Serum in horses refers to the component of blood that remains after the removal of cells and clotting factors. It contains a variety of proteins, electrolytes, hormones, and metabolic waste products. Serum analysis is a valuable tool in veterinary medicine for assessing the health status of horses. It provides insights into organ function, nutritional status, and the presence of disease. Common parameters measured in equine serum include enzymes, such as aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT), as well as electrolytes like sodium and potassium. This page assembles peer-reviewed research studies and scholarly articles that explore the composition, diagnostic applications, and implications of serum analysis in equine veterinary practice.
Rico AG, Braun JP, Benard P, Bardies J, Thouvenot JP, Periquet B, Plantavid M.A wide blood serum biochemical profile, concerning especially blood lipids has been performed in 31 apparently healthy Shetland and Potiock ponies. These blood standard values will be useful for studies on ponies' hyperlipemia.
Trommershausen-Smith A, Suzuki Y.A family study of an index case in the Arabian breed of horses demonstrated the presence of a new allele in the prealbumin (Pr) system of electrophoretically determined markers in horse serum which, when homozygous, results in the absence of any recognizable zones in the Pr region. The symbol PrO is proposed for this allele which has an estimated frequency in Arabian horses of 0.09.
Fisher RA, Scott AM.A new method for separating the isozymes of horse serum esterase is described. The improved resolution has enabled us to detect several previously undescribed phenotypes. This method has also been used to detect two different apparently 'silent' alleles.
Gutekunst DE, Malmquist WA, Becvar CS.Antiserums prepared in specific pathogen free (SPF) ponies were used in direct and indirect immunofluorescence, immunodiffusion, complement fixation and serum neutralization procedures to study the interrelationships of the three types of equine herpes viruses (EHV-1, EHV-2, and EHV-3). Equine cell cultures infected with each type virus fluoresced when stained with homologous conjugated antiserum. In reciprocal tests EHV-1 and EHV-3 cross-fluoresced, but EHV-2 did not cross-fluoresce. Non-infected cell cultures did not fluoresce when stained with the 3 conjugates. EHV-1 and EHV-3 cross-fluores...
Nyindo MB, Ristic M, Lewis GE, Huxsoll DL, Stephenson EH.Four ponies experimentally infected with Ehrlichia equi developed substantial cell-mediated immune responses, as measured by the leukocyte migration-inhibition test. Serum anti-E equi antibodies up to 1:1,280 were demonstrated by the indirect fluorescent antibody test. Cell-mediated immune responses returned to a base-line value by day 200 after primary inoculation, but serum antibody titers persisted for at least 300 days after inoculation. Two additional susceptible ponies, which were inoculated with convalescent blood or organ homogenates from ponies recovered from acute equine ehrlichiosis...
Juneja RK, Gahne B, Sandberg K.Horizontal polyacrylamide gel electrophoreses, on 10% separation gel, of horse serum revealed polymorphism of the vitamin D binding protein (Gc protein) and another post-albumin protein (Pa). Family data supported the hypothesis that Gc and Pa types were controlled by autosomal codominant alleles. For both Gc and Pa proteins, the homozygous types showed a single fraction while the heterozygous type had two fractions. Pa types were found to be identical to the post-albumin types reported earlier by starch gel electrophoresis. Two Gc alleles, GcF and GcS, and three Pa alleles, Pa D, Pa F and Pa ...
Hillidge CJ.The serum activities of creatine kinase (CPK), aldolase (ALD) and alpha-hydroxybutyrate dehydrogenase (HBD) were determined in a group of Welsh Mountain ponies before and after a 30 minute period of neuroleptanalgesia induced by i.v. injection of Immobilon and terminated by i.v. injection of Revivon. There were slight but significant increases in the serum activities of CPK and HBD following neuroleptanalgesia, but no change in the serum activity of ALD. It is suggested that this form of neuroleptanalgesia may be associated, in ponies, with a degree of reversible myocardial hypoxic change, pos...
Main AR, McKnelly SC, Burgess-Miller SK.A butyrylcholinesterase of mol.wt. approx. 83000 was observed in pooled rabbit serum. The enzyme was named monomeric butyrylcholinesterase to distinguish it from the larger oligomeric butyrylcholinesterase of horse and human serum whose subunits are the same size as the monomeric enzyme. The active-site concentration of monomeric butyrylcholinesterase in the pooled serum was 0.18mum, which is five times the concentration of butyrylcholinesterase in pooled horse serum. This was surprising, since the horse serum is regarded as a rich source of butyrylcholinesterase, whereas rabbit serum is not g...
Dutta SK, Campbell DL.Blastic transformation of peripheral blood mononuclear cells and serum neutralization antibody levels for equine herpesivurs type 1 were measured in 19 mares from three farms at the time of termination of their pregnancy by normal foaling or viral abortion. The stimulation indexes of lymphocytes obtained from the mares from two farms (Farm 1 and 2) which had virus abortions, ranged from 2.1 to 10.8. But there was no significant difference in stimulation index levels between the aborting and normal foaling mares on these two farms. Equine herpesvirus type 1 was isolated from the mononuclear cel...
Blackmore DJ, Palmer A.Examination of tissues obtained from thoroughbred horses showed that the 'intestinal' phosphatase activity could be differentiated from other phosphatases by analysis at a pH of 9-5 and inhibition with 15 mM L-phenylalanine. A simple method for the measurement of 'intestinal' phosphatase in heparinised plasma or serum is described. Application of the technique to serum or plasma from normal and diseased horses indicates that the increase in the activity of 'intestinal' phosphatase is associated with cases showing clinical, biochemical and haematological evidence of intestinal damage.
Buening GM, Perryman LE, McGuire TC.Serum concentrations of immunoglobulin M (IgM) and immunoglobulin G (IgG) can be determined in the horse with a satisfactory degree of accuracy, using commercially available reagents. Selected lots of anti-human IgM can be used in precipitation tests to detect and quantitate equine IgM. Commercially available anti-equine IgG tended to overestimate the amount of IgG in single radial immunodiffusion tests. Even with these limitations, commercial reagents can be used to differentiate immunodeficiency disorders of foals, including combined immunodeficiency and failure of passive transfer of colost...
Corbella E, Ottonello S, Ubaldi A.The serum antiprotease (AAT) levels are reported in healthy horses and horses with respiratory diseases. Of the methods used, only the STIC test seemed to give useful results; this test showed variations in horses with respiratory diseases, especially in horses with acute alveolar pulmonary emphysema.
Kristensen F, Firth EC.Using agarose as a supporting matrix, electrophoresis was conducted on 50 serum samples and 20 cerebrospinal fluid samples from clinically normal horses (n = 50) of various ages and breeds. The technique was shown to be reliable. A positive correlation between age and gamma-globulin concentration was found in young horses. Features of the electrophoretograms of serum and cerebrospinal fluid samples are discussed, and a nomenclature based on Rf values is proposed.
Beech J, Kohn C, Leitch M, Weinstein AJ, Gallagher M.Serum, synovial fluid, and urine concentrations of gentamicin were measured in normal mature horses which had been given a single dose of the drug. Mean peak serum concentration (16.8 microgram/ml) occurred in horses 30 minutes after they were given a single intramuscular dose of 4.4 mg of gentamicin/kg of body weight. In horses given a smaller dose of gentamicin (1.7 mg/kg), mean peak serum concentrations of gentamicin (10.2 microgram/ml) appeared at 1 hour. Synovial fluid concentration was maximum at 2 hours for both doses; in horses given the larger dose, mean peak concentration was 6.4 mic...
Moore RM, Moulthrop JI, Sather GE, Holmes CL, Parker RL.Field studies were conducted in 1972 to determine the immunization status of equines along the Mexico, Arizona, and New Mexico borders. Interviews with horse owners were conducted along roads selected at random in the counties of Santa Cruz and Yuma, Ariz., and in Dona Ana County, N. Mex. At least 450 horse owners in each county were asked about the vaccination status of their animals, and information was taken on 1,260 animals. Blood specimens were obtained from every third equine, regardless of stated vaccination status, and tested for the presence of Venezuelan equine encephalitis (VEE), we...
Rico AG, Braun JP, Benard P, El Hassan AA, Cazieux A.In the horse, gamma-glutamyl transferase (GGT) was found to be mainly located in the kidneys, liver and pancreas. As renal lesions are followed by a urinary escape of enzyme, it can be assumed that if there are raised serum enzyme levels then the source will be chiefly from the liver and pancreas. In the blood, GGT can be measured either in plasma or serum. Its mean level in 58 horses was 12 U/L. This level was not affected by moderate dilution or slight haemolysis and its activity was only slightly decreased by storage at--30 degrees C. The relative hepatic specificity of this enzyme and its ...
Liberg P, Magnusson LE, Schougaard H.Synovial fluid and blood were collected from 18 clinically healthy brood mares in resting conidition. The following parameters were analysed: total leucocytes, glucose, alkaline phosphatase (AP), lactate dehydrogenase (LDH), total protein, albumin, total globulin, albumin/globulin ratio and electrophoretic protein picture. The serum/synovia ratios were calculated for all parameters. It was considered to be of greater diagnostic value to compare these serum/synovia ratios rather than to look at the individual concentrations in synovia. The results obtained did not materially differ from those i...
Thompson DL, Pickett BW, Berndtson WE, Voss JL, Mett TM.Stallions were subjected to a gradually increasing photoperiod beginning on October 15, 1973. The maximum artificial daylength (16 hr) was imposed on February 8, 1974, and maintained until October 6, 1974. Two ejaculates were collected from each of five treated and four control stallions weekly, with an interval of 24 hr between die paired ejaculates on the first and alternate weeks, and an interval of 1 hr on the second and alternate weeks. During summer, stallions subjected to the artificial photoperiod produced less (P<.05) gel-free semen and gel per ejaculate and had more (P<.05) spermatoz...
Gaskin JM, Neal FC, Rubin HL.Precipitin lines not associated with equine infectious anemia (EIA) were observed in routine agar gel immunodiffusion (AGID) testing for the infection. The serums which produced these lines were obtained from horses which had been given multiple vaccinations with commercially available cell culture-origin equine virus vaccines as part of a comprehensive herd health program. The lines formed against cell culture-derived, but not spleen-derived EIA viral antigens. Investigation revealed that bovine serum proteins in the vaccines induced precipitating antibodies which reacted with bovine serum pr...
Holley DC, Evans JW.Total and ultrafilterable calcium (Ca) and magnesium (Mg) values were determined for Shetland pony stallions, stallions, and pregnant and diestrous mares, using a simple, inexpensive, quick procedure to obtain an ultrafiltrate of serum. There was no significant difference between horses and ponies, between stallions and mares, or between pregnant and nonpregnant mares. The percentage of total serum Ca that was ultrafilterable was 63.4+/-1.7 for horses and 64.8+/-2.2 for ponies. The percentage of total serum Mg that was ultrafilterable was 75.6+/-1.5 for horses and 77.0+/-1.7 for ponies. Total ...
Oxender WD, Noden PA, Hafs HD.On December 11, 1974, 15 seasonally anestrous mares were assigned at random to 1 of 3 experimental groups: outdoor-control, indoor-control, or indoor light-treated (a 16-hour photo-period). This experiment was terminated on April 21, 1975. The five mares in the indoor light-treated group ovulated 59.0+/-6.9 days later, which was 74 days earlier (P less than 0.01) than 2 of the 5 outdoor-controls (the other 3 ovulated after April 21 during a subsequent experiment) and 50 days earlier (P less than 0.05) than the indoor-controls. Durations of the 1st estrus for the 3 groups of mares were 13.3+/-3...
Carlson GP, Harrold DR.A highly significant correlation between the water content and protein concentration of equine serum and plasma samples was demonstrated over a wide range of concentrations. A close correlation was also observed between protein concentration as estimated by refractometry and as determined by the biuret procedure for equine serum and plasma samples.
Wilks CR.The immune response in horses following experimental infection with equine herpesvirus type 1 (EHV-1) was assessed by measuring cytotoxicity for EHV-1-infected target cells. A technique was developed, using [125I]5-iodo-2'-deoxyuridine ([125I]IUDR)-labeled equine fetal kidney cells infected with EHV-1 as the target cells. It was shown that peripheral blood leukocytes from a recovered horse were capable of lysing target cells, as measured by the loss of radio-active label. Following the experimental infection of specific-pathogen-free ponies with EHV-1, cytotoxicity was obtained with fresh auto...
Gilmour JS, Mould DL.Plasma, serum and cells were prepared from blood taken from acute cases of grass sickness, and plasma was fractionated by gel filtration and salt precipatation. These preparations were all tested for neurotoxic activity by injection into ponies. Plasma and serum were found to produce the neurohistological changes seen in grass sickness, as was a plasma protein fraction of molecular weight 30,000 or greater. Activity was retained following storage at--75 degrees C for 15 months. Plasma given orally to a pony produced no detectable effect, nor was activity demonstrated following the injection of...
Ghaeli T, Karimi B, Kojouri GA, Dehkordi RR, Ahadi AM.One of the initial responses of the host's innate immunity of newborns against pathogens is the use of oxidative enzymes. This study aimed to evaluate changes in serum xanthine oxidoreductase (XOR) activity, the leukocyte myeloperoxidase (MPO) and XOR genes expression, and some biochemical parameters in healthy Darehshuri newborn foals up to 60 days of life. Blood samples were collected from 16 foals at 1, 7, 15, 30, and 60 days and used for detecting XOR activity, biochemical parameters, and also gene expression by real-time RT-PCR. High activity of XOR was observed at birth, explained by phy...
Hassanain MM, al-Afaleq AI, Soliman IM, Abdullah SK.Two 7-year old Arabian racing horses were reported to show typical AHS symptoms in Qatar and died shortly after. The horses had been vaccinated with formol inactivated vaccine approximately 10 days before the onset of the disease. Blood samples from these horses were collected and AHS virus isolated from one sample after intracerebral (i.c.) inoculation into suckling mice. The virus identity was confirmed by complement fixation test (CFT) using the virus antigen and reference type 9 of AHS virus hyperimmune serum. The serotype of the isolated virus was identified by serum neutralization test (...
Dos Santos GC, Di Filippo PA, da Fonseca LA, Quirino CR.The purpose of this study was to compare the extent of inflammation response in the middle carpal joints of healthy horses following intra-articular injection of 2% lidocaine, 0.5% bupivacaine, or 0.9% saline solution. The right middle carpal joint of 20 horses was injected with 5 mL of 0.5% bupivacaine (GB, n = 10) or 5 mL of 2% lidocaine (GL, n = 10). The left middle carpal joint of horses was used as a control (5 mL 0.9% saline). Serum and synovial fluid (SF) were aseptically collected before and at predetermined times after each injection. Serum and synovial fluid protein, albumin, tra...
Lee JJ, Hsieh CL, Widman J, Mingala C, Ardeza Villanueva M, Feng H, Divers T, Chang YF.Current serological tests cannot discriminate between bactericidal Borrelia burgdorferi antibodies from others that are merely a response to Borrelia antigenic stimulation. Objective: To develop a sensitive and convenient luminescence-based serum bactericidal assay (L-SBA) to identify serum borreliacidal activity. Methods: Prospective validation study and method comparison. Methods: Serum samples were obtained either from archives of the Animal Health Diagnostic Center at Cornell University (N = 7) or from a vaccination trial (N = 238). Endogenous complement-inactivated serum sample was in...
Ek N.Studies of transferrin (Tf) concentration in sera of sick horses were carried out using Mancini’s immunodiffusion technique. Relative values against a chosen reference serum were determined for a total of 112 horses. Horses with acute infections had Tf values significantly below the normal. The lowest individual Tf value in this group (46%) was found in a six-months-old foal with temperature 41°C and watery diarrhoea. Horses suffering from acute laminitis also had decreased Tf values. The lowest value in the whole material (45%) was found in a horse belonging to this group. There was a posi...
Hansen S, Laustsen L, Otten ND, Skovgaard K, Bech R, Byrgesen S, Hopster-Iversen C, Fjeldborg J.Alternative treatment options to glucocorticoids for equine asthma is desirable due to withdrawal time. The objective was to evaluate if serum and Respiratory Gene Technology (RGT), a commercial kit to produce autologous conditioned serum, was effective in reducing bronchoalveolar lavage (BAL) neutrophils and mast cells in racehorses with cytological evidence of mild equine asthma . Thirty-six Standardbred trotters in active training were enrolled in this randomized clinical trial; a healthy control group (n=11), a RGT group (n=12) and a serum group (n=13). Endoscopy including tracheal wash (T...
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...
Afonso T, Giguère S, Rapoport G, Brown SA, Coleman AE.Benazepril has been shown to inhibit circulating angiotensin-converting enzyme (ACE) activity in horses but the optimal dosage is unknown. Objective: To determine the lowest tested dose of benazepril that results in ≥75% attenuation in the response of arterial blood pressure (BP) to exogenous angiotensin I (ANG-I) administration. Methods: Prospective experimental study. Methods: A total of 5 healthy horses were instrumented for the direct measurement of BP. Each horse received 4 intragastric doses of benazepril (0.5, 1, 2 and 4 mg/kg bwt) with a washout period of 7 days between doses. Prior ...
Malekinejad H, Alizadeh-Tabrizi N, Ostadi A, Fink-Gremmels J.The pathogenesis of equine grass sickness (EGS) has not fully understood. A better understanding of the exact pathogenesis of diseases can help to make an accurate diagnosis. Previous studies reported some pathological damage of neuronal cells in EGS patients. In this study, primarily cytotoxicity of serum from three clinically EGS-diagnosed horses on PC12 Tet-off (PTO) cells was assessed. Subsequently, the apoptotic tests including cytochrome C release, caspase-3/7 activity measurement and DNA fragmentation assay were conducted to clarify the apoptotic effect of serum from EGS patients. Addit...
Thomas DP, Foley JP.Detection of prohibited substances in equestrian sports typically involves time-consuming and tedious sample-preparation methods. Micellar LC (MLC) allows for direct injection of equine serum to detect prohibited NSAIDs. Results: The method was linear over the range of standards examined, with recoveries of 94.2-95.1% for phenylbutazone (12-18 µg/ml), and 83.9-88.7% and 87.9-105.0% for diclofenac and flunixin, respectively (0.1-1.2 µg/ml). The limit of detection was 0.1 µg/ml for all compounds and the limit of quantitation was 0.2 µg/ml for phenylbutazone and 0.3 µg/ml for diclofenac and ...
Raidal SL, Edwards S.To determine the pharmacokinetics of potassium bromide (KBr) in horses after single and multiple oral doses. Methods: Twelve adult Standardbred and Thoroughbred mares. Methods: Horses were randomly assigned to two treatment groups. Group 1 horses were given a single oral dose of 120 mg/kg potassium bromide. 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 KBr were measured to construct concentration versus time curves and to calculate pharmacokinetic parameters. Treated horses ...
Parraga ME, Kittleson MD, Drake CM.The aim of this study was to determine if quinidine administration increases steady state serum digoxin concentration in horses. Digoxin (0.01 mg/kg q. 12 h per os) was administered to 6 horses for 7 days. Steady state was confirmed by identifying statistically indistinguishable peak and trough serum digoxin concentrations on Days 4, 5, and 6. On Day 6, serum digoxin concentration was measured at baseline and 0.25, 0.5, 1, 2, 4, 6, 8 and 12 h after digoxin administration. On Day 7, quinidine (20 g at baseline and 10 g at 2, 4 and 6 h) was administered per os and serum digoxin concentration was...
Kuwabara M, Inukai N, Inanami O, Miyake YI, Tsunoda N, Maki Y, Sato F.Hotbred (Thoroughbred) horses were grouped into three classes according to the levels of constant physical exercise (foals, 6 months old; racing horses, 5 years old; horses for breeding, 6-10 years old), and lipid peroxide levels in their sera were measured as thiobarbituric acid-reactive substances. No significant differences were observed among them. The superoxide-scavenging abilities of sera were measured next; to examine the antioxidative properties of hotbreds, and were found to be highest in the racing horses. The higher scavenging ability of the racing horses might contribute to keep t...
Hinchcliff KW, Sams RA.To determine the effect of administration of commercially available sodium bicarbonate (NaHCO3) on carbon 13 (13C) isotopic enrichment of carbon dioxide (CO2) in serum of horses. Methods: 7 healthy Thoroughbreds. Methods: Sodium bicarbonate (450 g) was administered via nasogastric intubation to horses. Horses had been fed a diet obtained from the same source and had access to water from the same source for 3 months before the study. Blood samples were collected immediately before and at 2, 4, 6, and 24 hours after administration of NaHCO3. The concentration of total CO2 in serum was measured b...
Rapp HJ.During the combination of oral and intravenous application of saline solution for treatment of the COPD of horses the level of hydraemia basing on the total protein concentration in the serum, the urine production and the specific weight of urine was determined. Additionally the development of serum concentration and of renal excretion rates of potassium, calcium and magnesium were ascertained. The level of hydraemia resulting from the combined method is almost identical with the solely intravenous performed hyperinfusion therapy. Due to the excessive application of fluid an extremely high lev...
Pedersoli WM, Fazeli MH, Haddad NS, Ravis WR, Carson RL.Endometrial tissue and blood serum gentamicin (GT) concentrations were determined in 6 ovariectomized pony mares given intrauterine infusions (50 ml of a 5% commercial aqueous solution of GT) each day for 5 consecutive days. The mares were subjected to the following 3 treatments: (1) GT infusion only (trial A, control); (2) progesterone plus GT (trial B, P + G); and (3) estradiol plus GT (trial C, E + G). Endometrial tissue concentrations of GT (micrograms/g) at 24 and 120 hours were significantly higher (P less than 0.05) in trials B (65.54 +/- 15.57 and 100.33 +/- 19.27) and C (73.33 +/- 22....
Mair TS, Stokes CR, Bourne FJ.The immunoglobulin (Ig) content of serum and tracheal lavage fluid was measured in 50 horses suffering from chronic obstructive pulmonary disease (COPD) and 40 control horses. The mean immunoglobulin: albumin ratios of the lavage fluids of both groups were significantly higher than the corresponding values for serum, which indicates significant local production of immunoglobulins in the lower respiratory tract. The IgA: albumin ratio of lavage fluid was significantly higher in diseased compared with normal horses, which implies increased local production of IgA in this disease. The IgG: albumi...
Chaffin MK, Cohen ND.To determine whether administration of commercially available Escherichia coli antiserum to neonatal foals would affect serum IgG concentration or morbidity and mortality rates during the first 60 days of life. Methods: Randomized controlled trial. Methods: 271 neonatal foals on 4 well-managed farms. Methods: Foals were randomly assigned to a treatment or control group. All foals were allowed to suckle colostrum normally. In addition, treatment-group foals were given E coli antiserum (10 micromilligrams) orally between 0 and 8 hours after birth. Serum samples were obtained between 18 and 36 ho...
Monzón CM.A direct agglutination test is described to diagnose 'Mal de Caderas' caused by Trypanosoma evansi. The antigen used was a suspension of trypsin-treated parasites stabilized with formalin. The test was evaluated in horses with both natural and experimental infections. Test sensitivity and specificity were 94 and 97%, respectively. Treatment of serum with 2-mercaptoethanol before testing permitted the differentiation of IgM and IgG antibodies, and possible differentiation of current infection from past exposure to the parasite. The antigen was stable over a 6-month evaluation period and also sh...
Romano MC, Francis KA, Janes JG, Poppenga RH, Filigenzi MS, Stefanovski D, Gaskill CL.Poisoning of nontarget species is a major concern with the use of anticoagulant rodenticides (ARs). At postmortem examination, differentiating toxicosis from incidental exposure is sometimes difficult. Clotting profiles cannot be performed on postmortem samples, and clinically significant serum, blood, and liver AR concentrations are not well-established in most species. We chose diphacinone for our study because, at the time, it was the publicly available AR most commonly detected in samples analyzed at the University of Kentucky Veterinary Diagnostic Laboratory. We determined an approximate ...
Lammers TW, Roussel AJ, Boothe DM, Cohen ND.To evaluate the effect of an indwelling nasogastric tube on gastric emptying of liquids in horses. Methods: 9 healthy adult horses. Methods: A randomized block crossover design was used. For treatment group horses, a nasogastric tube was placed and 18 hours later, acetaminophen was administered; the nasogastric tube remained in place until the experiment was complete. For control group horses, a nasogastric tube was passed into t stomach, acetaminophen was administered, and the nasogastric tube was removed immediately. Serial blood samples were collected 15 minutes before and after administrat...
Cohen ND, Kahn SK, Cywes-Bentley C, Ramirez-Cortez S, Schuckert AE, Vinacur M, Bordin AI, Pier GB.Rhodococcus equi is a prevalent cause of pneumonia in foals worldwide. Our laboratory has demonstrated that vaccination against the surface polysaccharide β-1→6-poly-N-acetylglucosamine (PNAG) protects foals against intrabronchial infection with R. equi when challenged at age 28 days. However, it is important that the efficacy of this vaccine be evaluated in foals when they are infected at an earlier age, because foals are naturally exposed to virulent R. equi in their environment from birth and because susceptibility is inversely related to age in foals. Using a randomized, blind experim...
Rojas-Núñez I, Gomez AM, Palmer S, Mohammed HO.Neurofilaments are structural proteins that are concentrated in the body and axons of neurons. Damage to the neurons or axons as a result of trauma or infectious diseases leads to the release of neurofilaments into blood and cerebrospinal fluid (CSF). This case-control study was carried out to compare serum levels of phosphorylated neurofilament heavy chain (pNF-H) between clinically healthy Thoroughbred (TB) horses and TB horses that suffered catastrophic musculoskeletal injuries (cMSI), and to investigate the correlation between putative risk factors and serum concentrations of pNF-H in inju...
Moss A, Leise B, Hackett E.Laminitis is a complex and debilitating disease of horses. Numerous predisposing factors contribute to laminitis development, however the exact pathogenesis remains undetermined. Serum T4, cortisol, and histamine are components of the innate stress response and could play a causative or contributory role. Stress hormone concentrations in laminitis are largely unknown. Objective: To evaluate parameters associated with stress response in horses with laminitis, and compare these to healthy horses and horses with gastrointestinal (GI) disease. Methods: Thirty-eight adult horses presenting for non-...
Cebulj-Kadunc N, Kosec M, Cestnik V.To determine seasonal changes in circulating leptin concentrations, as well as leptin fluctuations in various patterns of seasonal ovarian activity, blood samples were taken in 107 Lipizzan fillies aged 1-4 years over the whole year from January to December. Serum concentrations were measured in samples obtained once a month (leptin) or twice a month (progesterone), and evaluated with respect to the age of animals (yearlings, 2-, 3- and 4-year olds) and the pattern of ovarian activity (anoestrous, seasonal cycle, prolonged cyclicity, continuous cyclicity). The mean and monthly leptin concentra...
Muñoz A, Esgueva M, Gómez-Díez M, Serrano-Caballero JM, Castejón-Riber C, Serrano-Rodríguez JM.Changes in blood pressure (BP) during acute hypertension in response to angiotensin-converting enzyme inhibitors (ACEIs) have not been investigated in normotensive horses. In this study, six healthy horses were subjected to five trials, consisting in a treadmill exercise workload of 8 m/s for 1 min, 2 h after oral administration (PO) of placebo (0 mg/kg), enalapril (2.0 mg/kg), quinapril (1.0 mg/kg), ramipril (0.2 mg/kg) or benazepril (0.5 mg/kg). Serum angiotensin converting enzyme (ACE) activity was measured and systolic (SBP) and diastolic (DBP) blood pressures were recorded...
Henderson KM, Eayrs K.To develop a means of determining pregnancy status in horses based on measuring serum oestrone sulphate (OS) concentrations using a rapid lateral flow immunoassay, and to determine the assay's effectiveness using a visual end-point. Methods: Serum samples from mares >100 days post-mating (n=701) were assayed using a nitrocellulose membrane-based lateral flow immunoassay device. The device was developed using membrane-bound 1,3,5 (10)-estratrien-3-ol-17-one conjugated to bovine serum albumin as the capture antigen, and an OS-detection monoclonal antibody coupled to colloidal gold as the visi...
Bowman KF, Dix LP, Riond JL, Riviere JE.Pharmacokinetics of ampicillin sodium (11 mg/kg), gentamicin sulfate (2.2 mg/kg), and combination ampicillin sodium-gentamicin sulfate were determined for serum and synovia of healthy horses given single-dose IV injection and were not found to be different from those from other reports; however, a prolonged terminal gamma-phase for gentamicin (8,498 +/- 1,842 minutes) in serum of horses was found to exist. Pharmacokinetic interaction between combination ampicillin sodium-gentamicin sulfate was not observed int he serum or synovia. Prediction of ampicillin sodium or gentamicin sulfate concentra...
Cervantes CC, Brown MP, Gronwall R, Merritt K.Each of 5 healthy mares was given 5 consecutive IM injections of ceftiofur sodium (2 mg/kg of body weight; 50 mg/ml) at 12-hour intervals. Ceftiofur concentrations were measured serially in serum, synovial fluid, peritoneal fluid, and urine, and were measured in CSF and endometrial tissue after the fifth dose. Mean elimination rate constant was 0.354 +/- 0.101 h-1 and elimination half-life was 2.49 +/- 0.49 hour. Mean serum ceftiofur concentrations peaked approximately 1 hour after each injection. The highest mean ceftiofur concentration was 5.09 micrograms/ml at 1 hour after the fifth dose fo...
