Canine Estrous Cycle, Vaginal Cytology, Endocrine Tests Flashcards
Timeline of events:
- Puberty
- Seasonality
- Estrous cycle
- 6-24 months, avg. is 7-10 months
- Bitch is non-seasonal monoestrus
- Divided into four stages (Proestrus, estrus, diestrus, anestrus)
LH surge occurs between _____ and _____
proestrus and estrus
increased ____ and fall of ____ causes ___ ___ to trigger ovulation
Progesterone; estrogen; LH surge
What hormone is a source of preovulatory follicles?
Estrogen
What hormone is a source of CL along with some adrenals?
Progesterone
____ and ____ hormones source are pituitary
LH and FSH
Hypothalamus produces this hormone–
GnRH
Hormone actions:
- what causes the release of LH and FSH?
- What stimulates preovulatory follicles?
- What initiates proestrus?
- What maintains preg?
- what causes ovulation?
- GnRH
- FSH from estrogen input
- Estrogen
- Progesterone
- LH
What is this stage:
Bitch is attractive but not receptive, vulva swelling and discharge, estrogen level is rising and progesterone level is low (basal)
Proestrus
How long does the proestrus phase last?
6-11 days (avg. 9 days)
What phase is this bitch:
Attractive and receptive, vulva is less swollen and discharge is straw colored, estrogen is peaks and progesterone is rising
Estrus
How long does the estrus phase last? Why does vulva become less swollen than it was in proestrus?
Lasts 3-20 days (9 day average); because lower estrogen as compared to proestrus
What phase is the bitch in:
Not accepting males, vulva shrinks in size, no discharge, CL begins to produce large amounts of progesterone
Diestrus
How long does the diestrus phase last?
57 days if pregnant, if NOT pregnant, then lasts 45-75 days
______ is a period of uterine involution and prepares for the next cycle. Behavior will be similar to spayed female
Anestrus
Progesterone and estrogen are both low in what phase?
Anestrus
How long does anestrus last?
2-9 months
- Proestrus averages ___ days
- Estrus averages ___ days
- ____ ____ triggers ovulation in ___ hours
- 9
- 9
- LH surge; 48 hours
Bitch ovulates primary oocytes over a period of ___ hours, each oocyte undergoes a final phase of meiosis that takes ___ hours
48 hours; 48 hours
Eggs are fertilized in the oviducts in __-__ days after LH Surge and they remain in the ovaduct for __-___ days
4-5 days; 8-10 days
Fertilized eggs remain in the ovaduct for __-___ days. Embryos migrate to the uterus by day ____ and implantation occurs.
8-10 days; day 15
What structure supports pregnancy all throughout gestation?
CL
Cornified cells on vaginal cytology means ___ levels are (or were recently) elevated
Estrogen
_____ cells indicate estrogen levels are low
Parabasal
Where do we swab for a vaginal cytology?
Cranial vagina
What cells will we see in a vaginal cytology of a bitch in proestrus?
Some parabasal cells and some cornified cells increased and proestrus progresses into estrus. May also see RBCs and superficial cells
Estrus- majority of the cells are _____ and anuclear. Some bacteria may also be seen.
cornified,
Abrupt return to parabasal and intermediate cells with lots of WBCs, metestrum cell, and foam cells seen tell us we are in what stage?
Diestrus
Progesterone testing of a bitch: what does each P4 coincide with??
P4 rising through 2.0 coincides with LH surge
P4 between 4-5 coincides with ovulation
P4 > 10 coincides with fertile period
LH surge–_____–_____ _____
LH surge- ovulation- fertile period
How long is the time between LH surge and fertile period (between ovulation)?
Two days
When should we breed bitch?
Breed 3-6 days after LH peak
