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.
Dumoulin M, Pille F, van den Abeele AM, Boyen F, Boussauw B, Oosterlinck M, Pasmans F, Gasthuys F, Martens A.Standard methods for culturing equine synovial fluid (SF) are often unrewarding. Evidence-based information on the relative efficiency of different systems used for optimisation of isolation of microorganisms from equine SF is lacking. Objective: To compare the results of different culture systems performed in parallel on SF samples from horses clinically diagnosed with synovial sepsis. Methods: Synovial fluid specimens were collected between February 2007 and October 2008 from all horses admitted to a referral hospital that were clinically diagnosed with synovial sepsis and from control horse...
Southwood LL, Gassert T, Lindborg S.It is the impression of some surgeons that geriatric horses have a lower survival rate compared to mature nongeriatric horses following colic surgery. One possible reason for this is that geriatric horses may be more critically ill at admission and have more severe disease than mature nongeriatric horses. Objective: To compare admission historical, physical examination and laboratory data for geriatric and mature nongeriatric horses referred for signs of colic. Methods: Medical records of horses admitted with a presenting complaint of colic between 2000 and 2006 were reviewed. Geriatric horses...
Kornreich B, Enyeart M, Jesty SA, Nydam DV, Divers T.Pentoxifylline (PTX) possesses a number of vasomotor, immunomodulatory, and hemorheologic properties. Based upon the hypothesis that equine laminitis and navicular disease result from microthrombosis, the inhibitory effects of PTX on inflammatory cytokines, and its inhibitory effects on human platelet aggregation, PTX has been widely used to treat equine endotoxemia, navicular disease, and laminitis. Despite this, the effects of PTX on equine platelet aggregation have not been investigated previously. Objective: PTX decreases platelet aggregation in equine whole blood at concentrations approxi...
Bailly-Chouriberry L, Noguier F, Manchon L, Piquemal D, Garcia P, Popot MA, Bonnaire Y.Recombinant human erythropoietins (rHuEPOs) are glycoproteins drugs, produced by the pharmaceutical industry to restore production of red blood cells by stimulating human bone marrow for which this pathology has been diagnosed. It is suspected that these molecules are diverted as doping agents in horseracing to enhance oxygen transport and aerobic power in racehorses. Although indirect double-blotting or direct liquid chromatography-mass spectrometry (LC-MS) methods have been developed to confirm the presence of rHuEPO in a sample, the short detection time (48 h) is still a problem for doping ...
Muñoz A, Riber C, Trigo P, Castejón FM, Lucas RG, Palacio J.This study investigated the effect of hypertonic dehydration on exercise in horses. Valencian draft horses (n=43) with hypertonic dehydration following water and food deprivation and competing in pulling events (COM), were compared to euhydrated horses (n=11) during a pulling exercise test (PET). Both groups were divided into bodyweight (BW) categories A (≤350 kg), B (351-450 kg), and C (≥451 kg), and pulled 2, 2.25, and 2.5 times BW, respectively. Exercise duration (ED) was 1.3±0.8 min. Heart rate, respiratory rate, rectal temperature and blood samples were taken at rest, after exercise,...
Owens SD, Johns JL, Walker NJ, Librach FA, Carrade DD, Tablin F, Borjesson DL.To evaluate N-hydroxysuccinimide (NHS)-biotin labeling of equine RBCs and determine posttransfusion survival of autologous equine RBCs stored in citrate phosphate dextrose adenine-1 (CPDA-1) for 0, 1, 14, and 28 days. Methods: 13 healthy adult Thoroughbreds. Methods: Serial dilutions of biotin and streptavidin-phycoerythrin (PE) were evaluated in vitro in blood collected from 3 horses. One horse was used to determine RBC distribution and recovery. Twelve horses were allocated to 4 groups for in vivo experiments in which blood was collected into CPDA-1. Blood was labeled with biotin and reinfus...
Suagee JK, Burk AO, Quinn RW, Hartsock TG, Douglass LW.Low-grade inflammation precedes the development of obesity-related metabolic disorders in humans, but whether the same is true in the horse is not known. The objective of this study was to examine the effects of weight gain and diet on the inflammatory state of horses as determined by serum concentrations of tumour necrosis factor-α (TNF), an inflammatory cytokine. Fifteen mature Thoroughbred geldings with an initial body weight (BW) of 519±12 kg and body condition score (BCS) of 4.3±0.1 were fed a diet of hay plus a concentrate that was either high in non-structural carbohydrates (NSC) (i....
Flores J, Corvera Poiré E, del Rio JA, López de Haro M.We consider a simple model to give a plausible mechanical explanation of what are the actual resting heart rates of mammals optimized for. We study what is the optimal frequency for a viscoelastic fluid circulating in a pulsatile way through a network of tubes and conclude that the heart rate is not optimized to transport blood through the whole net. Rather, actual resting heart rates of mammals happen at frequencies that optimize flow in vessels of radii that correspond to large arteries, which bring oxygenated blood rapidly far away from the heart, towards head and limbs. Our results for the...
Frank N, Elliott SB, Chameroy KA, Tóth F, Chumbler NS, McClamroch R.Pituitary pars intermedia dysfunction (PPID) is a risk factor for pasture-associated laminitis, which follows a seasonal pattern. Objective: Hormonal responses to season differ between PPID and unaffected horses. Methods: Seventeen horses aged 8-30 years (14 horses ≥ 20 years of age). Methods: Longitudinal observational study. Blood was collected monthly from August 2007 until July 2008 after pasture grazing and again after overnight stall confinement. Blood hormone and metabolite concentrations were measured and pasture grass samples were analyzed to determine carbohydrate content. Analysis...
Peiró JR, Barnabé PA, Cadioli FA, Cunha FQ, Lima VM, Mendonça VH, Santana AE, Malheiros EB, Perri SH, Valadão CA.The clinical efficacy of IV infusion of lidocaine for treatment of equine endotoxemia has not been studied. Objective: Lidocaine infusion after exposure to lipopolysaccharide (LPS) will inhibit the inflammatory response and have inhibitory effects on the hemodynamic and cytokine responses to endotoxemia. Methods: Twelve horses. Methods: Two equal groups (n=6): saline (GI) and lidocaine (GII). In all animals, endotoxin (500 ng/kg body weight [BW]) was injected intraperitoneally over 5 minutes. Twenty minutes later, animals received a bolus of GI or GII (1.3 mg/kg BW) over 5 minutes, followed by...
Yan W, Faisal SM, Divers T, McDonough SP, Akey B, Chang YF.Little information is available about experimental induction of leptospirosis in horses. Objective: Determine serologic, hematologic responses of horses to Leptospira interrogans serovar Kennewicki infection. Methods: Four adult horses seronegative for leptospirosis. Methods: Experimental and observational study. Horses were challenged with an equine isolate of L. interrogans serovar Kennewicki at 2 different doses and different inoculation sites. After challenge, the horses were monitored for 60 days. Blood, urine, and aqueous humor samples were collected at intervals until euthanasia 60 days...
Ferris RA, McCue PM.Persistent mating induced endometritis is among the most common causes of infertility in the mare. Recently, improved pregnancy rates have been reported when corticosteroids were administered to 'problem mares' specifically, to modulate the post mating inflammatory response; however, the effect of treatment on pituitary and ovarian function requires further study. Objective: To evaluate the effects of prolonged treatment with glucocorticoids on pituitary and ovarian function. Methods: Eighteen cycling Quarter Horse mares in early oestrus were assigned randomly to one of 3 treatment groups: dex...
Alberghina D, Amorini AM, Lazzarino G.To evaluate the changes in plasma and platelet serotonin (5-HT) as markers of the serotoninergic system in equines, 5-HT content was measured by high performance liquid chromatography (HPLC) in deproteinized plasma obtained from peripheral blood samples of 12 clinically healthy horses, before and after feeding. 5-HT was measured in platelet rich plasma (PRP) and in platelet poor plasma (PPP). 5-HT in platelets (p5-HT) was obtained by subtracting free 5-HT in PPP (f5-HT) from 5-HT in PRP. After food ingestion, significant increases in p5-HT and f5-HT (p < 0.001), and no changes in the f5-HT/p5-...
Haffner JC, Fecteau KA, Eiler H, Tserendorj T, Hoffman RM, Oliver JW.Traditionally, analysis of blood cortisol alone has been used to evaluate adrenal function. Currently, multisteroid analyses are considered more informative than analysis of a single hormone to assess adrenal function. The objective of the present research was to create a database for steroid reference values for domestic Mongolian horses. Seven adrenal steroid levels were determined in the blood of 18 colts, 34 stallions, 25 geldings, 17 fillies, and 29 mares. Results were as follows (lowest and highest group median, in nanograms per milliliter): progesterone: <0.030 (fillies), 4.30 (mares), ...
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...
Pusterla N, Hussey SB, Mapes S, Johnson C, Collier JR, Hill J, Lunn DP, Wilson WD.Recrudescence of latent equine herpesvirus 1 (EHV-1) with subsequent viral shedding via nasal secretions is a potential source of infection for susceptible horses and has been implicated in outbreaks occurring in closed populations. Objective: To describe the viral kinetics of reactivated EHV-1 in blood and nasal secretions from latently infected horses after administration of corticosteroids, and to study the infectious nature of reactivated EHV-1 to sentinel horses. Methods: Eight healthy horses. Methods: Four horses infected 4 months previously with EHV-1 received dexamethasone on 5 consecu...
Opałka M, Kamińska B, Jaworski Z.Blood and feces samples were collected from Polish Konik stallions kept under conventional stable conditions and in the forest reserve during a 1-year study period. Levels of testosterone (T) and androstenedione (A(4)) were measured using radioimmunoassay. Positive correlation between fecal and plasma concentrations of androgens was observed. Fecal T concentrations increased in April and May reaching peak value mid-April in the stallions from the reserve group and 2 weeks later in the stallions from the stable group. Comparatively, concentrations of T were higher in the stable group. Levels of...
Chen JW, Uboh CE, Soma LR, Li X, Guan F, You Y, Liu Y.A novel multiplex of independent dinucleotide tandem repeat (DTR) loci was previously described that is capable of not only discriminating human and equine DNA, but of identifying a single equine source. We report a case in which a bloodstained syringe and two needles were found during inspection of a barn by inspectors of the Pennsylvania Racing Commissions. Using the multiplex and single-locus detection, all 21 equine DTR markers were detected in a suspect horse and two evidence samples, indicating the evidence samples came from the suspect animal. Only six markers were detected in the third...
Albayrak H, Ozan E.Equine infectious anaemia is a retroviral infection of horses. All infected horses, including those that are asymptomatic, become carriers and are infectious for life. In this study, blood samples of all equines in the province of Ardahan were collected. The material consisted of 8,947 equines, including 8,769 horses and 178 donkeys, from Ardahan province in northeastern Turkey. Blood was collected from all horses and donkeys and the sera were analysed for the presence of antibodies to equine infectious anaemia virus (EIAV) using an enzyme-linked immunosorbent assay. The results revealed that ...
Brosnan RJ, Steffey EP, Esteller-Vico A, Vaughan B, Liu IK.Digital perfusion pressure (DPP) equals mean arterial pressure (MAP) at the hoof coronet minus digital interstitial pressure (DIP) within the hoof. To test whether lamellar blood flow (LBF) changes proportionately to DPP, anesthesia was induced and maintained with isoflurane in six horses to target a MAP of 60 mmHg. Arterial, venous, and hoof interstitial pressures were measured in each pelvic limb. LBF was measured using fluorescent microspheres during dobutamine infusions targeting either 60 (low), 80 (medium), or 100 (high) mmHg MAP. Following euthanasia, hoof lamina was collected for micro...
Bertelsmann H, Keppler S, Höltershinken M, Bollwein H, Behne D, Alber D, Bukalis G, Kyriakopoulos A, Sieme H.The essential trace element selenium is indispensable for male fertility in mammals. Until now, little data existed regarding the relationship between selenium and sperm quality in the stallion. Selenium, or selenium-dependent glutathione peroxidase activity, was determined in red blood cells, semen, seminal plasma and spermatozoa, and the percentages of spermatozoa with progressive motility (PMS), intact membranes (PMI), altered (positive) acrosomal status (PAS) and detectable DNA damage, determined by the sperm chromatin structure assay, were evaluated in 41 healthy stallions (three samples ...
Péters F, Franck T, Pequito M, de la Rebière G, Grulke S, Salccicia A, Verwilghen D, Chiavaccini L, Deby-Dupont G, Serteyn D.The previous experiments have shown that some phenothiazines have antioxidant and anti-inflammatory properties in vitro. In this study the inhibition of the production of reactive oxygen species (ROS) by neutrophils was studied in two groups of horses, which received a dose of 0.1 mg/kg of either acepromazine or promethazine intravenously. Blood samples were collected before (T0) and 0.5, 1, 3 and 5 h after drug administration. The chemiluminescence (CML) response of neutrophils was measured ex vivo in the presence of luminol for a period of 10 min and the maximum CML value (peak value) record...
Peiró JR, Borges AS, Gonçalves RC, Mendes LC.To compare results reported for blood gas partial pressures, electrolyte concentrations, and Hct in venous blood samples collected from cattle, horses, and sheep and analyzed by use of a portable clinical analyzer (PCA) and reference analyzer (RA). Methods: Clinically normal animals (24 cattle, 22 horses, and 22 sheep). Methods: pH; Pco(2); Po(2); total carbon dioxide concentration; oxygen saturation; base excess; concentrations of HCO(3)(-), Na(+), K(+), and ionized calcium; Hct; and hemoglobin concentration were determined with a PCA. Results were compared with those obtained for the same bl...
Dieckmann SM, Winkler M, Groebel K, Dieckmann MP, Hofmann-Lehmann R, Hoelzle K, Wittenbrink MM, Hoelzle LE.Haemotrophic mycoplasmas (HM) are parasites on the surface of red blood cells and known to infect a wide range of animals. However, there are no previous evidences of HM infections in horses. In this study HM were detected for the first time in the blood of two horses suffering from poor performance, apathy, weight loss, and anaemia. Using a HM specific PCR assay and subsequent sequencing the infective agents isolated from the blood of said horses were confirmed as closely related to the HM species Mycoplasma haemofelis and 'Candidatus Mycoplasma haemobos'.
Trombetta MF, Accorsi PA, Falaschini A.When the mare's estrous cycle resumes in winter, the β-carotene content of hay is depleted. Sixty Italian trotter mares were randomly assigned to a Control or a Treated Group. Treated Group received 1g/d synthetic β-carotene for 15 days from parturition. Blood samples collected at parturition and on days 5, 10 and 15 after partum were analysed for β-carotene, vitamins A, progesterone, 17 β-estradiol, the energy parameters (glucose, cholesterol, NEFA), the protein profile (total protein, albumin, urea) and LDH. Some changes in these measures were attributable to treatment, which significant...
Bellier S, Cordonnier N.The goal of this article is to present the technical aspects and the applications of the blood cells examination and haemostasis in dogs and cats. Technical realisation of blood counts, cytology of normal and abnormal blood cells and significance of the pathologic cell counts are successively treated. Distinctive features of cytology and cell counts in herbivores, horses and cattle, are detailed in a separate chapter.Difficulties of veterinary haematology lie in qualitative and quantitative differences between blood cells of various animal species.Bone marrow cells exploration is not performed...
Kuznetsova LP, Nikitina ER, Sochilina EE, Vasil'eva KA.The influence of some cationic detergents on the catalytic activity of the horse blood plasma cholinesterase in reaction of hydrolysis of alpha-naphthylacetate at different pH were investigated. It was shown, that in the absence of detergents in acid pH of the reaction medium the Km value increases, but V remain constant. In the range of pH from 8.5 to 5.0 in the presence of detergents the Km and V values are not practically changed. That is why the activation of cholinesterase hydrolysis of alpha-naphthylacetate in the presence of detergents is considerably higher than that of the neutral pH....
Ohta M, Wakuno A, Okada J, Kodaira K, Nagata S, Ito M, Oku K.To evaluate the effects of IV fentanyl administration on the end-tidal sevoflurane concentration (ET(SEVO)) in thoroughbred racehorses, the ET(SEVO) required for internal fixation of longitudinal fractures was compared between horses anesthetized with sevoflurane-fentanyl (Group SF; n=9) and those anesthetized with sevoflurane alone (Group S; n=9). The loading dose of fentanyl (5.0 µg/kg) was administered over 15 min followed by a maintenance dose of fentanyl (0.1 µg/kg/min) throughout the operation in Group SF. The mean ET(SEVO) during the operation in Group SF (2.6 ± 0.2%) was significant...
Baragli P, Pacchini S, Gatta D, Ducci M, Sighieri C.Four untrained standardbred horses performed a standardized exercise test on the treadmill and an automated blood collection system programmed to obtain blood samples every 15 s was used for blood collection in order to evaluate the kinetics of adrenaline and noradrenaline. The highest average values obtained for adrenaline and noradrenaline were 15.0 +/- 3.0 and 15.8 +/- 2.8 nmol/l respectively, with exponential accumulation of adrenaline (r = 0.977) and noradrenaline (r = 0.976) during the test. Analysis of the correlation between noradrenaline and adrenaline for each phase of the test shows...
Filipović N, Stojević Z, Prvanović N.The changes in blood serum fructosamine concentrations as indicators of glycaemia during a longer period of time were investigated in mares during late pregnancy and early lactation, as well as their relationship to the changes in the concentration of biochemical indicators of energetic status. The samples were taken from eleven mares on 60 +/- 10 and 20 +/- 10 days before foaling, and 20 +/- 10 and 60 +/- 10 days after foaling. Concentrations of serum fructosamine, non-esterified fatty acids and triglycerides were higher during late pregnancy (from P < 0.05 to P < 0.0005), while the con...
Raidal SL, Edwards S.To determine the pharmacokinetics of potassium bromide (KBr) in horses after a single and multiple oral doses. Methods: Twelve adult Standardbred and Thoroughbred mares. Methods: Horses were randomly assigned into two treatment groups. In Part 1 of the study, horses were given a single oral dose of 120 mg/kg KBr. Part 2 of the study evaluated a loading dose of 120 mg/kg KBr daily by stomach tube for 5 days, followed by 40 mg/kg daily in feed for 7 days. Serum concentrations of bromide were determined by colorimetric spectrophotometry following drug administration to permit determination of con...
Engle CC, Foley CW.Uterine tubal fluids were collected twice a day from mares for 5 consecutive estrous cycles between March 15 and September 1. Follicular fluids were aspirated from the follicles of exteriorized ovaries of 3 mares between days 2 and 5 of estrus. Uterine tubal fluid and follicular fluid were analyzed for osmolarity, dry matter, total lipids, total free fatty acids, glucose, fructose, and lactic acid. Blood samples were collected (jugular venipuncture) throughout the estrous cycle, and the same physical and biochemical analyses were made on blood plasma. A difference (P less than 0.01) was found ...
El-Hage CM, Bannai H, Wiethoelter AK, Firestone SM, Heislers CM, Allen JL, Waller AS, Gilkerson JR.To determine the nature of serological responses in Australian horses using a commercial duplex indirect ELISA (iELISA) following vaccination against strangles. Methods: A group (n = 19) of client-owned horses from five properties were recruited to receive a primary course of a Streptococcus equi subsp. equi (S. equi) extract vaccine. Serological responses were determined by duplex iELISA incorporating S. equi-specific fragments of two cell wall proteins, SEQ2190 and SeM (antigens (Ag) A and C, respectively). Methods: The horses were administered a primary strangles vaccination course. Blood w...
Marichal G, Trigo P, Soto C, Meikle A, Suárez G.The Raid Uruguayo (RAID) is an equestrian endurance competition. This study characterized the hydroelectrolytic parameters (Na, K, Cl, tCa, and iCa), hematocrit (Ht), total plasma protein (TPP), and blood pH from 900 equine athletes (finishers and non-finishers) competing over distances of 80 to 115 km under different climate conditions. Paired blood samples were taken prior to the start of the competition (sample 1) and at the end of the race or at the time of leaving the competition (sample 2). The association of the comfort index (CI: low, moderate, and high) with blood parameters was evalu...
Miki W, Oniyama H, Takeda N, Kimura Y, Haneda S, Matsui M, Taya K, Nambo Y.We observed structural changes in the follicles and uterus of heavy draft mares during estrus and examined the effect of a single injection of the gonadotropin-releasing hormone analog buserelin on ovulation and endocrine profiles. Twenty-two heavy draft mares were divided into a buserelin-treated group (n=8) and a control group (n=14). Mares were given an intramuscular injection of 40 µg buserelin when they presented signs of estrus to a teaser stallion, had ≥45 mm diameter follicles, and presented decreased uterine edema compared with the previous examination. The follicles and uterus wer...
Gill J, Kompanowska-Jezierska E.In 34 pure-bred Arabian horses, divided into four groups (Gr. I, 10 pregnant mares; Gr. II, seven barren mares; Gr. III, 10 foals born in 1981; Gr. IV, seven foals born in 1982), seasonal changes in haemoglobin level, haematocrit value, sedimentation rate, red blood cell number and diameter, percentage of erythroblasts and reticulocytes, and index F were studied. Seasonal cyclicity was found in all groups in the haemoglobin level, haematocrit value and RBC diameter. It was also found in the sedimentation rate (PCV) and in index F, but not for the youngest foals (Gr. IV). For the RBC number the...
Williams KJ, Derksen FJ, Defeijter-Rupp HL, Robinson NE.Exercise-induced pulmonary haemorrhage (EIPH) occurs in nearly all strenuously exercising horses. Recent studies have attempted to identify the role of free blood within the airspaces, in the lung fibrosis that develops within the lungs of EIPH horses. Objective: Repeated exposure of the equine lung to autologous blood results in lung fibrosis similar to that observed in spontaneous EIPH. Methods: Forty ml of autologous blood from the jugular vein was instilled into preselected lung regions of 6 horses one, 2, 3, 4 or 5 times at 2 week intervals, with 40 ml of saline instilled into the contral...
De Auer , Ng JC, Seawright AA.The copper and zinc concentrations in the blood of stabled thoroughbred horses and in Australian Stock Horses mares at pasture, either late pregnant or lactating were determined by an atomic absorption spectroscopic method. The plasma concentration of the trace elements in these apparently normal horses were generally below the "normal" range. The plasma copper, caeruloplasmin copper, whole blood copper and plasma zinc concentrations in the stabled thoroughbreds were 0.76 +/- 0.19 micrograms/ml (n = 82), 0.56 +/- 0.14 micrograms/ml (n = 83), 0.75 +/- 0.18 micrograms/ml (n = 82) and 0.47 +/- 0....
Bradbery AN, Coverdale JA, Vernon KL, Leatherwood JL, Arnold CE, Dabareiner RA, Kahn MK, Millican AA, Welsh TH.Seventeen yearling Quarter Horses were used in a randomized complete block design for a 56-d trial to determine ability of dietary CLA to mitigate joint inflammation and alter cartilage turnover following an inflammatory insult. Horses were blocked by age, sex, and BW, and randomly assigned to dietary treatments consisting of commercial concentrate offered at 1% BW (as-fed) supplemented with either 1% soybean oil (CON; n = 6), 0.5% soybean oil and 0.5% CLA (LOW; n = 5; 55% purity; Lutalin, BASF Corp., Florham Park, NJ), or 1% CLA (HIGH; n = 6) top-dressed daily. Horses were fed individually ev...
Boucher JH, Ferguson EW, Wilhelmsen CL, Statham N, McMeekin RR.The erythrocytes of 14 conditioned horses participating in a 157-km endurance ride (requiring 14-21 h) were examined before the ride, immediately upon entering the 44-91-, and 130-km rest stops, and at the finish. At the first rest stop (44 km), the mean erythrocyte count increased 41% (P less than 0.001), the mean hematocrit (Hct) increased 30% (P less than 0.001) and the mean hemoglobin (Hb) increased 33% ( P less than 0.001). Although subsequent mean erythrocyte counts, Hct, and Hb values remained significantly elevated above controls, the values decreased 9-9% from the 4-km values later in...
Holman PJ, Becu T, Bakos E, Polledo G, Cruz D, Wagner GG.Babesia equi, a causative agent of equine piroplasmosis, was isolated from horses in the Chaco Province of Argentina, a known piroplasmosis endemic region. Fifteen B. equi field isolates were acquired by culture from 23 actively working horses from 2 ranches. The horses appeared healthy with no clinical signs or histories indicative of equine piroplasmosis. All 23 horses had B. equi-specific antibody activity by the indirect fluorescent antibody test and 18 were also complement fixation test positive for B. equi. Equine erythrocytes were prepared for parasite culture using a microcentrifuge tu...
Nurcahyo W, Yowi MRK, Hartati S, Prastowo J.Horses have a strategic and vital role to play in the lives of the people of Sumba Island, East Nusa Tenggara Province. They act as social animals that are involved in death ceremonies, horse races, and during pasola, thereby supporting tourism, and are given away as dowry in wedding ceremonies. This study aimed to investigate the prevalence of trypanosomiasis among horses in four districts of Sumba Island by examining clinical symptoms and detecting parasites, antibodies, and other factors that are related to infection in horses. Methods: We studied a total of 211 horses that belonged to 88 ...
Sevinga M, Barkema HW, Hesselink JW.The purpose of the present study was to compare serum calcium and magnesium concentrations in mares with or without a retained placenta (RP) and to evaluate treatment of mares with RP with oxytocin versus oxytocin combined with Ca-Mg-borogluconate solution. Blood samples were obtained within 12 h of foaling from Friesian mares with and without an RP (n = 90 and 65, respectively). Serum Ca and Mg concentrations were analyzed by atomic absorption spectrophotometry. In total, we treated 112 cases of RP in 101 Friesian mares by infusion of either oxytocin dissolved in saline solution or oxytocin d...
Pagan JD, Hauss AA, Pagan EC, Simons JL, Waldridge BM.To assess the relationship between plasma and RBC fatty acid composition and incidence and severity of squamous gastric ulcers when altered by short-chain (SC) or long-chain (LC) polyunsaturated fatty acid (PUFA) supplementation. 13 fit Thoroughbred horses in training. Horses were evaluated by gastroscopy for squamous ulcer score, gastric pH, and blood fatty acid composition prior to supplementation (UNSUPP) and after 3 months of supplementation with a corn-flax oil blend of alpha-linolenic acid and linoleic acid (SC-PUFA) or a gamma-linolenic acid (GLA)-fish oil blend of GLA, eicosapentaenoic...
Taylor PM, White KL, Fowden AL, Giussani DA, Bloomfield M, Sear JW.To characterize propofol anaesthesia in pregnant ponies. Methods: Fourteen pony mares, at 256 ± 49 days gestation, undergoing abdominal surgery to implant fetal and maternal vascular catheters. Methods: Pre-anaesthetic medication with intravenous (IV) acepromazine (20 µg kg), butorphanol (20 µg kg) and detomidine (10 µg kg) was given 30 minutes before induction of anaesthesia with detomidine (10 µg kg) and ketamine (2 mg kg) IV Maternal arterial blood pressure was recorded (facial artery) throughout anaesthesia. Arterial blood gas values and plasma concentrations of glucose, lactate, cort...
Loganathan D, Yi R, Patel B, Zhang J, Kong N.Resolution of cathinone enantiomers in equine anti-doping analysis is becoming more important to distinguish the inadvertent ingestion of plant-based products from those of deliberate administration of designer synthetic analogs. With this in mind, a rapid and sensitive method was developed and validated for the detection, resolution and quantitative determination of cathinone enantiomers in horse blood plasma and urine. The analytes were recovered from the blood plasma and urine matrices by using a liquid-liquid extraction after adjusting the pH to 9. The recovered analytes were derivatized w...
Boscan P, Van Hoogmoed LM, Pypendop BH, Farver TB, Snyder JR.To determine the pharmacokinetics and effects of the morphine antagonist N-methylnaltrexone (MNTX) on gastrointestinal tract function in horses when administered alone and in combination with morphine. Methods: 5 healthy adult horses. Methods: Horses were treated with MNTX (1 mg/kg, IV), and serial blood samples were collected for determination of drug pharmacokinetics. For evaluation of effects on the gastrointestinal tract when administered alone, MNTX was administered at a dosage of 0.75 mg/kg, IV, twice daily for 4 days. For evaluation of effects when administered concurrently with morphin...
Riggs CM, Thompson SL, So YM, Wong JKY, Wan TSM, Robinson P, Stewart BD, Ho ENM.Administration of bisphosphonates, including tiludronic acid, to Thoroughbred racehorses below 3 and a half years of age is prohibited in most racing jurisdictions. Objective: To determine if evidence of administration of tiludronic acid could be obtained from analysis of blood and urine samples beyond 40 days after administration. Methods: Retrospective cohort. Methods: Horses maintained in a highly controlled environment and treated with Tildren®a were selected from clinical records. Twenty-four horses were identified, 21 of which were still in race training. Blood and urine samples were c...
Bozorgmanesh R, Thornton J, Snyder J, Fletcher C, Mack R, Coyne M, Murphy R, Hegarty E, Slovis N.Symmetric dimethylarginine (SDMA) is a renal biomarker correlated with glomerular filtration rate (GFR). Objective: Describe changes in SDMA in clinically healthy foals and their mares during the first month postfoaling. Methods: Convenience sampling of healthy periparturient Thoroughbred mares and their full-term foals from a population of client-owned horses. Methods: Serum and EDTA whole blood samples were collected from mares in their last month of pregnancy and then from mares and foals at approximately <12 hours, 48 hours, 7 days, and 30 days postbirth. Samples were processed ...
Smarsh DN, Liburt N, Streltsova J, McKeever K, Williams CA.Many nutraceuticals are used as equine supplements without their efficacy having been scientifically tested. Black tea, cranberries, orange peel and ginger are a few of those nutraceuticals that warrant further study. Objective: To test the effects of single doses of black tea, cranberry, orange peel and ginger extract on markers of oxidative stress and antioxidant status following exercise in horses. Methods: In Study 1, 9 mature, healthy but unfit Standardbred mares were administered 2 l of a control (water), orange peel extract (30 g extract) or decaffeinated black tea extract (28 g extract...
Romagnoli N, Al-Qudah KM, Armorini S, Lambertini C, Zaghini A, Spadari A, Roncada P.The aims of this study were to assess the plasma concentrations of romifidine in horses after intravenous injection, to evaluate the red blood cell (RBC) partitioning of the anaesthetic drug, and to improve knowledge regarding its sedative effect in horses describing the pharmacokinetic model. Eight adult Standardbred horses received a single bolus of romifidine at a dosage of 100 g/kg. Blood samples (5 mL) were collected immediately before romifidine administration (), and at 2, 5, 10, 15, 20, 25, 30, 40, 50, 60, 75, 90, 105, 120, 150 and 180 min after injection. A sedation score was recor...
Skarda RT, Muir WW.A new technique for producing continuous caudal epidural analgesia (CEA) and caudal subarachnoid analgesia (CSA) in adult horses (mares) without causing loss of pelvic limb function is described. A modified 17-gauge Huber-point directional needle was used to place a catheter with stylet into either the epidural or subarachnoid space at the lumbosacral intervertebral junction. The catheter was positioned at either the midsacral (S2-3) subarachnoid space or caudal portion of the sacral (S-3 to S-5) epidural space in 7 mares. The position of the catheter was confirmed radiographically. A 2% solut...
Zweygarth E, Lopez-Rebollar LM, Meyer P.Twenty blood samples of zebras (Equus zebra zebra) from the Karoo National Park and the Bontebok National Park in South Africa, all seropositive for Theileria equi, were subjected to in vitro culture to identify carrier animals and to isolate the parasites. Sixteen animals had a detectable parasitaemia in Giemsa-stained blood smears examined before culture initiation, the remaining four animals were identified as T. equi carriers by in vitro culture. Cultures were initiated either in an oxygen-reduced gas mixture or in a 5% CO2-in-air atmosphere. Out of the 20 blood samples, 12 cultures of T. ...
Fenger CK, McKeever KH, Hinchcliff KW, Kohn CW.To determine components of the increase in oxygen consumption (VO2) and evaluate determinants of hemoglobin saturation (SO2) during incremental treadmill exercise in unfit horses. Methods: 7 unfit adult mares. Methods: Horses performed 1 preliminary exercise test (EXT) and 2 experimental EXT. Arterial and mixed venous blood samples and hemodynamic measurements were taken during the last 30 seconds of each step of the GXT to measure PO2, hemoglobin concentration ([Hb]), SO2, and determinants of acid-base state (protein, electrolytes, and PCO2). Results: Increased VO2 during exercise was facilit...
Hurcombe SD, Scott VH.To determine whether direct intra-abdominal pressures (IAP) and calculated direct abdominal perfusion pressures (APP) are location dependent within the abdomen of standing horses. We hypothesize that IAP will be increased and calculated APP will be decreased at a ventral abdominal location (V) when compared to values obtained from the left (LFl) or right flank (RFl). Methods: Prospective experimental design. Methods: University-based equine research facility. Methods: Seven healthy adult horses, 4 geldings and 3 mares. Methods: Measurements of direct IAP obtained from the RFl, LFl, and V locat...
Essén-Gustavsson B, Jensen-Waern M.Glycogenolysis and lipolysis are essential for energy production in muscle during prolonged exercise but less is known about the role of amino acid metabolism. The aim was to study the effect of an endurance race on pro- and macroglycogen, triglycerides and amino acid concentrations in muscle and on selected blood parameters, especially the amino acid response in the blood during the recovery phase. Seven endurance-trained horses completed a race covering 100-120 km. Blood samples were collected one day before the race, after the finish and 1 and 8 days after the race. Needle biopsy specimens ...
Kutasi O, Vörös K, Biksi I, Szenci O, Sötonyi P.This paper presents the embryological and pathological features as well as the terminology and classification of common atrioventricular canal, a type of endocardial cushion defect. The authors give a complete description of an extremely rare congenital cardiac malformation in an equine neonate. The diagnosis of a complete, balanced common atrioventricular canal of type C in Rastelli's classification scheme was based on two-dimensional, contrast and colour Doppler echocardiography and subsequent postmortem gross pathology. To support our diagnosis and study the pathophysiological effect of the...
Whitehair KJ, Steffey EP, Woliner MJ, Willits NH.To study the effects of inhalation anesthetic agents on the response of horses to 3 hours of hypoxemia. Methods: Controlled crossover study. Methods: Five healthy adult horses. Methods: Horses were anesthetized twice: once with halothane, and once with isoflurane in O2. Anesthetized horses were positioned in left lateral recumbency. Constant conditions for the study began at 2 hours of anesthesia. A constant agent dose of 1.2 minimum alveolar concentration, PaO2 of 50 +/- 5 mm of Hg, and PaCO2 of 45 +/- 5 mm of Hg were maintained for 3 hours. Circulatory measurements were made at 0.5, 1, 2, an...
Haase B, Obexer-Ruff G, Dolf G, Rieder S, Burger D, Poncet PA, Gerber V, Howard J, Leeb T.The KIT receptor protein-tyrosine kinase plays an important role during embryonic development. Activation of KIT is crucial for the development of various cell lineages such as melanoblasts, stem cells of the haematopoietic system, spermatogonia and intestinal cells of Cajal. In mice, many mutations in the Kit gene cause pigmentation disorders accompanied by pleiotropic effects on blood cells and male fertility. Previous work has demonstrated that dominant white Franches-Montagnes horses carry one copy of the KIT gene with the p.Y717X mutation. The targeted breeding of white horses would be et...
Castro T, Oliveira FA, Siddiqui MA, Baldrighi JM, Wolf CA, Ginther OJ.A study was performed on the effect of a single dose per mare of 0 (n = 9), 100 (n = 8), or 300 (n = 9) of GnRH on Day 10 (Day 0 = ovulation) on concentrations of LH, FSH, and progesterone (P4) and blood flow to the CL ovary. Hormone concentration and blood flow measurements were performed at hours 0 (hour of treatment), 0.25, 0.5, 1, 2, 3, 4, and 6. Blood flow was assessed by spectral Doppler ultrasonography for resistance to blood flow in an ovarian artery before entry into the CL ovary. The percentage of the CL with color Doppler signals of blood flow was estimated from videotapes of real-t...
