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CLIN SCI: Urogenital System > Equine Reproduction > Flashcards

Equine Reproduction Flashcards

1
Q

When does the mare cycle

A

during times of long daylight

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2
Q

What kind of cycle do mares have

A

Seasonally polyestrous

cycle during times of long daylight

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3
Q

How long is the mare’s cycle

A

21-23 days
Estrus: 5-7 days where she is receptive. Stands for stallion, leans, lifts tail, and urinates

Diestrus: 14-16 days, not receptive, walks away, ignores stallion, swishes tail, ears back, bites or kicks

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4
Q

What kind of behavior changes is seen with estrus in the horse

A

5-7 days where she is receptive. Stands for stallion, leans, lifts tail, and urinates

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5
Q

What kinds of behavior changes is seen with mares in diestrus

A

14-16 days, not receptive, walks away, ignores stallion, swishes tail, ears back, bites or kicks

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6
Q

what is a speculum used for

A

to examine the vagina and posterior cervix
Determine
1) Stage of cycle
2) Abnormalities
3) Obtain culture sample
4) AI for mares in which standard AI insemination is difficult

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7
Q

What 4 things might you use a speculum exam for

A

1) Stage of cycle
2) Abnormalities
3) Obtain culture sample
4) AI for mares in which standard AI insemination is difficult

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8
Q

Cervix characteristics of a mare during estrus

A

Relaxes and softens
1) Open
2) Edema
3) Rests on ventral vagina
4) Clear mucus
5) Pink

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9
Q

Cervix characteristics of a mare during diestrus

A

Tightens and closes
1) Closed
2) Protruding into vagina
3) Mucus tacky and dry
4) Pale pink coloration

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10
Q

Upon a speculum exam you see that the cervix is resting on the ventral vagina, is pink with clear mucous, and have edema. What stage of her cycle is she in

A

Estrus

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11
Q

Upon a speculum exam you see that the cervix is protruding into the vagina, closed, mucus tacky and dry with a pale pink coloration. What stage of her cycle is she in

A

Diestrus

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12
Q

area of vulvovaginal fold that may contain circular opening or strands of tissue
may occasionally be complete

A

persistent hymen

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13
Q

what can be a consequence of palpating mares

A

Rectal tears

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14
Q

Why might rectal tears occur when palpating a mare

A

1) Improper technique
2) Distractions
3) Weakened tissue

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15
Q

How might you be able to prevent the mare from excessive straining or movements to prevent rectal tears

A

Confine
Entertain
Twitch
Sedate
Buscapan
Palpate back- never push forward into the rectum

Always examine sleeve for blood after palpation

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16
Q

provides movement of the rectum during palpation

A

Mesorectum

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17
Q

Steps of tract palpation

A

1) Identify bifurcation of uterine forns
2) LSide hand along uterine horns to ovaries
3) Palpate cervix last
(1= tightly closed, 3 = wide open)

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18
Q

Can you palpate a CL on a mare?

A

N- the CL is internal to the ovary cannot reliably palpate

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19
Q

How many follicles do mares usually ovulate

A

single ovulation usually
*increases 3-5mm in diameter per day during estrus
about 45 mm diameter before ovulation

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20
Q

How much does the mare’s follicle increase each day of estrus*

A

about 3-5 mm in diameter per day during estrus

about 45mm diameter before ovulation

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21
Q

How can you measure follicle size on ultrasonography *

A

there are 10mm (1cm) increment marks on the top of the ultrasound

mark will point to front of transducer (be aware of direction)

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22
Q

The bladder is ______ to the pelvis and _______ to the uterus

A

anterior to pelvis
ventral to the uterus

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23
Q

What does the bladder look like on ultrasound

A

Echogenic (grey) urine

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24
Q

What are the ultrasound goals of the uterus in the horse

A

1) Endometrial edema
2) Stage of cycle- edema during estris

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25
Q

What causes edema within the uterus

A

Estrogen
*most pronounced in early estrus

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26
Q

When is edema most prominent in the mare

A

early estris
estrogen causes edema within the uterus

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27
Q

What can you tell about the mare’s ovary on ultrasound

A

Identify follicle and corpus luteum

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28
Q

How many waves do mares have

A

Most have 1 wave
however some mares have two waves but as long as there is a CL, the follicles will grow and then atresia- regression if ovulation doesnt occur

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29
Q

What do mare’s follicles look like on ultrasound

A

1) Round
2) Black (anechoic)
3) Multiple follicles will be present on ovaries- growing and regressing
4) Dominant (ovulatory) follicle- grows 3-5mm per day, usually single ovulation at 45mm diamter

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30
Q

release of the oocyte
occurs rapidly

will see:
ultrasound- irregular shape and defined border
and
palpation: pain and softening
right before

A

Ovulation

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31
Q

How do you determine ovulation in the mare

A

difficult to determine/image with ultrasound
grey (similar appearance to stroma), no defined borders, can have central fluid

palpating edema, soft area, indentation, pain

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32
Q

How does the follicle shape size change prior to ovulation

A

irregular shape with a defined border

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33
Q

What will you see on ultrasound after a mare’s ovulation

A

difficult to determine/image with ultrasound
grey (similar appearance to stroma), no defined borders, can have central fluid

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34
Q

What does an early luteum look like on ultrasound

A

Echoic: moderate to bright grey or white

easy to image

can have central trabeculated area

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35
Q

What will the mare’s corpus luteum look like on ultrasound

A

Moderate gray
can have trabeculated center

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36
Q

When is the mare’s CL considered mature

A

5 days

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37
Q

What does the corpus albicans (CL regression) look like under ultrasound in the horse

A

Small
Black ring
often bright center

14-16 days for natural luteolysis
prostaglandin administration

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38
Q

How is the mare’s cycle manipulated

A

1) Induction of ovulation
2) Lysis of CL- short cycle
3) Time, shorten or synchronize cycles

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39
Q

What is the criteria for induction of ovulation in the mare

A

1) 35mm follicle
2) Estrus: Uterine edema, relaxed tone uterus, open cervix, estrus behavior

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40
Q

What drugs can you use to induce ovulation in mares

A

1) hCG
2) GnRH analogs- ie SucroMate

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41
Q

hCG for inducing ovulation in the horse

A

acts at the follicle
mare will ovulate 36 hours later

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42
Q

How long after hCG administration will the mare ovulate

A

36 hours later

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43
Q

What is a downside to hCG to induce ovulation in the mare

A

reduced response with repeated use in the same breeding season

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44
Q

a GnRH analog used to induce ovulation in the horse

A

SucroMate (Deslorelin acetate)
causes pituitary release of endogenous LH

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45
Q

What is the mechanism of action of SucroMate

A

causes pituitary release of endogenous LH to induce ovulation about 40 hours later

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46
Q

How long does it take for SucroMate to induce ovulation in the mare after injection

A

about 40 hours

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47
Q

What induces ovulation in the horse quicker?

SucroMate or hCG

A

hCG- 36 hours

SucroMate- 40 hours

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48
Q

What is the trade name of Deslorelin acetate

A

SucroMate
-used to induce ovulation in the horse

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49
Q

will cause the lysis of the CL and return to estrus in mares
short cycle about a week

A

prostaglandin

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50
Q

The CL is not fully susceptible to the luteolytic effects of prostaglandin until ________________ in the mare *

A

until 5 days after ovulation

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51
Q

What are different prostaglandins you can use to short cycle a mare

A

1) Cloprostenol (Estrumate) - most often used, 250ug, IM, prostaglandin analog

2) Dinoprost (Lutalyse) - 5-10mg, IM, native prostaglandin, more side effects

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52
Q

Cloprostenol in the mare is a ___________ used to ________ and has the trade name of _______

A

prostaglandin used to short cycle (lyse CL)
trade name of Estrumate

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53
Q

What is the trade name of Cloprostenol

A

Estrumate

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54
Q

What is the trade name of Dinoprost

A

Lutalyse

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55
Q

Dinoprost in the mare is a _____ used to _______ and has the trade name ______

A

prostaglandin
short cycle (lyse CL)
Lutalyse

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56
Q

________ is a synthetic prostaglandin while ______ is a native prostaglandin used to lyse the CL in horses, only susceptible about 5 days after ovulation

A

Cloprostenol (Estrumate) = synthetic

Dinoprost (Lutalyse) = native

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57
Q

What are the side effects of prostaglandins in the horse

A

Short duration
sweat
scour
mild colic

Dinoprost (Lutalyse) has more side effects than Cloprostenol (Estrumate)

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58
Q

Does Dinoprost (Lutalyse) or Cloprostenol (Estrumate) have more side effects

A

Dinoprost (Lutalyse)

Short duration
sweat
scour
mild colic

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59
Q

Following luteolysis, most horses will return to estrus in _____ days and ovulate in _______

A

Estrus in 2-5 days
Ovulation in about 9 days, varies depending on follicle sizes

if administer with smaller (~20mm) diestrus follicles, most mares will be ready to be breed in 1 week
often, ovulation induction in 5-6 days

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60
Q

What occurs if you administer prosaglanidns in a horse with smaller (~20mm) diestrus follciles

A

if administer with smaller (~20mm) diestrus follicles, most mares will be ready to be breed in 1 week
often, ovulation induction in 5-6 days

different from the normal 9 days *

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61
Q

What occurs during the winter in mares

A

Winter anestrus
1) Does not cycle
2) Minimal ovarian activity
3) Flaccid uterus

*More pronounced in colder climates and further from equator

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62
Q

How is the horse a seasonal breeder

A

1) Increase in day length stimulates the hypothalamic-pituitary-ovarian axis
2) Spring (vernal) transition: 2-3 months in length, FSH increases prior to LH; waves of follicular growth (increasing follicle diameters, no ovulation)
Estrus - long, variable periods

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63
Q

What occurs during the spring transition in the horse

A

2-3 months in length
FSH increases prior to LH causing waves of follicular growth

-Follicles increase in diameter but no ovulation

-Estrus is long and variable periods

-Most mares naturally ovulate in April

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64
Q

What commonly indicates that a mare is ready to ovulate after the spring transition

A

Shedding at the first ovulation

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65
Q

What is the natural breeding season of the horse

A

Varies with location
April to September
Longer as closer to the equator

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66
Q

What is the artificial horse breeding season

A

February 15- July 15
“January 1 considered birth date”
-a foal born anytime during the year is considered 1 year old on January 1 of the following year

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67
Q

How do you hasten ovulation because clients want foals early in the year

A

Artificial photoperiod
14 to 16 hours of light
~2months
Lights in December to breed in February
Also pertains to foaling mares and stallions (for max sperm output)

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68
Q

Horses kept under lights all year can eventually _____

A

go into an anestrous period

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69
Q

Is the stallion a seasonal breeder

A

yes but unlike the mare there is no cessation of sperm production
-Low number sperm during short daylight

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70
Q

How does the stallion produce less sperm in the winter

A

reduced GnRH secretion leading to lower LH and testosterone

*Artificial lighting- same as mare, will alter timing of peak sperm Feb 15-July

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71
Q

T/F: you can influence the stallion to artificial light, just like the mare to alter the timing of peak sperm

A

True

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72
Q

When do male horses hit puberty

A

about 2 years

generally start to breed at 3 year

sexually mature at 5-6 years

*Sperm production increases until 9-16 years

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73
Q

In the stallion, sperm production increases until about

A

9-16 years

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74
Q

stallion sexual behavior

A

libido is often a limiting factor
hormonal component
environmental factors: stallion handling, housing, frequent using

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75
Q

What is total scrotal width of a stallion

A

about 9.5-11.5cm

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76
Q

What is evaluated in the breeding soundness exam of a stallion

A

1) Scrotal width (9.5-11.5cm)
2) Libido and mating behavior
3) Cultures of urethra, seme
4) Semen evaluation 4-12 billion
5) Progressive motility
6) Sperm morphology

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77
Q

What are steps of artificial insemination

A

1) Restrain mare, wrap tail, wash with mild soap and rinse 3X or until clean
2) Introduce pipette into vestibule
3) Move hand dorsal above vulvo-vaginal fold to avoid urethral os
4) Pass through cervix and deposit semen into uterine body

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78
Q

What are the different types of semen used for insemination

A

fresh, cooled, and frozen

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79
Q

What type of semen has the best survivability

A

fresh (2 days) >
Cooled (1 day) >
Frozen (12 hours) >

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80
Q

What type of semen has the best fertility

A

fresh > cooled > frozen

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81
Q

What are the temperatures of the different kinds of semen

A

Fresh: room/body temp
Cooled: 5C
Frozen: Liquid nitrogen

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82
Q

What is the sperm dose for different kinds of semen in horse

A

Fresh: 500million
Cooled: 1 billion
Frozen: 800 million

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83
Q

when a mare is bred naturally

A

live cover

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84
Q

What is the longevity of different kinds of semen

A

Live cover: 2 days
Fresh AI: 2 days
Cooled: 1 day
Frozen: 0.5 day

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85
Q

What is the criteria for inducing ovulation in a mare ***

A

1) 35mm follicle
2) Endometrial edema
3) Estrus
4) relaxed uterine tone
5) Open cervix

Induce with hCG or GnRH analog: 1.5-2 days until ovulation

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86
Q

The equine oocyte will remain viable for ____- hours after ovulation

A

less than 12 hours after ovulation

Want to breed 6-8 hours after ovulation

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87
Q

you should breed the mare within _____ hours after ovulation

A

12 hours (aim for 6-8 hours)

the equine oocyte is not viable after 12 hours

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88
Q

How do you diagnose early pregnancy in the mare

A

12-16 days: initial detection
16: Return to estrus
25: Heartbeat
35: Cup formation
Checked later for mare management

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89
Q

When is palpation for pregnancy detection in the mare able to be done

A

25-35 days

earlier will feel toned uterus and tight cervix

ventral bulge at base of uterine horn

careful not to confused with bladder (60-90days): tight cervix and ovaries pulled central

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90
Q

when will a mare return to estrus if she is not pregnant

A

in about 16 days

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91
Q

maternal recognition of pregnancy in the mare

A

migration of embyo- uterine contractions

-prevents the release of prostaglandin and luteal regression

Until 17-19 days (depends on uterine and vesicle size)

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92
Q

when searching for an embryo in the mare, how do you ultrasound?

A

move across the horse and scan cross-section until you get to the body and then turn the probe to scan down

go back and forth to look for it

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93
Q

when does the mare’s embryo proper begin to form

A

at about day 25- indicator of viability
“Heartbeat”

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94
Q

What does the chorionic girdle produce

A

ecG or PMSG on day 35 of gestation (act like FSH/LH)

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95
Q

When is eCG produced from the chorionic girdle

A

on about 35 day of gestation

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96
Q

When can you detect the pregnant mare’s fetal heartbeat

A

day 25 of gestation

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97
Q

When do endometrial cups begin to form

A

Day 35

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98
Q

What occurs during the motility phase of the equine embryo

A

the embryo rapidly increases in size, round, and changes locations

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99
Q
A
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100
Q

What is importance of endometrial cups

A

important for equine pregnancy maintenance

specialized cells from the placenta that migrate into endometrium

produce eCG (PMSG)

maintained until programmed cell death 35-120 days

101
Q

when do endometrial cups typically go away

A

day 120
individual variation
regardless of fetal survival after uterine invasion
prevents rebreeeds of mare until about 4 months from initial conception if pregnancy is lost after cup formation. failure of normal ovulation

102
Q

secondary corpora lutea in the mare

A

large ovaries and luteinized structures that form during gestation
increase progesterone until they eventuall regress

103
Q

If you do a blood assay and the mare is positive for eCG, what does this tell you

A

there are endometrial cups present. The mare is either pregnant or was pregnant

104
Q

When might you have a false negative on eCG assay

A

the time of sample collection

endometrial cups are typically present from day 35-120 of the mare’s gestation

105
Q

When might you have a false positive on eCG assay

A

fetal death after cup formation

however, most pregnancy losses occur prior to cup formation

106
Q

What maintains the mare’s pregnancy after 120 days

A

placental progestins
-minimal ovarian activity

107
Q

Can you measure progesterone for mare’s pregnancy diagnosis

A

NO- not diagnostic, not progestins
variable results
depends on the cross reactivity

108
Q

When do plancental progestins take over to maintain the mare’s pregnancy

A

about 120 days (90-150)

109
Q

Why might a pregnant mare act “studdy” during pregnancy

A

Fetal gonads increase in size in mid gestation but regress in late gestation

-Testosterone is produced (Colt or filly)

-can induce behavioral changes in the mare (more aggressive or stallion-like behavior)

110
Q

How might you use estrogen-based pregnancy tests in mares

A

Estrone and estradiol are produced by the fetal-placental unit increasing at about day 90 of gestation

-estone sulfate initial increase on day 45 of gestation

from ovaries of mares stimulated by eCG

111
Q

What stimulates the estrogen seen to increase around day 90 of gestation in the mare

A

estrogens are produced from the ovaries of mares
-stimualted by eCG

112
Q

When can you sex the mare’s fetus

A

After 60 ays - genital tubercle is identified

113
Q

How do you tell the bladder vs pregnancy

A

1) allantoid fluid is anechoic
2) ovaries are pulled central
3) Cervix is tight

*Identify bladder or nonpregnant uterus
*Fetus and umbilical cord may be hard to image

114
Q

what does allantoid fluid look like on ultrasound

A

Anechoic

115
Q

Most twin pregnancies in the mare will

A

have a reduction with 60% resulting in live single deliveries

1% have two live foals but it is undesirable as insufficient uterine capacity

116
Q

Most twins in a mare are caused by

A

two ovulations (identical twins are rare but seen more with ICSI programs)

117
Q

When should you do manual reduction of equine twins

A

12-15 days

118
Q

If you identify twins in the mare what should you do?

A

Manual reduction: 12-15 days - squish one of embryos after separating

Abortion: optimally before 35 days and formation of endometrial cups, repeated doses of prostaglandin

-Later procedures are less successful

119
Q

How do you do abortion in a mare with twins

A

optimally before 35 days and formation of endometrial cups, repeated doses of prostaglandin

120
Q

post fixation twins

A

outcome often relative to position and size
end pregnancy by 35 days to rebreed
-endometrial formation after 35 days
-will not return to estrus after cups form until regression
-probable bad outcome without intervention

Cessation of pregnancy with prostaglandin

121
Q

What is the difference between bilateral equine twins vs unilateral equine twins

A

Bilateral: >80% maintain after 40 days

Unilateral: Most reduce to singleton- dissimilar size and location of cord

122
Q

Early pregnancy maintaince in equine, progesterone needs to be

A

> 4ng/mL

initial pregnancy maintenance from primary CL then secondary CLs

123
Q

Should you supplement the mare’s pregnancy with progesterone

A

precaution, for mares with
history of embryo loss
older, problem mares

seen when repro exam
-small ,regressing CL
-poor tone to uterus or cervix
-endometrial edema

use short acting or long acting progesterone (daily vs weekly administration)

Altrenogest (ReguMate)- supplement until placental maintenance (120days)

124
Q

Why is Altrenogest nice

A

because you can determine the mare’s endogenous progesterone
-not detected by progesterone assays
-supplement until placental maintenance (120 days)

125
Q

What is another name for Altrenogest

A

Regu-Mate

126
Q

Why might an embryo be lost?

A

-luteal insufficiency
-uterine inflammation
-uterine fibrosis
-embryo defects
-delayed fertilization
-embryo insult
-infectious/diseasese/ misc

127
Q

How long is the mare’s gestation *

A

Normal: 340 days

Range 320-260 days

Premature <320 days

128
Q

What species has a gestation of 340 days but can range from 320 days

A

the horse

129
Q

foals are considered premature when they are before before

A

320 days of gestation

130
Q

What are some preparation need to be made for foaling

A

1) Move to foaling site about 1 month prior
2) Vaccinate- colostrum (Tetanus)
3) Open the caslicks

131
Q

What are some signs that a mare is going to foal

A

1) Mammary gland development: 2-6 weeks
2) Ventral edema
3) Dropped abdomen: 2-3 weeks
4) Perineal relaxation: 1-3 weeks
5) Teat engorgement: 7-10 days
6) Mammary electrolyte changes
7) Waxing *: colostrum dripping 48-72 hours
8) Elongation of vulva: 0-24 hours
9) Behavior changes

132
Q

What occurs during Stage I parturition in the mare

A

1) Uterine contractions: restless or nervous, frequent lying down, pawing, patchy sweating, running mild, dripping milk
2) Rupture of the chorioallantoic membrane

1-4 hour: foal repositioning

133
Q

What marks the end of stage I of labor

A

rupture of chorioallantoic membrane

134
Q

What occurs during Stage II of labor in the mare

A

active straining
appearance of amnion
birth of foal- front legs and nose, one foot in front of the other and nose

last 10-60minutes

135
Q

what do you want to do to the foal once they are expelled from mom

A

1) clear nostrils
2) Dip umbilical cord (0.5% chlorhexadine or 1 part 2% novalsan solution and 3 parts distilled water)

136
Q

What is stage III of parturition in the horse

A

Expel placenta via uterine involution and myometrial contractions (takes 15min to 3 hours (average 1.5 hours)

Mild colic signs

Retained if not passed in 3 hours

evaluate the placenta to make sure all is there

137
Q

In the horse, the placenta is considered retained when it is not passed in

A

3 hours (average time is 1.5 hours)

tip of horn is most common spot, evaluate horn

138
Q

premature separation of the placenta happens when

A

the chorioallantoic membrane fails to rupture and the placenta separates from the endometrium

*emergency condition - loss of blood supply to the fetus

139
Q

What is red bag delivery

A

when the chorioallantoic membrane fails to rupture and the placenta separates from the endometrium

*emergency condition - loss of blood supply to the fetus- hypoxia, open membrane immediately and prompt delivery of foal and oxygen

140
Q

the portion of the placenta in the mare that does not have microvilli because of contact to the cervix

A

cervical star

141
Q

the most common early postpartum problem in the mare is

A

retained placenta - can be the full placenta or a tip of the nonpregnant horn

142
Q

How do you prevent retained placenta

A

examine the placenta after foaling
have the client remove from stall and save for evaluation

143
Q

What are symptoms of a retained placenta in the horse

A

fetid, red-brown discharge
depression
anorexia
fever

from
metritis and systemic issues- endotoxins, systemic endotoxemia

144
Q

How do you treat retained placenta in a horse

A

1) Oxytocin
2) uterine lavage and treatments
infusion of fluid into allantoic space
3) Additional treatments
systemic and uterine antibiotics
uterine lavage
nsaids
laminitis support

*Be careful not to apply too much pressure, dont want to rip out

145
Q

What is the interval to ovulation after parturition in the horse

A

short interval- based on season and lights, can be 7 days

often best to assure at least 9 days to ovulation after foaling if wanting to breed on foal heat

146
Q

the first heat cycle a mare goes through after foaling and a manager’s first opportunity to breed her. It typically occurs six to 12 days after foaling.

A

foal heat

often best to assure at least 9 days to ovulation after foaling if wanting to breed, endometrium needs to recover

147
Q

What are some considerations in breeding a postpartum mare

A

1) often best to assure at least 9 days to ovulation after foaling if wanting to breed on foal heat
-mares may cycle earlier in summer, endometrium needs to recover
2) Confirm no discharge or signs of uterine fluid
3) If needed, allow to ovulate then short cycle for breeding

148
Q

What issues might affect a mare’s ability to get pregnant

A

-Systemic health
-Endocrine issues (Equine metabolic syndrome), PPID (pituitary pars intermedia dysfunction)
-Stress and pain
-Aging
-Drugs and diet

149
Q

Why might a mare have no follicular growth

A

1) Winter anestrus- change hemisphere or other alter light exposure
2) Aging
3) Endocrine problems
4) Tumors
5) Chromosomal abnormalities

150
Q

Why is the most common tumor of the mare reproductive tract

A

granuloma cell tumor

-leads to behavioral changes, stallion characteristics
-usually do not cycle on contralateral ovary

151
Q

T/F: horses with granulosa cell tumors usually do not cycle on contralateral ovary

A

True

152
Q

How do you diagnose granulosa cell tumors in mares

A

Endocrine paramaters:
Tumor profile- testosterone, inhibin
and AMH

153
Q

What are reasons why a mare might try to mount another mare

A

1) Pregnant
2) Granulosa Cell Tumor

154
Q

What do granulosa cell tumors look like grossely

A

typical cystic appearance

155
Q

How do treat granulosa cell tumors in horses

A

surgical removal- they are able to be bred again with a single ovary

156
Q

Are mares with granulosa cell tumors fertile

A

most mares will cycle and be fertile

157
Q

What are other differentials for granulosa cell tumors in mares

A

1) Teratoma- variety of tissue types, echogenic and cystic areas
2) Cystadenoma- usually unilateral, does not affect the contralateral ovary

*You will not see any behavioral changes and will have an active contralateral ovary with these

158
Q

How might you diagnose anovulatory follicles in horses

A

ultrasound- spot, strands in the follicle

typically occur in older mares in the spring and fall transition

159
Q

Anovulatory follicles typically occur in mares that are

A

typically occur in older mares in the spring and fall transition

160
Q

What are hemorrhagic follicles

A

follicles that fail to ovulate
increase in size
blood and fibrin in the antrum
oocyte trapped
regress over time
may respond to prostaglandin

161
Q

the oocyte must be competent for fertilization and embryo development, what might affect the oocyte

A

age, heat, and stress

162
Q

Fertilization in the mare occurs in the

A

ampulla

sperm reservoir at the UTJ or isthmus

163
Q

a developmental remnant that is generally not clincially significant
may be confused with a follicle
palpation important to differentiate
may be large

A

Paraovarian cyst

164
Q

hydrosalphynx

A

a fluid accumulation in the oviduct
rare unilateral

165
Q

What are occluding masses to the oviduct

A

gelatinous with fibroblast leading to occluding of the oviduct
undiagnosed reproductive failure
difficult to confirm

treat with oviduct flush and/or PGE2

166
Q

What are barrier to the uterus

A

1) Cervix
2) Vestibular sphincter
3) Vulva

167
Q

What is the normal vulva confirmation of a hare

A

1/3 of vulva above the brim of the pelvic
2/3 below the brim of the pelvis

168
Q

poor vulva conformation predisposed the mare to

A

uterine inflammation or infection and reduced fertility

169
Q

common cervix issues in the mare

A

-anatomical defect
-fibrosis
-adhesions
-tears

*Cervical problems can be difficult to correct

170
Q

A small amount of intraluminal fluid is normal in ______ but not normal in ______ of the mare

A

Normal in estrus
Not normal in diestrus

*grey appearance on ultrasound

171
Q

What intraluminal apperance of the uterus is bad news in the mare

A

grey appearance - cellular debris

*Any fluid in diestrus is bad news, but if clear in estrus, it is okay

172
Q

What causes uterine cysts

A

blocked lymphatic vessels- indication of scar tissue

173
Q

What do uterine cysts look like on ultrasound

A

often multilobulated
variable shapes and locations
can be pedunculated or within uterine tissue

*Be careful to not confuse with embryo
cyst will not change location, size, or have a heartbeat

174
Q

How do you differentiate uterine cysts from embryos

A

cyst will not change location, size, or have a heartbeat

175
Q

What might cause pneumouterus or pneumovagina

A

poor perineal conformation
can also observe air within tract after AI or other procedures, try to prevent

176
Q

What is the issue with pneumouterus/pneumovagina?

A

can be an irritant- prevent pregnancy or introduce infection

177
Q

What does pneumouterus/pneumovagina look like on ultraound

A

hyperechoic areas- dots or line (reverberation)

178
Q

types of foreign bodies that can occur in the reproductive tract?

A

-mummified fetal bones
-culture swab tip
-marbles

Diagnosis and Tx
-hyperechoic- shadow
-removal

179
Q

What is one of the most common cocci found in mare’s repro tract

A

Strep equi sbsp zooepidemicus

180
Q

Uterine biopsies assess _____

A

1) Health of uterus
2) Glands- number and activity
3) Scar tissue
4) Cell types- inflammation and infection

*No nerve endings, cant hurt mare

181
Q

Most common bacteria associated with endometritis in the mare

A

1) Streptococcus equi ssp zooepidemicus
2) Escherichia coli
3) Pseudomonas aerginosa
4) Klebsiella pneumoniae

also yeast and fungus

182
Q

What mares are susceptible to endometritis

A

1) delayed uterine clearance
2) fibrotic cervix
3) poor perineal conformation

other causes: semen, contamination, techniques

183
Q

How do you diagnose endometritis in the mare

A

1) failure to conceive
2) early return to estrus
3) vaginal discharge
4) fluid within lumen of uterus- grey on ultrasound
5)culture
6) cytology

184
Q

How do you treat endometritis in mare

A

Treat predisposing problems

Prostaglandin to return to estrus
, uterus more resistant to infectious agents, cervix open to allow removal of debris

185
Q

What are ecbolics

A

induce uterine contractions and promote clearance
1) oxytocin (10-20 IU): 30-60min contractions, 4 hours to reset receptors
2) Prostaglandin: 250ug cloprostenol (Estrumate): 2-4hours of contractions, could affect early luteal formation or induce ovulation

186
Q

removal of dead cells and infectious organisms using LRS or saline solution of the uterus
remove debris prior to antibiotic treatments

1 L at a time, repeat until clear

A

uterine lavage

187
Q

Do you want to do a uterine lavage before or after antibiotic treatments

A

remove debris prior to antibiotic treatments

188
Q

For endometritis, antibiotic choice is based on

A

safety of antibiotic prior to use and based on culture and sensitivity information
-ampicillin, ceftiofur, gentocin, ticarcillin

189
Q

What antibiotic is not for intrauterine use in horse

A

Baytryl

190
Q

What antibiotic needs to be buffered with bicarb before intrauterine use in the mare

A

Gentamicin

191
Q

T/F: mares with pyometra are systemically ill

A

FALSE

192
Q

What is the prognosis of pyometra in mares returning to fertility

A

low prognosis for return to fertility

193
Q

What is mating-induced endometritis in the mare

A

transient inflammatory response is normal
peaks about 8 hours after breeding
nromal mare will clear inflammation but some mare are susceptible to sustained inflammation
check uterus after AI/breeding

treat with ecbolic and/or lavage

194
Q

degenerative changes in the uterine lining of the mare that can affect embryo survival and placental function
consequence of aging, inflammation, insults
not correctable- pregnancy failure

A

uterine fibrosis

195
Q

How do you diagnose uterine fibrosis

A

uterine biopsy

196
Q

urine poolin the the uterus in mares is common in

A

often older or postpartum mares with sunken uterus
pool urine in front of cervix, urine enters uterus in estrus when cervix is open

manage with time, weight and exercise
surgery
caslick is not a corrective surgery

197
Q

T/F: A Caslick treats uterine pooling in a mare *

A

False- it is not a corrective surgery

198
Q

It is April 1 in Colorado, and you go to Maybelle Mayberry’s house to check her mare, Sassy. Sassy is out in a pasture during the day; but in the evening, Ms. Mayberry puts her into a large pen with lights on one side. She has done so since January 20. She wants to breed her asap to get an early foal next year. Sassy is in good body condition, but she still has a long, winter hair coat. Ms. Mayberry says that Sassy has been showing signs of estrus during the last week to a gelding. The owner would like to get Sassy bred this week. Ultrasound images show Sassy’s uterus and left and right ovaries. What will you tell Ms. Mayberry?

A

Sassy is still transitional and not yet ready to breed this year. While there were lights in the pen, the pen was not lighted evenly, so Sassy may have been standing outside of the lighted areas. Consequently, she did not respond to the artificial lighting. This is supported by her long, winter hair coat.

199
Q

Because of the artificial breeding season for horses, many mares are put under lights, so they foal in the winter. To get foaling mares to cycle early in the year after foaling, they also have to remain under artificial lighting. How does artificial lighting affect the stallion?

A

Increase daily sperm production earlier in the year.

200
Q

Dash Me Too is to be bred to a local stallion. When you palpate her, you feel a large follicle on her left ovary; but her cervix is closed, and her uterus is toned. See images of Dash’s ovaries and uterus. Please select the most appropriate statement.

A

Dash is in diestrus with a larger follicle. Either wait for her to return to estrus naturally or administer prostaglandin.

201
Q

You are called to Mr. McDonald’s farm to check two mares, Bessie and Boogie. Mr. McDonald has seen both mares “teasing” (showing signs of estrus) to his stallion for the last couple of days. He wants to breed them to his neighbor’s stallion, and he would like to bring them there today. You ultrasound the mares’ reproductive tracts.

Bessie has small follicles on her right ovary. Her uterus is relaxed, and her cervix is open. Her left ovary and uterine horn are imaged below.

Boogie had small follicles on her left ovary. Her uterus is only slightly toned, and her cervix is moderately open. The ultrasound image is of her uterine horn and her right ovary.

A

Breed Bessie today. Boogie has ovulated, so wait 5 days and give her prostaglandin if the owner wants to short cycle her.

202
Q

a soft tissue structure that guides the movement of the testes during embryonic development

A

gubernaculum

203
Q

What are the components of the spermatic cord

A

1) Cremaster muscle
2) Ductus deferens (continuation of epididymis)
3) Testicular artery
4) Pampiniform plexus (veins)
5) Nerves
6) Lymphatics

204
Q

Should you always remove the smaller or larger horse testis first? *

A

always remove the smaller testis first

205
Q

In horses, you should wait to castrate once ________ *

A

Both testes are descended and present
confirm with palpation +/- sedation

DO NOT REMOVE ONE TESTIS

206
Q

T/F: monochordism is very rare in horses *

A

true

207
Q

What is an open castration

A

a castration where you cut through the tunic and the testi is exposed

208
Q

What is a closed castration

A

a castration where the tunic is intact and then you cut the cord

209
Q

About 75% of the quarter horses that are cryptorchid have a _____abdominal testis

A

left

210
Q

What should you confirm when castrating a horse

A

there are two structures - testi and epipididymis
and both testes are present

211
Q

Is standing or recumbent castration more preferred

A

really the surgeon’s preference but standing is more expensive and dangerous

some breeds like draft horses have a larger inguinal canal so when doing them standing, its hard to keep things from falling down the inguinal canal

212
Q

Is open or closed castration better?

A

Based on personal preference and size of the horse

213
Q

What kind of peri-operative medications can be given during equine castration *

A

1) Tetanus toxoid
2) Analgesics
3) Antibiotics? decided by the surgeon based on speed, environment, and experience

214
Q

What supplies are needed for equine castration? *

A

-Antisepetic for site preparation
-Local anesthetic
-Roll cotton or gauze
-Container for antiseptics and cotton gauze
-scalpel handle and blade
-towel clamp
-hemostat
-needle holder for ligation?
-Metzenbaum scissors
-gauze
-emasculator (Serra triple cut or Reimer Ratchet)

215
Q

During castration, which way should the emasculators should go

A

NUT to NUT- otherwise you will have a mangled testi

216
Q

What are good sedation drugs for equine standing castration? *

A

Detomidine + Butorphanol

217
Q

How should you apply local anesthetic for standing castration *

A

Into the skin and testes (testes takes about 10 minutes to desensitize)

218
Q

How long does it take for the testes to desensitize after applying local anesthetic?

A

about 10 minutes

219
Q

What drugs should you use for recumbent castration

A

Xylazine + Ketamine +/- valium

220
Q

How do the drugs for recumbent castration differ from drugs for standing *

A

Standing: Detomidine + Butorphanol

Recumbent: Xylazine + Ketamine

221
Q

Is local anesthetic worthwhile in equine castration

A

yes- some evidence for better recovery

222
Q

based upon incising or not incising the common vaginal tunic

A

open vs closed castration

223
Q

Why might you chose open vs closed castration *

A

Closed: theoretical that it limits ascending infection because it crushes the vaginal tunic which is continuous with the peritoneum

Open: larger / older horses you can open up the cord to view all the structures like the pampiniform plexus so you can do a double emasculation instead of just a single

224
Q

What kind of castration is best for a young small horse up to 3 years old

A

Closed castration

225
Q

A single emasculation is (more/less) secure on crushing larger testes and (more/less) secure on crushing small testes

A

single = less secure on larger testes and more secure on crushing small testes

226
Q

How do you perform a closed castration in a horse

A

1) incise skin
2) Strip fat from tunic
3) Emasculate

227
Q

An open castration is preferred in a horse

A

older horses with large testes and spermatic cords

*more secure crushing

228
Q

How do you perform an open castration in a horse

A

1) incise tunic over testicle
2) extend incision proximally
3) separate vasculature
4) Double emasculate- nut to nut a) vasculature b) tunic/cremaster/ductus

229
Q

What two structures do you hit when doing double emasculation in a horse *

A

1) Vasculature
2) Tunic/cremaster/ductus

230
Q

What should you tell the owner with equine castration post-operative care

A

Rest for 1st 24 hours - hemostatsis and swelling

Exercise 7-10 days forced for encouraged drainage

231
Q

What are the common equine castration complications *

A

1) Hemorrhage- too much if you cant count the drops
2) Excessive swelling
3) Infection
4) Eventration- internal inguinal ring, small intestine, omentum; in certain breeds (draft, mustang, standardbred)
5) Penile prolapse - drug related
6) Hydrocele- fluid within the retained vaginal tunic; varicocele is caused by dilated testicular veins
7) Penile amputation- be careful in youngsters
8) Scirrous cord
9) Peritonitis

232
Q

failure of testicule to descent into the scrotum due to improper gubernaculum function

A

cryptorchid

233
Q

After 2 weeks of age, the horse’s testicles are either in the

A

scrotum
inguinal canal
abdomen

does not go back and forth

234
Q

in the quarter horse, cryporchidism is more common in the

A

left testi

235
Q

How do you diagnose cryptochidism in horses?

A

history
palpation +/0 sedation
Ultrasound- trans-abdominal, transrectal
hCG stimulation- history

236
Q

How do you perform cryptochid castration

A

Inguinal- high flanker, routine castration, easier in dorsal recumbency, may need to go over external inguinal ring

Abdominal- inguinal, para-inguinal, or laparoscopic

237
Q

What should you do in a horse with unknown castration histroy *

A

Do not rely on castration incisions
diagnose with palpation- external or rectal, ultrasound, testosterone and/or hCG stimulation

look for stallion-like behavior

238
Q

What is the indication for performing the caslick procedure?

A

1) older mares
2) multiple pregnancies
3) Loss of condition
4) perineal lacerations

239
Q

What is a normal perineal conformation in the horse *

A

almost perpendicular to the ground
10-20 degrees

240
Q

What is an abnormal perineal conformation in the horse *

A

1) <80 degrees from vertical 2) >50% of the vulva above the ischial arch

anus can contaminate the vulva
need for life of the life, remove and replace for breeding/foaling

241
Q

What is needed for the caslick procedure?

A

Sedation
tail wrap
anti-septic for preparation
local anesthesia with needle and syringe
scalpel (preferred) or scissors
needle holder and suture
thumb forceps

242
Q

How far should you suture when doing a caslicks? *****

A

down to the level of the tuber ischii

243
Q

What suture pattern should you use for the caslick procedure

A

simple continuous

244
Q

What suture type should you use for caslick procedure

A

absorbable or absorbable

245
Q

T/F: you can redo caslick throughout a mare’s life

A

True- just do not remove too much skin/mucosa

a scalpel is much better than scissors at not doing this

246
Q

T/F: you need to remove the caslick before doing AI

A

false- it does not need to be removed for AI

it does if you are doing live-cover

247
Q

What are the 4 major common complication with equine castration *
which ones do you refer?

A

1) Hemorrhage- too much if you cant count the drops
2) Excessive swelling
3) Infection
4) Eventration- internal inguinal ring, small intestine, omentum; in certain breeds (draft, mustang, standardbred)

extreme hemorrhage and eventration

248
Q

Should you remove the abdominal or scrotal testi first

A

abdominal

249
Q

You pregnancy check a mare at 12 days, but she has numerous cysts within the uterus. How do you differentiate the cysts from an embryonic vesicle?

A

The embryo will grow, and cysts will not increase in size.

The embryo will change positions in the uterus, and the cysts will not.

The embryo is usually round, while cysts are often (but not always) irregular in shape.

CLIN SCI: Urogenital System (6 decks)

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