Estrous Cycle Flashcards

Question

Equine Estrus Vaginal Speculum Examinaition

Answer 1

During Estrus, progesterone levels are low and the cervix is swollen with relaxed folds which hang down over hte open orifice

Answer 2

Obvious interest in the stallion, urination, vulva eversion, and squatting

Answer 3

Aka Luteal Phase of the Estrous Cycle Time of progesterone dominance Lasts 14-15 days The mare refuses the stallion Progesterone comes from the CL Endogenous PGF2a is secreted by uterus if no maternal recognition of pregnancy by day 13-14 PGF2a causes CL lysis and a rapid decline in progesterone production the last few days of diestrus

Answer 4

During diestrus, progesterone levels are high and the os cervix is tightly closed and surrounded by firm, well-defined folds

Answer 5

Obvious hostility to the stallion, ears back, striking, biting, squealing

Answer 6

Anestrus Proestus Estrus Diestrus Interestrus = diestrus + anestrus

Answer 7

Evaluating vaginal cytology is an important clinical skill in canine repro management Use cotton-tipped swab to gently exfoliate cells form the vaginal vault Decrease estrogen means the bitch is not interested in breeding and the vaginal lining is thin. Vaginal cells are close to the blood supply and very healthy looking Increased estrogen means the bithc is interested in mating and the vagina needs to “toughen up” and become thicker. The vaginal cells on the surface are now far from the blood supply and are dead

Answer 8

Lasts for a variable amount of time after diestrus ~ 90-150 days Anestrus is a time of mandatory endometrial repair Neither male nor female shows sexual interest the vulva appears normal, not swollen or edematous Progesterone is at baseline concentrations \<1ng/ml Prolactin secretion by the pituitary may promote anestrus, becuase prolactin inhibitors can be used to terminate anestrus

Answer 9

Relatively constant One sees primarily proabasal and small intermediate epithelial vaginal cells Neutrophils may or may not be present and RBCs are usually absent Bacteria may or may not be seen

Answer 10

Averages 5-10 days Males are interested in the female, but female is not interested in males The vulva is swollen because of estrogen secretion by the growing follicles THere is serosanguinous discharge form the vulva that results form diapedesis of RBCs through urterine vessels The most reliable clinical sign of hte onset of proestrus is noting the first day of a bloody vaginal discharge LH has an increased pulse-frequency FSH suppressed Estrogen comes from the growing follicles and peaks at end of proestrus Testosterone is relatively high at the end of proestrus. This may result from a “backup” in estrogen synthesis. This may result in some masculine behavior by the bitch such as mounting other dogs

Answer 11

Similar to bithc in anestrus except, for the presence of varying ninbers of red blood cells RBCs numerous parabasal cella nd intermediate cells Neutrophils are common although usually not abundant and bacterai the background is granual or “dirty”

Answer 12

THe first evidence of continued estrogen effect on the vaginal cytology is the disappearance of neutrophils Fewer parabasal and small intermediate cells, more large intermediate and superficial intermediate cells RBC may ro may not be present The background is dirty or clear

Answer 13

No neutrophils, RBC are variable background is clear Greather than 80% of the vagianl cells are superficial cells, with pyknotic nuclei or anuclear superficial celsl

Answer 14

Average 9 days THe make and female are both interested in each other The estrous behavior results from the abrupt decline of estrogen following the peak in leat proestrus

Answer 15

Time of progesterone dominance the hormonal events of diestrus are essentially the same in both pregnant and non-pregnant bitches The female refuses male advances Progesterone comes form the CL and rises through the first half of diestrus Endongenous PGF does not appear to be luteolytic in the bitch Exogenous prostaglandins are luteolytic in the bitch as early as 5 days after the beginning of diestrus

Answer 16

clearly demarcated from that from a bitch that is nearing the end of estrus within 24-48 hours at the end of estrus the percentage of superficial cells falls to approxiamately 20%, with the remainder of cells usually being intermediate cells neutrophils occasionally reappear ovulation happend 6 days ago

Answer 17

averages 1 day or less rejects males, but displays rolling, head rubbing, vocalization, crouching

Answer 18

averages 6 to 7 days accepts male - deviation of tail to one side and allows male to grasp dorsum of neck Intestsification of proestrus behavior: rolling, head rubbing, vocalizing, crouching INDUCED OVULATOR

Answer 19

if mating does not occur, LH is not released Multiple matings results in higher and more prolonged LH release Ovulation occurs about 50 hours after LH peak

Answer 20

lasts about 1-2 weeks if not mated and LH is not released - no ovulation occurs and follicles regress during metestrus If queen does not ovulate - progesterone does not rise above base-line

Answer 21

One time palpation of ovarian structures will NOT determine chates of cycle Uterine tone differs based on dominate steroid homrone: relaxed with progesterone, turgid with estrogen; not reliable Progesterone concentration in milk Estrus detection - standing to be mounted

Answer 22

breed AI 12 hours after first detection in estrus secondary signs: riding other cows, mud on back, increased activity Gomer (penile deviation) bull, androgenized cows Color-change patches or tail-head paint ot indicate riding Electronic mounting detector Electronic behavior monitoring

Answer 23

Estrus detection: Ewes are subtle - difficult to detect in estrus To detect estrus in order to utilize AI - need a vasectomized ram

Answer 24

Estrus Detection Does will vocalize more and increased tail wagging Vulva becomes reddened and vaginal discharge may be noted To detect estrus in order to utilize AI - need a vasectomized buck

Answer 25

One-time palpation of ovarian structures will NOT determine stages of cycle Serial ovarian palpation of folicle size can be used to determine timing of ovulation Cervical tone differs based on dominate steroid hormone Estrus detection - teasing witha stallion

Answer 26

daily during breeding season take at least 15-20 minutes Estrus behavior may be suppressed in: maiden mares, timid mares, mares with foals, during inclement weather, or early in the breeding season

Answer 27

Standing to be mounted Twice daily is recommended Boars and females brought to neutral pen or boar is walked next to femal pen Boar-odor sprays or audio recordings of boar “chant” can be used in absence of a live boar Handler applies pressure to females back in the presence of a boar - females in heat will stand firmly

Answer 28

Estrus detection - most common method for natural mating Vaginal Cytolog - NOT precise enough to use alone for AI Serum Progesterone

Answer 29

First rise in P4 \>1ng/ml is correleated with LH peak Ovulation begins 24-48 hours later, and oocytes are fertile 24-48 hours after ovulation Measure every 2 days starting on day 5 of proestrus Breed 4-6 days after first rise in P4 Breed first day P4\>5-7.5ng/ml Breed 72hrs after first day P4 \>5-7.5ng/ml Frozen semen)

Answer 30

used in conjunction with P4 measurments Typically measured every day starting on Day 5 of proestrus There are several rises in LH prior to the ovulatory peak This assay is not always used

Estrous Cycle Flashcards

(54 cards)