Lecture 20: Canine Repro (Kelleman) Flashcards
what is a dog’s “heat” or “in season”?
the combination of estrus and proestrus. the time when vulvar discharge is seen
why type of estrous cycle do dogs have?
monoestrous - 1 estrous cycle per year, non-seasonal
when does puberty occur in dogs?
onset of first estrous cycle - 6 months to 2 years of age
interestrus interval
the time between one proestrus and the next
4.5 - 12 months
german shepherds - shorter
Basenji - longer (yearly estrus)
describe the follicular phase
- estrogen
- subdivided into proestrus and estrus
describe the luteal phase
dominated by progesterone
in the bitch, it is generally NOT subdivided into metestrus & diestrus
canine estrous cycle
- proestrus
- estrus
- diestrus (aka metestrus)
- anestrus
vaginal cytology
gives you a basic idea of where a bitch is in the estrous cycle. useful when used in conjunction with progesterone.
bioassay for presence of ESTROGEN
vaginal cytology results: what is the significance of cornification?
non-cornified epithelial cells vs. non-cornified epithelial cells
cornification shows the progression of epithelial cell death resulting from tissue thickening due to estrogen.
non-cornified epithelial cells: parabasal and intermediate
cornified epithelial cells: superficial and anuclear squamous
what is the effect of LH in dogs?
ovulation
effect of estrogen in dogs?
- vaginal lining epithelial cells and wall thickness
- behavior and physical signs
do non-pregnant bitches produce progesterone?
Yes! progesterone is produced in pregnant and non-pregnant bitches!
effect of relaxin in dogs?
- produced by the canine placenta
- relaxes pelvic canal and cervix
- blood test for pregnancy determination
what diagnostic test is more accurate than any qualitative test?
canine ovulation timing test - tests progesterone levels
length of proestrus
0 -27 days; average 9 days
behavior during proestrus
attractive to the male but not receptive. will NOT stand to be bred
what does a vaginal cytology show during proestrus
progressive cornification
endocrinology of estrogen and progesterone during proestrus
estrogen rising to peak!
pre-ovulatory rise in progesterone! - preovulatory luteinzation
anatomy during proestrus
vulvar swelling and serosanguinous discharge, vaginal fold thickening, follicular development
- source of RBC’s is uterine via diapedesis
length of estrus in dogs
4 - 24 days; average 9 days
behavior of dogs during estrus
receptive, STANDS TO BE BRED
vaginal cytology of dogs in estrus
cornification prominent. should not have WBCs
endocrinology of dogs in estrus
estrogen is FALLING pre-ovulatory rise in progesterone continues! LH peak (estrus; junction btwn proestrus/estrus)
anatomy of dog in estrus
less vulvar swelling and serous to serosanguinous discharge; vaingal fold CRENULATION; further follicular development and OVULATION
what is unique about the bitch in estrus?
- progesterone is rising pre-ovulatory!
- and estrogen is falling
what happens during estrus?
LH peak
abrupt and short
ovulation occurs 24 - 48 hours later
ovulation in the dog - how is it different?
she ovulates primarily OOCYTES!
- they must then mature with meiosis to secondary oocyte prior to fertilization.
- first division in meiosis is reductional
when should you breed the bitch?
4 and 6 days after the LH peak for optimally mature oocytes
behavior in the bitch during diestrus
NOT RECEPTIVE
what will be seen on vaginal cytology during diestrus in the bitch?
ABRUPT change to NON-cornification; WBC normal
endocrinology of the bitch during diestrus
HIGH progesterone
anatomy of the bitch during diestrus
less vulvar swelling; discharge quality variable, then stops; vaginal fold thinning; has CL
length of anestrus in the bitch
4.5 - 5 months
behavior of the bitch during anestrus
NOT RECEPTIVE
vaginal cytology of the bitch during anestrus
non cornified
endocrinology of bitch during anestrus
no progesterone or estrogen
late in the cycle just before pro-estrus there is some LH, FSH and estrogen
anatomy of the bitch during anestrous
no vulvar swelling; no discharge, vaginal folds thin, inactive ovaries!
stages of mating in the dog (3)
- first stage coitus
- the turn
- second stage coitus
what is the level of progesterone in diestrus
it is high; irrespective of pregnancy status
CANNOT be used as pregnancy test
CL dependent to term!!
what type of placentation does the dog have
endotheliochorial, zonary, deciduate
- can get marginal hematomas
- green pigment - uteroverdin
4 ways to diagnose pregnancy
- ultrasound
- palpation
- relaxation
- radiographs
mechanism used to induce parturition
similar to ruminant:
cortisol, PGF, oxytocin
gestation period of the dog
57 - 72 days
Stage I - Preparation
- variable timing
- nesting, poor appetite
- cervical softening
Stage II - fetal expulsion
- contractions
- generally half to 1 hour between pups
- licks neonate
a prolonged uteroverdin vulvar discharge without birth of pup indicates placental separation and thus fetal life at risk
Stage III - what happens?
- fetal membrane passage - generally with each pup
- bitch may eat membranes
puerperium: how long is involution? how long can they have lochia?
involution is prolonged - a minimum of 2 months
lochia - is brick-red to brown in color, can have it for several weeks, should be odorless
pseudocyesis what is it?
“pseudopregnancy”
- it is every non-pregnant diestrus.
- the progesterone falls during diestrus which stimulates prolactin rise which is instrumental in lactation
canine dystocia: obstructive
feto-maternal disproportion, brachycephalics, large singleton
canine dystocia: non-obstructive
- primary uterine inertia: hypocalcemia, myometrial atony
2. secondary uterine inertia: maternal exhaustion
dystocia treatment: obstructive, non-obstructive, live compromised pups, and dead pups
obstructive: vaginal exam, c-section, NO ecbolics (dx that induce contraction)
non-obstructive: calcium, oxytocin, c-section
live compromised pups: c-section
dead pups with no obstruction: vaginal delivery, calcium, oxytocin, c-section
