflammation and oxidative stress and so that has been considered as a supplement for high-performance animals. In this study, we aimed to evaluate the effects of astaxanthin on oxidative stress, inflammation, and mitochondrial health in peripheral blood mononuclear cells (PBMC) isolated from Arabian racehorses. Horse-derived peripheral blood mononuclear cells exposed to hydrogen peroxide (H₂O₂) presented increased reactive oxygen species (ROS) accumulation and overexpression of pro-inflammatory cytoki...
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 ...
Chang X, Zhang Z, Yao X, Meng J, Ren W, Zeng Y.The equine lipid metabolism is activated during and after endurance exercise to provide energy in response to the metabolic and physiological changes in the body caused by prolonged exercise; however, the specific regulatory mechanisms remain controversial and identifying differential lipid metabolites associated with equine endurance is essential to elucidate these regulatory mechanisms. In this study, blood samples for lipid metabolomic analysis and biochemical indices were collected before and after a 26 km race from 12 Yili horses with different endurance performance. The biochemical res...
Toft K, Mardahl M, Hedberg-Alm Y, Anlén K, Tydén E, Nielsen MK, Honoré ML, Fromm B, Nielsen LN, Nejsum P, Thamsborg SM, Cirera S, Pihl TH.Non-strangulating intestinal infarctions (NSII) associated with Strongylus vulgaris infection and idiopathic peritonitis (IP) share similar clinical presentation but require different treatment approaches. Horses with NSII need surgical intervention, while idiopathic peritonitis cases can be successfully treated with antimicrobials. A correct diagnosis is thus crucial, but because the two diseases overlap in clinicopathological features, differentiation is difficult in clinical practice. MicroRNAs (miRNAs) are non-coding RNAs that exhibit measurable changes in abundance in tissues and circulat...
Midon M, Clark-Price SC, Lin HC, Lascola KM, Boone L.To determine if serum iron concentrations decrease acutely during and after general anesthesia in healthy horses. Methods: Prospective experimental study. Methods: A convenience sample of 24 healthy adult horses (eight females, 16 geldings), weighing 545 ± 33 kg (mean ± standard deviation). Methods: Horses were anesthetized for 120 minutes with isoflurane, after premedication with intravenous (IV) xylazine (0.8 mg kg-1) and induction with IV midazolam (0.1 mg kg-1) and ketamine (2.2 mg kg-1). Blood samples for serum iron analysis were obtained just before premedication (baseline), after 60 m...
Pinn-Woodcock TL, Aprea MS, Lejeune M, Tomlinson JE.A common diagnostic approach for febrile horses is to test for a panel of potential pathogens. Panels are curated by expert opinion and vary between diagnostic laboratories. Objective: To report the results of a newly developed equine fever diagnostic panel (EFDP) between 2019 and 2023 and evaluate the frequency of positive results. Methods: Retrospective descriptive study. Methods: The EFDP requires submission of whole blood, nasal swab, and faecal samples, and includes PCR tests for 12 pathogens that can present as fever without localising signs of illness or infection. Submission metadata a...
Ballados-González GG, Cruz-Romero A, Martínez-Hernández JM, Aguilar-Domínguez M, Vieira RFC, Grostieta E, Becker I, Sánchez-Montes S.Hemotropic mycoplasmas (HM) are emerging pathogens known to infect a wide range of mammals, including ungulates like horses. These infections can lead to severe haematological conditions, posing a threat to animal health and welfare. Recent studies have begun shedding light on the prevalence and impact of HM on horse populations worldwide. For instance, in Germany, Iran, Nigeria, and Brazil, at least three species of HM have been identified in horses, with a lack in knowledge in Latin American countries like Mexico. Our research aims to fill a crucial knowledge gap regarding the presence of HM...
Ho HSM, Mizzi JX, Ho ENM, Wong WT.Ranitidine is a histamine H-receptor antagonist commonly used to treat gastric ulceration in horses. The author's laboratory conducted a study some years ago in the early 2000s on its metabolism as well as its urinary elimination profile in two geldings. With the technology advancement as well as popularity of blood for doping control testing, the laboratory has recently conducted another administration trials of the substance in six horses to study the in vivo metabolism of ranitidine, aiming to identify and reinvestigate the appropriate target(s) for controlling misuse of ranitidine in hors...
Mizuguchi Y, Niwa H, Inoue H, Iwano H.Hypoproteinaemia/hypoalbuminaemia is a typical clinical feature of Lawsonia intracellularis infection in horses, but amino acid perturbations in these horses have not been investigated. Objective: Clarifying blood amino acid levels in horses suffering from Lawsonia intracellularis infection to identify novel aspects of the disease. Methods: Retrospective observational study. Methods: A total of 135 serum samples collected from horses from 59 farms were used in this study. Horses diagnosed with the clinical form of equine proliferative enteropathy (EPE) were enrolled as a clinical group (n =...
In the present study, the changes in the markers of stress and inflammatory responses of 12 Standardbred horses were investigated before and after exercise during late spring and summer. The environmental temperature, relative humidity, and temperature-humidity index (THI) were assessed during this study. From horses, blood sampling, measurement of heart and respiratory rate (HR and RR), and measurement of rectal temperature (RT) were performed before exercise (Pre) and within 5 min following the end of the exercise (Post). THI values showed mild stress in June and high stress in July. Direct ...
Duaso J, Perez-Ecija A, Martínez E, Navarro A, De Las Heras A, Mendoza FJ.Equine piroplasmosis (EP) is a tick-borne disease affecting equids worldwide. Diagnosis is based on direct methods (blood smear or PCR) or indirect methods (serology); however, these techniques yield positive and negative results. Thus, an alternative, reliable, rapid, and cost-effective complementary tool, such as hematologic parameters and newly described hematologic ratios, could help in the EP diagnosis. This study describes the changes induced by piroplasmosis infection on hematologic parameters and ratios in horses. PCR-positive horses exhibited anemia and thrombocytopenia, whereas PCR...
Bardhi A, Barbarossa A, Joubert A, Gehring R, Lambertini C, Romagnoli N.Dried blood spot (DBS) sampling has emerged as a promising microsampling technique in biomedical and clinical research, offering advantages such as reduced invasiveness, minimal blood volume requirements, and enhanced analyte stability. Although well established in human medicine for neonatal screening and diagnostic applications, its potential in veterinary pharmacology remains underexplored. This study investigated the feasibility of using DBS samples to quantify anesthetic agents-ketamine and medetomidine in cats and lidocaine in horses-during routine surgical procedures at a veterinary tea...
Parra-Moyano LA, Cedeño A, Darby S, Johnson JP, Gomez DE.The effectiveness of the peritoneal fluid L-lactate-to-total solids ratio (PFL:PFTS) as a diagnostic marker for strangulating lesions of the small intestine (SI) and large colon (LC) has not been investigated. Objective: Describe and compare the PFL:PTFS and blood lactate (BL), peritoneal fluid lactate (PFL) and PFL:BL difference and PFL:BL ratio of horses with SI and LC strangulating (SO) and non-strangulating (NSO) obstructions and determine sensitivity and specificity to predict SO. Methods: A total of 282 horses, 117 with SI lesions (59 classified as SINSO and 58 as SISO), and 165 with LC ...
Nikvand AA, Jalali SM, Bahrami S, Rahij Torfi H.Trypanosoma evansi (T. evansi) is a hemoprotozoan parasite affecting camels and equids, such as horses, mules, and donkeys, and is known to cause surra disease in these animals. Despite the worldwide distribution of T. evansi infections in equids, surra has not been reported in Arabian horses in Khuzestan Province for over 60 years. In September 2018, a 7-year-old Arabian mare was referred from a 10-horse farm in the suburbs of Ahvaz City. The mare presented with a history of weight loss, poor appetite, and proximity to a camel herd. Physical examination revealed a poor body condition score ...
Parsley AL, Hollingshead NA, Gruber EJ.To minimise storage-related artefacts, EDTA-anticoagulated whole blood should be evaluated promptly or refrigerated, a challenge in ambulatory practice. The effects of suboptimal blood storage on equine leukocyte parameters are not well-documented. Objective: Document changes in leukocyte number, automated and manual differential counts, and morphology in equine blood stored at four temperatures for up to 5 days. Methods: In vitro experimental. Methods: EDTA-anticoagulated whole blood from 13 horses was stored in a refrigerator (4°C), cooler with icepacks (3°C-19°C), room temperature (22...
Aragona F, Giannetto C, Piccione G, Arfuso F, Arrigo F, Costa A, De Caro S, Cannuli A, Fazio F.The present study aimed to investigate the effect of time of day and physical exercise on some inflammatory biomarkers (white blood cell count-WBCs, leukocyte subpopulation CD4 + and CD8 + cells, total proteins, Interleukins IL-6, IL-1β and Tumor Necrosis Factor TNFα) in trained saddle horses. Unassigned: Blood samples were collected from 10 horses before, immediately (following 5 min) and 1 h after the training session in the morning (am) and afternoon (pm). Unassigned: Statistical analysis showed increasing value of WBCs immediately and 1 h after exercise ( < 0.01: <...
Simões J, Santos AM, Santos C, Silva AS, Vintém C, Fonseca J, Coelho C.Show jumping is a popular and complex equestrian modality practiced by a athletes of different levels. However, most studies focus on elite athletes. Objective: The aim of this work was to assess the effect of a show jumping test (SJT), designed for novice athletes, on the physiological biomarkers and energy indexes of a group of horses, bred and trained in Portugal. Methods: In this prospective cross-sectional study, thirteen horses and their riders performed a SJT with obstacles set at 80 cm height using a heart rate monitor (M430 with H10 sensor). Physical examination and blood samples, for...
Sanigavatee K, Wonghanchao T, Poochipakorn C, Pongnarudech P, Suchairat T, Jitsopin S, Wanichayanon B, Sripiboon S, Chanda M.Long-distance road transport is known to be stressful for horses, with most research conducted in temperate climates. This study investigated horses' stress responses during long-distance transport before and after a jumping competition in a tropical environment. Ten healthy horses (aged 7.9 ± 1.9 years) were studied. Blood cortisol concentrations, haematology, and heart rate variability (HRV) were monitored during outbound (OTJ) and inbound journeys (INJ). Cortisol concentrations increased five minutes after unloading and remained elevated for up to 180 minutes in the OTJ (P < 0.05-0.001)...
Kiełbik P, Witkowska-Piłaszewicz O.Iron is unquestionably an essential element of physical performance for horses, just as it is for many other animals, including humans. Although post-exercise equine iron deficiency is not a common problem, recent studies showed that equine athletes may be considered a model for human exercise physiology. Sports anemia among human athletes is a common nutritional issue and remains one reason for poor physical fitness. Thus, this study area needs comprehensive knowledge since iron homeostasis changes in equine athletes remain unrecognized. The current review aims to summarize studies describing...
Santos L, Werfel K, Ferlini-Agne G.Accurate measurement of haemoglobin concentration is crucial for monitoring the oxygen-carrying capacity in anaesthetised horses. This prospective study aimed to determine the agreement in haemoglobin concentration in anaesthetised horses using the SpHb pulse co-oximeter, an Epoc® blood gas analyser, and values derived from packed cell volume (PCV), which served as the reference method in this study. The study included 34 horses undergoing elective surgeries. Blood samples were collected from each horse and divided for analysis using the microhaematocrit method to estimate haemoglobin concent...
Tretow M, Hain AM, Bienert-Zeit A.The dental syndrome EOTRH is a painful, progressive dental disease with an unknown aetiology. The often painful nature of EOTRH emphasises the need for a better knowledge of the underlying pathogenic mechanism and risk factors. A comparative analysis of haematological, biochemical and endocrine values in EOTRH-affected and non-affected horses has not been described. Objective: To compare haematological, biochemical, and endocrine parameters in EOTRH-affected and non-affected horses to detect risk factors for horses developing EOTRH. Methods: Cross sectional. Methods: Blood samples of 154 Icela...
James C, Lloyd EM, Arthur PG.The extent to which muscle strain or tears are affecting race performance in horses is unknown because it is difficult to objectively identify muscle damage. One approach includes the use of physiological markers in blood. Recently, we linked the level of plasma thiol-oxidised albumin, an oxidative stress biomarker, to muscle damage in humans. Objective: This aim of this work was to investigate whether the level of plasma thiol-oxidised albumin was elevated in the days following a thoroughbred horse race. Methods: 'In vivo' experiments. Methods: Blood collection was performed by each trainer a...
Murase H, Wachi S, Matsuyama R, Makita K, Sato F.Pituitary pars intermedia dysfunction (PPID) is an age-related disease considered to have a negative impact on fertility. To understand the true impact of PPID on fertility, the influence of age must be considered. Objective: This study aimed to assess the impact of PPID on fertility while accounting for the effect of aging. Methods: A total of 332 Thoroughbred mares aged 10-20 years and managed across 137 private farms in Hidaka, Hokkaido, Japan were classified as PPID, equivocal, or non-PPID based on plasma adrenocorticotropic hormone concentration in 2019 and 2020. The prevalence of PPID an...
Wermer K, Korbacska-Kutasi O, Berkecz R, Csupor D, Ágh N, Sztojkov-Ivanov A, Cserhalmi D.Cannabidiol (CBD) has shown potential therapeutic benefits in veterinary medicine, but further investigations are needed to establish its pharmacokinetics and therapeutic dosing in horses and ponies. The present study aimed to investigate the pharmacokinetic properties of CBD in Connemara ponies following oral administration of CBD oil. Unassigned: Ten healthy ponies received a single oral dose of CBD oil at 2 mg/kg. Blood samples were collected before dosing and up to 16 days post-administration, with physical examinations conducted at baseline and at 8, 12, and 24 h post-dose. Addition...
Frisch V, Ramsauer AS, Preining I, Unterköfler MS, Fuehrer HP, Hofer M, Lyrakis M, Bouhsira E, Liénard E, Cavalleri JV.Equine hepacivirus (EqHV) from the family, has been detected in horses worldwide with a global RNA prevalence of up to 7.9%. While vertical transmission and iatrogenic transmission with infected blood products have been demonstrated for this virus, field infection rates suggest an additional horizontal transmission route. The aim of this study was to investigate the potential role of (Diptera, Muscidae) – a hematophagous fly that is found in stables with ruminants and horses as preferred hosts– in the transmission of EqHV RNA. From 2021 to 2022, were collected from three horse barns in ...
Hildebrandt D, Venner M, Hart KA, Berghaus L.Early and specific diagnosis of bronchopneumonia in foals is important to prevent severe disease. In human medicine, C-reactive protein (CRP) and interleukin-6 (IL-6) are important diagnostic and prognostic biomarkers in neonatal pneumonia in other species. Evaluation of these markers in foals with naturally occurring respiratory diseases is lacking. Objective: To determine if CRP and IL-6 were useful predictors of respiratory disease in foals from birth to weaning. Methods: Prospective cohort study. Methods: Periodic blood samples from 200 initially healthy foals were collected from birth to ...
Jing H, Liu P, Zheng S, Cao K, Li X.Total Mixed Ration (TMR) is recognized for its balanced nutritional composition, improved feed efficiency, enhanced animal production, and stabilization of the gastrointestinal microbiome. It has been extensively implemented in intensive ruminant farming, particularly for cattle and sheep, with demonstrated positive outcomes. However, its effects on the nutritional health of non-ruminant herbivores, such as horses, remain insufficiently investigated. This study aims to evaluate the comparative effects of TMR feeding versus conventional feeding practices in Akhal-Teke horses while maintaining i...
Gazzano V, Curadi MC, Capsoni S, Baragli P, Kêdzierski W, Cecchi F, Gazzano A.In humans, aging is often accompanied by cognitive decline, as seen in Alzheimer's disease. In contrast, the aging process in horses remains poorly characterized. This study aims to explore the presence of blood-based biomarkers associated with cognitive degeneration in this species. Twenty-three Arabian horses were enrolled, and 5 mL of blood was collected from each to measure serum levels of β-amyloid peptides (Aβ40 and Aβ42) and phosphorylated tau protein (pTau181), both considered reliable indicators of cognitive impairment in other species. Aβ42 was undetectable in all samples, while ...
Duaso J, Perez-Ecija A, Navarro A, Martínez E, De Las Heras A, Mendoza FJ.Equine piroplasmosis (EP), caused by and , is a worldwide tick-borne disease with severe economic, commercial, and sanitary implications for equids. Although diagnosis is based on direct (blood smear or PCR) or indirect (serology) methods, these techniques are expensive, laborious, and false-negative and false-positive results can be yielded. Biochemistry blood profiles are routinely performed in horses. Biochemical parameters and ratios could be a reliable complementary diagnostic tool to assist clinicians in EP diagnosis, mainly in endemic areas, or for discarding similar disorders (piro-li...
