Canine Estrous Cycle Flashcards
What is the significance of collecting swabs at the cervix?
Caudal to hymen: originates from ectoderm;
cranial to hymen: originates from mesoderm
T or F:
Pubertal bitches are less likely to demonstrate estrus when ovulation occurs.
True
What is a silent heat?
ovulation occurs in absence of proestrus-estrus behavior or signs
What is the timeframe for fertilization in the bitch?
9 days!
What is unique to the bitch’s cycle prior to ovulation with regard to hormone levels?
Pre-ovulatory follicles produce PROGESTERONE…
When do E2 levels peak in the bitch estrous cycle?
late proestrus
T or F:
Only in the bitch do you have a stage where there are high P4 and high E2 at the same time.
true; this happens when E2 is peaking
How long is anestrus typically in the bitch?
90-150+ days
{involution following diestrus is this long}
How long is the bitch’s cycle?
~5-7months
What do we call the time from the beginning of one estrus to beginning of next estrus?
interestrus period;
{larger dogs tend to have shorter interestrus period;
older dogs >8yo, tend to have longer interestrus period }
What is the minimum requirement for cycle length?
4 months;
fertility is low if <90day anestrus :(
During the luteal phase, what hormone dominates and is the dog pregnant or not?
progesterone;
could be pregnant or pseudopregnant
What is the maximum cycle length in the bitch?
12 months
{holdover from wild canids; 1 cycle/year}
If longer than 12 mo, investigate:
Hyperprolactemia?
T or F:
Cornification of vaginal epithelial cells accurately predicts time of receptivity, LH surge, or ovulation.
FALSE;
coordinate cytology, hormone concentration, & speculum examination
If you’re not pointing the swab up twd the tail/dorsum, what do we risk?
catheterization of the urethra
What type of cell is this?
Parabasal
{round or oval, large nucleus}
What type of cell is this?
Small-Lg intermediate cells
{larger than parabasal cells; borders irregular}
What type of cell is this?
Superficial cells
{largest seen, borders irregular, no nucleus present; fully cornified!}
What is the most likely stage this bitch is in?
- Late* Proestrus;
- suggest breeding in 4-5 days*
What stage?
Proestrus
What period of the estrous cycle is marked by a sharp decrease in superficial cells & increase in parabasal & sm.intermediate cells?
DIESTRUS
P4 peaks around how many days after the LH surge?
15-30 days
Vaginal cytology of the bitch demonstrating RBCs & mixed epithelial cells would indicate what phase of estrous?
Proestrus
Based on vaginoscopy/endoscopy, what phase is the best time to breed?
Angular {or declining…} Phase
If P4 was between 2.0-2.9ng/mL, when would you want to breed the bitch?
{LH surge is happening}
4-6 days
