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
The progesterone concentration increases to peaks of ____ng/mL at midpregnancy and then gradually declines until it falls abruptly just prior to parturition or the end of diestrus in the nonpregnant bitch
15–90
Why progesterone cannot be used for pregnancy diagnosis?
progesterone profiles of pregnant and
nonpregnant bitches do not differ significantly.
However,progesterone levels above 2.6 ng/mL are required throughout the entire pregnancy to maintain pregnancy.
Define Hypoluteoidism?
a condition in which the progesterone levels become too low and the bitch either aborts or resorbs. Serum progesterone
should be monitored every 1 to 2 weeks in bitches with a history of pregnancy failure or luteal insufficiency.
Which is most accurate for pregnancy length estimate .
- time from LH surge
- time from ovulation
- time from fertilization
Time from LH surge
Pregnancy lengths based on time of the LH surge (synonymous with PC of ~2 ng/mL), ovulation (5–8 ng/mL), and fertilization (~10 ng/mL) are respectively _ days, _ days, and _ days, with the latter two being less accurate than the former.
65
63
61
If progesterone is below 2.8 ng/mL, there is a 99% probability of whelp within ____ hours, and if the level is below 1.0 ng/mL this probability is 100%
48
%. Conversely, if the progesterone is 5 ng/mL or above, the probability of onset of spontaneous parturition within the following 12 hours is less than _%
2
For bitch in heat or reproductively quiescent bitch
Progesterone ng/dl = <1
Likely event?
Action?
Likely event: Anestrus
Action: Retest in 3-4 d
For bitch in heat or reproductively quiescent bitch
Progesterone ng/dl = 1-2
Likely event?
Action?
likely event: proestrus and early estrus l Pre-LH surge
Action: Retest in 2 d
For bitch in heat or reproductively quiescent bitch
Progesterone ng/dl = 2-3
Likely event?
Action?
likely event: LH surge
Action: Retest in 2 days to confirm continued rise in progesterone. Aim for breeding 4–7 days after the rise above 2 ng/mL
For bitch in heat or reproductively quiescent bitch
Progesterone ng/dl = 3.1-4.9
Likely event?
Action?
Likely event: Post LH surge, pre-ovulation
Action: Aim for breeding 3–5 days after this date
For bitch in heat or reproductively quiescent bitch
Progesterone ng/dl = 5-8
Likely event?
Action?
Likely event: at or near ovulation
action: Retest in 2 days to confirm continued rise in progesterone Aim for breeding 2–4 days after this date
For bitch in heat or reproductively quiescent bitch
Progesterone ng/dl = 8-10 and above
Likely event?
Action?
likely event: in fertilizable period
Action: Aim for breeding on this day and for another 2–3 days hereafter
Fresh semen with natural breeding.
suggested breeding days after LH surge?
day 4 and 6
Fresh semen with artificial insemination
suggested breeding days after LH surge?
day 4 and 6
Frozen/chilled semen on compromised semen.
suggested breeding days after LH surge?
day 6 and 7
progesterone interpretation around the preparturient period in pregnant bitches.
> 5
Onset of parturition is likely 12 hours or longer away. Less than 2% of pregnant bitches with this PC
are likely to enter spontaneous whelp within the following 12 hours
Places bitch at low risk for need for overnight parturition observation
progesterone interpretation around the preparturient period in pregnant bitches.
<2
Most of the bitches will be within 48 hours of onset of parturition
Bitch owners must be on high alert for the next 48 hours
progesterone interpretation around the preparturient period in pregnant bitches.
<1
All bitches are very likely within 24 hours of onset of spontaneous parturition
Bitch owners must be on high alert for next 24 hours
