Veterinary science and horses encompass the study and application of medical, surgical, and therapeutic practices to maintain and improve the health and welfare of equines. This field addresses a wide range of topics, including disease prevention, diagnosis, and treatment, as well as nutrition, reproduction, and behavior. Research in veterinary science for horses often involves understanding the pathophysiology of equine-specific diseases, developing advanced diagnostic techniques, and improving treatment protocols. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary science related to horses, providing insights into the latest advancements and methodologies in equine healthcare.
Fratzl P, Schreiber S, Boyde A.The size and the orientation of the bone salt (mineral) crystals in the cranial and caudal zones in the transverse midshaft section of the equine radius were investigated by small-angle X-ray scattering (SAXS). The results are interpreted as indicating that the crystals had an elongated shape with an average thickness of T = 3.17 +/- 0. 15 nm in the caudal region and T = 3.79 +/- 0.20 nm in the cranial region. Their orientation was predominantly in the longitudinal direction of the bone. There was no preferential orientation within the transverse plane. The distribution of tilt angles with res...
The Journal of physiologyApril 15, 1996
Volume 492 ( Pt 2), Issue Pt 2 587-596 doi: 10.1113/jphysiol.1996.sp021331
Lafortuna CL, Reinach E, Saibene F.1. To investigate the effect of locomotor activity on the pattern of breathing in quadrupeds, ventilatory response was studied in four healthy horses during horizontal and inclined (7%) treadmill exercise at different velocities (1.4-6.9 m s(-1)) and during chemical stimulation with a rebreathing method. Stride frequency (f(s)) and locomotor-respiratory coupling (LRC) were also simultaneously determined by means of video recordings synchronized with respiratory events. 2. Tidal volume (V(T)) was positively correlated with pulmonary ventilation (V(E)) but significantly different linear regressi...
Dobrinski I, Suarez SS, Ball BA.Interaction of spermatozoa with oviductal epithelial cells (OEC) in the oviductal isthmus prolongs the life span of spermatozoa. The hypothesis that the interaction of equine spermatozoa with OEC affects their intracellular calcium concentration ([Ca2+]i) was tested in a sperm-OEC coculture model. Changes in [Ca2+]i in spermatozoa loaded with the fluorescent calcium indicator indo-1 acetoxymethylester (AM) were determined for spermatozoa attached to OEC or to Matrigel, as well as for free-swimming spermatozoa incubated without oviductal epithelium. [Ca2+]i was determined before incubation and ...
Zhang XY, Robinson NE, Zhu FX.We tested the hypothesis that increasing intracellular levels of adenosine 3', 5'-cyclic monophosphate (cAMP) increases acetylcholine (ACh) release from airway parasympathetic nerves. Muscle strips from equine trachea were preincubated for 60 min with 10(-7)M atropine, 10(-6)M neostigmine, and 10(-5) M guanethidine. The ACh release was evoked by electrical field stimulation (EFS, 20 V, 0.5 ms, 0.5 Hz) and measured by high-performance liquid chromatography with electrochemical detection. Agents known to increase cAMP, i.e., forskolin (10(-6) - 10(-4) M), 8-bromoadenosine 3', 5'-cyclic monophosp...
Rodriguez H, Bustos Obregon E.The fertilizing ability of stallion semen was analyzed using fresh and frozen samples, obtained before (June-July) or during (October-November) the breeding season. Thirty ejaculates obtained from 4 stallions were used. The analysis comprises routine seminogram; ATP concentration (Comhaire et al., 1983); subjective and objective motility and sperm velocity (Makler, 1980). Freezing was done following the technique of Martin et al. (1979). Sperm velocity, ATP content and objective motility in ejaculates of subjective motility >50% show values of 14.0 + or - 0.84 mu m s(-1); 4.8 + or - 2.7x10(...
Raudsepp T, Frönicke L, Scherthan H, Gustavsson I, Chowdhary BP.Human chromosome specific libraries (CSLs) were individually applied to equine metaphase chromosomes using the fluorescence in situ hybridization (FISH) technique. All CSLs, except Y, showed painting signals on one or several horse chromosomes. In total 43 conserved chromosomal segments were painted. Homoeology could not, however, be detected for some segments of the equine genome. This is most likely related to the very weak signals displayed by some libraries, rather than to the absence of similarity with the human genome. In spite of divergence from the human genome, dated 70-80 million yea...
Pearson RA, Ouassat M.The age, sex, liveweight and body measurements (heart girth, umbilical girth, height, length from elbow to tuber ischii and circumference of the foreleg cannon bone) of 516 donkeys used to transport goods in Morocco were recorded. There were few donkeys over 12 years of age. For adult donkeys weighing from 74 to 252 kg, the best equation with only one variable for predicting liveweight was: liveweight (kg) = heart girth (cm)2.65/2188. The inclusion of two variables improved the prediction marginally, but the addition of further variables gave little further improvement. The best prediction equ...
Evans MJ, Mulligan RS, Livesey JH, Donald RA.Perifused equine anterior pituitary cells were used to investigate the relationships between the secretion of ACTH and substances known to either stimulate (corticotrophin-releasing hormone (CRH), and arginine vasopressin (AVP)) or inhibit (cortisol) ACTH secretion. The experiments were designed to mimic the hormone milieu present in vivo in the horse, with cortisol (0 or 100 nmol/l) and CRH (0 or 0.02 nmol/l) perifused continuously, and pulses of AVP (10 nmol/l) applied for 5 min at 30-min intervals. In columns perifused with 0.02 nmol CRH/l there was no significant overall effect of 100 nmol...
Morvan B, Bonnemoy F, Fonty G, Gouet P.Total number of bacteria, cellulolytic bacteria, and H2-utilizing microbial populations (methanogenic archaea, acetogenic and sulfate-reducing bacteria) were enumerated in fresh rumen samples from sheep, cattle, buffaloes, deer, llamas, and caecal samples from horses. Methanogens and sulfate reducers were found in all samples, whereas acetogenes were not detected in some samples of each animal. Archaea methanogens were the largest H2-utilizing populations in all animals, and a correlation was observed between the numbers of methanogens and those of cellulolytic microorganisms. Higher counts of...
Woldemeskel M, Gebreab F.A survey of Sarcocystis was conducted in cattle, sheep, goats, donkeys and chickens. A total of 671 haematoxylin-eosin (H-E) stained muscle tissue samples, including diaphragm, masseter, cardiac and oesophageal musculatures were examined. Additionally, cardiac muscle samples from 40 fetuses were included. An infestation rate of 93% in sheep, 82% in cattle, 81% in goats, 16.6% in donkeys and 6.6% in chickens was noted. The infestation rate of diaphragm, masseter, cardiac and oesophageal musculatures seems to be similar. None of the 40 fetal heart muscle samples from bovine, ovine, caprine and d...
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...
Pearson RA, Lawrence PR, Smith AJ.Draught animal research carried out by scientists at the Centre for Topical Veterinary Medicine (CTVM) in Edinburgh and overseas is reviewed and the major findings are reported. The remit for the work has been to provide basic information on draught animals which can be applied by researchers and extension workers to their own geographic situations. Instrumentation is described which has been designed and manufactured to assist in the measurement of draught animal performance, particularly work output and energy consumption. Energy requirements of cattle, buffaloes and equids for work and ways...
Chopineau M, Stewart F.Reverse transcription-PCR was used to clone the coding region of the donkey (Equus asinus) glycoprotein hormone alpha-subunit transcript from pituitary gland RNA. The donkey alpha-subunit sequence demonstrated considerable identity with the horse (97% at the nucleotide level), confirming the very close evolutionary linkage between these two species. The predicted amino acid sequence revealed that the donkey alpha-subunit has the same unusual C-terminus as the horse alpha-subunit, when compared with all other mammalian alpha-subunits, including a Tyr-His transposition between positions 87 and 9...
Nouri-Sorkhabi MH, Agar NS, Sullivan DR, Gallagher C, Kuchel PW.The phospholipid classes of erythrocyte membranes and plasma from several domestic animals and marsupials were quantified by 31P NMR using detergents. Washed erythrocyte samples were thoroughly haemolysed by tip-sonication and dissolved in sodium cholate; plasma samples were dissolved in Triton X-100. The species studied were: common wombat (Vombatus ursinus), black-striped wallaby (Macropus dorsalis), bandicoot (Isoodon macrocarpus), Eastern grey kangaroo (Macropus giganteus), Tammar wallaby (Macropus eugenii), sheep (Ovis aries), goat (Capra hircus), cattle (Bos taurus), horse (Equus caballu...
Willemen MA, Savelberg HH, Jacobs MW, Barneveld A.In many Western European countries rocker-toed shoes are applied routinely in sound horses. This is in contrast to most Anglo-Saxon countries where rocker-toed shoes are used almost exclusively for corrective or orthopaedic shoeing. The purposes of rocker-toed shoes are to hasten or facilitate breakover, or to encourage breakover to occur at the centre of the toe. This study compares the biomechanical effects of rocker-toed shoes with standard flat shoes in twelve sound Dutch warmblood horses, using a modified CODA-3 gait analysis system and a force plate. The variables analysed were speed of ...
Desmecht D, Linden A, Amory H, Art T, Lekeux P.Fifty-eight healthy horses were studied during five sporting events of various intensities and durations, namely show-jumping (n = 6), cross-country in a three-day event (n = 30), trotting races (n = 7), galloping races (n = 7) and endurance rides (n = 8). Venous blood samples were collected at rest and immediately after exercise and analysed for plasma cortisol (CORT) and lactate (LA) levels. The experimental procedure was the same throughout the investigation so as to permit a reliable comparison between the five types of exercise. The type of event significantly affected both the resting (p...
Fourie LJ, Kok DJ, Krugel L, Snyman A, Van Der Lingen F.Karoo paralysis, caused by feeding Ixodes rubicundus females, is a major disease of small stock in South Africa. Control methods currently practised are almost exclusively chemical based. To limit overdependance on chemicals, vegetation management was investigated as a possible method for control, to be incorporated in an integrated tick management system. Laboratory and field experiments were conducted to determine, firstly, the extent of vertical migration and survival of ticks on long and short copper rods which simulated grasses as questing substrates; secondly, the infestation burdens of ...
Back W, Schamhardt HC, Barneveld A.In purchase examinations or at studbook selection sales the locomotor apparatus of horses is judged both at walk and trot. To evaluate whether kinematics of the walk are related to the locomotion at the trot, fore and hind limb movements of a group of 24 26-month-old warmbloods were recorded at walk and trot on a treadmill (1.6 and 4 m/s) using a modified CODA-3 gait analysis system. The intralimb coordination patterns at walk and trot were compared, and temporal and spatial variables of these gaits were related. Stride and stance durations (s) were shorter at the trot, while the stance distan...
Davankar SP, Deane NJ, Davies AS, Firth EC, Hodge H, Parry DA.Since horses bred for the racing industry are subject to rigorous training procedures there is a real need to understand how the stresses experienced by their tendons and ligaments in vivo relate to the major load-bearing elements-the collagen fibrils. Consequently, an age-related study has been made of the collagen fibril diameter distributions of nine ligaments in and around the equine carpus. This is the first stage of a larger study aimed at understanding the ultrastructural changes that occur as a result of exercise. Most of the ligaments showed a bimodal diameter distribution at maturity...
Mizobe M, Kondo F, Kumamoto K, Terada T, Nasu H.Rapid and quantitative analytical methods for bilirubin using high-performance liquid chromatography (HPLC) with UV detection were developed for samples from equines at a meat inspection site. Sharp HPLC peaks for bilirubins, unconjugated bilirubin (UCBL) and conjugated bilirubin (CBL), were obtained using a simple mobile phase of methanol:0.5 M Tris-HCl buffer (65:35, v/v, pH 7.4). A variable wavelength detector set at 450 nm, 0.01 AUFS and a recorder set at 4 cm/min were used for detection. Peaks for UCBL and CBL occurred at 7.1 min and 4.9 min, the lower limits of detection ranged between 0...
Basic life sciencesJanuary 1, 1996
Volume 64 17-27 doi: 10.1007/978-1-4615-5847-7_2
Bacon GE.The familiar extremes of crystalline material are single-crystals and random powders. In between these two extremes are polycrystalline aggregates, not randomly arranged but possessing some preferred orientation and this is the form taken by constructional materials, be they steel girders or the bones of a human or animal skeleton. The details of the preferred orientation determine the ability of the material to withstand stress in any direction. In the case of bone the crucial factor is the orientation of the c-axes of the mineral content-the crystals of the hexagonal hydroxyapatite- and this...
Fraser DG, Bailey E.Single-strand conformational polymorphism (SSCP) gel electrophoresis and DNA sequencing were used to characterize the second exon of the horse DRB homologue as well as to identify eight new DRB alleles. The SSCP gels presented a complex pattern, with phenotypes exhibiting between 4 and 13 bands. The DRB SSCP patterns were studied for two families (6 to 13 bands per pattern). For both families, the patterns showed simple Mendelian inheritance. The polymerase chain reaction products from two individuals possessing homozygous major histocompatibility complex (MHC) alleles by descent were cloned a...
Bucci TJ, Hansen DK, LaBorde JB.Two of five pregnant rabbits gavaged with purified fumonisin B1 at 1.75 mg/kg/day died, one after 9 and one after 13 doses. Microscopic examination revealed focal small hemorrhages in cerebral white matter in both animals, with malacia and hemorrhage also present in the hippocampus of one. The lesions were bilateral. Both animals also had marked degeneration of renal tubule epithelium and of hepatocytes. Apoptosis was the dominant degenerative change in kidney and liver. Fumonisin is known to cause leukoencephalomalacia and hemorrhage in equines, but CNS changes associated with exposure to fum...
Peham C, Schobesberger H.Knowledge of load effects is crucial for the understanding of the aetiology and pathogenesis of equine back problems. Objective: To investigate different load scenarios of the equine back, such as being ridden or increased muscle tone, using biomechanical simulations. Methods: Kinetic and kinematic data of 15 sound horses and the electromyelograph of their long back muscles were recorded. A biomechanical simulation model was used for simulations under different biomechanical scenarios (ridden/unridden, localised increased stiffness) using ADAMS. Results: The vertical forces acting through a ri...
Hernández-Jáuregui P, Sosa A, González-Angulo A.Equine spermatozoa were obtained from ejaculates of young stallions. The seminal plasma was removed and the sperm pellets washed three times with 0-15 M-NaCl solution before final centrifugation at 4500 g for 15 min. The pellets were fixed in a mixture of 2-5% glutaraldehyde in 0-1 M-cacodylate buffer, pH 7-4, with 0-5% Alcian blue and post-fixed in 1% osmium tetroxide with 1% lanthanum nitrate; other samples were treated with ruthenium red. All samples were dehydrated in ascending concentrations of ethanol, embedded in araldite and thin sections examined in an electron microscope. Electron de...
Van Huffel XM, Varner DD, Hinrichs K, Garcia MC, Strzemienski PJ, Kenney RM.A photomicrographic method for evaluation of stallion spermatozoal motility was developed, and spermatozoal image and velocity characteristics were defined. The photomicrographic method was compared with visual estimation of motility in the same semen sample over time. Using photomicrography, velocities and percentages of individual spermatozoal image characteristics were determined. Although there was a high correlation between results of the 2 methods, results of the photomicrographic method were more repeatable than were those of the visual method.
Ball BA, Altschul M, Freeman KP, Hillman RB.Trophoblastic vesicles have been used to study early embryonic development and maternal recognition of pregnancy in domestic animals. The purpose of this study was to characterize the formation of trophoblastic vesicles from Day-12 to Day-16 equine conceptuses. Conceptuses (n = 19) were collected nonsurgically from mares, the capsule was removed, and the conceptus (trophoblast and inner cell mass) was dissected into 2- to 4-mm fragments. Conceptus fragments were cultured in either Ham's F10 (HF10) or Minimum Essential Media (MEM) with 10% fetal bovine serum (FBS) in 24-well plates. Plates were...
Ginther OJ.The estrous cycles of heifers and mares are used for illustrating pitfalls at the animal level in research in reproductive biology. Infrequent monitoring for characterizing the change in hormone concentrations or for detecting a reproductive event can be a pitfall when the interval for obtaining data exceeds the interval between events. For example, hourly collection of blood samples has shown that the luteolytic period (decreasing progesterone) encompasses 24 hours in heifers and mares. Collection of samples every 6-24 hours results in the illusion that luteolysis requires 2-3 days, owing to ...
Schusser GE, White NA.To determine the number of myenteric plexuses and neurons in the large colon of clinically normal horses and whether the number was decreased in the large colon of horses with colon disease. Methods: Prospective study. Methods: Colon samples from 15 clinically normal horses and 31 horses with colon disease. Methods: Samples were obtained, fixed, and stained with H&E. The number of myenteric plexuses and neurons and longitudinal muscle thickness were determined in each segment of colon for clinically normal horses. Counts for segments were compared with each other and with counts in the sam...
Ganiev I, Alexandrova N, Aimaletdinov A, Rutland C, Malanyeva A, Rizvanov A, Zakirova E.One of the major problems observed in veterinary practice is articular cartilage injuries in animals. In terms of agriculture, it leads to their culling from the herd, even if they are highly productive animals. With companion animals, owners usually have to decide between euthanasia or long-term sometimes lifelong treatment of the injury by a veterinarian. The use of mesenchymal stem cells (MSCs) for the treatment of cartilage injury in veterinary medicine is based on the good results observed in preclinical studies, where large animals have been used as experimental models to study the regen...
Kania M, Mikołajewska D, Marycz K, Kobielarz M.The aim of this research was to assess the effect of diet supplementation with zinc and copper, in different chemical forms (organic and inorganic), on the mechanical properties of the hair of healthy English thoroughbred horses. Hairs were taken from 18 horses which had been fed with oats and hay for a period of 110 days. Twelve of the horses had been additionally given a daily dose of 700 g of highquality 44-ingredients Fohlengold St-Hippolyt muesli made by Muhle Ebert Dilheim. Six of them had received the muesli-containing organic zinc and copper (OS), while the other six horses had receive...
Fock U, Jockusch BM, Schubert WD, Hinssen H.The actin-binding protein gelsolin is highly conserved in vertebrates and exists in two isoforms, a cytoplasmic and an extracellular variant, generated by alternative splicing. In mammals, these isoforms differ only by an N-terminal extension in plasma gelsolin, a short sequence of up to 25 amino acids. Cells and tissues may contain both variants, as plasma gelsolin is secreted by many cell types. The tertiary structure of equine plasma gelsolin has been elucidated, but without any information on the N-terminal extension. In this paper, we present topographical data on the N-terminal extension...
Väihkönen LK, Pösö AR.To study in standardbred horses interindividual variation in the influx of lactate into red blood cells, venous blood samples were collected from 89 horses from 2 wk to 9 yr of age. For 62 horses, the rate of influx was normally distributed with a mean rate of 4.09 nmol.mg protein-1.min-1 at a lactate concentration of 10 mM, and the respective value for the other 27 horses was 0.58 nmol.mg protein-1.min-1. At 30 mM of lactate, the rates were 8.71 and 1.97 nmol.mg protein-1.min-1, respectively. This bimodal distribution was independent of age. In horses with high transport activity, the monocar...
Sancler-Silva YFR, Silva-Junior ER, Fedorka CE, Scheeren VFC, Cavalero TS, Papa PM, Alvarenga MA, Dell'Aqua JA, Papa FO.The aim of this report is to describe a new methodology to successfully treat stallions diagnosed with urethral rent. Four stallions of ages ranging from 7 to 12 years (median 9) with hemospermia were admitted for clinical evaluation, breeding soundness examination, and urethroscopy for inspection of the urethra and vesicular glands. Once the presence of urethral rent was identified and/or other sources of hemorrhage were excluded, a topical treatment was performed with 4% Policresulen solution (Albocresil). The treatment was carried out by infusing 100 mL of the solution into the lumen of t...
Caetano AR, Bowling AT.Insulin-like growth factor 1 (IGF1) regulates growth and metabolic functions in vertebrates. A dinucleotide repeat sequence located at the promoter region of the IGF1 gene has been reported in several vertebrate species and may affect the control of the transcriptional activity of this gene. The genotypes of animals from seven horse breeds were determined in order to study the potential association of allelic forms of this microsatellite with adult body size differences found in domestic horses. Among these breeds, five alleles were found. Breed-specific differences in adult body size could no...
Condon V, Wilson B, Fleming PJS, Kennedy BPA, Keeley T, Barwick J, McGreevy P.Feral horses, also known as brumbies, are widely distributed across Australia with some populations being managed largely by human intervention. Rehoming of suitable feral horses following passive trapping has wide community acceptance as a management tool. However, there is little information about the number and relative economic value of feral horses compared with cohorts in the riding horse market. We examined 15,404 advertisements of horses for sale in 53 editions of Horse Deals, published from February 2017 to July 2022. Despite the considerable media attention and public scrutiny surrou...
Slater MR, Hood DM, Carter GK.A descriptive and matched case-control study of laminitis was conducted in 7 private practices and at the Texas Veterinary Medical Centre (TVMC) between May 1992 and July 1993. Out of 108 horses with laminitis, 19 acute (49%) and 20 chronic (51%) cases were seen in private practice and 16 acute (23%) and 53 (77%) cases at the TVMC. Gastrointestinal disease was the most common problem in 19/35 horses (54%), occurring just prior to the onset of acute laminitis in all hospitals. Among all horses in the study, most commonly used drugs were phenylbutazone (68%), acepromazine (34%), dimethyl sulphox...
Colas C, Popot MA, Garcia P, Bonnaire Y, Bouchonnet S.LC/ESI-MS n methods have been previously set up to detect the administration of (i) Harpagophytum and (ii) preparations containing a plant capable of anti-stress properties: Eleutherococcus senticosus. Harpagoside has been found to be the main indicator of Harpagophytum administration in the horse. These methods have been applied to a large number of horse urine samples of various origins. Regarding the detection of Harpagophytum administration, harpagoside, harpagide and 8-para-coumaroyl harpagide were detected together in only one sample out of 317. Eleutheroside E was found to be the main i...
Grossi B, Canals M.We analyzed the morphology and the walk-trot and trot-gallop transition velocities of nine juvenile horses and compared them with their mothers. We also compared the relative stride length and the duty factor of the juveniles with respect to adults at three equivalent trotting speeds (Froude numbers 0.5, 0.75, and 1.0), to determine dynamic similarity. Juveniles had a negative allometry in their leg bones, mainly because of little size changes of the distal portions. The negative allometry of extremities allows juveniles to increase stride length without increasing step frequency, which can be...
Turek B, Potyński A, Wajler C, Szara T, Czopowicz M, Drewnowska O.Diaphyseal fractures of the III metacarpal bone represent 22% of all fractures of the long bones in horses. Treatment of such cases is difficult. The most popular solution used in these types of fractures is two plates applied directly to the bone surface, but they are not applicable on contaminated and infected fractures. External fixators are quite commonly used in human medicine, although in veterinary practice there is no typical stabilizer designed for the treatment of diaphyseal fractures of the III metacarpal bone so far. In this study, an external semicircular fixator of our own design...
Lawler DF, Brazil TJ, Dagleish MP, Watson ED.This study investigated the chemotactic activity of equine CL at different stages of the oestrous cycle. The purpose of this was to ascertain whether luteal tissue itself contributes to the massive influx of leucocytes around the time of natural and induced luteal regression. Corpora lutea were collected at different stages of dioestrus and after treatment with PGF2alpha. Culture medium harvested after incubation of luteal tissue for 20 h was chemotactic for both polymorphonuclear and mononuclear cells in late dioestrus (before functional regression) as well as after natural and induced luteal...
Cí·¯ord D, Woodhead A, Muirhead R.The potential of short-cutting cycle, high temperature-dried alfalfa as a source of calcium for horses was determined by means of a 4 x 4 Latin square digestibility trial using four thoroughbred horses (mean liveweight 531 kg). The four dietary treatments were timothy hay alone, 33 per cent alfalfa and 67 per cent timothy hay, 67 per cent alfalfa and 33 per cent timothy hay, and alfalfa alone. Significantly more calcium and magnesium were absorbed from the alfalfa than from the hay. Phosphorus absorption appeared to be unaffected by treatment. Alfalfa calcium was more available than timothy ha...
Dumasia MC, Houghton E.1. Isomers of 3,17-dihydroxyandrostan-16-one, 3,16-dihydroxyandrostan-17-one and androstane-3,16,17-triol have been identified as urinary metabolites of testosterone in the horse. 2. Following XAD-2 extraction of urine samples, Sephadex LH-20 chromatography was used to separate the extract into conjugate groups. Metabolites obtained after hydrolysis of the conjugates have been investigated by g.l.c.-mass spectrometry. 3. Testosterone, 3,17-dihydroxyandrostan-16-one and 3,16-dihydroxyandrostan-17-one were found only in the sulphate fraction. 5 alpha-Androstane-3 beta,17 beta-diol, and two isome...
Hagen J, Brouwer J, Lux S, Weiske F, Jung FT.The aim of the current in vivo, observational study was to investigate the effects of different hoof manipulations on landing duration (LandD), location (IC) and angle of initial contact (IC) in the front feet of horses. A novel, hoof-mounted, inertial measurement unit sensor system (IMU) was used. Ten sound, crossbred horses were fitted with an IMU sensor at the dorsal hoof wall and examined barefoot and after trimming. Additionally, the application of 120 g lateral weights and 5° medial side wedges as well as steel, aluminium, egg bar, and lateral extension shoes were tested. Horses were gu...
de Rezende MPG, de Souza JC, Carneiro PLS, Bozzi R, Jardim RJD, Malhado CHM.Evaluating phenotypic diversity makes it possible to identify discrepancies in aptitudes among animals of different genetic bases, which is an indicator of adaptive or selective differences between populations. The objective of this work was to evaluate the morphofunctional diversity of 452 male and female adult equines (Arabian, Quarter Mile, Pantaneiro, and Criollo breeds, and undefined crossbreeds of horses and mules) raised in the Pantanal biome (Brazil). Linear measurements were performed to estimate conformation indexes. Initially, a discriminant analysis was performed, regardless of the...
Combarnous Y, Salesse R, Garnier J.Pregnant mare serum gonadotropin exhibits a dissociation at acid pH as shown by the drop of s20,w values from 3.52 S at pH 8.1 to 2.52 S at pH 2.0. The dissociation is accompanied by an absorbance change with a maximum at 287 nm and a parallel loss of both follicle-stimulating hormone (FSH) and luteinizing hormone (LH) activities as followed by radioreceptor assays. The apparent pKa of the acid transition is 3.45 with an extremely slow and temperature-dependent rate at pH 2.0 (1.8 . 10(-4) s-1 at 37 degrees C). By gel filtration the molecular weight of the active hormone is estimated to be 45 ...
Siegel RC, Cathou RE.Complexes of IgM equine anti-dansyl antibodies and different dansyl substituted carriers were tested for their ability to fix complement (C). Only dansyl92-Ficoll and dansyl12-poly-L-lysine were found to be effective. Dansyl13-bovine serum albumin, dansyl127-keyhole limpet hemocyanin, and reduced and alkylated dansyl10-ribonuclease were all ineffective. Lack of C fixation by the dansyl-ribonuclease was not due to lack of antibody-antigen complex formation, since binding at the concentrations employed for C fixation was established. However, in contrast, polymerized dansyl-ribonuclease (polydis...
Smith DF.The future of veterinary medicine is best understood in the context of history. What began as a profession rooted in urban centers in proximity to horses, physicians, and medical schools, was transformed into a land grant-based agricultural profession with the arrival of the internal combustion engine in the early twentieth century. Most of the United States' current veterinary colleges are still located in towns or small cities in the middle section of the country, outside the largest metropolitan areas where most veterinarians practice companion-animal medicine. Throughout veterinarian histo...
McGreevy PD, McLean AN, Keay KA, Thomson PC.Trained responses are said to be under stimulus control when they appear reliably and exclusively on cue. The SMART system is a conceptual, three-dimensional graphic that uses four quadrants to chart a horse's responsiveness to various cues from two reins and the trainer's legs and seat. The current plots have been designed for ridden horses. The models assume that the trainer's cues are bilaterally equivalent, unless the intention is to signal a turn or a lateral movement. The extent to which 'go' signals manifest as straight, forward locomotion reflect the bilateral balance of the horse's re...
Szalai G, Bailey E, Gerber H, Lazary S.The genetic diversity at the ELA DQ beta locus was investigated using polymerase chain reaction and DNA sequencing. Based upon serological methods 16 class II homozygous animals were selected and their genomic DNA was used. A DQ beta gene from an equine cDNA library was also sequenced. Our methodology and the similarity between the genomic and the cDNA sequences suggest that the studied locus is expressed on equine lymphocytes. In the predicted amino acid sequence the most extensive variation is located at residues 56-60. The pattern of these five amino acids is strongly correlated to the sero...
D'Arcy-Moskwa E, Weston L, Noble GN, Raidal SL.Mucosal integrity may be objectively assessed by determination of the absorption of exogenous substances such as sucrose. Gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-mass spectrometry (LC/MS) have been reported for the accurate quantification of low concentrations of sucrose in serum. LC/MS offered the advantage of high sensitivity and mass selectivity without the need for extensive sample derivatization required for GC/MS methods. However, the high polarity and non-volatile nature of the sucrose molecule renders LC/MS techniques challenging. Previously published rep...
Gandini M, Giusto G, Iotti B, Valazza A, Sammartano F.Stapled jejunocecal anastomoses are commonly performed in equine abdominal surgery. They carry higher complication rates compared to handsewn techniques. In human surgery various causes likely to lead to failure of stapled techniques have been evaluated, including staple line failure. Recently Freeman proposed a technique to perform a stapled jejunocecal anastomosis in horses while avoiding blind pouch formation. The aim of this study is to describe a method for stapled side-to-side jejunocecal anastomosis in horses and to compare it with other techniques with computed tomography to assess sto...
McKeever KH, Hinchcliff KW, Schmall LM, Reed SM, Lamb DR, Muir WW.Six untrained mares were subjected to incremental treadmill exercise to examine exercise-induced changes in plasma renin activity (PRA) and plasma aldosterone (ALDO) and plasma arginine vasopressin (AVP) concentrations. Plasma renin activity, ALDO and AVP concentrations, and heart rate (HR) were measured at each step of an incremental maximal exercise test. Mares ran up a 6 degree slope on a treadmill set at an initial speed of 4 m/s. Speed was increased 1 m/s each minute until HR reached a plateau. Plasma obtained was stored at -80 C and later was thawed, extracted, and assayed for PRA and AL...
