Veterinary research in horses encompasses the study of diseases, health management, and medical treatments specific to equine species. This field investigates various aspects of horse health, including infectious diseases, metabolic disorders, and musculoskeletal conditions. Researchers focus on understanding the pathophysiology of equine ailments, developing diagnostic tools, and evaluating therapeutic interventions. The study of horse health also involves examining preventive measures such as vaccination protocols and nutritional management to promote overall well-being. This page collects peer-reviewed research studies and scholarly articles that explore the diverse areas of veterinary science related to horses, providing insights into disease mechanisms, treatment strategies, and advancements in equine healthcare.
Seguin JC, Walker RD, Caron JP, Kloos WE, George CG, Hollis RJ, Jones RN, Pfaller MA.During a 13-month period, 11 equine patients visiting a veterinary teaching hospital for various diagnostic and surgical procedures developed postprocedural infections from which methicillin (oxacillin)-resistant Staphylococcus aureus (MRSA) strains were isolated. The S. aureus isolates were identified by conventional methods that included Gram staining, tests for colonial morphology, tests for clumping factor, and tests for coagulase and urease activities and were also tested with the API STAPH IDENT system. Antimicrobial susceptibility tests were performed by the disk diffusion method. The b...
Robinson NE, Derksen FJ, Olszewski M, Berney C, Boehler D, Matson C, Hakala J.In six COPD-affected horses, we analysed the factors responsible for the changes in pleural pressure (delta Pplmax) that occur during tidal breathing. Four-hundred-and-sixty-eight measurements of each parameter: pulmonary resistance (RL), dynamic elastance (Edyn), air flow rates, and the timing of breathing, were gathered during a trial of the bronchodilator pirbuterol. Data were placed into seven ranks, based on the magnitude of delta Pplmax; rank 1: 5-15; rank 2: 15-25; rank 3: 25-35; rank 4: 35-45; rank 5: 45-55; rank 6: 55-65; and rank 7 > 65 cm H2O. Up to rank 4 (45 cm H2O), the increa...
Weaver SC, Powers AM, Brault AC, Barrett AD.Recent studies using molecular genetic approaches have made important contributions to our understanding of the epidemiology of veterinary arboviral encephalitides. Viruses utilizing avian enzootic hosts, such as Western equine encephalitis virus (WEEV) and North American Eastern equine encephalitis virus (EEEV), evolve as relatively few, highly conserved genotypes that extend over wide geographic regions; viruses utilizing mammalian hosts with more limited dispersal evolve within multiple genotypes, each geographically restricted. Similar findings have been reported for Australian alphaviruse...
Munroe G.A survey of 169 neonatal thoroughbred foals revealed that 8.3 per cent had subconjunctival haemorrhages, but there was no indication of a relationship between retinal and subconjunctival haemorrhages. The haemorrhages were not related to any abnormality of the foals and there was no sex or eye predisposition. In most cases the haemorrhages were fresh and red, occurred mainly dorsally or dorsonasally and extended up to the limbus; they resolved completely within four to 10 days, depending on their initial severity and extent. They had no effect on the foals' vision in the short or long term. Th...
Rothaug PG, Tulleners EP.To describe a technique of contact neodymium:yttrium-aluminum-garnet (Nd:YAG) laser-assisted excision of progressive ethmoid hematoma (PEH) in horses, to determine the recurrence rate of clinical signs of PEH in horses with follow-up time of a minimum of 12 months, and to compare this result with reported results achieved by using conventional techniques. Methods: Retrospective study. Methods: 21 horses with 26 PEH. Methods: Medical records of all horses with PEH treated by Nd:YAG laser excision from December 1986 through August 1996 were analyzed. Twenty-one horses underwent unilateral (18 su...
Van Hoogmoed L, Rodger LD, Spier SJ, Gardner IA, Yarbrough TB, Snyder JR.To determine whether peritoneal fluid pH, glucose concentration, and lactate dehydrogenase activity can be used to differentiate horses with septic peritonitis from those with nonseptic peritonitis. Methods: Prospective study. Methods: 46 horses, including 10 healthy horses, 15 horses with septic peritonitis, and 21 horses with nonseptic peritonitis. Methods: Peritoneal fluid and blood samples were analyzed for pH, glucose concentration, and lactate dehydrogenase activity. Complete blood cell counts were performed, and peritoneal fluid samples were submitted for bacterial culture. Results: Hor...
Lonning SM, Zhang W, McGuire TC.Antigen-specific T-helper (Th) lymphocytes are critical for the development of antiviral humoral responses and the expansion of cytotoxic T lymphocytes (CTL). Identification of relevant Th lymphocyte epitopes remains an important step in the development of an efficacious subunit peptide vaccine against equine infectious anemia virus (EIAV), a naturally occurring lentivirus of horses. This study describes Th lymphocyte reactivity in EIAV carrier horses to two proteins, p26 and p15, encoded by the relatively conserved EIAV gag gene. Using partially overlapping peptides, multideterminant and poss...
Anzai T, Sheoran AS, Kuwamoto Y, Kondo T, Wada R, Inoue T, Timoney JF.Streptococcus equi causes equine strangles. The acute disease has many of the hallmarks of an acute response including high fever, elevated plasma fibrinogen and neutrophilia, affects known to be mediated by proinflammatory cytokines. The objective of this study was to screen-culture supernatants from equine clinical isolates of S. equi and S. zooepidemicus for stimulation of mitogenic responses by horse peripheral blood mononuclear cells. Mitogenicity comparable to that of concanavalin A was detected in culture supernatants of S. equi strains but not in those of S. zooepidemicus. Mitogenicity...
Cothran EG, van Dyk E.Genetic variability at 7 blood-group and 10 biochemical genetic loci was examined in 3 South African horse breeds, the Nooitgedacht, Boerperd and Basuto Pony. Observed heterozygosity for these breeds was intermediate for domestic horses, with the highest heterozygosity in the Boerperd and the lowest in the Basuto Pony. The 3 breeds show greater genetic similarity to each other than to other domestic horse breeds. Compared to other breeds, the South African breeds show greater genetic similarity to breeds such as the Thoroughbred, Holstein, Trakehner and Hanovarian and also to North American br...
Stegmann GF, Jones RS.The cortisol response to anaesthesia and surgery was studied in 2 groups of horses undergoing either abdominal or non-abdominal surgery. The preoperative mean plasma cortisol concentration (pcc) of 381.7 nmol/l (s.d. 254.7) was markedly higher in the abdominal group than the early-morning mean pcc of 115.6 nmol/l (s.d. 78.4) in the non-abdominal group. During halothane anaesthesia and surgery the mean pcc increased significantly (p < 0.05) from the preoperative mean of 119.2 to 215.9 nmol/l (s.d. 79.8) after 30 min of surgery in the non-abdominal group. In the abdominal group a decrease occ...
Kim SK, Bowles DE, O'callaghan DJ.The equine herpesvirus 1 immediate-early (IE) phosphoprotein is essential for the activation of transcription from viral early and late promoters and trans-represses its own promoter. Transient-transfection assays showed that the IE protein trans-represses the gamma2 late gK promoter. Gel shift and DNase I footprinting assays demonstrated that the IE protein binds to the gK promoter sequences from -42 to -26 and from -13 to +12 that overlap the transcription initiation site (+1). These results indicated that the IE protein binds to the transcription initiation site of the gK promoter sequences...
Guthrie AJ, Stevens KB, Bosman PP.Equine-2 influenza A virus (H3N8) infection first occurred among naïve horses in South Africa in December 1986. The virus was introduced following the importation of six horses from the United States of America. While the release of in-contact horses from quarantine three days after the arrival of these six horses played a role in the rapid spread of the disease in South Africa, other outbreaks of disease were associated with viral introduction by personnel or contaminated instruments. The control measures and implications of the introduction of equine influenza to South Africa are also discu...
Wijesundera WS, Chandrasekharan NV, Karunanayake EH.A sensitive PCR assay for the detection of Setaria digitata has been developed. Two oligonucleotide primers (17 nt) were designed from a previously cloned and characterized tandemly arranged repetitive sequence of Setaria digitata. Using these primers, it was possible to amplify small quantities (100 fg) of S. digitata genomic DNA. A simple procedure, using proteinase K and non-ionic detergent NP 40, was followed to process the host blood samples and mosquitoes harbouring L3 larvae. The sensitivity of the polymerase chain reaction based assay surpasses the microscopic detection and the previou...
Votion D, Ghafir Y, Vandenput S, Duvivier DH, Art T, Lekeux P.Scintigraphical analysis of the ratio of inhalation (I) to perfusion (Q) was designed to determine whether chronic pulmonary disease in horses induced mismatches in I/Q and to assess whether medical treatment would restore an I/Q distribution pattern identical to that of control horses. In addition, the results of the I/Q analysis were correlated with the alveolar-arterial PO2 difference (AaDO2). The I/Q matching found in a group of control horses was compared with the I/Q analysis of a group of diseased horses before and after their clinical signs had been treated. The analysis indicated that...
Brama PA, TeKoppele JM, Bank RA, van Weeren PR, Barneveld A.To determine variations in biochemical characteristics of equine articular cartilage in relation to age and the degree of predisposition for osteochondral disease at a specific site. Methods: Articular cartilage specimens from 53 horses 4 to 30 years old. Methods: Healthy specimens were obtained from 2 locations on the proximal articular surface of the first phalanx that had different disease prevalences (site 1 at the mediodorsal margin and site 2 at the center of the medial cavity). Water, total collagen, and hydroxylysine contents and enzymatic (hydroxylysylpyridinoline [HP]) and nonenzymat...
Frisbie DD, Ray CS, Ionescu M, Poole AR, Chapman PL, McIlwraith CW.To determine whether serum or synovial fluid concentrations of chondroitin sulfate epitope 846 and carboxy propeptides of type II collagen (CPII) can be used to diagnose osteochondral fragmentation (OC) in horses. Methods: 38 horses with unilateral OC of the radiocarpal (n = 31) or intercarpal (33) joints and 8 clinically and radiographically normal horses. Procedures-For horses with OC, serum and synovial fluid concentrations of epitope 846, CPII, and keratan sulfate (KS) were determined, along with synovial fluid WBC counts and total protein concentrations. Serum epitope 846, CPII, and KS co...
Sloet van Oldruitenborgh-Oosterbaan MM.Hyperkalaemic periodic paralysis(HYPP) is characterized by intermittent episodes of muscular tremor, weakness, and collapse, and is probably caused by abnormal electrolyte transport in the muscle cell membrane. During an episode of HYPP, most animals are severely hyperkalaemic. HYPP is a hereditary disease and occurs only in American Quarter horses or crossbreds. Because these horses are now being imported into the Netherlands, HYPP should be included in the differential diagnosis of horses showing signs of muscle tremor, paresis, or paralysis. The present article reviews the literature on HYP...
Hobo S, Ogasawara Y, Kuroki Y, Akino T, Yoshihara T.To characterize surfactant protein D (SP-D) isolated from bronchoalveolar lavage fluid (BALF) of healthy horses. Methods: BALF from 10 Thoroughbreds (5 males, 5 females; 26 to 40 months old) without history or clinical signs of respiratory tract disease. Methods: BALF was obtained and centrifuged at 33,000 X g. The supernatant was applied to a mannose-Sepharose 6B affinity column in the presence of calcium, and the bound protein fraction was analyzed by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblot analysis; amino acid composition was determined and partial seque...
González G, Castro B, Massaldi H.Equine chorionic gonadotrophin (eCG) is a hormone of practical value in veterinary medicine and animal production. Here we report a novel preparation procedure based on its direct adsorption onto anionic-exchange resins in a batch-wise mode. The active plasma is previously conditioned to reduce pH and ionic strength to required levels. After the adsorption stage, a 90% recovery of the initial eCG is achieved, with a concentration factor of about 50 and an enrichment factor around 500, with high preservation of biological activity. Further purification is carried out by cation-exchange column c...
Banks EM, Kyriakidou M, Little S, Hamblin AS.Leucocytes in the lung epithelium play an important role in the ability of an animal to respond appropriately to inhaled pathogens. The distribution of lymphoid and myeloid cells associated with the lung epithelium was examined immunohistochemically throughout the respiratory tract of four horses, comprising two adults from an abattoir, one pregnant mare, and her fetus (in the final stage of gestation). Cross and tangential cryosections were labelled with monoclonal antibodies against T-cell, B-cell, macrophage/dendritic myeloid cell, and major histocompatibility Class (MHC) II surface antigen...
Walker C, Perotti VM, Love DN, Whalley JM.The abortigenic effects of equine herpesvirus 1 (EHV-1) strain HVS25A, given intranasally, were assessed in pregnant BALB/c, C57BL/6J and Quakenbush mice at day 16 of pregnancy. All EHV-1-infected BALB/c mice showed clinical signs typical of EHV-1-induced disease, together with evidence of abortion. However, although there were fetal and neonatal deaths in some C57BL/6J and Quakenbush litters, the respiratory and systemic effects of EHV-1 infection in the dams were inconsistent. BALB/c dams were then inoculated at day 15 of pregnancy with either EHV-1 or rabbit kidney (RK) cell lysate (control...
Render JA, Common RS, Kennedy FA, Jones MZ, Fyfe JC.Three Quarter Horses, a stillborn filly (horse No. 1), a female fetus aborted at approximately 6 months of gestation (horse No. 2), and a 1-month-old colt that had been weak at birth (horse No. 3), had myopathy characterized histologically by large spherical or ovoid inclusions in skeletal and cardiac myofibers. Smaller inclusions were also found in brain and spinal cord and in some cells of all other tissues examined. These inclusions were basophilic, red-purple after staining with periodic acid-Schiff (both before and after digestion with diastase), and moderately dark blue after staining wi...
Payne SL, La Celle K, Pei XF, Qi XM, Shao H, Steagall WK, Perry S, Fuller F.The Wyoming strain of equine infectious anaemia virus (EIAV) is a highly virulent field strain that replicates to high titre in vitro only in primary equine monocyte-derived macrophages. In contrast, Wyoming-derived fibroblast-adapted EIAV strains (Malmquist virus) replicate in primary foetal equine kidney and equine dermis cells as well as in the cell lines FEA and Cf2Th. Wyoming and Malmquist viruses differ extensively both in long terminal repeat (LTR) and envelope region sequences. We have compared the promoter activities of the Wyoming LTR with those of LTRs derived from fibroblast-adapte...
The Journal of infectionMarch 25, 1999
Volume 38, Issue 1 22-23 doi: 10.1016/s0163-4453(99)90023-3
McCormack JG, Allworth AM, Selvey LA, Selleck PW.Determination of potential infectivity of a new paramyxovirus equine morbillivirus (EMV) from horses to humans and humans to humans as a result of two outbreaks in Queensland which involved 23 horses and three humans. Methods: Seroepidemiological testing using neutralizing and immunofluorescing antibodies on people with variable levels of exposure to infected horses and humans. Results: All serological testing on a total of 298 individual contacts was negative. Conclusions: While the three human cases of EMV were probably infected as a result of very close contact with horses, these data sugge...
Sellon DC, Russell KE, Monroe VL, Walker KM.Seven ponies were infected with the virulent wild-type Wyoming strain of equine infectious anaemia virus (EIAV). Infection status was monitored by serum reverse transcriptase activity, rectal temperature, and complete blood count. Preinfection serum and serum obtained during the initial febrile episode following infection were assayed for interleukin 6 (IL-6) activity. Postinfection IL-6 activity was significantly increased as compared to preinfection values. The magnitude of increase in IL-6 was positively correlated with reverse transcriptase activity (an indirect measure of viraemia) but wa...
Johnson PJ, Mrad DR, Schwartz AJ, Kellam L.Outcome and complications associated with administration of moxidectin gel to 3 foals < 4 months old are described. Two foals became comatose but survived following supportive treatment. One foal died following loss of consciousness associated with moxidectin administration. Risk of moxidectin overdose exists, because horse owners often fail to read or comprehend the package insert instructions pertaining to use of the syringe-locking mechanism. In addition, moxidectin should not be administered to foals < 4 months old, because it is likely that treated foals will become comatose.
Brandstetter J, Stanek C, Hinterhofer C.The use of handmade particulate reinforced alloy horseshoes (MMC metal matrix composites) was tested in a field study on 15 riding and draught horses. All horseshoes have been tempered after having been manually forged and tested concerning their surface imperfection. Forging temperature ranged between 350 degrees and 420 degrees C. Horseshoes in series A consisted of particulate reinforced wrought alloy (22% Al2O3 in alloy matrix). 11 shoeing periods with a duration of mean = 49.7 days (sd = 13.6) were evaluated. Horseshoes in series B consisted of particulate reinforced foundry alloy (20% Si...
Otto P, Elschner M, Schulze P, Prudlo J, Schrader R.The commercially available immunoassay "OnSite Rotavirus" was used for the detection of animal rotaviruses in 113 faecal samples. The sensitivity of the test was 88% and the specificity 96% compared with reference methods (EIA, EM). This test would detect approximately 4.4 x 10(6) to 1.8 x 10(7) virus particles per ml. The presence of virus could be demonstrated in fresh faecal samples from cattle, horses and pigs within a few minutes. The rotaviruses of group A were identified independently of the virus serotype. Further results and additional problems of using this test kit are described.
Littlejohn A, Bowles F.Pressure curves obtained by cardiac catheterization of the pulmonary artery, right ventricle and right atrium of 9 horses and ponies with chronic obstructive pulmonary disease (COPD) were compared with those similarly recorded from 6 clinically normal control subjects. The mean pulmonary peak systolic, pulmonary minimum diastolic and ventricular peak systolic pressures of the COPD subjects were significantly higher (P less than 0,01) than the corresponding mean pressures of the clinically normal control subjects. The mean pressure calculated from pressure curves obtained from 8 Thoroughbreds i...
Gao Y, Hannan MA, Murata K, Rajabi-Toustani R, Nambo Y.Equine-Assisted Therapy (EAT) is gaining popularity. Ultrasound examination is used to decrease the abortion rate in horses. In this study, to monitor fetal well-being throughout the gestation for EAT, we measured fetal heart rate (FHR), fetal eye orbit (FEO), fetal gonad length (FGL), fetal kidney length (FKL), and the combined thickness of the uterus and placenta (CTUP) by ultrasonography in pony mares. Additionally, we measured the plasma progesterone (P4) and estradiol (E2) concentrations in pregnant horses using enzyme immunoassay. The FGL peaked at week 32 and then decreased to term, and...
Moeller BC, Flores L, Clifford A, Alarcio G, Mosburg M, Arthur RM.Methylphenidate is a powerful central nervous system stimulant with a high potential for abuse in horse racing. The detection of methylphenidate use is of interest to horse racing authorities for both prior to and during competition. The use of hair as an alternative sampling matrix for equine anti-doping has increased as the number of detectable compounds has expanded. Our laboratory developed a liquid chromatography-high-resolution mass spectrometry method to detect the presence of methylphenidate in submitted samples. Briefly, hair was decontaminated, cut, and pulverized prior to liquid-liq...
Köhne M, Ille N, Erber R, Adib Razavi MS, Walter I, Aurich C.Progestin concentration in plasma during the early luteal phase is crucial for endometrial function and conceptus development. We hypothesized that periovulatory gonadotrophin treatment via support of luteal function affects endometrial gene expression in horses. Effect of age was analyzed as well. Shetland mares (n = 8, age 4-25 years) were assigned to the following treatments during five consecutive cycles in alternating order following a cross-over design: treatment hCG/-: preovulatory injection of hCG, but no gonadotrophin injection at detection of ovulation, treatment -/hCG: no preovulat...
Fielding CL, Magdesian KG, Carlson GP, Rhodes DM, Ruby RE.To apply the principle of sodium dilution to calculate the changes in the extracellular fluid (ECF) volume (ECFV) and intracellular fluid volume (ICFV) that occur during dehydration and rehydration in horses. Methods: 8 healthy horses of various breeds. Methods: Horses were dehydrated over 4 hours by withholding water and administering furosemide. Saline (0.9% NaCl) solution was administered IV during the next 2 hours (20 mL/kg/h; total 40 mL/kg). Horses were monitored for an additional hour following IV fluid administration. Initial ECFV was determined by use of multifrequency bioelectrical i...
Weerasinghe CU, Learmonth GS, Gilkerson JR, Foote CE, Wellington JE, Whalley JM.The envelope glycoprotein D of EHV-1 (EHV-1 gD) is essential for virus infectivity and entry of virus into cells and is a potent inducer of virus-neutralizing antibody. In this study, truncated EHV-1 gD (gDt) was expressed with a C-terminal hexahistidine tag in E. coli using a pET vector. Western blot analysis using an anti-gD monoclonal antibody demonstrated the presence of gDt bands at 37.5, 36, 29.5 and 28 kDa. The immunogenicity and protective efficacy of partially purified gDt was compared with gD expressed in insect cells by a recombinant baculovirus (Bac gD) using a BALB/c mouse model o...
Labens R, Blikslager A.Methods of 3D wound imaging in man play an important role in monitoring of healing and determination of the prognosis. Standard photographic assessments in equine wound management consist of 2D analyses, which provide little quantitative information on the wound bed. Objective: 3D imaging of equine wounds is feasible using principles of stereophotogrammetry. 3D measurements differ significantly and are more precise than results with standard 2D assessments. Methods: Repeated specialised photographic imaging of 4 clinical wounds left to heal by second intention was performed. The intraoperator ...
Flood PF, Jong A, Betteridge KJ.The oviducts of 24 mares were examined to determine the site of retention of unfertilized eggs. The ampullary-isthmic junction regions of 42 of the 48 oviducts were serially sectioned and examined histologically. The remaining parts of the oviducts were flushed and the flushings searched microscopically. Of 45 eggs located, 40 were in the sectioned segments of 24 oviducts and only 5 were in the flushings. All but one of the sectioned segments contained prominent masses of material obstructing the lumen, but these were apparently not the direct cause of egg retention since eggs were found on bo...
Jackson K, Kelty E.Equine peripheral caries is a common condition characterized by demineralization and degradation of the clinical crown of equine cheek teeth. The condition can cause significant pain and morbidity, particularly in severe cases. Recent studies indicate that the condition is driven by environmental conditions within the mouth, as only the clinical crown of the tooth is affected (the reserve crown below the gingival margin remains unaffected). It is hypothesized that peripheral caries is driven by changes in oral pH, with risk factors for the condition including the intake of high-sugar feeds (oa...
Villar E, Calvo P, Cabezas JA.1. Peripheral blood serum alpha-L-fucosidases have been studied from various mammalian species: Sus scropha var domestica L. (pig), Capra hircus L. (goat), Bos taurus L. (bull, races Morucha and Charolais), Equus caballus L. (horse) and Equus asinus L. (donkey). 2. Fluorimetric and spectrophotometric procedures were used for determination of alpha-L-fucosidases. 3. alpha-L-Fucosidases were more active towards fluorescent substrates than towards chromogenic substrates. 4. pH optima values of the enzymes are: (A) 5.5 for sera from all above-mentioned species when fluorescent substrates were empl...
Neto LM, Andraus MH, Salvadori MC.A method is described for the qualitative and quantitative determination of phenylbutazone and oxyphenbutazone in horse urine and plasma samples viewing antidoping control. A horse was administered intravenously with 3 g of phenylbutazone. For the qualitative determination, a screening by HPLC was performed after acidic extraction of the urine samples and the confirmation process was realized by GC-MS. Using the proposed method it was possible to detect phenylbutazone and oxyphenbutazone in urine for up to 48 and 120 h, respectively. For the quantitation of these drugs the plasma was deprotein...
Bleyaert HF, Madison JB, Bailey JE, Johnson CM.Six ponies divided into two groups of three were used in a double crossover study design. Group 1 ponies had a small intestinal resection and anastomosis performed using a biofragmentable anastomosis ring (BAR); group 2 ponies had a hand-sewn small intestinal resection and anastomosis using a Gambee suture pattern. Approximately 30 days later, all ponies had a second celiotomy and anastomosed segments were removed. Group 1 ponies had a hand-sewn anastomosis performed and group 2 had a BAR. The anastomotic sites were collected at necropsy approximately 30 days later. Anastomosed intestinal segm...
Heyneman RA.The subcellular distribution of the superoxide-forming enzyme in horse polymorphonuclear leukocytes was investigated. After activation of the cells with sodium oleate, a relatively stable and NAD(P)H-dependent oxygen consumption and superoxide production was found in association with the plasma membranes. The pH dependence displayed an optimum near neutrality. The apparent Km values were 38 x 10(-6) mol/l for NADPH and 1,560 x 10(-6) mol/l for NADH, suggesting that NADPH is the physiological donor. The rates of oxygen uptake, O2- production, and NADP consumption were consistent with the stoich...
Burn JF, Portus B, Brockington C.The equine carpus has a well-defined limit to joint extension at approximately 180 degrees . During locomotion however, the carpus hyperextends during stance phase. Hyperextension is resisted by the carpal bones and ligaments, and it has been proposed that large increased hyperextension might relate to potentially damaging stress levels in the carpus. The aim of this study was to investigate the relationship between peak hyperextension of the carpus (PCE) and speed during locomotion on the level and on an incline. Five Thoroughbred horses were exercised on a treadmill at speeds between 1.8 and...
Jönsson L, Beck-Friis J, Renström LH, Nikkilä T, Thebo P, Sundquist B.Ten aborted foals, diagnosed as infected with Equine Herpes Virus 1 (EHV-1) on histopathological criteria, were examined for the presence of EHV-1 using immunohistology as the investigative instrument. The primary reagent was an antiserum specific for viral envelope glycoproteins. Immunohistology localised EHV-1 to areas of liver necrosis and to the cytoplasm of infected Kupffer cells and hepatocytes. Cytoplasmic immunolabelling was also prominent in reticular cells of the red pulp of the spleen and in intact and degenerated bronchiolar epithelium. Cytoplasmic immunolabelling was seen in morph...
Davis JL, Gilger BC, Spaulding K, Robertson ID, Jones SL.A 9-year-old Trakehner gelding was examined because of right exophthalmus. Clinical findings included a lack of menace response in the right eye, reduced direct and consensual right pupillary light reflexes, ventrolateral strabismus of the right eye, mild right-sided facial asymmetry, a head tilt to the left, and increased extensor tone in the right limbs. Findings were suggestive of a multifocal lesion affecting the right forebrain; right optic, oculomotor, and facial nerves; and left vestibulocochlear nerve. Ultrasonographic examination of the right eye revealed a vascular retrobulbar mass. ...
Genetzky RM, Schneider EJ, Butler HC, Guffy MM.Arthrodesis of the proximal interphalangeal joint in horses, with 2 screws crisscrossing the joint, was compared with arthrodesis achieved by placement of 3 screws crossing the joint parallel to the long axis of the bone. The comparison was made by means of radiography, gross and histologic examinations, and motion evaluation. Additionally, the fused 1st and 2nd phalanges resulting from each method were subjected to breaking forces. Motion evaluation and direct examination of the fused area demonstrated that either procedure can be used to achieve arthrodesis consistently, and the breaking pro...
Urschel KL, Geor RJ, Hanigan MD, Harris PA.Stable isotope infusion methods have not been extensively used in horses to study protein metabolism. The objectives were to develop infusion and sampling methodologies for [1-(13)C] phenylalanine and apply these methods to determine whether the addition of supplemental amino acids to a control diet affected whole-body phenylalanine kinetics in mature horses. Arabian geldings were studied using a 6-h primed (9 μmol/kg), constant (6 μmol · kg(-1) · h(-1)) i.v. infusion of L-[1-(13)C] phenylalanine, with blood and breath sampled every 30 min, to measure whole-body phenylalanine kinet...
Fidani M, Pompa G, Mungiguerra F, Casati A, Fracchiolla ML, Arioli F.After the detection of low concentrations of prednisolone in racehorse urine samples collected at Italian racetracks, a study was initiated to investigate the accuracy of the analytical protocol used and the possible endogenous origin of detected prednisolone. Methods: Multiple reaction monitoring (MRM) MS(2) acquisition with a triple quadrupole (n = 780) and full scan MS(2) and MS(3) (n = 180) acquisition with a linear ion trap were checked. As a further confirmation, ten urine samples were analysed by high-resolution mass spectrometry (HRMS). Results: The study showed the difficulty of ident...
Grünig G, Hulliger C, Hermann M, Winder C, von Fellenberg R.Bronchopulmonary lavage was performed in 10 healthy horses and in 39 horses with chronic pulmonary disease. The predominant cell types were macrophages in healthy horses and neutrophils in severely diseased horses. Procoagulant activity (PCA) was detected in all 32 cell-free supernatants examined and in all 49 unpurified cell suspensions. Cells were separated by centrifugation on discontinuous gradients prepared either with Percoll or with Metrizamide. Macrophages were enriched in subpopulations of low density. Neutrophils could not be purified by density gradient centrifugation using either g...
Pusterla N, Jackson R, Mapes SM, Noland J, Stenbom RM, Gebhart C.The humoral immune response and fecal shedding of Lawsonia intracellularis was investigated in 20 weanling foals following intra-rectal administration of frozen-thawed or lyophilized avirulent live L. intracellularis vaccine. Foals received either 30 mL frozen-thawed or lyophilized vaccine intra-rectally, given twice, 4 weeks apart. Serum samples from each foal were collected every 4 weeks for 16 weeks following the first vaccination and tested for anti-L. intracellularis specific IgG by immunoperoxidase monolayer assay. Rectal swabs were collected every other day following the first vaccinati...
Yamauchi S.The horse fetal adrenal gland was shown to begin to increase in weight from about the end of the 4th month of pregnancy when the fetus has a crown-rump length of about 20 cm. Growth then proceeds steadily to term but, in contrast to the adult horse, the medulla remains thicker than the cortex throughout fetal life. The cortex also becomes established around 20 cm crown-rump length and at the same time the glomerular and fascicular zones become distinguishable. In contrast the reticular zone is not differentiated until around 50 cm crown-rump length. In the fetal adrenal cortex, the fascicular ...
Gunn HM, Fraher JP.The incidence of sarcocysts was examined in postural, propulsive and respiratory muscles from 74 horses ranging in age from mid-gestation to 14 years post-natal. Cryostat sections were stained for myosin adenosine triphosphatase (ATPase) at pH 9.5 and the type of muscle fibre containing sarcocysts was identified. Sarcocysts were found in muscles from three animals, all aged 1 year or more. Counts showed that they displayed no preference for any particular muscle. However, fibres with a high activity for myosin ATPase were preferentially colonized. Transverse sectional profiles of sarcocysts sh...