Estrous cycle Flashcards
reproductive cycle is…
regularly occurring periods during which the female is sexually active and receptive, separated by periods in which there is no sexual activity
what is the reproductive cycle controlled by?
hormones
what is the normal number of estrous cycle for dogs?
what can cause this to differ?
twice a year
breed and individual dogs
what are the stages of the estrous cycle? (4)
- Proestrus
- Estrus
- Diestrus
- Anestrus
what is the average length of time for proestrus?
9 days
what hormone change will be seen in proestrus?
high estrogen levels
what physical signs are seen in proestrus?
Bloody discharge, firm/swollen vulva, attracts males, won’t accept mating
what is the average length of time for estrus?
9 days
what hormone changes are seen during estrus? (3)
- Luteinizing hormone surge
- increasing progesterone
- decreasing estrogen
what can happen to the cervix during proestrus?
may open a little
what physical changes happen during estrus?
Swollen vulva softens, bitch will stand to be bred
which stage does ovulation occur?
estrus
how long is diestrus?
2 months
what hormonal changes are seen during diestrus?
High progesterone
how long can sperm survive in the uterus?
72 hours
how long is anestrus?
2-10 months
No indication of reproductive activity
what hormonal changes happen during anestrus? (2)
Low progesterone and low estrogen
which stage of estrous will the bitch not allow the male to mount?
diestrus
which stage of estrous is there no indication of reproductive activity?
anestrus
what can predicting the time of estrus increase?
the chance of pregnancy conception
how can a vaginal cytology be useful?
can help predict estrus
what lines the reproductive tract?
what do they respond to?
epithelial cells
ovarian hormones
what are the epithelial cell seen in the reproductive tract?
Basal cell
Parabasal
Intermediate
Superficial (cornified)
what are some ways a superficial cell can appear?
With nucleus
Nucleus disappearing
No nucleus
which epithelial cells are seen during early proestrus?
which ones will take their place during late proestrus?
Parabasal and intermediate cells
increasing #’s of superficial/cornified
what other cells can be seen during proestrus?
Some neutrophils and RBC’s
what epithelial cells are seen during estrus?
> 90% superficial epithelial cells
which phase are neutrophils not present?
estrus
what happens to the RBC during estrus?
decrease
which epithelial cell are seen in anestrus?
parabasal and intermediate cells
what epithelial cells are seen during diestrus?
Increasing # of parabasal and intermediate cells
decreasing # of superficial cells
what other cells are seen during anestrus?
possible neutrophils
what other cells are seen during diestrus?
Some neutrophils
when do progesterone levels rise?
Serum progesterone levels rise 2-3 days before ovulation
what are the progesterone levels?
1-1.9 ng/ml ovulation in 2 days
2-3.9 ng/ml ovulation in 1 day
4-10 ng/ml ovulation the same day
