Lecture 24 Flashcards by Danika Boltz

What are the characteristics of sexual maturation in the bitch?

-any time between 3.5 and 24 months
-average is 10 to 12 months
-small breeds mature earlier
-affected by genetics, nutrition, and body size

How well did you know this?

Not at all

Perfectly

What are the characteristics of ovulation in the bitch?

-non-seasonal
-spontaneous

How well did you know this?

Not at all

Perfectly

What are the characteristics of the inter-estrus interval in the bitch?

-lasts 5 to 12 months regardless of pregnancy
-minimum of 4 months to allow time for uterine involution

How well did you know this?

Not at all

Perfectly

What are the characteristics of uterine anatomy in the bitch?

-consists of uterine body, uterine horns, and ovarian bursae
-fat pad at opening of the bursa allows access to the bursa itself
-infundibulum lies under the fat pad

How well did you know this?

Not at all

Perfectly

What are the characteristics of the vaginal/cervical anatomy in the bitch?

-dorsal vaginal fold leads up to the cervix
-blind end past the cervix is known as the fornix
-90 degree angle between the vagina and the cervix

How well did you know this?

Not at all

Perfectly

What is the role of the infundibulum?

wraps around the ovary to catch the ova as they ovulate

How well did you know this?

Not at all

Perfectly

What are the types of changes that can be associated with the estrous cycle?

*measurable changes
-endocrine

*observable changes
-physical
-behavioral
-cytological

How well did you know this?

Not at all

Perfectly

How does LH play a role in the bitch’s estrous cycle?

LH surge occurs and causes ovulation about 2 days later

How well did you know this?

Not at all

Perfectly

How does progesterone play a role in the bitch’s estrous cycle?

progesterone begins rising at the start of the LH surge

How well did you know this?

Not at all

Perfectly

What are the signs of proestrus?

*estrogen dependent:
-vulva edema and swelling
-serosanguineous discharge
-vaginal epithelial hyperplasia
-males attracted by pheromones
-mounting attempts rejected early on

How well did you know this?

Not at all

Perfectly

What are the events associated with estrus?

-estradiol (E2) stimulates LH surge
-LH surge lasts 24 to 48 hours
-E2 continues to decrease after onset of estrus
-progesterone (P4) begins to increase before ovulation, in conjunction with LH peak, due to preovulatory luteinization of follicles
-serum P4 conc. double the baseline (2 ng/mL) during proestrus coincides with the day of the LH peak
-ovulation is spontaneous and occurs ~ 48 hours after LH peak
-oocytes are ovulated as primary oocytes; need 48 to 72 hours in oviduct to become secondary oocytes
-decrease in peripheral E2 and preovulatory rise in P4 results in estrus behavior

How well did you know this?

Not at all

Perfectly

What are the characteristics of ovulation and oocyte development?

-ovulation occurs ~ 48 hours after LH surge
-canids ovulate primary oocytes incapable of fertilization
-primary oocytes must mature to secondary oocytes; takes 48 to 72 hours

How well did you know this?

Not at all

Perfectly

What are the characteristics of estrus in the bitch?

-period in which the bitch allows mating
-stimulation of perineal area will cause bitch to deflect her tail and rotate her pelvis to facilitate intromission
-bitch responds to lumbar pressure by standing firmly and arching back slightly
-vulva is usually reduced in size and less turgid compared to proestrus
-serosanguineous discharge is decreased

How well did you know this?

Not at all

Perfectly

What is the duration of estrus in the bitch?

-average of around 9 days based on endocrine and cytologic changes
-range from 3 to 21 days based on behavior

How well did you know this?

Not at all

Perfectly

What are the outward signs of the LH surge?

-vulva edema softens around 48 hours after onset
-discharge is straw-colored

How well did you know this?

Not at all

Perfectly

What are the characteristics of metestrus?

-in other species, the CL becomes functional during metestrus
-in the bitch, the CL becomes functional during cytologic estrus; metestrus can be interpreted as diestrus

How well did you know this?

Not at all

Perfectly

When does diestrus occur based on serum P4?

-occurs around day 62 to 63 in pregnancy
-occurs between day 60 to 90 in pseudopregnancy
-CL is maintained regardless of the animal being pregnant or not

How well did you know this?

Not at all

Perfectly

When does diestrus occur based on vaginal cytology?

around day 57

How well did you know this?

Not at all

Perfectly

What are the characteristics of diestrus?

*serum P4 peaks around 1 month after ovulation
-gradually declines until whelping/pseudopregnancy
-rapid decline 24 to 36 hours prior to whelping
-must have > 2ng/mL conc. to maintain pregnancy

*prolactin rises as P4 declines
*prolactin and LH are luteotrophic

How well did you know this?

Not at all

Perfectly

What are the events that occur in diestrus?

-onset of behavioral diestrus/resists mating attempts
-vulvar swelling subsides
-vaginal thickening disappears
-vaginal folds are reduced
-mammary enlargement as diestrus proceeds
-lactation begins in late stages of diestrus

How well did you know this?

Not at all

Perfectly

What are the characteristics of anestrus?

-period between end of diestrus and next proestrus
-> 4 months is desirable
-allows time for uterine involution
-basal hormonal profiles
-minimum follicular activity

How well did you know this?

Not at all

Perfectly

What are the cell layers seen on vaginal cytology, from the basement membrane to the vaginal lumen?

basement membrane

-para-basal
-small intermediate
-large intermediate
-superficials (corn-flake shape)
-fully keratinized

vaginal lumen

How well did you know this?

Not at all

Perfectly

How does the thickness of the vaginal epithelium vary between anestrus and estrus?

Study These Flashcards

vaginal epithelium is much thicker during estrus

What are the steps to obtaining a vaginal swab?

Study These Flashcards

-use an otoscope cone as a speculum
-insert swab up and over to avoid urethra
-roll the swab out onto a slide in two rows

What are the vaginal cytology findings during anestrus?

*non-degenerate PMNs *non-cornified epithelial cells -parabasal cells -small intermediate epithelial cells

How can parabasal cells be distinguished from small intermediate epithelial cells?

-parabasal cells look like fried eggs -small intermediate epithelial cells have a much smaller nucleus

What are the vaginal cytology findings in early proestrus?

-RBCs -parabasal cells -small intermediate epithelial cells -PMNs

What are the vaginal cytology findings as proestrus continues?

-increased proportion of superficial cells -> 90% cornified epithelial cells -cells in sheets -cells becoming more angular

What are the vaginal cytology findings during estrus?

-> 90% of epithelial cells are cornified -> 50% anuclear squame cells -no PMNs -possible RBCs -bacteria are common *cells look like cornflakes; need milk (semen)

What are the vaginal cytology findings as estrus progresses?

*first day of estrus: -sudden decrease in cornified epithelial cells -< 50% cornified epithelial cells *progresses to no cornified epithelial cells *neutrophils in parabasal or intermediate cells (metestral cells)

Which disorders are associated with abnormally cornified vaginal cytology?

-ovarian remnant syndrome -ovarian cystic disease -ovarian tumor -exogenous estrogen ingestion -adrenal disease

What are the vaginoscopy findings during proestrus?

plicae: -edema -thickened -rounded -moist

What are the vaginoscopy findings during estrus?

-less edema -wrinkling/crumpling (crenation)

What are the vaginoscopy findings during diestrus/anestrus?

vaginal folds: -low -rounded -even

What is the stage for this vaginal cytology?

proestrus

What is the stage for this vaginal cytology?

diestrus

What is the stage for this vaginoscopy?

proestrus

What is the stage for this vaginoscopy?

estrus

What is the stage for this vaginoscopy?

diestrus/anestrus

What are these pathologies seen on vaginoscopy?

left: vaginal septum right: vaginitis

What are the characteristics of natural mating and conception?

-80 to 90% of normal bitches mate naturally to fertile males -behavior correlates well with endocrine and cytological events in normal bitches -problems arise when bitch is not normal, natural mating is not permitted, or chilled/frozen semen is used

What are the steps to normal mating in canines?

-male mounts and clasps flanks with front legs -male begins pelvic thrusting -penile contact with vulva leads to full erection -penis is turned around/rotated 180 deg. -"the tie" occurs -tie is broken and male dismounts

Why must the male's penis rotate once in the bitch's vagina?

to aim the tip of the penis at the cervix

What is the role of the bulbus glandis portion of the penis?

swells to lock the penis in the bitch's vagina

When is the fertile period considered to occur in bitches?

from ~ 2 days before the LH surge to about 6-7 days after the LH surge

When is the fertilization period considered to occur in bitches?

between ~ 3 to 6 days after the LH surge

What are the characteristics of canine sperm?

-long lifespan within uterus of an estrus bitch -have fertilizing capacity for 6 or more days post-ejaculation -cause superfecundation/multiple eggs fertilized per ovulation cycle -can have litter with multiple sires due to length of fertilization capacity

What is the timeline for natural service of the bitch based on behavior?

-every other day once receptive -days 9, 11, 13, and 15 from onset of proestrus

What is the ideal breeding timeline based on cytology?

-first cytological exam at onset of proestrus -continue exams every other day until diestrus -breed 4 days before diestrus -3 to 10 days before diestrus is considered acceptable -if P4 levels are unknown, breed from onset of estrus every other day until cytological diestrus is observed -ovulation occurs 6 to 7 days before diestrus; whelping is about 57 days later

What are the timelines for breeding when P4 is measured?

breed [2 and 4] or [3 and 5] days after 1st progesterone elevation

What are the characteristics of breeding based on progesterone measurement?

*take serial samples for serum P4 every other day once proestrus begins *serum P4 to approximate LH surge: -P4 levels ~ 2 ng/mL = LH surge -do a single breeding 4 to 6 days later *serum P4 to approximate ovulation: -P4 levels ~ 4-10 ng/mL = ovulation -do a single breeding 2 to 3 days later

How can progesterone be measured?

*ELISA: -produced by zoetis -known as OvuCHECK -color change -read outs are < 2 ng/mL, 2 ng/mL, or > 2 ng/mL *RIA: -start during proestrus -run every other day -expensive

What are the characteristics of using frozen semen?

-lifespan is shorter than fresh/chilled -want to deposit intrauterine -can do surgical or trans-cervical AI -want to use endocrinology to time breeding

What is the 3 day period of oocyte viability?

-4, 5, and 6 days post LH surge -2, 3, and 4 days post ovulation

What are the semen viability times once in the bitch?

-< 24 hr if frozen -< 36 to 48 hours if chilled -3 to 7 days if fresh

Lecture 24 Flashcards

(55 cards)