Fetal health in horses encompasses the study of the development and well-being of the equine fetus during gestation. This area of research focuses on understanding the physiological processes that occur from conception to birth, including fetal growth, placental function, and maternal-fetal interactions. Factors influencing fetal health can include genetics, nutrition, environmental conditions, and maternal health status. Monitoring fetal health is important for identifying potential complications such as developmental abnormalities or pregnancy loss. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, assessment methods, and implications of fetal health in equine reproduction.
Stewart F, Allen WR, Moor RM.Rat testicular radioreceptor assays specific for FSH and LH were used to determine the FSH:LH ratio of PMSG produced by horse, donkey, mule and hinny conceptuses. Measurements of FSH and LH activities in PMSG produced both in vivo and in vitro by the four types of conceptuses showed that the genotype of the foetus markedly influences the FSH:LH ratio of PMSG. The FSH:LH ratio of PMSG produced by the horse conceptus was around unity whereas the ratio of PMSG produced by the donkey conceptus was as low as 0-2. Furthermore, the hybrid mule and hinny conceptuses both produced PMSG with an FSH:LH r...
Parkes RD, Colles CM.Fetal electrocardiography (FECG) in the mare has been investigated by several workers (Holmes and Darke 1968, Kanagawa and others 1967). This short paper seeks to evaluate previous work, present new findings, and provide a practical technique enabling veterinary surgeons to diagnose singleton and twin pregnancies in the latter part of pregnancy.
Bowen JM, Gaboury C, Bousquet D.A case of uterine torsion is described and its correction under general anaesthesia by a method described by Schaffer for the cow. The degree of torsion was 180 degrees and in a clockwise direction. After correction the foal was found to be alive and in anterior presentation and ventral position; it was born normally 84 days later.
Gleeson LJ, Sullivan ND, Studdert MJ.The inoculation of equine herpesvirus type 3 (EHV3) strain 65/61 into the amniotic cavity of a mare 6-7 months pregnant resulted in abortion 11 days later. Following abortion typical lesions of coital exanthema were not observed in the genital tract of the mare, nor was EHV3 isolated from her. Serological evidence, however, indicated that the mare was infected with EHV3 following inoculation. Grossly the foetal disease was characterised by placentitis, focal ulcerative dermatitis, focal necrosis of the lungs and a striking diptheritic gastritis. Histological findings were interstitial pneumoni...
Vandeplassche M, Bouters R, Spincemaille J, Bonte P.Eight cases of severe dropsy of the fetal sacs have been observed in mares. All were in multiparous mares whose ages ranged from five to 20 years and who were 7 1/2 to 10 3/4 months pregnant. Abortion started spontaneously in four cases and had to be induced in the remaining four by manual dilation of the cervix, rupture of the tough allantochorion and the siphoning off of 120 to 220 litres of allantoic fluid. The amnion was normal. Dystocia, due to uterine inertia, occurred in all eight cases, one hydrocephalic fetus needing fetotomy. All fetuses were alive at delivery although four were tera...
Tervit HR.Recent advances in reproductive physiology offer ways for exploiting superior, female cattle and for manipulating physiological events such as parturition. The techniques involved in these advances and their associated hazards are the subject of this review.
Hafs HD.Often in developing hormone assays, hormones that may interfere with the assay by cross-reaction are not available for testing the validity of the assay. For example, horse TSH was unavailable to test for cross-reaction in an LH radioimmunoassay (RIA). The authors devised an indirect means of accomplishing the same goal, and the evidence from the indirect test of cross-reaction was at least as persuasive as a direct test might have been. Other examples are given of experiments where extensive effort was devoted to validation of steroid RIA, but there were substantial quantitative differences i...
Matheka HD, Coggins L, Shively JN, Norcross NL.EIA virus was purified from equine fetal kidney cell cultures by PEG-precipitation, two sucrose-gradient sedimentations (5-30 per cent) and (25 to 60 per cent) centrifugation, using the immunodiffusion test to follow the procedure. Purified EIA virus had a density (20 degrees C) of 1.162 and a sedimentation constant of S20w=656. electron microscopy revealed a particle of about 100 nm in diameter with a very flexible but usually spherical shape. The dense core may be at various locations inside the membrane bound particle.
Sharma OP.The concentrations of PGF-2alpha in the peripheral blood of five foaling mares were measured by radioimmunoassay. Low levels of PGF-2alpha were detected as early as 1 week before foaling in two of the mares. These levels increased steadily, reaching a peak (1-74 +/- 0-44 ng/ml) during fetal expulsion. A relatively high PGF-2alpha level was found in samples collected 60 min after foaling.
Verberne LR, Mirck MH.The toxicity of parbendazole in different doses was investigated with 52 horses and 16 ponies, in twelve groups. Side effects observed with the anthelmintic were laxation (soft dung, diarrhoea), anorexia, and listlessness. The seriousness of these symptoms depended greatly on the dose used. Half the therapeutic dose of parbendazole (2.5 to 3.75 mg/kg) administered on two consecutive days led, as a rule, to only slight toxic symptoms and proved highly effective with regard to gastro-intestinal nematodes occurring in horses and ponies. The utilisation of "standard powders" (not commercially avai...
Silver M, Comline RS.Mares and fetuses with indwelling catheters in the umbilical and uterine vessels have been used to monitor transplacental blood gas tensions, pH, O2 affinities and the concentration of various metabolites in fetal and maternal blood during late gestation. Measurements of umbilical and uterine blood flows and arterio-venous differences enabled the uptake of O2 and glucose by the fetus and the uterus to be estimated. The present findings are compared with those from other species in comparable conditions.
Spincemaille J, Bouters R, Vandeplassche M, Bonte P.Two females of heterosexual pairs of chimaeric horse twins were fertilized by their co-twin brother and PMSG production examined during gestation. Four pregnancies developed in one mare and two in the other. The levels of PMSG were high in both mares and remained detectable in the peripheral blood until 220 and 265 days of gestation. The fetal membranes of one mare contained remnants of cup secretion with PMSG activity at term. The findings support the thesis of Allen & Moor (1972) that the endometrial cups are of fetal origin and that they are destroyed by immunological mechanisms.
Deanesly R.A histological study of the developing germinal epithelium in the fetal horse ovary shows an enormous wastage of oocytes during the meiotic phase, between Days 73 and 150 of pregnancy. The first groups of oocytes to enter this phage undergo mass degeneration and eventually disappear; few, if any, oocytes develop to primordial follicles. Peripheral oogonia, dividing by mitosis, give rise to more oocytes which pass through the same changes and are also reduced by degeneration, but by Day 150 primordial follicles are fairly common.
Barnes RJ, Nathanielsz PW, Rossdale PD, Comline RS, Silver M.Normal Thoroughbred and catheterized Pony mares and their fetuses were used. Fetal oestrogen and progestagen concentrations in late gestation were much higher than maternal values. A major feature of the umbilical steroid concentrations was a large venous-arterial difference in progestagens and total oestrogens throughout late gestation which may indicate a metabolic cycle in the fetus between progesterone and other steroid metabolites. Metabolites of 20alpha-dihydroprogesterone were present in high concentrations in maternal and fetal plasma. In Thoroughbreds, and to a lesser extent in Pony m...
González-Angulo A, Hernández-Jáuregui P, Martínez-Zedilo G.Light and electron microscopic studies of the gonads of the fetal horse have shown that, in their hypertrophic condition which begins during the 3rd month, the interstitial cells contain large amounts of smooth endoplasmic reticulum, suggesting a secretory activity. Hydroxylating activity which was cytochrome P-450-dependent was observed in the fetal testis and may be involved in steroid biosynthesis.
Samuel CA, Allen WR, Steven DH.Microcotyledons, which are a distinctive feature of the mature equine placenta, are fully formed by Day 150 of gestation. The fetal component of each microcotyledon is developed from several primary folds of trophoblast which become elaborately subdivided as gestation proceeds. These changes are reflected in the structure of the maternal crypts, which receive the fetal villi. Between Days 60 and 150 of gestation the maternal epithelium is greatly reduced in height. No such change occurs on the fetal side of the placenta, but between Days 100 and 250 a progressive indentation of the epithelium ...
Marrable AW, Flood PF.A sequence of ten known-age embryos recovered from Dartmoor Ponies during the first 4 months of gestation is described. Changes in size, shape and vascularity of the conceptus are recorded, as well as the growth and decline of the yolk-sac and the succeeding establishment of the allantochorion. The progress of equine somatogenesis is compared with that of the pig which it lags on average of about 4 days. Some quantitative data are presented.
Morgan DO, Bryans JT, Mock RE.The foal is born without detectable antibody and except for small amounts of IgM is devoid of immunoglobulins. Intrafetal administration of either Venezuelan equine encephalomyelitis virus (VEE-TC83) or ovine erythrocytes elicited IgGa, IgGb and a trace of IgG(T). The fetal blood VEE-TC83 neutralization titre was higher than the neutralization titre elicited by the same preparation in older horses.
Kitchen H, Bunn HF.Studies were made of the O2 affinities of fetal and maternal haemoglobins in the horse, and correlations were found with erythrocytic levels of 2,3-diphosphoglycerate.
Steven DH, Samuel CA.The study of the equine placenta, which began in Venice in 1598, has a long but discontinuous history. Early observations were purely morphological, but new techniques have stimulated a broader and more functional approach. Histological and ultrastructural observations at various stages of pregnancy have shown that the fetal side of the placenta comes to acquire certain features in common with the air-blood barrier of the mammalian lung. These changes may reflect the increasing O2 requirements of the fetus as gestation proceeds.
Moor RM, Allen WR, Hamilton DW.Biochemical and morphological studies were carried out to determine the origin and histogenesis of endometrial cups in mares. A wide range of fetal and maternal tissues were cultured in vitro and their ability to secrete gonadotrophin (PMSG) was monitored. High levels of PMSG were produced in culture only by cells from the restricted area of the equine trophoblast known as the chorionic girdle which is an annular band of highly specialized cells at the junction of the allantois and the regressing yolk sac. The morphological appearance of girdle cells after cultivation in vitro and after alloge...
Allen WR.The influence of fetal genotype upon gonadotrophin (PMSG) and progestagen production in mares and donkeys during the first half of pregnancy was examined. The production of PMSG was greatly reduced in mares carrying mule conceptuses and greatly increased in donkeys carrying hinny conceptuses. Fetal genotype had no obvious influence upon progestagen production in mares, but donkeys carrying hinny conceptuses showed extremely high peripheral plasma progestagen concentrations when serum PMSG levels were elevated. Fetal genotype profoundly influences the intensity and rate of success of the matern...
Comline RS, Hall LW, Lavelle R, Silver M.Methods developed for the insertion of catheters into the umbilical artery and vein and the uterine vein of the pregnancy mare are described. The technique requires careful anaesthesia and the maintenance of normal blood gas tensions, pH and arterial blood pressure. Fetal survival was variable: three mares delivered live foals and six fetuses survived more than 15 days with a maximal period of 41 days. The erythrocytes sedimentation rate (ESR) of the fetal foal was always very low at operation but subsequently increased slightly; a sudden large rise in ESR usually indicated imminent fetal deat...
Nathanielsz PW, Rossdale PD, Silver M, Comline RS.Fetal plasma cortisol concentrations (mean +/- S.E.M.) in ten animals with indwelling umbilical catheters ranged from 13-9 +/- 1-5 ng/ml (227 to 244 days) to 18-1 +/- 2-2 ng/ml (290 to 310 days). Maternal values did not change over this period (15-9 +/- 1-7 ng/ml). Fetal cortisol production rates in two fetuses were 3-6 and 3-8 mg/kg/day at 291 days; there was little placental transfer of cortisol. In three fetuses (319 to 321 days) plasma cortisol values 1 to 10 days before birth were higher (30 to 50 ng/ml) than in any other group, and at birth the values were comparable with those found in ...
Nieman RT, Lamim LI, Del Fava C.Fetal loss in mares can result from a range of causes, including infectious agents or noninfectious conditions such as neoplasia, which may originate from either the fetus or the dam. Among neoplastic conditions, teratomas are rarely reported and, to date, have not been described in the equine fetal testis. Teratomas arise from the partial differentiation of pluripotent germ cells and may occur in young and adult horses, typically in cryptorchid testes. Their gross and histopathological features vary widely between cases. This report describes a rare case of bilateral fetal testicular teratoma...
Deanesly R.During the 340 day pregnancy of the horse, the germ cells in the fetal ovary showed a meiotic prophase which began in days 60-70 and might be prolonged after day 200. Three or four successive oogonial mitotic proliferations passed into the meiotic prophase but the great majority of the oocytes first involved degenerated, and no appreciable numbers of primordial follicles were left behind. At 150 days of pregnancy and again at 197 days, oocytes in early meiotic stages filled the ovarian cortex. Primordial follicles were present, but rare. As the prophase gradually came to an end, groups of oocy...
Lusi CM, Davies HMS.Passive dynamics is an aspect of locomotion which is entirely dependent on the mechanical configuration and linkages of adjacent body segments. Tension distribution along mechanical linkages enables the execution of movement patterns with reduced need for complex neurological pathways and may play a role in reestablishing postural stability following external disturbances. Here we demonstrate a uni-directional mechanical relationship between the equine forelimb, head and neck, which may have implications for balance and forelimb loading in the horse. These observations suggest that forelimb, h...
Becsek A, Schweizer A, Knutti B, Bollwein H.The aim of this study was to compare transrectal two-dimensional (2D) and three-dimensional (3D) ultrasound examination with regards to required time and accuracy of fetal sex determination in early pregnant mares. Methods: For this purpose 47 mares were examined transrectally once between days 58 and 115 of gestation. Initially, the fetal sex was determined by identifying the location of the genital tubercle (GT) or external genitalia using 2D-ultrasound. Subsequently, the ultrasound machine was switched to 3D-mode to obtain images for later computer-based evaluation. Results: The gestational...
Magalhaes HB, Canisso IF.Practitioners are frequently requested to diagnose and stage pregnancy in donkeys with unknown breeding dates; however, scant work has been done to stage pregnancy in the species. Therefore, this study aimed to determine the association between measurements of fetal aortic, thoracic, and heartbeat with gestational age in donkeys carrying and delivering healthy foals. Multiparous Dezhou donkeys (n = 50) ranging from 4 to 16 years were enrolled in the study by 150 days of gestation. Transabdominal ultrasonography coupled with a 3.5 MHz sectorial convex transducer was performed at 30 day-interv...
Henker LC, Lorenzett MP, Piva MM, Wronski JG, de Andrade DGA, Borges AS, Driemeier D, Oliveira-Filho JP, Pavarini SP.Holoprosencephaly is a central nervous system malformation, characterized by incomplete or total lack of division of prosencephalon hemispheres, which is commonly accompanied by craniofacial malformations. A 9-month-gestation aborted American Quarter Horse fetus was submitted for postmortem examination. The fetus lacked haircoat and had severe facial malformations including marked shortening/absence of the maxillary, incisive and nasal bones, bilateral anophthalmia, and pre-maxillary agenesis. The prosencephalon was small and nearly spherical, represented by a single lobe, with no visible sepa...
Lanci A, Ingallinesi M, Morini M, Freccero F, Castagnetti C, Mariella J.Hydramnios is an excessive accumulation of fluid within the amniotic compartment. It is a rare condition in mares, often associated with fetal anomalies. Hydrops of fetal membranes predisposes to the rupture of the prepubic tendon, and many authors suggest the induction of parturition to preserve mare's reproductive career. This report presents the case of a 15-year-old multiparous Quarter Horse mare, referred at 268 days of gestation for suspected hydrops. Repeated ultrasonographic exams confirmed an increase in the depth of the amniotic fluid and reduced fetal viability. During the hospitali...
Ginther OJ, Williams D, Curran S.Transrectal ultrasonic examinations were made in 31 pregnant pony mares once a week during Months 6 to 11. Each uterine horn was divided into 3 approximately equal segments (caudal, middle, cranial). The percentage of examinations with cranial fetal presentation increased (P<0.05) progressively from 58% at Month 6 to 99% at Month 9 and was followed in all mares by entry of the fetal hind limbs into one uterine horn. The mean number of uterinehorn segments with limb parts increased (P<0.05) between each set of consecutive months from Month 6 to Month 10. Initially (Months 7 and 8), retrac...
Cohen ND, Carey VJ, Donahue JG, Seahorn JL, Harrison LR.Epidemiological and pathological findings of 433 late-term abortions associated with the mare reproductive loss syndrome (MRLS) in central Kentucky were identified by reviewing the records of the University of Kentucky Livestock Diseases Diagnostic Center. The distribution of dates of abortion was clustered during a brief period of time, presumably from a simultaneous environmental exposure. The most common pathological findings were microscopic pulmonary lesions consisting of squamous epithelial cells present in alveoli with or without concurrent infiltration of inflammatory cells (neutrophil...
Roberts SJ, Myhre G.Equine twinning, related abortion and progestogen plasma concentrations during the gestation period were reviewed. The supplemental administration of exogenous progesterone apparently prevented impending twin abortions in three mares after midgestation. A single viable twin and a mummified fetus were delivered at term by the mares.
Palm F, Walter I, Nowotny N, Budik S, Helmreich M, Aurich C.In most mammalian species, progestins have a major function in maintaining pregnancy. In humans, the physiologic initiation of parturition bears similarities with inflammatory processes and anti-inflammatory effects of progestins have been suggested to postpone birth until term. To examine if comparable effects exist in the horse, mares were treated with the synthetic progestin altrenogest from day 280 of gestation until parturition (N = 5) or were left untreated as controls (N = 7). Tissue from the amnion (AMN), allantochorion (AC), and endometrium (EM) was collected at foaling and mRNA expre...
Vandeplassche M, Simoens P, Bouters R, De Vos N, Verschooten F.In 214 cases of severe dystocia in mares, of which 141 (66 per cent) were Draught horses, deviation of the head and neck, with or without torticollis, malformed head and limbs were found to be the cause of dystocia. No evidence of a genetic lethal factor was found and torticollis was often combined with scoliosis of the head and, frequently, with malformation of one or more limbs. This is considered evidence of a common aetiology and pathogenesis of the syndrome of malformation. The malformations were found to be associated with an increased incidence of caudal and, particularly, transverse pr...
Mutoh K, Watanabe S, Wakuri H.The glands of pelvis renalis in adult and fetal horses were examined by histochemically. The glandular terminal was divided into two types, intraepithelial gland (IE) and extraepithelial gland (EE) by their locations and histochemical characters. Both glands were composed of mucous cells. The former lay in the transitional epithelium and were stained reddish with galactose oxidase-Schiff (GOS) and mild oxidation-Schiff (MOS), bluish purple with periodic acid-cold thionine Schiff-NaOH-PAS (PCP). The latter distributed in the lamina propria, but was not discovered in the fetus. They were stained...
Kadivar A, Rashidzadeh H, Davoodian N, Nazari H, Dehghani Tafti R, Heidari Khoei H, Seidi Samani H, Modaresi J, Ahmadi E.Accurate diagnosis of foetal sex in pregnant mare is helpful for many breeders, both for private or commercial purposes. In this study, in order to pre-natal foetal sexing in equine, we used TaqMan duplex real-time PCR to detect the specific regions of SRY and TSPY genes on extracted cell-free foetal DNA from maternal blood. Peripheral blood samples from 50 pregnant Arabian mares with singleton foetuses were collected. Cell-free foetal DNA was extracted from maternal plasma, and duplex real-time PCR assays were performed with TaqMan probes and primers. Amplification of glyceraldehyde-3-phospha...
Steven DH, Jeffcott LB, Mallon KA, Ricketts SW, Rossdale PD, Samuel CA.Post-partum placentae and uterine biopsy samples from mares after normal and abnormal foalings are described. After normal delivery there is little damage to fetal or maternal tissues. The villous epitheliochorial palcenta separates cleanly at the maternal-fetal interface and the afterbirth consists almost exclusively of fetal tissue. Uterine involution is well advanced by the 3rd and 4th days post partum and the changes are usually complete by the oestrus 7--10 days after parturition. Placental separation and involution of the uterus appear to proceed normally in malpresented foals and in oth...
Pascoe DR, Stover SM.Twenty-one pregnant mares with single or twin conceptuses between 41 and 65 days of gestational age were allotted to 5 treatment groups. A ventral median celiotomy was performed in all mares. In group-1 mares (3 mares, single conceptus), the uterus and fetus were palpated for 5 minutes. In group-2 mares (3 mares, single conceptus, flunixin meglumine), 250 ml of sterile placental fluid was injected into the nongravid uterine horn. In group-3 mares (4 mares, unicornuate twin conceptuses), group-4 mares (3 mares, unicornuate twin conceptuses, flunixin meglumine), and group-5 mares (8 mares, bicor...
Yamanouchi K, Hirasawa K, Hondo E, Hasegawa T, Ikeda A, Sugawara Y, Matsuyama S, Miyazawa K, Sawasaki T, Tojo H, Tachi C, Takahashi M.The expression of inhibin alpha-subunit mRNA in equine fetal gonads during pregnancy (Days 90 to 300) was examined by means of Northern blot analysis. In all samples examined, a single species of transcript was detected at the size of 1.5 kb. A digoxigenin-labeled antisense cRNA probe specific to equine inhibin alpha-subunit was synthesized and in situ hybridization analysis to locate the inhibin alpha-subunit mRNA positive cells was performed using frozen tissue sections of equine fetal ovary (day 150 of pregnancy) and equine fetal testis (day 180 of pregnancy). In the fetal ovary, positive c...
Mukaiya R, Kimura T, Ochiai K, Wada R, Umemura T.Equine herpesvirus-1 (EHV-1) infection was demonstrated in the lung tissue of seven aborted fetuses by immunohistochemical labelling and polymerase chain reaction. The placentas of the fetuses were also examined by non-isotopic in-situ hybridization for the EHV-1 glycoprotein B (gB) gene. Positive hybridization signals were observed in the cytoplasm of trophoblasts, especially in microcotyledons, of all seven placentas, and in villous epithelium of the allantochorion of six placentas. Despite the presence of EHV-1 RNA, EHV-1 antigens were not detected in placentas by immunohistochemical examin...
Glatzel PS, Kangasniemi A, Belz JP, Lange A.The investigations were done on 108 mares (78 warm-blooded horses, 25 cold-blooded horses and 5 trotters). To pursue the question in the title, progesterone and estradiol values in jugular vein-blood were examined starting from 30 days before the calculated date of parturition until 30 days after that event. In parallel to that Ca/Mg ratio was measured by means of a semiquantitative test-strip in the milk. Clinical signs of the birth, parturition itself and the post partum period were recorded. In respect to the P4 and E2 values it was that the P4:E2 ratio changed towards parturition in favour...
Ginther OJ.After the cessation of equine embryo mobility (fixation) on mean Day 16, the embryonic vesicle is rotated or oriented so that the pole with the embryo proper is opposite to the mesometrial attachment. Orientation involves massage of the vesicle by contractions of the turgid uterine horn and greater thickening of the vesicle at the pole with the embryo proper. Thickening of the dorsal endometrium (encroachment) especially on each side of the mesometrial attachment accounts for a guitar-pick shape of the vesicle when viewed in cross section of the uterine horn. On Days 21-40, the allantoic sac e...
Tsogtgerel M, Murase H, Moriyama H, Sato F, Nambo Y.Late-term fetal loss in horses is a major problem in the horse-breeding industry globally. Abnormal pregnancies should be diagnosed as early as possible to prevent abortions and other gestational problems. According to our previous longitudinal study in healthy pregnant mares, the plasma activin A concentration increases as pregnancy progresses. The aim of the present study was to compare plasma activin A concentrations in healthy pregnant Thoroughbred mares (n=40) with those in pregnant mares that suffered fetal loss or showed abnormal symptoms (n=30) during late gestation. This field study f...
Rook JS, Braselton WE, Nachreiner RF, Lloyd JW, Shea ME, Shelle JE, Hitzler PR.To document and determine changes in the mineral profiles of sera and mammary secretions from a population of periparturient mares. Methods: 18 clinically normal periparturient Arabian broodmares. Methods: Inductively coupled argon emission spectroscopy was used to measure Ca, Cu, Fe, K, Mg, Mn, Na, P, and Zn concentrations in sera and mammary secretions of periparturient mares. In addition, S was measured in mammary secretions. Results: Serum concentrations of Ca, Cu, Fe, K, Mg, Na, P, and Zn remained constant throughout late pregnancy and the first 7 days of lactation. Compared with values o...
Vincze B, Gáspárdy A, Kovács L, Albert E, Kézér L, Baska F, Szenci O.Transabdominal ultrasonography has been shown to be a useful and reliable method for assessing fetal well-being in horses and cattle. To test the applicability of fetal aortic diameter measurement in cattle, 44 late-term pregnant cows and heifers were examined 21 to 0 days prior to calving. Mean fetal aortic diameter was 2.07 ± 0.14 cm and mean fetal heart rate (FHR) was 109 ± 17 bpm. Three dead calves were dissected and their aortic diameter was measured in a water bath. The mean birth weight (n = 44) was 39.9 ± 5.8 kg. There was a significant negative correlation between FHR and fetal aor...
Burns SJ, Irvine CH, Amoss MS.This study was undertaken to determine if fertility could be improved by increasing the interval from foaling to breeding. Forty-two mares, not bred during normal post-partum oestrus, were injected with a prostaglandin analogue on Day 6 or 7 following ovulation. Mares were mated artifically with antibiotic-treated semen during the resulting oestrus and, if necessary, for the following 4 cycles. Their fertility was compared, by cycles/pregnancy and rate of fetal loss, to mares bred by the same methods on 86 normal post-partum oestrous periods. The interval from foaling to the onset of breeding ...
Mitchell ARM, Delvescovo B, Tse M, Crouch EE, Cheong SH, Castillo JM, Felippe MJB, Ainsworth DM, de Amorim MD.A 6-year-old Standardbred mare was presented at 339 days of gestation for investigation of abnormal abdominal distension and ventral edema. Transrectal palpation and ultrasound examination revealed the uterus to be enlarged with an excessive volume of fetal fluid, characteristic of hydrops. Gradual transcervical drainage of 55 L of allantoic fluid over 45 minutes, with concurrent intravenous fluid therapy followed by assisted vaginal delivery, resulted in the birth of a live foal with long-term survival. The birth and long-term survival of a foal from a mare with hydrallantois at term has not ...
Aureli G, Lauria A.The results of a study on interstitial cells of the horse gonads from foetal life to puberty are reported. The morphological (also ultrastructural) histochemical, histophysical and histoenzymological findings both in the organ and in monolayer cultures, clarify the problem of the ontogenesis of these cells showing that: --foetal interstitial cells give origin to "xanthochrome" cells; --"xanthochrome" cells in the prepuberal gonad are continuously renewed; --the same type of cells which in th prepuberal period undergo lipochromic degeneration, differentiate at puberty into Leydig cells in the t...
Allen AL, Myers SL, Searcy GP, Fretz PB.The Hematologic values of 19 equine fetuses between 202 and 238 days gestation were compared with those of their dams. The red blood cell (RBC) count, hemoglobin concentration, hematocrit, and mean corpuscular hemoglobin concentration were significantly lower in fetal blood, while the mean corpuscular volume, mean corpuscular hemoglobin, and red cell distribution width were significantly higher. Mares had a significantly higher nucleated blood cell count than fetuses, and all nucleated cells were leukocytes (WBC). Most WBC in mare blood were segmented neutrophils and lymphocytes. In contrast, ...
Morehead JP, Blanchard TL, Thompson JA, Brinsko SP.To determine features of an early fetal loss (EFL) syndrome and evaluate potential risk factors for EFL in Thoroughbred broodmares on 4 farms in central Kentucky. Methods: Retrospective study. Methods: 288 pregnant broodmares. Methods: Year-2001 breeding records for 288 Thoroughbred broodmares were examined. Early fetal loss was defined as loss of a fetus that was viable at > or = 40 days of gestation but was subsequently lost by 5 months of gestation. Results: Overall 2001 EFL rate was 25% (73/288), median gestational age at time of fetal loss was 77 days, and median date of loss was May 7...
Gupta T, Chatterjee A.Pregnant mare's serum gonadotropin (PMSG) of 10 IU on day 5 of pregnancy induced luteal demise and consequently an absolute resorption of fetuses and placentae resulted on day 16 of pregnancy. Simultaneous regimen of PMSG and indomethacin or cortisone was found to be consistently effective in preventing the luteolytic effect of PMSG. The growth of the fetuses, placentae as well as corpora lutea was found to be parallel to controls. Similarly, shortening of the duration of pseudopregnancy to 10--12 days in the bilaterally hysterectomized rat by PMSG and its retaining the normal duration of 18--...
Webb PD, Steven DH.The adrenal cortex from twelve fetal foals (gestational ages from 61 to 300 days) was examined by light and electron microscopy. Adrenal glands from three newborn foals were also examined by light microscopy. Between 61 and 100 days of gestation the adrenal cortex became organised into two distinct regions, the zona glomerulosa and zona fasciculata, which grew steadily in thickness until the 300th day. Between 300 days and birth there was a dramatic increase in the width of the zona fasciculata. From 200 days a narrow band of compact cells marked the cortico-medullary border. Though these cell...
