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.
Tellhelm B, Fritsch R, Reckels FJ.Requirements for optimal radiography of the horsetoe are described. Examples are given for getting X-rays of high quality under practice conditions, by using special intensifying screens and all the possibilities of radiological technique to guarantee a short exposure time.
Evans DL, Rose RJ.Six detrained Thoroughbred horses performed incremental treadmill tests. Maximal oxygen uptake (VO2max) was measured during exercise by analysis of expired gas. The relationships between oxygen consumption (VO2) and work rate, heart rate (HR), cardiac output (Q), stroke volume (SV) and arteriovenous oxygen content difference [C(a-v)O2] were examined during submaximal and maximal exercise. The relative contributions of blood flow and extraction of oxygen from muscle capillaries were assessed during exercise at VO2max. Mean VO2max was 129.7 +/- 2.9 (mean +/- S.E.M.) ml kg-1 min-1, which occurred...
Houpt KA, Perry PJ, Hintz HF, Houpt TR.Twelve ponies were fed their total daily ration either as one large meal or divided into six small meals. Pre- and post-feeding behavior was recorded six times a day. Blood samples were taken for 30 min before and two hr after the meal. Plasma protein increased from 7.0 to a peak of 7.3 g/dl with small meals and from 7.3 to 8.1 g/dl with large meals, and returned to pre-feeding levels by 90 min post-feeding. Hematocrit rose from 33.3 to 34.1% with small meals and from 33.0 to 36.0% with large meals. These rapid and short-lived increases indicate a decrease in plasma volume. Plasma osmolality r...
Jones I, Madej A.Microtitre plates were coated with antiserum against oestradiol-17 beta-6-(O-carboxymethyl)-oxime bovine serum albumin raised in sheep. The plasma samples (0.2-1.0 ml) were extracted with peroxide-free diethyl ether prepared daily by treatment with Al2O3. The enzyme conjugate was prepared by coupling oestradiol-17 beta-6-(O-carboxymethyl)-oxime to horse-radish peroxidase. The conjugate was chromatographed on a Sephadex G-25 column. The standard curve ranged from 0.37 to 18.40 fmol/well of oestradiol-17 beta. The amount of oestradiol-17 beta causing a 50% reduction of maximum binding was 4.4 fm...
MacCluer JW, Bailey E, Weitkamp LR, Blangero J.We have analysed the effects of ELA alleles and sire-dam ELA incompatibility on two measures of fertility, gestation length and foaling rate, in American Standardbred horses. Using multivariate statistical methods, we corrected for the effects of confounding factors such as dam and sire age, parity, inbreeding, and sire-dam kinship. These analyses revealed substantial differences between Standardbred trotters and pacers in the effects of several confounding factors. There appear to be no ELA effects on gestation length in either trotters or pacers. However our results suggest that there may be...
Ansari HA, Hediger R, Fries R, Stranzinger G.The first gene assignment to a horse chromosome is reported for equine leucocyte antigen (ELA), the major histocompatibility complex of the horse. A cloned DNA sequence derived from a class I gene of the porcine major histocompatibility complex was used as a probe for an in situ hybridization experiment. We present the regional localization of ELA, using this sequence, to equine chromosome 20q14-q22.
Forster HV, Pan LG.In humans alveolar ventilation (VA) is adjusted almost perfectly to the metabolic demands of mild and moderate exercise. For example, in exercise transitions and in the steady state, PaCO2 rarely deviates by more than 1 to 3 mmHg from the value at rest. This near-homeostasis contrasts to most other mammalian species; equines for example, demonstrate a progressive hypocapnia and alkalosis as exercise intensity is increased to moderate levels. In equines, the control systems seem programmed for a specific hyperventilation that contributes to maintenance of PaO2 homeostasis. Generally, during hea...
Kono Y.The antigenic structure of 16 viruses isolated from four horses which were inoculated with a clone of equine infectious anemia (EIA) virus was compared by the neutralization test. The antigenic structure of viruses isolated after development of neutralizing antibody differed from virus to virus. Back mutation of the antigenic structure was also demonstrated by serial passage of the virus in horses. These results suggest that EIA virus is subject to multidirectional antigenic variation. The possibility that the variants originated in the heterologous virus population in the inoculum seems to be...
Silver IA, Eisinger M.We have examined the possible regulatory role of epidermal cell extract(s) (ECE) on skin cells, namely fibroblasts and keratinocytes, both in vivo and in vitro with particular reference to modification of scar formation. In an experimental wound model in pigs, it was found that extracts of cultured human and pig keratinocytes stimulated replication of epidermal cells and their migration from wound edges and remnants of hair follicles and sebaceous glands, together with hair growth, but at the same time suppressed fibroblast proliferation in the dermis. Sections of healing skin wounds that had ...
Boudouard M, Giudicelli J, Sudaka P.A rapid method for preparation of brush border membrane vesicles from a large amount of horse kidney cortex is described. Self-orienting Percoll-gradient centrifugation minimized contamination by microsomal membranes. The characteristics of this preparation were checked by electron microscopy and measurement of L-alanine uptake.
Bell K, Pollitt CC, Patterson SD.Subdivision of equine TfH into two variants, designated H1 (faster) and H2 (slower), has been accomplished by high voltage, thin layer polyacrylamide gel electrophoresis at pH 7.9. Transferrin H1 and H2 have been shown to be controlled by codominant alleles and gene frequencies of the Tf alleles have been determined in the Australian Thoroughbred, Standardbred. Quarter Horse and Arabian Horse breeds.
Mfitilodze MW, Hutchinson GW.The development of the free-living stages and yields of infective third stage strongyle larvae in faeces from a horse with a mixed natural infection deposited on pasture plots were studied over a 2-year period in a coastal area in tropical north Queensland. Two sets of faecal masses (one exposed to, and the other protected from the action of a natural population of dung beetles) were deposited monthly and after 7 days faecal samples were taken for larval recovery and counts. Hatching and development of the free-living stages occurred in faeces on pasture throughout the year. Development was ra...
Guerin G, Varewyck H, Bertaud M, Chasset P.A horse family in which a recombination occurred in the chromosome region coding for the serological specificities of the ELA complex and those of the A blood group system of a mare was further analysed by mixed lymphocyte reaction (MLR) and Southern blot hybridization. This family consisted of a stallion, a mare and five full sibs. The stallion and the mare were heterozygous for internationally recognized ELA specificities while only the mare was heterozygous for the A blood group system. MLR between all members of the family confirmed that the stallion possessed two different ELA haplotypes ...
Allen D, White NA, Tyler DE.The morphologic effects of induced intraluminal hydrostatic pressures (IHPs) of 0, 9, and 18 cm H2O were evaluated in 33 isolated equine jejunal segments. Fifteen segments were distended with Tyrode's solution for 1 hour and nine segments for 4 hours. Tyrode's solution was added as needed to maintain the prescribed pressures. Nine other segments were left undisturbed for 4 hours after the initial distention period. On decompression of the intestinal segments, progressive peristaltic contractions resumed in all segments. Evaluation of intestinal sections by light microscopy and transmission ele...
Hartmann E, Baumgärtner W, Hungerland C.The present report describes the clinical and pathological findings of a one year old foal presented with paralysis of the hind legs. Macroscopically and histologically, a lymphosarcoma in the vertebral body and the adjacent epidural space of T 16, in the spleen and the mesenterial lymph nodes was observed. The adjacent spinal cord showed focal degenerative changes characterized by dilatation of myelin sheaths, swollen axons and few macrophages.
Peterson RB, Goyal SM.A comparative study was carried out to determine the relative sensitivities of eight different cell culture systems to six different herpesviruses of animals. The cells used were: OFL (ovine fetal lung), ML (mink lung), FK (ferret kidney), PTK-2 (potoroo kidney), TEK (turkey embryo kidney), ED (equine dermal), BT (bovine turbinate), and PK15 (porcine kidney). The viruses tested were: PRV (pseudorabies) of swine, CPHV (caprine herpesvirus), IBRV (infectious bovine rhinotracheitis virus), DN-599 strain of bovine herpesvirus type 4, EHV-1 (equine herpesvirus), and CHV (canine herpesvirus). On the...
Littlejohn A, Snow DH.These studies investigated circulatory, respiratory and metabolic responses in four Thoroughbred geldings during the first 400 metres of galloping (mean speed 14.4 +/- 0.38 m.s-1), cantering (mean speed 10.0 +/- 0.61 m.s-1) and walking (mean speed 1.58 +/- 0.05 m.s-1) from a standing start. A radio-controlled device which collected blood samples anaerobically during each 100 m section of the exercise track allowed analyses of changes in and functional relationships of the variables measured. During the 400 m gallop, the mean heart rate (HR) increased from 125 to 201 beats.min-1 and the haemato...
Sweeney RW, Beech J, Simmons RD.Serum concentrations of ticarcillin and clavulanic acid were measured in healthy foals (2 to 6 months old) given the drugs in combination by intravenous and intramuscular routes of administration. Five foals were administered 50 mg of ticarcillin/kg of body weight and 1.67 mg of clavulanic acid/kg, IV. Five foals were administered 100 mg of ticarcillin/kg and 3.33 mg of clavulanic acid/kg, IV, and 4 of those 5 were given the same combined dose IM. The elimination half-life of ticarcillin for intravenous administration was 0.83 hour for the low dosage and 0.96 hour for the high dosage. After in...
Geerken C, Doreau M, Boulot S.Urea, compared with deuterium oxide (D2O) as a reference, was used as a body marker to estimate body water volume in ten 2-month old nursing foals. Plasma urea clearance was regular over 10 h and the R2 of the disappearance curve was between 0.93 and 0.98. Mean urea space was about 4% lower than D2O space, but the standard deviation of the proportion of water in body weight was higher with urea (3.8%) than with D2O (1.6%). Calculated urea entry rate was 49 mg/h/kg LW0.75.
White KL, Thomson DL, Wood TC.An indirect immunofluorescence assay was used to detect the presence of H-Y antigen on equine blastocysts. A total of 33 blastocyst stage horse embryos were collected 6 to 7 days post-ovulation by trans-cervical flush and were immediately evaluated for the presence of H-Y antigen. Additionally, 17 embryos, were collected and cultured for 72 h to the expanded blastocyst stage and similarly evaluated. Embryos were placed in medium containing monoclonal antibodies to H-Y antigen followed by incubation in medium containing 1/10 (v/v) fluorescein isothiocyanate conjugated goat anti-mouse IgM Fc spe...
Clem MF, DeBowes RM, Yovich JV, Douglass JP, Bennett SM.Sixty-eight cases of cortical bone sequestration in 67 equine patients were reviewed with regard to the clinical presentation, method of treatment, and outcome. All lesions were located in skeletal areas with minimal soft tissue coverage, with 53% of them in the metatarsal and metacarpal bones. At the time of admission, 60% of the patients with limb lesions were lame; the majority improved with therapy. After sequestrectomy, there was a trend for surgical wounds which could be managed by primary closure to heal more rapidly (3.8 weeks) than wounds which required second intention healing (6.4 w...
Silberzahn P, Gaillard JL, Quincey D, Dintinger T, Al-Timimi I.A single enzyme in the stallion testis was able to aromatize both testosterone and nortestosterone. This enzyme had a much lower affinity for nortestosterone than for testosterone. In contrast to human placental estrogen synthetase, this enzyme aromatized testosterone and 19-nortestosterone with similar efficiency. The differences observed (effects of monovalent cations, inhibition of androstenedione aromatization by testosterone and 19-nortestosterone and, above all, rate of norandrogen aromatization) suggest that the aromatase in the horse testis is not the same as that in the human placenta...
Jaeschke G, Wintzer HJ.This is a review on Morbus maculosus equorum (purpura haemorrhagica) on the base of literature data and of a case report on 13 own patients. It is shown, that the clinical picture of this disease has not changed within the last 150 years. Clinical main symptoms are haemorrhagic diathesis (petechiae, ecchymosis, suggillations) as well as peripheral edema and fever. The main haematological findings are neutrophilia, mostly going along with shift to the left and lymphopenia. In the last few years thrombocytopenia was also described in some cases. Basic therapeutics are glucocorticoids and penicil...
Thein P, Brown K.Infections with EHV1 can lead to manifestation at the CNS of horses followed by encephalomyelitis and "equine stroke". Horse experiments could confirm the clinical picture and gave links to the potential pathogenesis of the disease. We also have been in the position to isolate and characterize an EHV4 virus out of the brain of a horse with CNS disorders. The two viruses carry different biological properties which obviously dominate the pathogenesis. These properties as well as experimental and field cases are described and different diagnostic tests are discussed.
Stammers JP, Leadon DP, Hull D.The fatty acid composition of the plasma free fatty acid, triacylglycerol and phospholipid fractions was measured in blood and milk samples taken daily from 3 mares and their foals on Days 1-9 post partum inclusive, and from a total of 12 mares and foals on Days 22, 30 and 51. A rise in the plasma concentrations of triacylglycerol and phospholipid similar to that well documented in other species occurred in the neonatal period. Alterations in the composition of the foal plasma phospholipid after birth lend support to the view that the placenta rather than the fetus could be responsible for the...
Stachel CS, Weik HO.Incubation of equine very low density lipoproteins with lipoprotein lipase isolated from horse postheparin plasma resulted in the formation of lipoproteins of a higher density. Lipoproteins isolated after incubation and plasma lipoproteins had a different chemical composition and triacylglycerol fatty acid pattern. In vitro-obtained low density lipoproteins contained substantially more phospholipids and triacylglycerols but significantly less cholesteryl esters than native low density lipoproteins. Comparing the triacylglycerol fatty acid pattern of plasma very low density lipoproteins and in ...
Glazko VI, Oblap RV, Iasinetskaia NA, Kushnir AN.Analysis of albumin, transferrin, receptor to vitamin D, esterase, alpha 1-beta glycoprotein polymorphisms in Przhewalski's horse, Orlov's and Russian trotters, Guzul and Yakutian domestic horse breeds was carried out. The data about similarity of intraspecies differentiation of Przewalski's horse's populations and interbreed distinctions were obtained. Locus-specific particularities of genetic structures of investigated animal groups were revealed.
Margalit R, Schejter A.The specific binding of cations to horse heart ferrocytochrome c has been studied, using the gel
filtration method. The cations investigated were: Mg2+, Co2+, cinchonine and proflavine. The stability
constants are in the range of 5-8 mM-1, and the number of binding sites per protein molecule are
1 to 2. The temperature dependence of the stability constant for the Mg2+-ferrocytochrome system
was measured. The thermodynamic parameters were found to be: dH&s = 4-12 kcal/mol, dG;,,
(25 "C) = -5.6 kcal/mol and AS&, = +57 calxmol-lx K-I.
Yamagishi H, Ide S, Eiki T, Eiguchi Y, Nagamine T, Igarashi Y, Yoshioka I, Matumoto M.ESK cells, a stable cell line derived from a swine embryo kidney, were found to be a good medium for plaque formation of the Prague and Miami strains of equine influenza virus. Factors influencing the plaque formation were investigated and a plaque assay for these viruses was worked out. The method is not only simple enough for routine use, but also is as sensitive as the egg inoculation method. The method was readily adapted for a neutralization test.
Pinna AE, Okada CTC, Ferreira CSC et al. Double ovarian tumor in the mare: case report. Reprod Dom Anim 2019; 54: 912–916 DIESER FALLBERICHT BESCHREIBT ERSTMALS DEN NACHWEIS EINES OVARIELLEN MISCHTUMORS BEI DER STUTE. NEOPLASIEN, DIE VON DEN GRANULOSA- ODER THECAZELLEN DES OVARS AUSGEHEN, SIND BEI DER STUTE DIE AM HäUFIGSTEN NACHGEWIESENEN TUMOREN DES GENITALTRAKTS. ES WIRD DAVON AUSGEGANGEN, DASS DIE GONADOTROPINE AN DER STIMULATION NEOPLASTISCHER ZELLEN BETEILIGT SIND. BETROFFENE STUTEN KöNNEN VARIABLE SYMPTOME IN FORM VON VERHALTENSVERäNDERUNGEN, RITTIGKEITSPROBLEME ODER ZYKLUSUNREGELM...
Satoh M, Higuchi T, Inoue S, Miyakoshi D, Gotoh T.Assessment of the cricoarytenoideus dorsalis muscle (CAD) in horses using a transesophageal ultrasound, computed tomography, or magnetic resonance imaging is available in a limited number of hospitals. This study assessed the ease of ultrasonographic imaging of the CAD using an external transcutaneous technique in horses. After confirmation of the CAD in the cadavers, ultrasonography in twenty live horses was carried out using a transcutaneous approach. In live horses, ultrasonographic imaging of the CAD was possible by pushing the larynx from the opposite side with the other hand. It is belie...
O'Callaghan MW.When performed on selected clinical cases, ventilation/perfusion scintigraphy provides valuable additional information on regional lung function that is not obtainable from conventional thoracic radiographs. This is particularly true of horses with EIPH, COPD, and those suspected of having some form of small-airway disease. For horses with EIPH, the presence of a perfusion deficit on the scan is considered a key prognostic sign, because it is likely in these cases that irreversible bronchial arterial takeover has occurred in the affected areas of lung. Findings from horses with COPD have impro...
Immonen I, Cuervo-Arango J.The reproductive management of mares for frozen semen artificial insemination (AI) can be costly and labor intensive. Predicting the exact time of ovulation can be challenging even when ovulation-inducing drugs are used. The main objective of this retrospective study was to determine whether there was an effect of interval between examinations to detect ovulation on likelihood of pregnancy and early embryonic loss in mares after postovulatory breeding with a single straw of frozen/thawed semen. The second objective was to determine the efficacy of two different drugs (human chorionic gonadotro...
Harris PA, Marlin DJ, Scott CM, Harris RC, Mills PC, Michell AR, Orme CE, Roberts CA, Schroter RC, Marr CM.Four horses (H, J, N and M) undertook a simulated competition exercise test (CET), designed to simulate physiological and metabolic stresses of the Speed and Endurance (S & E) test of a 3-day-event, under 3 different environmental conditions: 20 degrees C/40% relative humidity (RH) (cool, dry [CD] 2 sessions); 30 degrees C/40% RH (hot, dry [HD]) and 30 degrees C/80% RH (hot, humid [HH]) (Marlin et al. 1995a). Venous blood samples for electrolyte and total protein (TP) determinations were collected from indwelling catheters at predetermined time points throughout each CET and initial 30 min...
Groman EV, Schultz RM, Engel LL, Orr JC.In the reduction of 17beta-hydroxy-5alpha-androstan-3-one to the 3beta-alcohol, horse liver alcohol dehydrogenase utilizes the 4-pro-R hydrogen of NADH whereas the 3(17)beta-hydroxysteroid dehydrogenase of Pseudomonas testosteroni utulized the 4-pro-S hydrogen. These observations provide an exception to the rule proposed by Alworth and Bentley that with regard to the paired methylene hydrogens at C-4 of NADH and NADPH "the stereospecificity of a particular reaction is fixed and does not vary with the source of the enzyme preparation". It is also apparent that for these two enzymes, the selecti...
Naden J, Squires EL, Nett TM, Amann RP.The pituitary response to exogenous GnRH was studied in 8 colts of Quarter Horse phenotype from 32 to 96 weeks of age. Colts were from dams treated daily from Day 20 to 325 of gestation with (1) 2 ml neobee oil per 50 kg body weight (controls); or (2) 2 ml altrenogest per 50 kg body weight. GnRH challenges (5 micrograms/kg body weight) were administered every 8 weeks from 32 to 96 weeks of age to estimate pituitary content of LH. Blood samples were collected every 20 min for 4 h before GnRH and 15, 30, 45, 60, 90, 120, 180, 240 and 360 min after GnRH. Serum concentrations of LH and FSH were de...
Dice PF, Cooley PL.This report involves a retrospective study of five horses with an unusual form of progressive peripheral corneal ulcers. These ulcers were located at the perilimbal region of the cornea and spread both centripetally to mid periphery and circumferentially. Lipping of the epithelial edge was observed often. The depth ranged from superficial to mid stroma. Patients ranged from two and a half to eight years, both sexes, and were referred after a variety of antibacterial therapy. Histories were similar in that all ulcers were initially located adjacent to the limbus in one or more quadrants. No tra...
Smith HL, Rosenblatt AJ, Suen WW, Owen H, Ahern BJ.A 6-week-old Thoroughbred filly was presented for evaluation of an expansile mass overlying the right nasal passage and causing respiratory stertor. On skull radiographs, there was a loculated, soft tissue-opaque mass identified dorsal to the right upper premolars and effacing the right nasal cavity. Computed tomography (CT) revealed a locally extensive mass with relatively benign characteristics located centrally on the tooth root apices of the deciduous second premolar (506). The mass extended axially into the right nasal cavity, occluding the meatuses and causing displacement of the nasal s...
Sugita S, Oki H, Hasegawa T, Ishida N.Estimation formulas for the morbidity of horses infected with equine influenza virus by linear regression, logistic regression and probit transformation were developed, using data from the outbreak at the Sha Tin Racing Track in Hong Kong in 1992. Using these formulas, we estimated the equine influenza virus morbidity rates at training centers belonging to the Japan Racing Association (JRA) in October 1997 and in October 1998. In 1998 JRA started a new vaccination program, and every horse must now be vaccinated twice per year. At that time, the vaccine included two US lineage virus strains, th...
Marais J.The vascular architecture of the dermal laminae was studied by scanning electron microscopy of vascular corrosion casts. Ultrastructurally, the laminar vasculature consisted of arterioles, capillaries, venules and veins, arranged in a sheet-like network. Through the laminae, arterioles ran parallel to the solar surface and branched at two levels to form a continuous arteriolar arcade, parallel to the hoof wall. Capillaries originating from these arcades formed hairpin loops joining the marginal vein prior to forming an axially situated venous network. Additional capillaries were also given off...
Irvine CH.Isoelectric focussing of crude extracts of equine pituitaries was used to obtain fractions containing FSH and LH. By comparison with FSH, LH was distributed over a similar but wider pH range indicating more marked polymorphism as determined from their isoelectric point (pI). Molecules with more sialic acid showed lower pI consistent with the concept that sialic acid is the major factor in determining pI and polymorphism in FSH and LH. Appropriate fractions were labelled with 125I, purified further and used in kinetic studies. FSH and LH molecules of similar pI had similar kinetics; however, LH...
Derisoud E, Jouneau L, Margat A, Gourtay C, Dubois C, Archilla C, Jaszczyszyn Y, Dahirel M, Daniel N, Peynot N, Briot L, De Geoffroy F, Wimel L....No abstract available
ElWishy AB.The morphological changes which take place in the sperm during their passage
through the excurrent ducts have been studied in the bull (BRANTON and SALISBURY
1947; HANCOCK 1955; BAILY and SMITH 1958; AMANN and ALMQUIST 1962; GUSTAFSSON and CRABO 1971 ; RAO 1971) and boar (GUSTAFSSON, CRABO and EINARSSON 1970).
Such knowledge is of major importance in understanding the origin and significance
of the different sperm abnormalties as well as providing the basis for proper appraisal
of semen picture and devising useful spermiograms.
The aim of the present work is to study the morphological ch...