Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
McKeever KH, Antas LA, Kearns CF.The objective of the present study was to measure plasma endothelin-1 (ET-1) at rest and during exercise in the horse. Six healthy, Standardbred and Thoroughbred mares (5.3+/-0.8 years; 445.2+/-13.1 kg) which were unfit, but otherwise accustomed to running on the treadmill, were used in the study. Plasma ET-1 concentrations were measured using a commercially available radioimmunoassay kit. Horses performed three trials: a standing control (CON) trial where blood was collected from the jugular vein every minute for 5 min; a graded exercise test (GXT) where blood samples were collected at the en...
Van Loon G, Duytschaever M, Tavernier R, Fonteyne W, Jordaens L, Deprez P.We describe the development and the different features of an experimental model of chronic atrial fibrillation (AF) in equines. In four healthy ponies a dual-chamber pacemaker, with an adapted pacemaker program, was implanted transvenously in the standing animal. This adapted pacemaker induced episodes of AF by delivering a 2s burst of electrical stimuli (42 Hz) as soon as sinus rhythm was detected. Simultaneous with a surface electrocardiogram, the intra-atrial electrogram could be recorded to determine the atrial electrogram morphology. Programmed electrical stimulation (PES) was used to det...
French NP, Smith J, Edwards GB, Proudman CJ.The reason for undertaking this study was that postoperative complications of colic surgery lead to patient discomfort, prolonged hospitalisation and increased cost. Potential risk factors for the 6 most common postoperative complications (jugular thrombosis, ileus, re-laparotomy, wound suppuration, incisional herniation and colic) were evaluated using multivariable models. Jugular thrombosis was associated significantly with heart rate greater than 60 beats/min and with increased packed cell volume (PCV) at admission. The risk of postoperative ileus also increased with increasing PCV at admis...
Andrews FM, Reinemeyer CR, McCracken MD, Blackford JT, Nadeau JA, Saabye L, Sötell M, Saxton A.Equine gastric ulcer syndrome (EGUS) represents a major health problem in performance horses. Much debate exists regarding endoscopic gastric ulcer scoring systems and their ability accurately to predict severity or depth of gastric ulcers. The purpose of this study was to evaluate the ability of an endoscopist to count gastric ulcers and predict gastric ulcer severity or depth using 2 endoscopic scoring systems and compare them to the same gastric ulcers see on necropsy and histopathology. Endoscopic examination of the stomach was performed under general anaesthesia on 23 mixed breed yearling...
Back W, Schamhardtt HC, Barneveld A, van Weeren PR.Nowadays, ponies are used more and more for competitive equine sports, driving and racing. The locomotor performance of ponies, however, has been evaluated in only a few kinematic and kinetic studies. To compare the longitudinal development of locomotor characteristics in the pony to the same process in the horse, the kinematics of 23 Shetland ponies were recorded at the trot on a treadmill (3 m/s) at ages 4 and 30 months using a modified CODA-3 apparatus. Furthermore, the influence of specific feeding and training regimes on this development was evaluated. It appeared that stride and stance d...
Korolainen R, Ruohoniemi M.In order to investigate the reliability of ultrasonography in revealing intestinal sand accumulations, the cranioventral parts of the abdomen of 32 horses (age 3-20 years) with signs suggestive of gastrointestinal sand were examined radiographically and ultrasonographically. The amount of sand and its localisation, relative to the ventral abdominal wall, were evaluated radiographically and graded (scale 0-4). Motility of the intestine and whether it was lying against the ventral abdominal wall were evaluated ultrasonographically and the findings summed and graded (scale 0-3) to express the lik...
Van hoogmoed LM, Snyder JR.Thermography is a non-contact, non-invasive technique that detects surface heat emitted as infrared radiation. Because skin temperature reflects the status of underlying tissue metabolism and blood circulation, abnormal thermal patterns can signify areas of superficial inflammation. The objective of this study was to determine if thermography could detect the injection of analgesic and neurolytic agents and surgical palmar digital neurectomy. Procedures evaluated include injection of the lumbar region, suspensory ligaments, tibial nerve, palmar digital nerves, and palmar digital neurectomy. Th...
van Hoogmoed LM, Harmon FA, Stanley S, White J, Snyder J.The objective of this study was to determine if a correlation exists between the presence of nitric oxide and prostaglandin release in the equine ventral colon smooth muscle, since this relationship may accentuate the inflammatory process during intestinal injury. Tissue was collected from the ventral colon, cut into muscle strips oriented along the circular, longitudinal and taenial layers, and mounted in a tissue bath system. Samples of the bath fluid were collected before, following electrical field stimulation (EFS), and following EFS in the presence of L-NAME, a nitric oxide synthase inhi...
Widdicombe JH, Pecson IS.Horses commonly suffer from respiratory diseases associated with excess secretions in the airway lumen, some of which are presumably derived from airway mucous glands. However, these structures have been little investigated in the horse. Accordingly, we describe here the number, distribution and size of equine tracheal mucous glands, and compare the data with similar information for other mammalian species. Two types of gland acini were present. In the thick connective tissue, up to 400 microm beneath the epithelium, gland acini were grouped in thin sheets that, in cross-section, averaged 20 m...
van der Kolk JH, Nachreiner RF, Refsal KR, Brouillet D, Wensing T.Our objectives were to 1) establish ionised calcium (ICa), C-terminal PTH and biologically active PTH (intact molecule) concentrations in blood from normal horses, 2) examine the stability of ionised calcium and acid-base values in stored equine heparinised blood and serum and 3) check the applicability of the formulas based on these parameters in certain disease states. Mean +/- s.d. % ionised calcium in heparinised blood of normal Warmbloods was 51 +/- 2.7 (n = 20) of total calcium, range 1.45-1.75 mmol/l (n = 15) at Michigan State University and 1.43-1.69 mmol/l (n = 20) at Utrecht Universi...
Weimann CD, Thoefner MB, Jensen AL.In a case-control study in colic horses the ability of spectrophotometric measurement of the haemoglobin concentration in the peritoneal fluid supernatant and visual assessment of the colour of peritoneal fluid supernatant to differentiate between surgical and medical treatment of colic was assessed. Based on previous studies, which have found anda association between peritoneal fluid colour and the kind of treatment required, our hypothesis was that the peritoneal fluid haemoglobin concentration would be higher in horses requiring surgical intervention than in horses amenable to medical treat...
Proudman CJ, Smith JE, Edwards GB, French NP.Colic surgery is a frequently performed operation with high postoperative mortality. This study was undertaken to identify variables associated with decreased postoperative survival. We used data from 321 horse years of postoperative survival time to model the probability of survival following recovery from colic surgery. Continuous variables were modelled using a 6 variable, penalised Cox regression model. This demonstrated approximately linear relationships between survival and the following variables: increase in packed cell volume (PCV), intestinal resection length, time to surgery (interv...
Abraham G, Brodde OE, Ungemach FR.In 12 healthy horses, the effects of the beta2-agonist clenbuterol and the glucocorticoid dexamethasone on the lymphocyte beta2-adrenoceptor density and affinity (determined by (-)-[125I]-iodocyanopindolol binding) as well as its responsiveness (assessed by lymphocyte cyclic AMP [cAMP] responses to 10 micromol/l (-)-isoprenaline) were studied. Clenbuterol treatment, 2 x 0.8 microg/kg/day i.v. for 12 days, decreased significantly ICYP binding sites by approximately 30-40%; concomitantly, lymphocyte cAMP response to (-)-isoprenaline was reduced. After withdrawal of clenbuterol, beta2-adrenocepto...
Steinman A, Isoherranen N, Ashoach O, Soback S.Gentamicin pharmacokinetics has not been studied in horses. Pharmacokinetics of gentamicin C1, C1a and C2 components following i.v. administration of total gentamicin at 6.6 mg/kg bwt to 6 healthy mature horses was determined. Significant differences in clearance, half-life (t 1/2), and mean residence time (MRT) between the gentamicin Cia and the 2 other components were found. The total body clearance (CL) of gentamicin C1a was 1.62 +/- 0.50 ml/min x kg and similar to the glomerular filtration rate (GFR) reported for horses. The CL of gentamicin C1 and C2 were 1.03 +/- 0.08 ml/min x kg and 1.1...
Zweygarth E, Lopez-Rebollar LM, Meyer P.Twenty blood samples of zebras (Equus zebra zebra) from the Karoo National Park and the Bontebok National Park in South Africa, all seropositive for Theileria equi, were subjected to in vitro culture to identify carrier animals and to isolate the parasites. Sixteen animals had a detectable parasitaemia in Giemsa-stained blood smears examined before culture initiation, the remaining four animals were identified as T. equi carriers by in vitro culture. Cultures were initiated either in an oxygen-reduced gas mixture or in a 5% CO2-in-air atmosphere. Out of the 20 blood samples, 12 cultures of T. ...
Proudman CJ, Smith JE, Edwards GB, French NP.Postoperative complications and mortality can occur many weeks or months after colic surgery. We are interested in the long-term outcome of these cases. This study documents patterns of mortality and morbidity among 341 horses that recovered from colic surgery March 1998-August 2000. The progress of each horse was rigorously followed by periodic telephone and postal questionnaires. Event time data were recorded for each animal and a total of 321 horse years of survival, together with death from all causes, colic-related death and various postoperative complications. Postoperative survival (of ...
Hillyer MH, Taylor FG, Proudman CJ, Edwards GB, Smith JE, French NP.A case control study was performed to identify risk factors for colic caused by simple colonic obstruction and distension (SCOD) in the horse. Case horses were recruited from 2 veterinary school clinics. Control horses were population based and matched by time of year. A number of risk factors were considered in the following areas: general carer and premises information; exercise information; husbandry information (housing- and pasture-related); feeding information; breeding information; behavioural information; travel information; preventive medicine information and previous medical informat...
Sutton DG, Bahr A, Preston T, Cohen ND, Love S, Roussel AJ.The 13C-octanoic acid breath test has been correlated significantly to radioscintigraphy for measurement of gastric emptying indices in healthy horses. The objective of this study was to investigate the validity of the test for measurement of equine delayed gastric emptying, prior to its potential clinical application for this purpose. A model of atropine-induced gastroparesis was used. Gastric emptying rate was measured twice in 8 horses using concurrent radioscintigraphy and/or breath test after treatment i.v. with either atropine (0.035 mg/kg bwt) or saline in randomised order. Analysis of ...
Lindner A, Dag S, Marti-Korff S, Quiroz-Rothe E, López Rivero JL, Drommer W.The collection of muscle samples in horses to estimate their performance potential, adaptations to training and diagnosis of exertional myopathies is of increasing interest. This study was designed to examine whether repeated biopsying of the gluteus medius muscle at 7 week intervals alters morphology and muscle fibre variables in the sampling area. The gluteus had been biopsied 3 times previously, each biopsy separated by a 7 week interval. Seven weeks after the last biopsy, this study was initiated. Percutaneous needle biopsies were taken from left and right muscles at 2 depths (2 and 6 cm) ...
Locke MM, Penedo MC, Bricker SJ, Millon LV, Murray JD.The progressive loss of colour in the hair of grey horses is controlled by a dominantly inherited allele at the Grey locus (GG). In this study, two paternal Quarter Horse (QH) families segregating for the GG allele were genotyped with a set of 101 microsatellite markers spanning the 31 autosomes and the X chromosome. This genome scan demonstrated linkage of Grey to COR018 (RF=0.02, LOD=12.04) on horse chromosome 25 (ECA25). Further chromosome-specific analysis of seven total QH families confirmed the linkage of Grey to a group of ECA25 markers and the map order of NVHEQ43-(0.24)-UCDEQ405-(0.09...
Reilas T, Katila T.Uterine lavage fluids from postpartum and nonparturient mares were compared to determine when the normal secretory capacity of the postpartum uterus is restored. Lavage fluids were obtained from cyclic nonparturient mares on the second, fourth or fifth day of oestrus, and 3, 8, or 14 days after ovulation (seven mares/sampling day). Twelve intact postpartum mares were sampled 1 to 28 days postpartum (group A: 1, 6, 12 and 20; group B: 2, 8, 14 and 24; group C: 4, 10, 16 and 28 days postpartum; four mares/group). Three ovariectomized (OVX) postpartum mares were sampled as mares in group C. Sampl...
Swinburne JE, Hopkins A, Binns MM.The dominant grey coat colour gene of horses has been mapped using a whole genome scanning approach. Samples from a large half-sibling pedigree of Thoroughbred horses were utilized in order to map the grey coat colour locus, G. Multiplex groups of microsatellite markers were developed and used to efficiently screen the horse genome at a resolution of approximately 22 cM, based on an estimated map length for the horse genome of 2720 cM. The grey gene was assigned to chromosome 25 (ECA25), one of the smaller acrocentric horse chromosomes. Based on the current state of knowledge of conserved synt...
Furr M.Eighteen normal horses were assigned to 1 of 3 treatment groups to investigate the effects of IM or intrathecal (IT) administration of ovalbumin on serum and cerebrospinal fluid (CSF) antibody production. Horses of group 1 were injected intramuscularly with ovalbumin and adjuvant, while horses in treatment groups 2 and 3 received ovalbumin intrathecally or intravenously, followed by IM injection as in group 1. Serum and CSF antibody titers were tested in group I every 30 days for 4 months, while serum and CSF were collected in group 2 and 3 horses at postvaccination day 60. Horses of group 1 (...
Morgan SJ, Van Houten DS.Cells found in the intima and media of the cranial mesenteric artery of a mature mare with chronic arteritis were identified as smooth muscle cells and occurred in association with collagen and elastin fibres. As no fibroblasts were demonstrable within these regions, the smooth muscle cells were the likely source of the extracellular matrix. In contrast, the abnormal adventitis from the same artery contained abundant fibroblasts which are considered to be the source of the adventitial collagen.
Morgan RE, Clegg PD, Hunt JA, Innes JF, Tew SR.The joint synovium consists of a heterogeneous cell population, chiefly comprised of macrophages, and fibroblast-like synoviocytes (FLS). An inter-species co-culture model was developed to examine interactions between these cells. Equine FLS and the canine macrophage line DH82 were differentially labeled using fluorescent markers and results from direct co-culture compared with those from both indirect co-culture, and conditioned media experiments. The transcript expression of IL-1β, IL-6, ADAMTS4, and ADAMTS5 in each cell type were determined using species-specific qPCR assays. Lipopolysacch...
Best LJ, Hendrix DV, Ward DA.To evaluate the tear film osmolality and electrolyte composition in healthy horses. Methods: 15 healthy adult horses. Methods: Each horse was manually restrained, and an ophthalmic examination, which included slit-lamp biomicroscopy, indirect ophthalmoscopy, and a Schirmer tear test, was performed. Tear samples were collected from both eyes with microcapillary tubes 3 times at 5-minute intervals. The tear samples for each horse were pooled, and the osmolality and electrolyte concentrations were measured. The mean (SD) was calculated for each variable to establish preliminary guidelines for tea...
McKeever KH.Exercise places large demands on the equine cardiovascular system which are further complicated by environmental factors. In many respects, performance is limited by fluid and electrolyte stores and the ability to maintain cardiovascular and thermoregulatory stability in the face of severe sweat losses. Studies in the exercising horse have been primarily descriptive or associative, with only a limited number seeking to identify physiologic mechanisms associated with the control of fluid and electrolyte balance. More mechanistic studies are needed to fully understand the integration of the card...
Ronen N, van Amstel SR, Nesbit JW, van Rensburg IB.Renal dysplasia is reported in two adult horses in chronic renal failure. Renal dysplasia, complicated by severe interstitial pyelonephritis, was diagnosed on renal biopsy and confirmed on post mortem examination.
Hallowell GD, Corley KT.Hypertonic saline and hydroxyethyl starches have been proposed as alternatives to isotonic crystalloids for reversal of hypovolemia in horses with colic. However, no direct comparison of these fluids has been performed in a clinical setting. Objective: Preoperative administration of hypertonic saline or pentastarch would produce similar effects on intra operative hemodynamics in horses with colic. Methods: Thirty horses requiring colic surgery were enrolled in this prospective, randomized, open-label clinical trial. Inclusion criteria were owner consent, and at least 2 of 3 clinicopathologic a...
Bramlage LR, Gabel AA, Hackett RP.Five horses with avulsion fractures of the proximal origin of the suspensory ligament were examined for lameness. The horses in the series each had lameness of acute onset; four were severely lame, and one was moderately lame. The condition was difficult to diagnose because commonly used local anesthetic blocks did not result in improvement during the routine examination. Local infiltration of the area with local anesthetic returned the horses to soundness. After a period of rest, varying from a few weeks in the acute injury to 6 months in the chronic injuries, the horses were returned to raci...
Araujo JM, Araújo JV, Braga FR, Tavela Ade O, Ferreira SR, Soares FE, Carvalho GR.Strongyloides westeri is the most prevalent nematode among equines aged up to four months and causes gastrointestinal disorders. The objective of this study was to observe the control of infective S. westeri larvae (L3) by the nematophagous fungi Duddingtonia flagrans (AC001) and Monacrosporium thaumasium (NF34) after passage through the gastrointestinal tract of female donkeys. Twelve dewormed female donkeys that were kept in stables were used. Two treatment groups each comprising four animals received orally 100 g of pellets made of sodium alginate matrix containing a mycelial mass of either...
Medica AJ, Lambourne S, Aitken RJ.This study aimed to determine whether an analysis of stallion ejaculate could accurately predict the likelihood of pregnancy resulting from artificial insemination in mares. This study involved 46 inseminations of 41 mares, using 7 standardbred stallions over a 5-week period at an Australian pacing stud. Semen quality was assessed immediately after collection and again after chilling at ~5 °C for 24 h. The assessment involved evaluating ejaculate volume, sperm concentration, and motility parameters using an iSperm® Equine portable device. After the initial evaluation, a subpopulation of cell...
Pinna A, Martins G, Souza G, Lilenbaum W.The aim of this study was to demonstrate that seroreactivity against Leptospira is significantly associated to the reproductive efficiency of recipient mares of an embryo transfer (ET) programme. A serosurvey was conducted from August 2007 to March 2009 in five herds from Rio de Janeiro, Brazil, with high rates of reproductive failure, as early embryonic death (>12%), abortion (>12%) and perinatal death. Detailed information about the losses was obtained from practitioner. A total of 338 recipient mares were tested by microscopic agglutination test, and 226 (66.9%) were seroreactive, mainly ag...
Hatazoe T, Kubota C, Fujiki M, Misumi K.To evaluate the influence of mating behavior on cardiac function, changes in heart rate (HR), electrocardiogram (ECG), hematocrit (Hct) and serum concentration of alpha-atrial natriuretic peptide (alpha-ANP) were evaluated in 10 clinically sound Thoroughbred stallions before and after mating behavior. The stallions were submitted twice to experimental pseudomating in the same month in 2009 and 2010. Measurements and blood samples were collected at a stable before mating (baseline) and at a covering yard before and after mating. ECG was recorded by a Holter-ECG system. Arrhythmias were detected...
Bras RJ, Redden R.Foot-related lameness is one of the most frequently encountered problems in the equine industry. Therapeutic shoeing is a frequently used preventative discipline for the treatment of many causes of lameness. The primary goal for therapeutic applications is to offset the mechanical limitations and enhance the healing environment. Equine podiatry is a blend of the 2 highly respected professions each contributing to the task at hand, but neither formally educated and trained as collaborative team members with a common thread of podiatry principles.
Pal M.A total of 257 samples (from 51 cattle, 43 buffalo, 32 goats, 25 dogs, 23 horses, 14 fowl, 9 camels, 7 rabbits, 5 donkeys, 4 antelopes, 3 pigs, 2 monkeys, 1 bear and 38 humans, all with cutaneous disorders) were examined for the presence of Dermatophilus congolensis using standard microbiological techniques. Dermatophilus was identified in 14 specimens (5.45%) both by direct microscopy and by cultural isolation of the pathogen from cutaneous specimens. The infection was recorded in 2 humans, 6 cattle, 3 buffalo, 1 goat, 1 horse and 1 antelope. A history of trauma to the skin was evident in 6 o...
Adams R, McClure JJ, Gossett KA, Koonce KL, Ezigbo C.gamma-Glutamyltranspeptidase (GGT) activity in equine urine was measured, using an assay developed for use with serum and was found to be reproducible. The GGT activity was measured in samples prepared by serial dilution of exogenous GGT with equine urine, and the activity was determined to be linear between 21 IU/L and 407 IU/L. The behavior of exogenously added GGT was compared in equine serum and urine. The enzyme behaved similarly in both fluids. The GGT activity was measured in serum and urine samples after storage at -20, 4, and 25 C for 24 and/or 72 hours. Enzyme activity decreased afte...
Daels PF, Shideler S, Lasley BL, Hughes JP, Stabenfeldt GH.Oestrogen secretion was determined by oestrogen conjugate (EC) analysis of urine in three groups of pregnant mares: Group I (N = 6), animals ovariectomized on Day 18-19 of gestation with pregnancy maintained by daily administration of an oral progestagen, altrenogest; Group II (N = 9), untreated, pregnant mares; Group III (N = 5) intact, pregnant mares treated daily with altrenogest. The mean EC concentrations in the ovariectomized mares in Group I increased in a constant linear manner from 17 ng/mg Cr on Day 20 to 291 ng/mg Cr on Day 70, with no apparent surge in oestrogen secretion around Da...
Tavanaeimanesh H, Azarnoosh A, Ashar FS, Dehghan MM, Mohebbi Z, Akbarinejad V, Corley K.The choice of analgesic agents for the horse is limited, and many have side effects that can restrict their use for chronic and prolonged pain. Little information has been published on tramadol and acetaminophen use in the horse. The study evaluated the analgesic effects of coadministration of tramadol and acetaminophen compared to those of each drug individually in a crossover study. The study was performed on six healthy horses each infused with the following over 1 hour: control (normal saline), tramadol, acetaminophen, or both (acetaminophen and tramadol infused together). Nociception (usi...
Buchanan BR, Sommardahl CS, Rohrbach BW, Andrews FM.To determine the effects of a 24-hour infusion of an isotonic electrolyte replacement fluid (IERF) on weight, serum and urine electrolyte concentrations, and other clinicopathologic variables in healthy neonatal foals. Methods: 4 healthy 4-day-old foals. Methods: Prospective study. Methods: An IERF was administered to each foal at an estimated rate of 80 mL/kg/d (36.4 mL/lb/d) for 24 hours. Body weight was measured before and after the infusion period. Urine was collected via catheter during 4-hour periods; blood samples were collected at 4-hour intervals. Variables including urine production;...
Dieckhöfer R.Borna Disease Virus (BDV) is a unique RNA virus, whose organs of manifestation are the brain and blood of animals as well as humans. The infection disrupts certain cell functions, but does not damage the cell structure. The infection with BDV can exist without associated clinical symptoms. Furthermore the majority of natural BDV-infections occur unnoticed without causing symptoms particularly those in connection with only a slight BDV-infection. BDV-infected horses can be detected by an extremely practicable ELISA based on blood samples and developed by the Berlin Working Group under guidance ...
Worthy K, Colquhoun K, Escreet R, Dunlop M, Renton JP, Douglas TA.Plasma prolactin concentrations were measured in mares using an homologous radioimmunoassay. An annual rhythm in plasma prolactin was found, with concentrations higher during the summer than during the winter. In addition to this seasonal pattern, occasional high concentrations of prolactin were seen when concentrations were otherwise basal. Blood samples taken from mares during an oestrous cycle in October-November showed that prolactin values were basal for most of the cycle, with a marked rise in prolactin shortly before the onset of oestrus. This prolactin peak was associated with an incre...
Farinelli F, de Rezende ASC, Fonseca MG, Lana ÂMQ, Leme FOP, Klein BON, Silva RHP, de Abreu AP, Damazio MJ, Melo MM.The Horse Agribusiness Complex is an important activity in the Brazilian agricultural sector. Mangalarga Marchador (MM) is the most numerous breed of horses in Brazil and its temperament and gait characteristics (4-beat stepping gait) allow for the constant growth of the breed and the performance of vs. equestrian activities. The training management currently adopted with MM horses is based on empiricism, and scientific support is necessary to improve the well-being of horses in competitions and maintain the physical integrity of these athletes. Therefore, this study aimed to verify the effect...
Forster HV, Pan LG, Bisgard GE, Flynn C, Dorsey SM, Britton MS.The objective of this study was to determine whether changes in limb motion per se influence arterial CO2 partial pressure (PaCO2) during muscular exercise in ponies. Fifteen ponies were studied at rest and during 8 min of treadmill exercise when the work load was constant or when the work load was increased after the 4th min. Five different treadmill settings were selected to provide for a range of metabolic rate achieved with primary changes in either speed or grade (1.8 mph at 3, 8, and 15% grade; or 3 and 6 mph at 3% grade). The ponies exercised either on all four legs or on only the hindl...
Herzog A, Höhn H, Klug E, Hecht W.In a 7 months old foal with a male pseudohermaphroditism the cytogenetic investigation revealed a XO/XYY-mosaic with a centric fusion of the Y-chromosomes.
Kai M, Hiraga A, Kubo K, Tokurik M.The purpose of this study was to determine whether there was any difference in the stride characteristics between cantering on a flat or inclined treadmill. Five 2-year-old Thoroughbred horses were cantered on a treadmill at 3 different velocities and at 3 different slopes. The sequence of speeds at each slope was chosen at random and 16 mm cinefilms at 300 frames/s were taken from a lateral view at a distance of 15 m from the treadmill to record the linear and temporal data. On the slope, stride length, stride duration, stance duration and swing duration did not change. However, midstep lengt...
Driancourt MA, Prunier A, Palmer E, Mariana JC.To define ovarian follicular kinetics in the equine ovary during anestrus and the breeding season, the follicular population of pony mares was investigated at mid-anestrus and at the beginning and end of the breeding season. There was a clear effect of season on the exit of reserve (primordial and initiated) follicles since at the beginning of the breeding season we noticed a higher mitotic index for the smaller preantral follicles, leading to an accumulation of small and medium antral follicles. In contrast, the ovaries sampled during anestrus or at the end of the breeding season were very si...
Slocombe RF, Covelli G, Bayly WM.Normal Standardbred horses were given an incremental exercise test on a horizontal treadmill to evaluate the influence of exercise on gas exchange, resistance, dynamic compliance and inertance of the respiratory system. The exercise test consisted of 2 min exercise steps at each of the following speeds: 2.4 m/sec (walk), 4.5 m/sec (slow trot), 7.0 m/sec (fast trot) and 10 m/sec (gallop). At rest and after 1 min of exercise at each step, airflow, tidal volume, respiratory frequency, pharyngeal, mid-oesophageal and transdiaphragmatic pressures and arterial blood gas tensions were measured. The s...
