progesterone -idex Flashcards
Proestrus is defined as
the period from onset of vulvar bleeding to the ____________
first acceptance of copulation
Proestrus duration averages ___ days, but it can range
from 1–27 days in extreme cases
9
_______ refers to the stage where the bitch shows outward signs of receptivity, and it is the
stage during which the bitch allows mating
Estrus
Estrus averages ___ days, but it can range from 3–21 days in extreme cases.
9
Fertilization typically occurs between
___-___ days before the end of estrus
3–4 days
some bitches may bleed throughout their entire heat period, whereas other may not. T/ F
T
Furthermore, some bitches may stand for a stud willingly, even long before there are eggs available for fertilization, whilst others may only be receptive for a day or two. T/F
T
Certain bitches may not be willing to stand for a stud at all because they only stand for a particular stud. T/F
T
It is also a common misconception among breeders that the duration of the different stages within a heat cycle and the point at which a bitch will allow copulation replicates itself in each repeating heat cycle of each individual bitch. T/F
T
Progesterone starts to rise just before
ovulation, toward the last week of the heat cycle. t/F
T
It is well established that as soon as the progesterone levels are around ___ ng/mL, the ovulation hormone (luteinizing hormone or LH) peaks and that ovulation takes place 2 days later when the
progesterone levels are around 5–8 ng/mL
2 ng/dl
Ovulation takes place ___ days after the LH surge when the progesterone levels are around ______ ng/dl
2
5-8 ng/dl
Canine eggs cannot be fertilized immediately after ovulation because they need another____ days to mature, and by that time the progesterone levels usually average ___ ng/mL or above.
2
10 ng/ml
Progesterone correlation to stages:
LH surge - ____ ng/dl
ovulation - ____ ng/dl
Fertilization - ____ ng/dl
2
5-8
10
Vaginal smears cannot accurately reflect the bitch’s heat cycle. T/F
T
They are only useful to confirm that the bitch is in heat and to see if there is pathology such as a severe vaginitis.
Vaginal smears are,however, very useful in determining when the bitch is out of heat, and this again is very helpful to accurately determining the
date of whelp.
Vaginal speculum examinations may save the breeder the cost of progesterone assays; however, for critical breedings (compromised semen, chilled, or frozen semen) and aberrant heat cycles, this method lacks precision. T/F
T
Serial progesterone assays are needed. T/F
T
Clinical experience shows that some bitches have a spurious rise of progesterone (sometimes as high as 2–3 ng/mL) that occurs during estrus followed by several days where the progesterone remains low (well below 2 ng/mL).
For critical breedings, an accurate estimate of the optimum time of fertilization is best achieved using three, four, or, if required, even more progesterone assays to cover the key events of the LH peak, ovulation, and onset of the fertile period. T/F
T
Less experienced practitioners are therefore advised to start collecting blood earlier in the estrous cycle rather than later. T/F
T
During proestrus and early estrus, the progesterone level may remain close to basal up to around 1 ng/mL for many days (10 days or longer). At this stage, the interval between collection
may be extended to around ___days.
4
As soon as the bitch starts to exhibit authentic signs of estrus, blood collection and assay should be performed how frequently?
Every second day
As soon as the progesterone has risen above 2 ng/ml, how often should the practitioner elect to collect the blood.
the practitioner may elect to collect blood daily or at least every second day to confirm a sharp and continued rise to 6 ng/mL or above
What should be interval between breeding ideally?
48 hours, even when using good quality fresh semen
as sperm may survive no longer than 1 or 2 days in female tract
Longevity of frozen sperm in reproductive tract is ____ hours
12
breeding should occur at the beginning of the optimum time of fertilization with an interval of 1 day when using frozen thawed semen
