Exam #3: Repro Pt. 1 Flashcards

1
Q

Structure and tubular tract of mare repro tract

A
  • Two ovaries: bean shaped
  • Tubular tract = paired oviducts, paired uterine horns, single uterine body, cervix (external os and fornix), vagina, vestibule, and vagina
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2
Q

What’s special about the equine ovary?

A

Inverted compared to other ovaries = inner cortex, outer medulla, ovulation fossa is internal (where ovulation occurs, includes surface germinal epithelium)

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3
Q

Where do we interrupt oocyte migration for oocyte transfer?

A

Infundibulum, before it enters the oviduct

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4
Q

Where does fertilization occur?

A

Ampulla of the oviduct

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5
Q

Where, in the female repro tract, is the sperm reservoir and deep insemination site?

A

Oviductal papilla, at the utero-tubal junction

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6
Q

Where is the more superficial and common insemination site?

A

Just past the cervix? - Go dorsal in the vagina (otherwise you’ll inseminate the bladder)

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7
Q

Extent of the vagina and vestibule, anatomically

A

Vagina = from external os of cervix to vestibulovaginal junction (up to the transverse fold, covering the urethral opening)

Vestibule = vestibulovaginal junction to vulva (includes urethral opening)

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8
Q

Clinical importance of clitoral sinuses and clitoral fossa

A
Sinuses = dorsal to clitoris
Fossa = ventral to clitoris

*Places that can potentially harbor venereal pathogens

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9
Q

Three physical barriers protecting the uterus

A

1) Vulva
2) Vestibulovaginal junction
3) Cervix

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10
Q

Position of epididymal tail and testes in the stallion

A

Testes = inguinal position

Epid. tail = should be caudal (not caudal? May indicate torsion)

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11
Q

What tissue surrounds the urethra and forms the glans penis/corona glandis?

A

Corpus spongiosum penis

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12
Q

Accessory sex glands in the stallion

A

> Have all three = vesicular glands, prostate, and bulbourethral (difficult to palpate) glands
- Ductus deferens become the ampulla

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13
Q

What important structures are on the tip of the stallion penis?

A
  • Urethral process = ventral

- Fossa glandis and urethral sinus = dorsal (where smegma can be impacting, harbor veneral disease)

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14
Q

Definition and clinical signs of puberty

A

> First achievement of the capability of successfully sexually reproduce

+ Maturation of genital organs
+ Development of secondary sex characteristics
+ Psychosocial interaction

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15
Q

Age of puberty of fillies and stallions

A
  • Filly = 15 months (range 8-37)

- Stallions = 2.5-4.5 years (start producing sperm at 19 months)

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16
Q

Things that influence puberty (6)

A
  • Breed = light weight horses come into puberty sooner than heavy draft breeds
  • Season of birth (born late in year, have to wait another year to come into heat)
  • Nutrition
  • Management
  • Systemic disease
  • Parasites
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17
Q

When do we start breeding fillies?

A

2-3 years (ideal) time, depending on breed and purpose

Any earlier (< 2 yrs) = irregular cycles, higher abortion rates

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18
Q

Seasonality and cyclicity of mares? Four phases?

A

Long day seasonal breeders (majority have winter anestrus) - POLYESTROUS

1) Spring transition
2) Ovulatory seasons
3) Fall transition
4) Anestrus

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19
Q

What hormones play a role in the seasonality of the mare’s cycle?

A

Increasing light/photoperiod = seen by retina, decreased secretion of melatonin from pineal gland = signals hypothalamus to secrete GnRH and pituitary gland to secrete LH, FSH = follicular growth, and increasing estrogen

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20
Q

Main events of the spring transition

A

> After winters solstice

  • Late winter = increasing FSH but inadequate LH to ovulate
  • Increasing steroidogenesis (estradiol) and follicle development, secrete LH
  • End of transition = sufficient LH to ovulate (first ovulation of the year)
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21
Q

Official birthday date program, and operational/physiologic breeding seasons

A
  • Birthday date (official) = all born on Jan 1st
  • Operational breeding = Feb 15th-July 15th
  • Physiologic = May to October
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22
Q

Use of artificial lighting in the spring transition

A

> > 14-16 hours

  • Minimum - 14.5 hours, 16 hrs is more common
  • Increase light in 30 min increments
  • Exposure in the evening&raquo_space; more important than morning
  • Start on Dec 1st, to ensure she’s cycling by Feb 15th (8-10 wks to first ovulation)
  • GOAL = make the spring transition earlier

OTHER = 1-hr pulse of light, 18.5 hrs after onset of daylight or 9.5 hrs after onset of darkness

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23
Q

Role of P4 in manipulating the spring transition

A

> Suppress LH = increase LH reserve available
- 10-15 days of P4, then PGF –> estrus in 3-7 days
+/- Addition of estradiol = stronger gonadotropin suppression (suppresses FSH)

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24
Q

Role of GnRH in manipulating the spring transition

A

Increase FSH/LH ==> IMPRACTICAL to administer frequently enough

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25
Q

Role of dopamine (D2) receptor antagonists

A

Increase in prolactin = increase of estradiol production from follicles = advances first ovulation (works better with artificial lighting)

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26
Q

Estrous cycle length of mares

A

21 days (19-24 days)

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27
Q

Estrus duration

A

7 days

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28
Q

Diestrus duration

A

14 days

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29
Q

Hormonal indication of estrus

A

< 1 ng/mL of progesterone

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30
Q

Clinical signs of estrus in the mare

A
> Receptive to the stallion
\+ Stands calmly 
\+ Squats
\+ Winks vulva
\+ Urinates
\+ Flags tail

Soft uterus and cervix, edematous endometrial folds, open/moist/pink cervix, follicles on ovary, no CL

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31
Q

When does ovulation occur in regards to estrus?

A

In the last 48 hrs of estrus

32
Q

Clinical signs of diestrus

A
> Non-receptivity to the stallion
\+ Agitated in the presence of a stallion (false positive if with a foal)
\+ Kicks
\+ Squeals
\+ Swishes tail
\+ Ears back 

Firm endometrium (no folds or edema), uniform endometrium echogenicity on U/S, long/narrow cervix, closed/dry/pale cervix, CL on ovary, varying sized follicles

33
Q

Hormonal indication of diestrus

A

> 1 ng/mL of progesterone = active and present CL

34
Q

How does natural luteolysis occur in the mare?

A

PGF-2-alpha = released from endometrium to GENERAL circulation (affects both ovaries)

35
Q

Pituitary, uterine, and ovarian hormones during estrus

A
  • Pituitary = FSH, LH (induce ovulation, lutenize into CL)
  • Uterus = PGF2
  • Ovary = estradiol (follicle), inhibin (from follicle), P4 (CL)
36
Q

Major and minor follicular waves

A

> Depends on the size of the follicle

MAJOR = Largest follicle of the wave attains the diameter of the dominant follicle (> 28 mm)

MINOR = Largest follicle of the wave doesn’t become dominant, max diameter ~ 23 mm

37
Q

Primary and secondary follicular waves

A

> Depends on whether ovulation occurs or not

Primary = wave emerge mid-cycle (day 10), dominant follicle evident ~7d before ovulation, ovulation DURING ESTRUS

Secondary = wave emerges in early diestrus, ovulation may occur during diestrus (other option = regress during estrus)

38
Q

What is deviation in the follicular wave?

A

Point at which the largest follicle becomes the dominant follicle (grows at the same rate), and all other follicles regress (growth rate slows down)

*Thought to be due to the transition between FSH and LH

Dominant follicle produces estradiol and inhibin

39
Q

Estrogen during the mares cycle

A
  • Increases during estrus, peaking one day before ovulation

- Low during diestrus

40
Q

LH during the mare’s cycle

A
  • Increases during estrus, before ovulation, peaks just after ovulation
  • Low during diestrus
41
Q

P4 during the mare’s cycle

A
  • Low during estrus

- High during diestrus

42
Q

FSH during the mare’s cycle

A
  • Larger peak at the end of diestrus = preparing for the primary wave
  • Smaller peak at the end of estrus = may induce a secondary wave
43
Q

PGF during the mare’s cycle

A
  • Peaks at the end of diestrus

- LOW during estrus

44
Q

Activity during the fall transition

A
  • Longer in length than spring transition
  • ABNORMAL CYCLES: prolonged/short diestrus, anovulatory follicles (increase in echogenicity), hemorrhagic follicles, silent heats
45
Q

Activity of anestrus

A

> ANOUVLATORY season

  • Follicles are < 15 mm
  • No CL is present
  • Poor uterine tone
46
Q

Differences of seasonality in the stallion and the mare

A

Effects of season and day length are not as dramatic in stallions and mares

Affects = testicular size, semen production, libido, hormone concentrations (decrease light, increase in melatonin, decrease in GnRH)

47
Q

Two main mating systems and management

A

1) Natural service/cover:
a- Pasture mating
b- Pen mating
c- In-hand mating

2) AI:
a- Fresh semen
b- Cooled semen
c- Frozen semen

48
Q

How to pasture mate, Pros/cons

A

> Stallion on pasture with a group of mares (all in different parts of their cycle

  • Requires experience stallions that know what they’re doing
  • Examine mares are frequent intervals to see who’s pregnant
  • Pros = save labor, achieve good conception rates
  • Cons = high risk of breeding injuries (esp to young/inexperienced stallions), poor breeding records if not kept track of, transfer of venereal disease
49
Q

How to pen mate, Pros/cons

A

> Mare in estrus in a pen with a stallion
*Not really used much

  • Pros = more control, may allow you to train young stallions
  • Cons = more labor, risk of breeding injuries
50
Q

How to in-hand mate, Pros/cons

A

MOST COMMON form of natural mating = mare is restrained and the stallion is brought over

  • Pros = good supervision and interaction (less injuries), controlled hygiene (less veneral disease), able to keep good records
  • Cons = labor intensive, limited interaction between mare/stallion
51
Q

What do you have to remember with stallions who only know how to in-hand mate?

A

Modifies their pre-copulatory behavior = won’t try and tease the mare, will just mount

52
Q

Pros/cons of artificial insemination

A
  • Pros = achieve genetic progress (more mares bred to stallions), ensure semen quality, safer, decreased disease transmission
  • Cons = lower conception rates (cooled, frozen), high labor
53
Q

What should you always do with any semen (fresh, cooled, frozen)?

A

Ensure quality (motility, morphology, etc).

54
Q

Indications for performing a mare BSE (4)

A

1) Routine management
2) Diagnostic for subfertility
3) Pre-purchase exams
4) Embryo transfer recipient

55
Q

Parts of the a mare BSE (5)

A

1) Signalment and history - age, breed, use of horse, past repro performance, prior dx tests or procedures
2) PE: TPR, BCS, coat, lameness, chronic condition, vax, parasite control, inspect udder/perineum
3) Rectal palpation
4) U/S
5) Libido = examine the mare before exposure to the stallion
+/- Endometrial cytology and culture
+/- Vaginoscopy, hysteroscopy, endometrial biopsy, endocrine teting

56
Q

Ideal vulvar conformation

A
  • Vertical (< 10% angle)

- More than 80% of vulva below the level of the ischial tuberosities (floor of the pelvis)

57
Q

Causes for small/inactive ovaries in the summer (6)

A

1) Prepubertal

2) Anestrus - stress, poor health, post-partum, exogenous anabolics, chromosomal abnormalities

58
Q

Two reasons for persistent CL on ovaries

A

1) Diestric ovulation = prolonged diestrus, ovulated to close to PGF release to undergo luteolysis
2) Failure of luteolysis = endometrial conditiosn

59
Q

Reasons for hemorrhagic anovulatory follicles (4)

A

1) Fall transition
2) Stress
3) Metabolic problems
4) Ovulatory problems (luteinization or not)

60
Q

Dx? Mare with abnormal behavior (anestrus or estrus w/o cause), stallion-like behavior

A

Granulosa cell tumor = slow growing and benign (won’t met)

DDx: anabolic steroid admin

61
Q

Palpation and U/S findings of granulosa cell tumors

A
  • Enlarged ovary unilateral (less frequent = bilateral)

- Multicystic or honeycombed on U/S (one large cyst = less frequent)

62
Q

Hormonal changes you can test for with granulosa cell tumors

A
  • Increase in steroid hormones = testosterone
  • INCREASED INHIBIN = suppresses FSH, stops the mare from cycling = low P4 and estradiol
  • Anti-mullerian hormone = specific to granulosa cell tumors, more sensitive?
63
Q

Treatment of granulosa cell tumors

A

Surgical extraction of affected ovary, contralateral ovary should resolve in 6-8 months (depends on how long the tumor has been there before things resolve)

64
Q

Problem with uterine cysts

A
  • No problematic unless they become too numerous to too large in size
  • RECORD IT = helps you differentiate between a uterine cyst and a pregnancy when you breed the mare
65
Q

Diagnosis of endometritis

A

+ U/S = fluid in uterus

  • Cytology = covered swab/cytobrush or low volume lavage (w/ centrifugation), put on slide and dye
  • Culture
  • Biopsy

*Examine at least 5 fields w/ 40x power to obtain an average # of neutrophils (1-2 = mild inflam, 3-4 = mod, >5 = severe)

66
Q

What may you want to perform if you have a history of infertility, persistent uterine fluid, positive cytology (infection), genital discharge, or if the owner just plain requests it?

A

Endometrial culture - DO IT BEFORE CYTOLOGY

  • Prep/rinse
  • Guarded swab with glove and non-spermicidal lube, have transport media ready
  • Collect
  • Streak on plate and incubate for 3 days
  • Follow-up = clitoral fossa/vaginal cultures, anaerobic cultures
67
Q

Interpretation of positive culture and cytology

A

Uterine infection

*If it fits with clinical signs

68
Q

Interpretation of positive cytology and negative culture

A

Uterine irritation/inflam

*If it fits with clinical signs

69
Q

Interpretation of negative cytology and positive culture

A

Contamination of culture sample

*If it fits with clinical signs

70
Q

True or false - sampling 1-3 locations in the distal body or proximal horn with endometrial biopsy will give you a sample that is representative of the whole uterus

A

True

71
Q

Endometrial biopsy categories and general interpretation

A

As the categories increase = probability of conceiving and foaling decreases

72
Q

Two main causes (etiologies) of endometritis

A

1) Post-breeding = “normal” uterine clearance of semen
2) Infectious = bacterial more commonly than fungal
- Etiologic = Strep zooepidemicus, E. coli, Pseudomonas, Klebsiella, Taylorella

73
Q

What do these things pre-dispose a mare to: poor vulvar conformation, cervical incompetence, pendulous uterus (difficult to clear fluid), frequent natural breeding (no time to clear uterus), persistent hymen (doesn’t allow fluid to escape), endometriosis?

A

Endometritis

74
Q

Treatment of endometritis

A
  • Address any primary problems
  • Uterine lavage - until the lavage fluid comes out clear
  • Ecbolics (oxytocin, PGF) = increase uterine contractions, PGF lasts longer but is weaker (don’t use after breeding)
  • Correct any predisposing factors
75
Q

Is pyometra common in mares?

A

NO