Final: Mare cycle and breeding; Non-pregnant mare Flashcards Preview

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Flashcards in Final: Mare cycle and breeding; Non-pregnant mare Deck (69)
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1
Q

Descibe the cervix of a receptive mare.

A

Short and soft

Like a wilted rose

2
Q

The dorsal commisure of the vulva should be at the level of the _________.

A

Ischial arch

3
Q

A second degree _____________ is a common, frequently overlooked and serious lesion that is easily corrected.

A

Perineal laceration

4
Q

What part of the anatomy helps create a seal between the vestibulum and the vagina?

A

Perineal body

5
Q

On US evaluation of the repro tract, in which orientation are the uterine body and uterine horns viewed?

A

UB: Longitudinal

UHs: Cross-section

6
Q

What is the ideal month for a foal destined to be racehorse to be born in?

A

January

7
Q

Follicles formed during the transition period are

a. steroidogenically incompetenet
b. enlarged
c. steroidogenically competent and form estradiol
d. hyperfertile

A

a. steroidogenically incompetenet

8
Q

How many waves do most horses have in their estrus cycle?

A

2

9
Q

How much do follicles grow per day? What hormone reduces the growth rate of follicles?

A

3mm/day

Progesterone

10
Q

At what size do follicles develop ovulatory capacity?

A

35mm

11
Q

Ovulation occurs in response to rising ___ levels that peak ___ days after ovulation.

A

LH

Two

12
Q

Which order is correct?

a. Follicle -> Ovulation -> Corpus luteum -> Corpus hemorrhagicum
b. Follicle -> Ovulation -> Corpus hemorrhagicum-> Corpus luteum

A

b. Follicle -> Ovulation -> Corpus hemorrhagicum-> Corpus luteum

13
Q

The sperm revervoir in the uterine tube is adequate by ___ hours/days after breeding or insemination. These sperm remain viable for at least ___ hours/days.

A

4 hours

2 days

14
Q

Occytes degenerate by ____ hours/days post-ovulation. This is why insemination should occur ____(prior to/ after) oculation.

A

12-16 hours

Prior to

15
Q

When do fertilized embryos enter the uterus?

A

By 5.5 days after fertilization

16
Q

What are the 2 requirements for inducing ovulation? What 2 agents can be used?

A

Must be in estrus and have a growing pre-ovulatory follicle at least 35mm large

hCG and GnRH

17
Q

Why can administering hCG cause anaphylaxis?

A

Can cause production of autoantibodies

18
Q

What is Deslorein accetate?

A

Long-acting injectable GnRH

19
Q

What account for the difference in when the mare will ovulate when giving hCG (36hrs) and GnRH (42hrs)?

A

hCG = LH -> goes straight to ovary

GnRH -> Pituitary -> releases LH -> ovary

20
Q

What are the side effects of Dinoprost (Lutalyse)?

A

Sweating

Colic

Depression

Prostaglandin labeled for horses (Cloprostenol/Estrumate is extra-label)

21
Q

On what does the interval between PGF2a administration and estrus or ovulation depend?

A

Follicle size

  • <25mm = 7-10d*
  • >25mm = 3-5d*
  • >35mm= 1-4d*
22
Q

What is the most common exogenous P4 product for horses?

A

Regu-Mate(tm)

(Altrenogest)

23
Q

How does a GnRH implant prevent estrus?

A

Superstimulation of GnRH receptors -> receptors internalize -> cannot be stimulated anymore

24
Q

What is the best way to determine whether a mare is receptive?

A

Teasing with a stallion

25
Q

How long does capacitation within the female repro tract take?

A

6 hours

This means it cannot immediately fertilize oocytes

26
Q

If you are performing AI on a mare and inseminating her very close to or right at ovulation, what type of semen are you using?

A

Frozen

Immediately fertile but doesn’t last as long

27
Q

Match the following types of semen with the expected rate of impregnation:

Fresh

Cooled

Frozen

50%

60%

70%

A

Fresh 70%

Cooled 60%

Frozen 50%

28
Q

How many 0.5mL straws are one dose of cryopreserved semen?

A

Eight

800 million to 1 billion semen

29
Q

How many progressively motile sperm is needed per dose of cryopreserved semen?

A

240 million

30% PM

30
Q

What is a ‘test freeze’? When can you not test freeze?

A

Testing the various sperm extenders with a stallion’s collected semen to determine which is most compatible

Can’t test freeze if extracting epididymal sperm (e.g. after stallion’s death or castration; within 24 hours of testicle death)

31
Q

How often should a mare be examined via US before AI?

A

Every 6 hours

So can inseminate as soon as ovulation is detected

32
Q

How many hours after deslorelin administration should you AI a mare? Single dose vs split/double dose?

A

If single dose: 32-33 hours

Split dose (2 inseminations): 36-48 hours

33
Q

T/F: The endometrial reaction to fresh semen is more exaggerated than to frozen-thawed semen.

A

False

Much more severe with frozen semen

Seminal plasma modulates response (not much in frozen) and during the freeze-thaw some of the sperm rupture releasing foreign antigens

34
Q

How can you improve the outcome with low dose insemination?

A

Inseminiate into the deep horn

35
Q

What is being described:

Stain semen with DNA dye

Put through flow cytometer in single file and in the correct orientation

Shine laser on the sperm and assess fluorescence

A

Sexing semen

Does not work well in horses, good in cows

36
Q

Why is prostaglandin given to the donor mare after embryo recovery?

A

To make sure she is not pregnant

Also recheck because prostaglandin may not be effective

37
Q

Is surgical or non-surgical embryo transfer more successful?

A

Non-surgical

38
Q

T/F: In vitro fertilization is a common practice in horses.

A

False, doesn’t work well in horses

39
Q

What is ICSI? When is it attractive, despite it being expensive?

A

IntraCytoplasmic Sperm Injection

When semen is extremely limiting

40
Q

What is the pregnancy rate per cycle for intracytoplasmic sperm injection?

A

5-10%

41
Q

What cells are usually used for cloning?

A

Fibroblasts

42
Q

What are the 3 main physical barriers to uterine infection?

A

Vulva and perineal body

Vestibulovaginal junction

Cervix

43
Q

How is cervical integrity best assessed?

A

(Vaginal) Palpation

44
Q

What are the most commonly culutred bacteria found on an endometrial biopsy?

A
  • E. coli*
  • Streptococcus* spp.
45
Q

What type of swab is best for endometrial cytology?

A

Brush

46
Q

How many % neutrophils on endometrial cytology indicates impaired infertility?

A

2

47
Q

What causes eosinophils in an endometrial cytology sample (2 things)?

A

Air

Urine

48
Q

What does an endometrial biospy reveal that cytology cannot?

A

Whether there is fibrosis in the uterus (irreversible changes to the uterus) which impairs fertility

49
Q

What are cysts in the uterus of a mare? Bitch?

A

Mare: Dilated lymphatics

Bitch: Dilated endometrial gland

50
Q

What is the main strategy for hastening the onset of the breeding season?

A

Artifical lighting

Start in November for cycling in late February

51
Q

What hormone can be given to inhibt GnRH? What can be given to increase GnRH? What unwanted side effect can administering this cause?

A

Dopamine

Sulride, Domperidone

Can cause lactation

52
Q

What does an irregular inner surface of the granulosa across from the ovulation fossa, aka serration, indicate?

A

Impending ovulation

53
Q

At what age are mares usually most fertile?

A

10 years

54
Q

What is the biggest predictor of fertility in horses?

A

Age

55
Q

What is the most effective way of dilating the cervix?

A

PGF2a

But expensive

56
Q

What’s going on here?

A

Persistent hymen (imperforate)

57
Q

Why can premature intervention with partution lead to urovagina?

A

Can damage vestibulovaginal junction

58
Q

What is the concequence of a mare having an inability to evacuate her uterus?

A

Endometrial cysts

  • Caused by dilated lymphatics*
  • On US looks like early embryo - careful*
59
Q

How can endometrial cysts impair pregnancy (2 ways)?

A

Cysts prevent free movement of embryo around uterus

If very large, the uterus cannot make villi over the cyst and thus the surface area of the uterus is diminished

60
Q

What are the most commonly found bacteria in free luminal fluid?

A

Streptococcus zooepidemicus (and other B-hemolytic strep)

  • Klebsiella pneumonia*
  • Enterobacter cloacae*
61
Q

Which is more sensitive endometrial cytology or culture?

A

Cytology

62
Q

What is used to establish the prognosis and monitor the progress of chronic endometritis?

A

Endometrial biopsy

63
Q

What drug is used to treat postbreeding endometritis?

A

Oxytocin

Frequent tiny doses

64
Q

What can you give a mare that is prone to postbreeding endometritis to help reduce the inflammatory response to semen?

A

Single dose of dexamethasone within 60 min of mating

65
Q

What is a possible concequence of overuse of an intrauterine infusion of antimicrobials to treat chronic endometritis?

A

Fungal endometritis

VERY persistent

66
Q

What can be used to disrupt biofilm and improve antimicrobial penetration when treating chronic endometritis? What is the best choice?

A

Best: N-acetylcystine (ACE)

DMSO

EDTA-TRIS (chelating agents)

Lavage uterus w/LRS, infuse ACE, leave in for 30-90 min, infuse ABx

67
Q

What capsule types of Klebsiella pneumoniae can grow on the penis of a stallion?

A

1, 2, 5

7 and 68

68
Q

What can cause a large ovary in a horse?

A

Abscess

Hematoma

Tumor (e.g. Granulosa, Theca)

Pregnancy

69
Q

What type of tumor is this?

A

Granulosa Cell Tumor

Mare’s may show stallion-like behavior