Therio final, I

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Therio final, I
2012-12-06 10:38:29
Therio final

Therio final, I
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  1. How long does the mare cycle normally last?
    18-21 days
  2. How long is estrus in the mare, and when does the duration of estrus become shorter?
    4-7 days, estrus is shorter as days grow longer (summer solstice)
  3. When the plasma progesterone exceeds what level, do mares stop showing signs of estrus?
    1-2 ng/ml
  4. How many follicular waves do mares have per cycle?
    usually one
  5. What are the size of ovulatory follicles in the mare?
    30-70 mm
  6. The highest incidence of double ovulations occur in what horse breeds?
    thoroughbred, warmblood, and draft horses
  7. When does the luteal or diestrus phase begin in the mare?
    with the formation of the corpus hemorrhagicum
  8. In the absence of pregnancy, when is PGF2s released from the endometrium in the mare?
    13-16 days postovulation
  9. How does PGF2a reach the ovaries in the mare?
    systemic route
  10. As the photoperiod increases what happens with melatonin, GnRH secretion, and ovarian follicular development?
    melatonin secretion decreases, GnRH secretion increases, and ovarian follicular development becomes more active
  11. When is the peak fertility in the mare?
    summer solstice
  12. What is a mare that has never been bred or never concieved and may be any age?
    maiden mare
  13. What is a mare that foaled during the current breeding season and often have high fertility?
    foaling mare
  14. What is a mare that bred the previous season that did not foal?
    barren mares
  15. What is it called when a mare is diagnosed as pregnant, and then looses the pregnancy?
    slipped mare
  16. When does hCG cause ovulation in the mare when given during late transition?
    48 hours after administration
  17. What drugs can be used in the mare to advance cycling and ovulation during late transition?
    P4, altrenogest, or progesterone and estrogen treatments
  18. What drugs are used for inducing ovulation of a preovulatory follicle in cycling mares?
    hCG and deslorelin
  19. What are the indications for administration of PGF2a in the mare?
    estrus synchronization, persistent luteal function following progestogen treatment to delay estrus, advancing the timing of a second estrus after foaling, induced abortion, treatment of persistent luteal function
  20. Pregnancy rates are higher in mares that ovulate after what amount of time postpartum?
    10 days (and with little or no fluid present in uterus)
  21. When does foal heat occur?
    10 days post breeding
  22. What is the normal gestation length for the mare?
    335 to 342
  23. Foaling before what day is considered abortion?
  24. Which foals, male or female, are carried longer?
  25. What toxins can increase gestation length by 2 weeks to 20 days?
    fescue grass infested with acremonium
  26. What is it called if the birth of a foal occurs at normal gestation length, but the foal is immature and undersized?
  27. The signal for materal recognition of pregnancy in the mare is what?
    fetal-endometrial contact
  28. By what day does the embryonic vesicle stop moving and becomes fixed in place at the base of one horn in the mare?
    day 16
  29. By what day is there full placental attachment in the forms of microplacentomes?
    day 150
  30. What is the function of endometrial cups?
    secrete eCG
  31. If pregnancy is lost, mare aborts, after 36-40 days does not return to estrus until what?
    endometrial cups regress
  32. Ovariectomy in the mare does not cause abortion after what day?
    100-140 days
  33. Why does an ovariectomy in the mare not cause abortion after day 100-140?
    progestins from the fetoplacental unit appear in circulation between 30-60 days and increase to day 300, support pregnancy
  34. When can eCG be detected in the mare?
    40-120 days
  35. When do false positives tests for eCG happen?
    if pregnancy lost after 40 days
  36. When do false negative tests for eCG happen?
    if evaluated before 40 days or after 120 days, common in mares carrying mule fetuses
  37. When does the circulation of estrus peak in the pregnant mare?
    180-240 days
  38. After 4 months, what hormones are present in the pregnant mares urine?
    equilin and equilenin, ring-B saturated estrogens
  39. By what days do estrogen concentrations in blood and urine exceed that of estrus in the pregnant mare?
    60-100 days
  40. What can be monitored to predict imminent foaling?
    change in udder size and secretions, monitoring milk secretions
  41. When does calcium and magnesium concentrations increase in the prefoaling milk?
    las 2-4 days
  42. What are indications for induction of foaling?
    high risk pregnancy, research, teaching, convenience
  43. When does oxytocin cause induction of foaling?
    15-90 min
  44. What drugs can be given to induce foaling?
    oxytocin and prostaglandin
  45. What happens most commonly during parturition, is when the chorion seperates from uterus and red, velvety surface appears at vulva rather than white amnion?
    premature placental seperation, "red bag"
  46. In midgestation, what is the cause of premature placental seperation?
    death of twin, abortion
  47. At parturition, what is the cause of premature placental seperation?
    placental edema caused by late gestational stress, placental edema caused by fescue/endophytes
  48. When are fetal membranes considered retained?
    if not expelled after 3 hours
  49. What are factors that contribute to retained placenta?
    dystocia, uterine trauma/myometrial exhaustion, placentitis, fetomaternal endocrine dysfunction
  50. What are sequelae of Retained placenta?
    metritis, septicemia/toxemia, laminitis, delayed uterine involution
  51. What is the treatment for retained placentas?
    oxytocin, warm saline, systemic/local antibiotics, laminitis tx/prevention
  52. What are the most common postparturient emergencies in the mare?
    uterine prolapse, invagination of uterine horn, uterine rupture, internal hemorrhage
  53. In internal hemorrhage of the mare (post-partum emergency) what artery normally ruptures?
    uterine artery or utero-ovarian artery (right side more common)
  54. What is a major cause of pregnancy loss in the mare, and accounts for 2% of births?
  55. Given a 50% conception rate, the outcomes on breeding a mare on double ovulations may be what?
    no embryos: 25%, one embryo: 50%, twins: 25%
  56. Natural elimination of one twin is more likely if both twins are what?
    adjacent to one another in the same horn (unilateral - 85% reduce to singletons) than if bilateral
  57. If twins are seen at 14 to 18 days, what are the choices the vet has?
    wait to see if one is lost, or eliminate one by pinching
  58. If twins are present at 32 days, what are the choices the vet has?
    abort both before endometrial cups are present, or let them go and see if one is lost in the next month
  59. What are microorganisms that can gain entrance to the uterus via the vagina and cause an ascending placentitis (common in mares w/ poor perineal conformation or small cervical tears)?
    strep, staph, e.coli, pseudomonas, klebsiella, aspergillus, mucor, and rarely yeast
  60. What are signs of impending abortion?
    vaginal discharge, bagging up of the udder, perineal relaxation, U/S evidence
  61. What is the treatment for impending abortion/early parturition in the mare?
    progestagens, antibiotics, isoxuprine (prevent uterine contractions)
  62. Does a bloody vulvar discharge toward the end of pregnancy always mean that the mare has placentitis?
    No, older mares get this due to vaginal varicosity
  63. Why should a vaginal examination of the pregnant mare always be avoided (unless in active labor)?
    could result in ascending placentitis or abortion
  64. What is excessuve fluid accumulation usually within the allantoic or amniotic cavities (rare in mare)?
    hydropic conditions
  65. Why should mares with hydrallantois have their pregnancies terminated?
    can rupture the abdominal wall or prepubic tendon due to increased strain and weight
  66. Why should mares with hydrallantois be bred to a different stallion the next time around?
    possibly hereditable, so guarded pregnancy prognosis
  67. What is the cause of Mare Reproductive Loss Syndrome?
    ingestion of eastern tent caterpillars
  68. What is the most common cause of infectious abortion in the mare during the last half of gestation?
    equine rhinopneumonitis virus (EHV-1,4)
  69. Which equine herpes viruses cause respiratory diseases?
    EHV 2, 4, and 5
  70. Which equine herpes virus cause equine coital exanthema (venereal herpes)?
  71. How is EHV-1 transmissed?
    inhalation/contact with infected secretions and fomites
  72. Initial viral replication of EHV-1 occurs where and is followed by what?
    occurs in upper respiratory tract and is followed by viremia
  73. EHV-1 invasion of what causes placental edema and seperation of the chorioallantosis?
  74. How is EHV-1 diagnosed?
    immunofluorescence or PCR, gross pathology/histology of fetus, neutralization or ELISA of fetal samples
  75. Can paired samples from the mare submitted 2-4 weeks apart confirm EHV-1 abortion?
    no, only useful to confirm acute EHV-1 disease