Termination of Pregnancy Flashcards
(44 cards)
What are the three types of pregnancy termination
1) abortion
2) induction of parturition
3) twin reduction
What are some indications for induction of abortion in cows?
- feedlot heifer
- incorrect sire
- heifers too young
- bull/colt/ram/buck got loose
Approach to pregnancy determination depends on what
whether the animal is CL dependent for the entire pregnancy or not
What animal species maintain the CL throughout gestation
cows
pigs
dogs
cats
goats
what animal species do not have progesterone contribution from the placenta
dogs
cats
pigs
goats
what is the contribution of the CL and placenta to progesterone production in sheep (ovine)
CL: <50-60d
Placenta: >50-60d
what is the contribution of the CL and placenta to progesterone production in horses
CL (endometrial cups): 120-150d
Placenta: >70d
when does the placenta start producing progesterone in cows
150-250d
what plays an important role in initiation of parturition and what is a caveat
fetal glucocorticoids, only if the feto-placental unit is alive and functioning
when can you induce abortion using PGF2a in cows
<150 d or >250d (when the placenta is not contributing to progesterone levels)
when can you induce abortion using dexamethasone in cows? when is it 100% effective?
starts to work at 150d (low efficacy) and becomes 100% after 250d
if you wanted to be 100% certain you can induce abortion in a cow and you don’t know what day of gestation, what can you use
both PGF2a (lyse the CL) and dexamethasone (stops placental secretion)
T/F you only need 1 injection of PGF2a if inducing abortion in a cow <150 or >250d of gestation
F; give 2 to ensure you induce complete luteolysis
what happens if you did not completely lyse the CL in a gestating cow using PGF2α
mummification
in cases of fetal mummification or maceration in cows, how do you induce abortion
PGF2a -> luteolysis -> drop in progesterone
what are indications for induction of abortion in horses?
1) wrong sire
2) unintentional breeding
3) twins
4) problem pregnancy (ex. hydrops, PPT rupture)
In the horse, what is significant:
- in the first 35 days
- at day 35
- between 35-120 days
- after 120 days
- in the first 35 days: only CL
- at day 35: endometrial cups formed
- between 35-120 days: eCG from endometrial cups -> acts like LH -> secondary CL formed -> progesterone
- after 120 days: only placental source of progesterone
how do we induce abortion in mares:
- <28 days of pregnancy:
- <35 days of pregnancy:
- 35-120 days of pregnancy:
- >120 days of pregnancy:
- <28 days: pinch one vesicle transrectally (in case of twins)
- <35 days: PGF2a
- 35-120 days: PGF2a twice daily for 3-5 days, may need manual extraction
- > 120 days: PGF2α twice daily for 3-5 days, oxytocin, assist and extract (usually need to euthanize fetus once born)
How do we induce abortion in sheep vs goats
in goats, only the CL is the source of progesterone, so 2 PGF2a injections can be given at any stage of gestation
in sheep, <50-60 days you can give 2 shots of PGF2a since only the CL is present; after 50-60 days you can give multiple injections of corticosteroids and manually dilate/extract
in pigs, how do we induce abortion
2 shots of PGF2a at any stage of gestation
what are the concerns with twinning in mares
- leading cause of abortion before ultrasound
- rarely go to term due to placental insufficiency
- severe damage to the mare, and usually neither fetus survives
T/F twinning in the mare can be unilateral or bilateral
T
how can you tell whether twins in a mare ovulated at the same time or not
if they are the same size or different sizes on ultrasound
when and how is manual twin reduction performed in the name
best at 14-17 days (before fixation) but can be done up to day 28; manually crush per rectum by massaging up the horn and popping