Theriogenology - Midterm

Front 1

GnRH:
where is it produced?
what is its action?

Back 1

produced by the hypothalamus, causes the release of LH from the pituitary

Front 2

LH:
where is it produced?
what is its action (male and female)?

Back 2

produced in the anterior pituitary,

- females: induces ovulation and lutenization of the theca interna cells of the follicle to become luteal cells

- males: stimulates testosterone production from the interstitial cells

Front 3

FSH:
where is it produced?
what is its action?

Back 3

produced in the anterior pituitary,

- female: stimulates follicular development on the ovary

- male: supports the seminiferous tubules by stimulation of the nurse cells

Front 4

fluid-filled structure on the ovary that contains a soon-to-be ovulated oocyte. Produces estrogen

Back 4

follicle

Front 5

previously a follicle, cells have converted from estrogen production to progesterone production under the influence of LH

Back 5

corpus luteum

Front 6

the cells in the testes that produce testosterone

Back 6

Leydig (interstitial) cells

Front 7

cells that nurture sperm as they develop

Back 7

Sertoli ("nurse") cells

Front 8

where is estrogen produced in the female? What (five) psychological and physiological effects does it have?

Back 8

produced by the granulosa cells of the ovarian follicle.

1. standing behavior in the female
2. opens the cervix
3. stimulates moisture in the vagina
4. increases the thickness of the vaginal epithelium
5. increases the immune protection of the uterus

Front 9

where is progesterone produced in the female? What (five) physiological effects does it have?

Back 9

produced by the CL

1. responsible for maintaining pregnancy
2. closes the cervix
3. dries out the vagina
4. thins the vaginal epithelium
5. stimulates the glandular development of the uterus to support a pregnancy

Front 10

where is testosterone produced in the male? What (three) psychological and physiological effects does it have with regards to reproduction?

Back 10

produced by the Leydig (interstitial) cells of the testes

1. libido
2. secondary sex characteristics
3. growth of secondary sex glands (e.g. prostate)

Front 11

- length of the cow estrus cycle?
- length of estrus?
- length of diestrus?

Back 11

- cycle: 21 days (+/- 3)
- estrus: 9 hours (+/- 6)
- diestrus: 20 days (+/- 3)

Front 12

protrusion of the CL through the cow ovary

Back 12

crown

Front 13

demarcation of the crown on the cow ovary

Back 13

waist

Front 14

cardinal sign of estrus in the cow

Back 14

standing to be mounted

Front 15

secondary signs of estrus in the cow

Back 15

- restlessness
- mounting other cows
- increased activity (walking, calling)
- clear mucus discharge from cervix
- drop in milk production

Front 16

what hormone is responsible for follicular waves?

Back 16

FSH

Front 17

how many follicular waves does a cow have per cycle?

Back 17

2-3

Front 18

what hormone normally induces ovulation?

Back 18

LH

Front 19

which hormone produces standing behavior?

Back 19

estrogen

Front 20

which hormone is present during the luteal phase?

Back 20

progesterone

Front 21

what are the functions of prostaglandin F2α?

Back 21

1. lyse the CL
2. smooth muscle contraction

Front 22

what are the three phases of a follicular wave?

Back 22

1. growing
2. static
3. regression

Front 23

what is the fate of most follicles?

Back 23

atresia

Front 24

in the cow estrus cycle, when is the maximum production of progesterone by the CL?

Back 24

days 8 & 9

Front 25

in the cow estrous cycle, when does PGF begin to lyse the CL?

Back 25

day 16

Front 26

when does a CL become responsive to PGF in the cow?

Back 26

day 5

Front 27

in cystic ovarian disease of the cow, what are three clinical signs?

Back 27

1. persistent estrus (follicular cyst)
2. irregular cycles
3. persistent anestrus (luteal cyst)
(depends on type of cyst)

Front 28

in the cow, what is the major cause of anestrus?

Back 28

pregnancy

Front 29

in the cow, what are some etiologies of COD?

Back 29

ovulation failure due to
- lack of LH (negative energy balance)
- inadequate release of LH
- inadequate response to LH

Front 30

in the cow how is COD treated?

Back 30

- GnRH - turn the cyst into a CL
- PGF to lyse the CL
- if inadequate LH production/response, can use hCG instead of GnRH
- progesterone for 14 days; gives her a chance to build up her LH stores

Front 31

in the cow, what are 9 rule-outs for anestrus?

Back 31

1. pregnancy
2. ovarian cysts
3. pyometra
4. mummified fetus
5. neoplasia
6. developmental abnormalities (e.g. freemartin)
7. negative energy balance
8. lactational anestrus (esp. beef cows)
9. inadequate heat detection

Front 32

in the cow, what is pyometra?

Back 32

defined as presistent CL with pus in the uterus

Front 33

what are four indications for GnRH administration in the cow?

Back 33

1. COD
2. timed insemination programs (e.g. Ovsynch)
3. repeat breeders with no conception (3+ times)
4. day 14 postpartum; shown to boost fertility

Front 34

what are three indications for administration of GnRH in the bull?

Back 34

induce testosterone release
1. measure testosterone
2. increase libido
3. diagnose cryptorchidism

Front 35

what are the two functions of oxytocin in the female?

Back 35

1. smooth muscle contraction in the uterus
2. smooth muscle contraction in the mammary myoepithelial cells (milk letdown)

Front 36

administration of oxytocin in the cow: time of peak plasma concentration and clearance time

Back 36

- peaks at 10 minutes
- gone in 20 minutes

Front 37

where is oxytocin produced and stored in the body?

Back 37

- produced by the hypothalamus
- stored in the posterior pituitary

Front 38

what are two indications for oxytocin administration in the cow?

Back 38

1. milk letdown
2. uterine contractions

Front 39

where is hCG harvested?

Back 39

from the urine of pregnant women

Front 40

what are indications for use of hCG in the female and male bovine?

Back 40

- COD (female)
- hastens ovulation
- stimulates testosterone production (male)

Front 41

what are two reasons why GnRH is preferred over hCG in the bovine?

Back 41

1. GnRH is cheaper
2. hCG is a large protein and can provoke an immune response

Front 42

FSH in the cow

- where is it produced?
- what is its function?
- what are its indications for administration?

Back 42

- produced in the anterior pituitary
- stimulates follicle growth
- indicated for superovulation (for embryo transfer)

Front 43

where is progesterone produced?

Back 43

1. luteal tissue
2. placenta
3. adrenal gland

Front 44

what are four indications for progesterone administration in the cow?

Back 44

1. COD
2. induction of lactation
3. pregnancy maintenance
4. synchronization of estrus

Front 45

how does progesterone prevent estrus?

Back 45

causes negative feedback on the pituitary gland, inhibiting the release of gonadotropins (FSH and LH)

Front 46

what is a CIDR?

Back 46

- controlled intervaginal drug release
- a device inserted into the cervix of the cow that releases progesterone, thus preventing estrus
- remove all CIDRs at the same time to synchronize estrus

Front 47

where is estrogen produced in the female?

Back 47

1. theca interna cells of the Graafian follicle
2. placenta
3. adrenal gland

Front 48

what are three indications for administration of estrogen in the cow?

Back 48

1. increase tone, blood supply, and immune response to uterus
2. relax cervix
3. induction of lactation

Front 49

where is the majority of testosterone produced in the male?

Back 49

in the interstitial (Leydig) cells of the testis

Front 50

when is testosterone administration indicated and contraindicated in the bovine?

Back 50

indicated:
1. teaser animal
2. estrus synchronization programs

contraindicated in intact males because it will cause testicular degeneration

Front 51

with regards to bovine theriogenology, what are the two main functions of cortiosteroids (endogenous and/or exogenous)?

Back 51

1. induction of parturition
2. maturation of fetal lungs

Front 52

how long is PGF effective to induce abortion in cows?

Back 52

150 days

Front 53

in a bovine estrus control program, what is the purpose of administering prostaglandin?

Back 53

lyse the CL and "short cycle" the females

Front 54

when injecting cows with prostaglandins,
- what percentage of cows will go into estrus after the first injection?
- how many days do you wait until giving a second injection?
- in the double-injection method, how many cows will go into estrus?

Back 54

- single injection: 60% estrus
- wait 11 days until next injection
- double injection: 80-95% estrus

Front 55

if you inject a cow on Monday with prostaglandin, what day will they be in estrus?

Back 55

Thursday

Front 56

what is a progestin? what two physiological effects do they have in the cow? what are three routes of administration?

Back 56

- progesterone analogs
EFFECTS
1. mimicks the luteal phase (diestrus)
2. negative feedback to the pituitary
ROUTES OF ADMINISTRATION
1. oral
2. injectable
3. CIDR pessiaries (vaginal insertable/removable device)

Front 57

Ovsynch:
which hormones are administered?
what is the program schedule?

Back 57

- GnRH and PGF
- GnRH on Monday
- PGF on following Monday
- GnRH again on Wednesday
- breed 8-16 hours later

Front 58

cow:
- normal gestation length
- primary source of progesterone
- when does placental progesterone become important?

Back 58

- 278-282 days (9 mo 9 days)
- CL is primary site of progesterone
- placental progesterone after day 150

Front 59

what are three causes of short gestation in the cow?

Back 59

- twins (1-2 weeks early)
- abortion
- heat stress

Front 60

what are four causes of prolonged gestation in the cow?

Back 60

- adrenal hypoplasia - fetal giants
- pituitary aplasia - small, malformed fetus
- age: cow > heifer
- fetus gender: male > female

Front 61

what are the four cardinal signs of pregnancy in the cow, palpated per rectum, and the day in which they occur?

Back 61

1. amniotic vesicle - 35-70 days
2. membrane slip - 35+ days
3. fetus - 70 days
4. placentome - 80+ days

Front 62

what are the size of placentomes in the cow depending on the length of pregnancy?

Back 62

- 90 days: dime
- 110 days: nickel
- 120 days: quarter
- 150 days: half-dollar

Front 63

what are four non-cardinal signs of pregnancy in the cow?

Back 63

- uterine fluid
- middle uterine artery fremitus
- elevated serum progesterone
- ballotment of fetus through flank

Front 64

what are five problems seen in the cow associated with twinning?

Back 64

1. retained placenta
2. metritis
3. abortion
4. less viable calf
5. freemartins

Front 65

what is the main cause of pregnancy wastage in the cow?

Back 65

early embryonic death

Front 66

when does early embryonic death become detectable in the cow?

Back 66

after day 16

Front 67

when in the cow are mummified fetuses normally seen? what are three etiologies? how is it treated?

Back 67

- 5-6 months
- retained CL, BVD, Neospora
- treat with PGF

Front 68

in the cow, what are the two hydrops conditions of pregnancy? what is the pathogenesis? what is the prognosis for dam and fetus?

Back 68

1. hydrops allantois; placental abonormailty - Na pump dysfunction draws fluid into choiroallantois; poor prognosis for both dam and fetus
2. hydrops amnii: fetal abnormality of the head - they can't adequately swallow (maintain) amniotic fluid; poor prognosis for fetus, good prognosis for cow

Front 69

what is the recommendation for a cow that has a vaginal prolapse during gestation?

Back 69

replace the vagina and attach retention sutures. After calving, cull the cow because this is recurrent

Front 70

what are six etiologies for a prolapsed vagina in the cow?

Back 70

1. inherited
2. poor perineal conformation
3. higher estrogen --> relaxed pelvic ligaments
4. increased abdominal pressure
5. irritation due to drying and frostbite
6. straining

Front 71

what initiates parturition in the cow?

Back 71

fetal cortisol

Front 72

what hormonal changes occur in the cow following release of fetal cortisol?

Back 72

- placenta makes estrogen instead of progesterone
- estrogen upregulates oxytocin receptors and stimulates PGF release
- PGF release = lysis of the CL

Front 73

what are three common indications for induction of parturition in the cow?

Back 73

1. when attendance at delivery is desired
2. excessive udder edema
3. hydrops conditions

Front 74

what is the common drug used to induce parturition in the cow?

Back 74

dexamethasone (sometimes with PGF)

Front 75

what are five common diseases seen in the cow during parturition or post-partum?

Back 75

1. hypocalcemia ("milk fever") - flaccid paralysis
2. uterine torsion
3. uterine prolapse
4. retained placenta
5. toxic metritis

Front 76

milk fever in the cow:
- clinical signs
- treatment

Back 76

- hypocalcemia, hypothermia, down (flaccid paralysis), uterine inertia, dystocia, uterine prolapse
- administer IV calcium

Front 77

uterine torsion in the cow
- when does it usually happen?
- clinical signs
- treatment
- prognosis

Back 77

- 1st stage of parturition
- no straining, tail up, restless, kicking at abdomen, spiral folds in vagina
- detorsion rod, or plank in the flank technique
- prognosis - good if early Dx

Front 78

uterine prolapse in the cow:
- Tx

Back 78

- EMERGENCY!
- don't transport
- epidural
- clean uterus and lift to relieve urine
- replace tissue and use retention sutures
- antibiotics, NSAIDs
- calcium and oxytocin

Front 79

when is a placenta in a cow considered retained? Tx?

Back 79

- 12-24 hours
- if cow is normal, allow 5-7 days; after that, Calcium, oxytocin, PGF
- if cow is sick, systemic antibiotics, oral/IV fluids, antipyretics, NSAIDs

Front 80

what are common causes and treatments of metritis in cows? prognosis?

Back 80

CAUSES
- retained placenta
- OB intervention - dystocia, twin
- abortion
- dirty environment during calving
- these allow opportunistic bacterial infections
TREATMENTS
- antipyretics (NSAID)
- antimicrobials
- IV fluids if needed
- oxytocin
PROGNOSIS: guarded if treated early

Front 81

what is the definition of pyometra in the cow?

Back 81

1. pus in the uterus
- AND -
2. persistent CL

Front 82

how is pyometra treated in the cow?

Back 82

- PGF Q 14 days
- gentle uterine lavage

Front 83

name two major venereal diseases of cattle

Back 83

1. Trichomoniasis
2. Camphylobacter (Vibrio)

Front 84

Tritrichomonas foetus:
- carrier
- where in the animal does it live?
- clinical signs

Back 84

- bulls are carriers
- lives in prepuce of bull, vagina, uterus, oviducts
- infertility (most common sign)
- embryonic/fetal death
- low pregnancy rates
- spread-out calving season
- pyometra/abortion
- bulls - asymptomatic

Front 85

Trichomoniasis in cattle:
- Dx
- Tx
- management and prevention

Back 85

DIAGNOSIS
- bull - culture preputial smegma
- cow: culture cervical mucus or pus
- in-pouch test - 3 negative tests to confirm absence of organism
TREATMENT
metronidazole, but it is illegal in food animals
MANAGEMENT & PREVENTION
- segregate cows > 5 mo pregnant
- cull abnormal infected cows
- normal cows: rest for > 3 heat cycles
- cull bulls
- AI: double-sheath
- replace with virgin heifers and bulls into dz-free herds
- vaccine

Front 86

Campylobacter in cattle:
- carrier
- clinical signs
- Dx
- Tx

Back 86

carrier - bulls in prepuce
CLINICAL SIGNS
- infertility (most common)
- cows: endometritis/salpingitis; embryonic/fetal death
- bulls: weight loss, low libido
DIAGNOSIS
- culture cervical mucus, prepuce, and fetal stomach contents
- VMAT (vaginal mucus agglutination test)
- blood/serum (false +)
TREATMENT
- antibiotics
- vaccination
- AI - double-sheath technique
- immunity develops in 4-5 months

Front 87

Neospora canium
- carrier
- clinical signs
- Dx
- Tx and prevention

Back 87

- dog (fecal)
CLINICAL SIGNS
- abortion at 3-9 months: fetus resorbed, mummified, or autolyzed;
- stillborn
- born alive but chronically infected
DIAGNOSIS
- histological examination of brain tissue
- PCR, ELISA, etc.
TREATMENT & PREVENTION
- vaccine (questionable)
- prevent contamination

Front 88

Brucella abortus in cows:
- transmission
- clinical signs
- definitive diagnosis
- control

Back 88

- spread via uterine transmission; intracellular pathogen
- mid to late gestation abortion due to placentitis
- bacterial culture of milk, blood, or uterine discharge
- cull if positive; vaccination

Front 89

Leptospira in cows:
- transmission
- where does it live?
- clinical signs
- Dx
- Tx

Back 89

- spread via contaminated urine, ponds
- lives in urogenital tract
- clinical signs: infertility, EED, abortion
- Dx: urine culture, serology, fetal fluids
- Tx: vaccination

Front 90

what are two types of viral agents associated with bovine reproduction and diseases associated with them?

Back 90

1. Bovine Herpesvirus (BHV-1): Infections Bovine Rhinotracheitis (IBR); Infectious Pustular Vulvovaginitis (IPV)
2. Orbivirus: bluetongue - EED in first trimester

Front 91

in the cow, what is an important technique to definitively diagnose an abortion disease alongside necropsy of fetus and placenta?

Back 91

serology

Front 92

in which type of bull is a breeding soundness exam most common

Back 92

beef bull

Front 93

how does bull age correlate with the number of cows he can service?

Back 93

- 2 years old - 20 cows
- 3 years old - 30 cows
- 4+ years old - 40 cows

Front 94

what are the four basic aspects of a bull breeding soundness exam?

Back 94

1. physical exam
2. scrotal circumference
3. rectal - seminal vesicles
4. semen evaulation

Front 95

in the bull, what accessory reproductive structures are palpated?

Back 95

1. seminal vesicles
2. prostate
3. bulbourethral glands
4. ampulla

Front 96

what are the two most common ways to collect semen from a bull?

Back 96

1. electroejaculator
2. AV

Front 97

what are the five parameters of a proper semen evaulation?

Back 97

1. volume (if collected by AV)
2. color
3. consistency
4. motility (>/= 30%)
5. morphology (>/= 70% normal cells)

Front 98

in the bull, rupture of the tunica albuginea at the distal sigmoid flexure

Back 98

penile hematoma

Front 99

penile hematoma in the bull
- Dx
- Tx
- sequela

Back 99

- Dx: swelling of various sizes at the neck of the scrotum
- Tx: cold hydrotherapy, antibiotics, sexual rest (at least 2 months)
- Sequela: damage to dorsal nerve (no sensation in glans); abscess; venous shunts (can't maintain erection); adhesions

Front 100

what are two genetic predispositions that can lead to preputial injuries in bulls?

Back 100

1. pendulous prepuce (Bos indicus)
2. lack of/weak preputial muscle (polled breeds, e.g. Hereford)

Front 101

preputial injury in the bull treatment

Back 101

- tight wraps to protect tissue
- hydrotherapy to reduce swelling
- antibiotics to lacerations
- 2-6 weeks
- complete healing before Sx

Front 102

what are four common genetic/acquired abnormalities of the bull penis.

Back 102

1. spiral deviation
2. shunts (can't maintain erection)
3. papilloma - warts
4. persistent frenulum

Front 103

why is seminal vesicle examination important in the bull?

Back 103

- it is an infection
- untreatable
- not sound to breed

Front 104

what are the three stages of normal parturition?

Back 104

1. cervical dilation
2. fetal expulsion
3. passing of the placenta

Front 105

for obstetrics in the cow, what are the three things to evaluate about the fetus via vaginal examination?

Back 105

1. viability
2. normality
3. presentation-position-posture

Front 106

for obstetrics in the cow, what are the two things to evaluate in the vaginal canal?

Back 106

1. maternal/fetal relative size
2. trauma to vaginal vault

Front 107

what is the definition of presentation of the fetus?

Back 107

relation of spinal axis of fetus to dam. (i.e. longitudinal vs. transverse; anterior versus posterior)

Front 108

what is the definition of position of the fetus?

Back 108

how the fetus is rolled, side-to-side, within that pelvic quarter.

Front 109

what is the definition of posture of the fetus?

Back 109

relation of extremities to the body of the fetus

Front 110

in the cow and mare, what is the normal presentation of the fetus?

Back 110

anterior longitudinal (lengthwise, head facing toward vagina)

Front 111

in the cow and mare, what is the normal position of the fetus?

Back 111

dorso-sacral

Front 112

in the cow and mare, what is the normal posture of the fetus?

Back 112

head resting on metacarpal/carpal bond of extended forelegs

Front 113

for the fetus, why does dystocia in the horse have a poorer prognosis than the cow?

Back 113

because the horse's diffuse epitheliochorial placenta disconnects quickly after 2nd stage of labor, whereas the cow's cotyledonary placenta holds on for 3-12 hours

Front 114

what is important to know about the J-lube used in lubrication of obstetrical operations?

Back 114

it is toxic to the peritoneum, so it must be cleaned off ASAP

Front 115

what three aspects of insemination are critical for optimum fertility?

Back 115

1. sufficient numbers of sperm
2. sufficient sperm quality
3. at the appropriate time

Front 116

what are the two waves of sperm transport?

Back 116

- 1st wave: uterus transports everything
- 2nd wave: sperm transport dependent

Front 117

where is sperm deposited in the cow? horse?

Back 117

cow - anterior vagina
horse - uterus

Front 118

what aspects of a spermiogram are evaluated
- macroscopically?
- microscopically? (include lens power when relevant)

Back 118

MAROSCOPIC
- color
- volume (if AV used to collect)
MICROSCOPIC
- gross motility (10X)
- individual motility (40X)
- viability (doesn't stain = live; stains = dead)
- concentration per mL of ejaculate
- Morphology (100X oil immersion)

Front 119

what two major environmental aspects affect sperm motility?

Back 119

- age of the semen
- temperature

Front 120

what environmental factors can influence sperm morphology in a spermiogram?

Back 120

1. temperature - want a warm slide
2. presence of spermicidal agents such as detergents, KY jelly (chlorhex)
3. mechanical prep damage (including aspiration into pipet)
4. osmotic damage - dry off straw after thawing
5. other: UV light, lube in monoject syringe

Front 121

what stain is used to evaluate sperm microscopically? How does the staining provide information? How is this information used?

Back 121

- "vital stain", e.g. Eosin-nigrosin (Hancock stain)
- live sperm exclude stain; dead sperm take up the stain
- not routinely used because of lack of correlation between live:dead with regard to fertility

Front 122

what are two measurements of sperm concentration? how is this measurement of count routinely made in the lab?

Back 122

1. sperm per mL of ejaculate
2. total sperm number (sperm per mL multiplied by mL of ejaculate)
- hemacytometer or densitometer is used to measure

Front 123

scrotal circumference:
- species
- what does it tell us?
- how is it used practically?

Back 123

- bull, buck, ram (pendulous scrotum species)
- positive correlation to sperm output
- young stock are selected for big balls

Front 124

what is the most important aspect of sperm morphology with regards to fertility?

Back 124

we need a minimum number of NORMAL sperm per ejaculate for optimum fertility.

Front 125

comment on the origin and appearance of
- primary sperm abnormalities
- secondary sperm abnormalities

Back 125

- primary: from testicle; abnormalities are head, midpiece, and severe tail defects
- secondary: from epididymis; abnormalities are detached heads, distal droplets, and mild tail defects

Front 126

what are some common abnormalities of the sperm in the
- head?
- midpiece?
- tail?

Back 126

- head: detaching acrosome, knobbed acrosome, small head
- midpiece: proximal droplet, coiled midpiece
- tail: severe coils or bent tails (can be artifact of the stain with non-bovines)

Front 127

what are four research tools used by specialized laboratories to evaluate sperm?

Back 127

1. zona penetration tests
2. specific stains
3. hypo-osmotic test
4. swim-up test

Front 128

what are the possible results of a breeding soundness exam on
- a mature bull?
- a young bull?

Back 128

- mature bull: unsatisfactory or satisfactory
- young bull: satisfactory potential breeder, unsatisfactory potential breeder

Front 129

how can cytology help a sperm evaulation?

Back 129

early detection of disease
- neutrophils in rams
- prostatitis in dogs

Front 130

how do the results of a bacterial culture of sperm affect interpretation?

Back 130

- mixed cultures with slight growth are incidental
- heavy growth of one organism is a red flag

Front 131

what three factors commonly lead to a decreased sperm viability in a spermogram?

Back 131

1. external factors
2. problems with accessory glands and epididymis
3. sub-optimal thermoregulation of testes

Front 132

if you see decreased motility in a spermogram, what should you do?

Back 132

- realize that this may be due to external factors
- centrifuge and reconstitute in semen extender to re-evaulate
- rule out external causes and see if this is a consistent finding

Front 133

reduced numbers of sperm in ejaculate

Back 133

oligospermia

Front 134

what are three common causes of oligospermia?

Back 134

1. small testicles
2. testicular degeneration
3. occlusion of efferent duct system

Front 135

equines have what types of estrus (include percentages)?

Back 135

- 80% are seasonally polyestrous (long-day breeders; estrus in late winter and spring)
- 20% cycle year round

Front 136

equine estrus
- cycle length
- seasonal variation
- horses versus other breeds/species

Back 136

- 21 days
- longer in the spring, shorter in the summer
- pony mares and jennies have a 24-26 day cycle

Front 137

what is the transition phase of equine estrous behavior? What are some important aspects of the transition phase?

Back 137

- erratic or prolonged estrous behavior between winter anestrous and the polyestrous breeding season
- early, ovaries are small and inactive
- late, there are multiple large follicles
- ends with the first ovulation
- responsible for breeding inefficiencies

Front 138

estrus in the horse:
- hormone
- length of estrus
- change in reproductive structures (and how do we see this in the clinic)
- what do follicles look like?

Back 138

- estrogen
- 7-9 days in the spring; 3-5 days as the season progresses
- relaxation of the cervix and uterus (pr or vaginoscopy)
- vagina pink and moist (vaginoscopy)
- endometrial edema (ultrasound)
- large follicle predominates over other smaller follicles

Front 139

what does the cervix look like in the horse that is in estrus?

Back 139

pale, soft, "Looks like it was made out of wax and somebody melted it"

Front 140

how can estrus in the horse be detected by ultrasonography?

Back 140

striations are indicative of endometrial edema, which occurs during estrus

Front 141

why can't you palpate the CL pr in the mare?

Back 141

because she ovulates via the ovulation fossa

Front 142

estrus in the horse:
- when does ovulation occur?
- how do we detect ovulation?
- seasonable variability of estrus

Back 142

- ovulation 24-48 hours before end of estrus
- ovulation is detected pr or by ultrasound
- Estrus longer in spring, shorter in summe

Front 143

horse:
- average cycle length
- length of estrus
- length of diestrus
- time of ovulation

Back 143

- average cycle length: 21 days
- length of estrus: 7-9 days in the spring; 3-5 days as the season progresses
- length of diestrus: 12-16 days
- time of ovulation: 1-2 days before end of estrus

Front 144

what are five behaviors indicative of estrus in the mare?

Back 144

1. positive attitude towards stallion
2. raising the tail
3. "winking"
4. urination
5. leaning into stallion

Front 145

what is foal heat? when does it occur? affect on fertility? how does breeding during foal heat affect the foaling date?

Back 145

- first postpartum estrus
- usually occurs around day 9
- good fertility if ovulation occurs after day 10
- moves the foaling date to earlier in the year

Front 146

what can happen to the foal during his mother's foal heat?

Back 146

foal may experience Foal Heat Diarrhea

Front 147

for thoroughbred horses, what is the worst birthday to have? the best? why?

Back 147

- worst: December 31st
- best: January 1st
- because all horses' "birthday" is January 1st of the year they were born

Front 148

diestrus in the mare:
- average duration
- appearance of parts of the repro tract
- follicle activity

Back 148

- 14-16 days
- cervix and uterus have moderate tone
- cervix is tightly closed
- follicles can be present on the ovaries
- diestrous ovulation can occur

Front 149

diestrus in the mare:
- detection of CL
- behavior

Back 149

- can't palpate pr; must use ultrasound to visulaize
- negative behavior towards the stallion

Front 150

in the horse, how does melatonin affect the gonads?

Back 150

increased melatonin (which is produced during the short daylight months) has an antigonadotropic efect

Front 151

anestrus in the mare:
- time of year
- geographic considerations
- appearance of parts of the repro tract
- behavior

Back 151

- Oct, Nov - Feb
- longer in northern latitudes
- very atonic cervix and uterus
- passive behavior towards stallion

Front 152

what are three common presentations of abnormal estrous cycles in the mare?

Back 152

1. persistent estrus
2. persistent anestrus
3. shortened luteal phase

Front 153

persistent estrus in the mare:
- stereotypical behavior
- name 3 pathogeneses

Back 153

- stereotypical behavior: nymphomania
ETIOLOGIES
1. granulosa cell tumors (recall they they can be estrogen secreting)
2. chromosomal abnormalities (e.g. XO) that lead to increased adrenal estrogens
3. ovariectomized mares that have overproduction of adrenal estrogens

Front 154

what are TWELVE etiologies of persistent anestrus in the mare? Note that this list contains normal causes, abnormal anestrus, and abnormal diestrus.

Back 154

1. winter anestrus - normal
2. postpartum anestrus after "foal heat" - normal
3. chromosomal abnormalities
4. ovarian tumors (e.g. granulosa cell tumor)
5. nutritional anestrus
6. ovarian senescence (old ovaries)
7. persistent CL - inadequate/lack of PGF - persistent diestrus
8. anovulatory follicle
9. diestrus ovulation - persistent diestrus
10. pseudopregnancies - persistent diestrus
11. hormonal therapy (progestorne or anabolic steriods)
12. persistent anovulatory follicles (PAF) - similar to COD in cows

Front 155

what is the basic cause (pathogenesis) of a shortened luteal phase in the mare?

Back 155

PGF secretion at the wrong time

Front 156

what are four causes of a PGF-mediated shortened luteal phase in the mare

Back 156

1. bacterial endometririts - infammation
2. (iatrogenic) fluid in the uterus - inflammation
3. invasive Dx procedures of the uterus - inflammation
4. endotoxins and other systemic illness such as colic

Front 157

equine early gestation:
- how long does the mare continue to ovulate?
- where does fertilization occur?
- when does the fertilized ova reach the uterus?
- when does embryonic motility end?

Back 157

- ovulation to day 40
- fertilization occurs in the oviduct
- zygote reaches uterus on day 6-7
- embryonic motility ends day 16

Front 158

equine early gestation:
- when can the amniotic vesicle be visualized by ultrasound?
- when does the cervix achieve extreme tone?
- why might the mare act like a stallion?

Back 158

- amniotic vesicle can be seen by U/S by day 12-14
- extreme tone of cervix at day 21
- mare may act like stallion because she has very active ovaries, secreting sex hormones

Front 159

in the mare, on a PR exam, how does day of pregnancy correspond to uterine swellings (in terms of the size of a sports ball)?

Back 159

- day 28: golf ball
- day 35: softball
- day 45: fluctuant
- day 60: football
- day 90: basketball

Front 160

in the pregnant mare, when does the endometrial cup phase begin? when do they regress? why do they regress?

Back 160

- begin at day 40
- regress at day 70
- immune reaction destroys the cups

Front 161

what hormone is produced by the equine endometrial cups? What hormone does this mimic?

Back 161

- produces eCG
- mimics LH in the mare (FSH in other animals)

Front 162

why does the mare stop ovulating at day 40 of pregnancy?

Back 162

because endometrial cups form and produce eCG. eCG acts like LH and produces secondary CLs, which have a negative feedback on pituitary FSH production.

Front 163

comment on the hormones involved in maintaining pregnancy in the mare on and after day 100.

Back 163

- the maternal CL has regressed
- placenta is maintaining the pregnancy by converting fetal gonad estrogens to progesterone
- ovaries are not even necessary after day 100!

Front 164

how would you perform a successful embryo transfer on an ovariectomized mare?

Back 164

- give her progesterone up until day 100
- after day 100, fetal gonads will produce all of the hormones necessary for pregnancy and the placenta will convert the hormones to progesterone

Front 165

what three methods are used to diagnose pregnancy in the mare?

Back 165

1. PR - uterus pulled over the brim of pelvis; fetus palpable by 7th month
2. estrogen present in the mare's urine
3. transabdominal ultrasound

Front 166

a pregnant horse with a huge pot belly probably has what? what is the prognosis?

Back 166

a ruptured prepubic tendon; poor prognosis for mare and fetus

Front 167

how can you tell if a mare has uterine torsion?

Back 167

you can feel the broad ligament pulled to one side on a rectal palpation

Front 168

what is the most accurate way of determining whether a mare is ready to foal?

Back 168

increased calcium in the milk

Front 169

what are five predictors of parturition in the mare?

Back 169

1. ***increased milk calcium (best indicator)
2. relaxation of pelvic ligaments (looks like the tailhead rose)
3. distention of mammary tissue
4. "waxing" of the teats
5. elongation and relaxation of vulva

Front 170

what is the average gestation length in the mare? what time of day to most births occur? what are three factors contributing to variability in length of gestation?

Back 170

- average is 11 months, 11 days (341 days)
- most births occur at night
VARIABILITY OF GESTATION LENGTH
1. male vs. female fetus
2. time of year
3. fescue toxicity

Front 171

what are some signs in the mare during the first stage of parturition?

Back 171

- slight sweating
- restlessness
- getting up and down frequently
- attempts to urinate
- frequent defecation
- yawning

Front 172

describe stage 2 of parturition in the mare

Back 172

- release of allantoic fluid ("water breaks")
- active contractions (groups of 3-4 followed by rest periods of 2-3 minutes)
- average duration: 20 minutes
- lateral recumbency

Front 173

if you see the umbilical cord pulsing after a foal is born, what does this mean?

Back 173

nothing. this is normal.

Front 174

why might a mare get up and down during the second stage of parturition?

Back 174

to help reposition the foal

Front 175

in the mare, after how long is the placenta considered retained?

Back 175

3 hours

Front 176

why should the mare's placenta be examined after a successful parturition?

Back 176

to make sure no bits and pieces are broken off and possibly retained in the uterus

Front 177

a white, fibrous discoloration in the otherwise red placenta of the mare

Back 177

cervical star

Front 178

at what age in the mare does fertility typically start to decrease?

Back 178

12 years

Front 179

what is the most important predictor of fertility in the mare?

Back 179

past breeding history

Front 180

what are the three "statuses" of a mare in a breeding soundness exam, depending on foaling?

Back 180

1. foaling or "wet" mare: most fertile
2. maiden mare: unproven - assume normal unless older
3. barren mare: a mare who has been pregnant, but for any reason whatsoever, is not pregnant now

Front 181

what are the four basic physical examinations in a breeding soundness exam in the mare?

Back 181

1. overall general health
2. external genitalia - extremely important
3. rectal exam, ultrasound
4. vaginal speculum examination

Front 182

what is the most important aspect of examining the external genitalia of a mare during a breeding soundness exam?

Back 182

perineal conformation

Front 183

during a breeding soundness exam, what are three aspects of a good perineal conformation in the mare?

Back 183

1. vulvar lips have a tight seal and opening is perpendicular to the ground
2. dorsal commissure is below the ischiatic arch
3. >60% of the vulva is below the ischiatic arch

Front 184

what are the "three seals" of the equine female reproductive tract?

Back 184

1. vulvar lips
2. vaginovestibular junction
3. cervix

Front 185

if you pull the vulvar lips apart in the mare and hear an inrush of air, what does this mean? why does this happen?

Back 185

- there is not a good seal (usually a defect in the vaginovestibular junction)
- pneumovagina
- this happens because the abdomen has negative pressure with respect to the outside of the body

Front 186

how does artificial selection for faster horses affect anatomical conformation and fertility?

Back 186

- faster horses, we select for a flatter croup
- this causes the vulva to raise and can cause problems in fertility if the vagina slips over the ischiatic arch

Front 187

why should you always do uterine cytology along with a uterine culture in the mare?

Back 187

to determine presence of inflammatory cells. The culture swab can be contaminated with normal flora

Front 188

in a uterine cytology, how does the appearance of PMN cells affect your interpretation?

Back 188

- "happy looking" neutrophils, with a lobulated nucleus and distinct cytoplasm are an incidental finding
- evidence of inflammation show swollen, eosinophilic neutrophils with no distinct cytoplasm (they are "fighting the war")

Front 189

describe the endometrial biopsy scores in the mare and their predictive foaling rate

Back 189

Grade I: normal - >80% foaling rate
Grade IIA: presence of inflammation: 75% foaling rate
Grade IIB: inflammation with mild fibrosis: 50% foaling rate
Grade III: extensive fibrosis: < 10% foaling rate

Front 190

what is the most common cause of infertility in the mare?

Back 190

endometritis

Front 191

what are six common pathogens of the mare's uterus and their origin

Back 191

1. Streptococci: endogenous
2. E. coli: endogenous
3. Klebsiella: from stallion
4. Pseudomonas: from stallion
5. Yeasts: overuse of antibiotics
6. CEM (contagious equine metritis): imported from Europe

Front 192

what are three important anatomical/physiological causes of endometritis in the mare?

Back 192

1. poor perineal anatomy (not a good seal)
2. inability of the uterus to evacuate
3. poor local immunity

Front 193

what are three common types of drugs used to treat endometritis in the mare?

Back 193

1. oxytocin
2. intrauterine antimicrobials
3. DMSO

Front 194

what are four manual techniques used to treat/prevent endometritis in the mare?

Back 194

1. uterine lavage
2. minimum contamination breeding techniques
3. curettage - mechanical or chemical debridement of the endometrial lining
4. vulvoplasty - "Caslick's" surgery

Front 195

what three properties of DMSO help to treat endometritis in the mare?

Back 195

1. antiinflammatory
2. antimicrobial
3. decreases fibroblast activity (less fibrosis associated with inflammation)

Front 196

what is Caslick's surgery? Why is this thought to help treat endometritis?

Back 196

- vulvoplasty of the mare involving suturing the vulvar lips together down to the ischiatic arch.
- less contamination of the reproductive tract, so the mare can clear herself of the infection

Front 197

what are five common anatomic abnormalities of the mare reproductive system that do not involve structures cranial to the cervix?

Back 197

- abnormal vulvar conformation
- urine pooling
- persistent hymen
- vaginal adhesions (especially from bilateral abrasions from dystocia healing together)
- cervical tears

Front 198

what are seven uterine abnormalities in the mare?

Back 198

1. endometrial fibrosis
2. endometrial hypoplasia
3. endometrial atrophy
4. endometrial cysts
5. uterine adhesions (+/- abscesses)
6. foreign bodies
7. tumors

Front 199

what are some indications for use of prostaglandin in the horse?

Back 199

1. lyse the CL
2. management of the stallion
3. avoid foal heat breedings
4. termination of persistent CL
5. treatment of (endo)metritis (estrogen boosts immunity)
6. elective abortion before 40 days

Front 200

in the mare, how long after pregnancy can PGF be used to induce abortion?

Back 200

< 40 days (recall endometrial cups begin at 40 days)

Front 201

what are three indications for use of oxytocin in the mare?

Back 201

1. induction of parturition (this will happen whether the foal is ready or not)
2. retained placenta (recall, after 3 hours)
3. uterine evacuation

Front 202

if you wanted to induce parturition in the mare to have a viable foal, what would be the best test as to whether the foal is ready to be born?

Back 202

higher calcium in the milk

Front 203

what are two indications for use of hCG in the horse?

Back 203

1. induction of ovulation (24-48 hours later)
2. detection of a cryptorchid male (measure serum testosterone before and after)

Front 204

what are some indications for use of progestin in the horse?

Back 204

1. bring her out of winter anestrus/transitional phase
2. control libido in mares and stallions
3. to maintain pregnancy in the deficiency of adequate progesterone
4. to prevent PGF release in a pregnant mare with colic

Front 205

why is synthetic GnRH (Sucromate® - Deslorelin) used in the mare?

Back 205

induction of ovulation

Front 206

why is thyroxin used in the mare?

Back 206

(anecdotal evidence)
- may help maintain pregnancy, especially in stressed mares (e.g. transport, low in the pecking order)

Front 207

when a mare is in estrus, when do you breed her and how often?

Back 207

- breed the 2nd day of estrus
- breed every day until out of heat

Front 208

what are pros and cons of pasture breeding?

Back 208

- best fertility results (the mare and stallion know best)
- limited number of mares that the stallion will breed
- exposes the stallion (especially inexperienced stallions) to injury

Front 209

light manipulation of the mare:
- how is light used?
- when is the best time to add light?
- how much light per day?
- brightness of light?
- how long after the start of using light will affects be apparent?

Back 209

- increasing the amount of light exposure to simulate more daylight
- best if light is added at the end of the day
- need 16 hours of light per day
- need 10 foot-candles of light
- need to start 60 days ahead of time

Front 210

what are the two types of lighting used for mares?

Back 210

- stall lighting (200W bulb in a 12x12 stall)
- pen lighting

Front 211

how do you manage the transitional phase in the mare?

Back 211

- use Regumate (synthetic GnRH) to mimic the lutel phase
- transition phase ends after 1st ovulation
- after 10-14 days, give PGF to lyse any CLs

Front 212

PGF administration in the mare:
- indication
- when would you expect estrus?
- when would you expect ovulation?

Back 212

- lyse the CL
- estrus in 3-5 days
- ovulation in 7-10 days

Front 213

hCG administration in the mare:
- indication
- when is ovulation expected?
- follicle size?

Back 213

- induce ovulation
- ovulation expected in 24-48 hours
- follicle size: 3 cm

Front 214

how long will properly collected, prepared, and refrigerated (not frozen) semen last?

Back 214

72 hours

Front 215

frozen semen is convenient for storage, but how does this affect how you would perform AI in the mare?

Back 215

- frozen semen has reduced longevity
- must AI within 4-6 hours of ovulation
- use with GnRH or hCG and time appropriately
- one or two breedings per cycle

Front 216

why do you need ultrasound to diagnose a pregnancy in a mare before 16 days?

Back 216

because the embryo does not implant until then

Front 217

when is early embryonic death most common in mares?

Back 217

prior to 42 days (before endometrial cups are in action)

Front 218

what is the leading cause of non-infectious abortion in mares?

Back 218

twinning

Front 219

what preventative measures with respect to infections are given to mares during gestation?

Back 219

- vaccinations: EHV-1, tetanus
- anthelmintics
- quarantine

Front 220

if a pregnant mare is grazing on fescue, when should she be removed from this pasture to ensure a normal gestation and foaling?

Back 220

day 300

Front 221

what are four clinical signs of fescue toxicosis in the horse?

Back 221

1. agalactia
2. prolonged gestation
3. thickened placenta
4. poor foal viability and hypothyroidism

Front 222

if you suspect fescue toxicosis in the pregnant mare, what two things should you do?

Back 222

1. remove from affective grass
2. give dopamine antagonists

Front 223

what six venereal infectious agents are carried by the stallion? which ones are asymptomatic in the stallion?

Back 223

1. Klebsiella - asymptomatic
2. Pseudomonas - asymptomatic
3. CEM (contagious equine metritis) - a bacterial infection - asymptomatic
4. equine viral arteritis - in the semen
5. coital exanthema - EHV-3
6. Trypanosoma equiperdum - dourine

Front 224

what are the two functions of LH in the female? what does it do in the male?

Back 224

- ovulation induction
- luteinize the follicle
- in the male: stimulates Leydig cells to produce testosterone

Front 225

what are the two functions of oxytocin?

Back 225

1. myometrial contraction
2. milk letdown

Front 226

why is a dopamine antagonist used in fescue toxicosis of the mare?

Back 226

because dopamine prevents prolactin secretion.

Front 227

what are the two functions of prostaglandin-F2α?

Back 227

- lyse the CL
- smooth muscle contraction

Front 228

what is the function of prostaglandin-E2

Back 228

relaxation of the cervix

Front 229

why would dopamine agonists be used in the dam?

Back 229

they inhibit prolactin secretion and thus stop lactation